Cleaning compositions containing hydroxylamine derivatives and processes using same for residue removal Number:7,144,848 from the United States Patent and Trademark Office (PTO) owispatent The present invention is directed to resist and etching residue removing compositions containing at least one nucleophilic amine compound possessing reduction and oxidation potentials, a two-carbon atom linkage alkanolamine compound, and optionally water and/or one or more corrosion inhibitors. The compositions may be substantially free of hydroxylamine, polar organic solvents, water, corrosion inhibitors, or a combination thereof. The compositions are useful in processes for removing resists and etching residue from metal or metal alloy substrates or substrate layers used in micro-circuitry fabrication.<H hydroxylamine, compositions, Cleaning, compos, 7144848.html, Patent, pto, 7144848

Title: Cleaning compositions containing hydroxylamine derivatives and processes using same for residue removal

Abstract: The present invention is directed to resist and etching residue removing compositions containing at least one nucleophilic amine compound possessing reduction and oxidation potentials, a two-carbon atom linkage alkanolamine compound, and optionally water and/or one or more corrosion inhibitors. The compositions may be substantially free of hydroxylamine, polar organic solvents, water, corrosion inhibitors, or a combination thereof. The compositions are useful in processes for removing resists and etching residue from metal or metal alloy substrates or substrate layers used in micro-circuitry fabrication.

Patent Number: 7,144,848 Issued on 12/05/2006 to Zhou, et al.

Inventors: Zhou; De-Ling (Sunnyvale, CA), Qiao; Jing (Fremont, CA), Lee; Shihying (Fremont, CA), Patel; Bakul P. (Pleasanton, CA), Hon; Becky Min (Milpitas, CA)
Assignee: EKC Technology, Inc. (Hayward, CA)

Appl. No.: 10/689,620

Filed: October 22, 2003

Related U.S. Patent Documents


Application Number	Filing Date	Patent Number	Issue Date
10162679	Jun., 2002	6825156
09988545	Nov., 2001
09603693	Jun., 2000	6319885
08654007	May., 1996	6110881
08078657	Jun., 1993
07911102	Jul., 1992	5334332

Current U.S. Class: 510/175 ; 510/176; 510/245; 510/255; 510/264; 510/407; 510/499

Current International Class: C11D 7/50 (20060101); C11D 7/32 (20060101)

Field of Search: 510/176,175,255,499,245,264 134/2,3,113

References Cited [Referenced By]

U.S. Patent Documents


4617251	October 1986	Sizensky
5417877	May 1995	Ward
5798323	August 1998	Honda et al.
5911835	June 1999	Lee et al.
5968848	October 1999	Tanabe et al.
5997658	December 1999	Peters et al.
6068000	May 2000	Tanabe et al.
6110881	August 2000	Lee et al.
6218087	April 2001	Tanabe et al.
6261745	July 2001	Tanabe et al.
6268323	July 2001	Honda et al.
6276372	August 2001	Lee
6319885	November 2001	Lee et al.
6320064	November 2001	Oftring et al.
6326130	December 2001	Schwartzkopf et al.
6372050	April 2002	Honda et al.
6372410	April 2002	Ikemoto et al.
6492311	December 2002	Lee et al.
6777380	August 2004	Small et al.

Foreign Patent Documents


1 178 359	Feb., 2002	EP
10321569	Dec., 1998	JP
2001077063	Mar., 2001	JP

Primary Examiner: Webb; Gregory
Attorney, Agent or Firm: Morgan Lewis & Bockius LLP

Parent Case Text

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of application Ser. No. 10/162,679 filed Jun. 6, 2002, now U.S. Pat. No. 6,825,156 entitled "Semiconductor process residue removal composition and process," and a continuation-in-part of application Ser. No. 09/988,545 filed Nov. 20, 2001, now abandoned entitled "Cleaning solutions including nucleophilic amine compound having reduction and oxidation potentials," which is a continuation of application Ser. No. 09/603,693 filed Jun. 26, 2000, which issued as U.S. Pat. No. 6,319,885 on Nov. 20, 2001, which is a continuation of application Ser. No. 08/654,007 filed May 28, 1996, which issued as U.S. Pat. No. 6,110,881 on Aug. 29, 2000, which is a continuation of application Ser. No. 08/078,657, filed Jun. 21, 1993, now abandoned, which is a continuation-in-part of application Ser. No. 07/911,102 filed Jul. 9, 1992, which issued as U.S. Pat. No. 5,334,332 on Aug. 2, 1994, the entire disclosures of each of which applications and/or patents is hereby incorporated by express reference hereto.

Claims

What is claimed is:

1. A resist and etching residue remover composition comprising: from about 1 wt % to about 30 wt % of N,N-diethylhydroxylamine from about 20 wt % to about 80 wt % of a two-carbon atom linkage alkanolamine compound having the formula ##STR00009## wherein R.sub.1, R.sub.1', R.sub.2, R.sub.2', and R.sub.3 are, independently in each case, hydrogen or a linear, branched, or cyclic hydrocarbon containing from 1 to 7 carbon atoms, wherein Z is a group having the formula -(-Q-CR.sub.1R.sub.1'--CR.sub.2R.sub.2'--).sub.m--, such that m is a whole number from 0 to 3, R.sub.1, R.sub.1', R.sub.2, and R.sub.2' are independently defined in each repeat unit, if m>1, within the parameters set forth for these moieties above, and Q is independently defined in each repeat unit, if m>1, each Q being independently either --O-- or --NR.sub.3--, and wherein X and Y are, independently in each case, hydrogen, a C.sub.1 C.sub.7 linear, branched, or cyclic hydrocarbon, or a group having the formula --CR.sub.1R.sub.1'--CR.sub.2 R.sub.2'-Z-F, with F being either --O--R.sub.3 or --NR.sub.3R.sub.4, where R.sub.4 is defined similarly to R.sub.1, R.sub.1', R.sub.2, R.sub.2', and R.sub.3 above, and with Z, R.sub.1, R.sub.1', R.sub.2, R.sub.2', and R.sub.3 defined as above, or wherein X and Y are linked together form a nitrogen-containing heterocyclic C.sub.4 C.sub.7 ring, wherein the two-carbon atom linkage alkanolamine compound comprises 2-(2-aminoethylamino)-ethanol; and from about 0.1 wt % to about 15 wt % of a corrosion inhibitor which comprises gallic acid, catechol, or an ethylenediamine tetracarboxylic acid compound; wherein the composition is substantially free of hydroxylamine and of fluoride ions, and the composition is capable of removing residue from a metal or metal alloy substrate or a metal or metal alloy substrate layer, while maintaining an acceptably low etch rate with respect to the metal or metal alloy substrate or substrate layer.

2. The composition of claim 1, further comprising water in an amount from about 5 wt % to about 40 wt %.

3. The composition of claim 1, wherein the composition is substantially free from water.

4. The composition of claim 1, further comprising a polar organic solvent in an amount from about 5 wt % to about 15 wt %.

5. The composition of claim 1, wherein the corrosion inhibitor comprises an ethylenediamine tetracarboxylic acid compound having the formula ##STR00010## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 can be either H, or NR.sub.5R.sub.6R.sub.7R.sub.8, where R.sub.5, R.sub.6, R.sub.7, and R.sub.8 are each independently hydrogen or a linear or branched C.sub.1 C.sub.6 hydrocarbon, or where two or more of R.sub.5, R.sub.6, R.sub.7, and R.sub.8 together form a heterocyclic C.sub.4 C.sub.7 ring, wherein R.sub.9 and R.sub.10 may be independently defined in each repeat unit and each of which are independently hydrogen or a linear or branched C.sub.1 C.sub.6 hydrocarbon, and wherein each of q, r, s, and t is a whole number from 0 to 4.

6. The composition of claim 1, wherein the two-carbon atom linkage alkanolamine compound has a boiling point of at least about 185.degree. C. and a flash point of at least about 95.degree. C.

7. The composition of claim 1, wherein more than one two-carbon atom linkage alkanolamine compound is present in the composition.

8. The composition of claim 1, wherein the corrosion inhibitor comprises gallic acid or catechol, and wherein the two-carbon atom linkage alkanolamine compound comprises 2-(2-aminoethyoxy)-ethanol.

9. A resist and etching residue remover composition comprising: from about 1 wt % to about 30 wt % of N,N-diethylhydroxylamine; from about 20 wt % to about 80 wt % of a two-carbon atom linkage alkanolamine compound having the formula ##STR00011## wherein R.sub.1, R.sub.1', R.sub.2, R.sub.2', and R.sub.3 are, independently in each case, hydrogen or a linear, branched, or cyclic hydrocarbon containing from 1 to 7 carbon atoms, wherein Z is a group having the formula -(-Q-CR.sub.1R.sub.1'--CR.sub.2R.sub.2'-)m-, such that m is a whole number from 0 to 3, R.sub.1, R.sub.1', R.sub.2, and R.sub.2'are independently defined in each repeat unit, if m>1, within the parameters set forth for these moieties above, and Q is independently defined in each repeat unit, if m>1, each Q being independently either --O-- or --NR.sub.3--, and wherein X and Y are, independently in each case, hydrogen, a C.sub.1 C.sub.7 linear, branched, or cyclic hydrocarbon, or a group having the formula --CR.sub.1R.sub.1'--CR.sub.2R.sub.2'-Z-F, with F being either --O--R.sub.3 or --NR.sub.3R.sub.4, where R.sub.4 is defined similarly to R.sub.1, R.sub.1', R.sub.2, R.sub.2', and R.sub.3 above, and with Z, R.sub.1, R.sub.1', R.sub.2, R.sub.2', and R.sub.3 defined as above, or wherein X and Y are linked together form a nitrogen-containing heterocyclic C.sub.4 C.sub.7 ring wherein the two-carbon atom linkage alkanolamine compound comprises 2-(2-aminoethylamino)-ethanol; and from about 5 wt % to about 45 wt % water, wherein the composition is substantially free of polar organic solvents and of fluoride ions, and the composition is capable of removing residue from a metal or metal alloy substrate or a metal or metal alloy substrate layer, while maintaining an acceptably low etch rate with respect to the metal or metal alloy substrate or substrate layer.

10. The substantially polar organic solvent-free composition of claim 9, wherein the composition is substantially free from corrosion inhibitors.

11. The substantially polar organic solvent-free composition of claim 9, wherein the two-carbon atom linkage alkanolamine compound has a boiling point of at least about 185.degree. C. and a flash point of at least about 95.degree. C.

12. The substantially polar organic solvent-free composition of claim 9, wherein the two-carbon atom linkage alkanolamine compound is 2-(2-aminoethoxy)-ethanol.

13. The substantially polar organic solvent-free composition of claim 9, further comprising hydroxylamine, wherein the ratio of hydroxylamine derivative to hydroxylamine is from about 20:1 to about 1:20, by weight.

14. A resist and etching remover composition comprising: from about 1 wt % to about 30 wt % of N,N-diethylhydroxylamine; from about 20 wt % to about 80 wt % of a two-carbon atom linkage alkanolamine compound having the formula ##STR00012## wherein R.sub.1, R.sub.1', R.sub.2, R.sub.2', and R.sub.3 are, independently in each case, hydrogen or a linear, branched, or cyclic hydrocarbon containing from 1 to 7 carbon atoms, wherein Z is a group having the formula -(-Q-CR.sub.1R.sub.1'--CR.sub.2R.sub.2'-)m-, such that m is a whole number from 0 to 3, R.sub.1, R.sub.1', R.sub.2, and R.sub.2'are independently defined in each repeat unit, if m>1, within the parameters set forth for these moieties above, and Q is independently defined in each repeat unit, if m>1, each Q being independently either --O-- or --NR.sub.3--, and wherein X and Y are, independently in each case, hydrogen, a C.sub.1 C.sub.7 linear, branched, or cyclic hydrocarbon, or a group having the formula --CR.sub.1R.sub.1'--CR.sub.2 R.sub.2'-Z-F, with F being either --O--R.sub.3 or --NR.sub.3R.sub.4, where R.sub.4 is defined similarly to R.sub.1, R.sub.1', R.sub.2, R.sub.2', and R.sub.3 above, and with Z, R.sub.1, R.sub.1', R.sub.2, R.sub.2', and R.sub.3 defined as above, or wherein X and Y are linked together form a nitrogen-containing heterocyclic C.sub.4 C.sub.7 ring, wherein the two-carbon atom linkage alkanolamine compound comprises 2-(2-aminoethylamino)-ethanol; and from about 5 wt % to about 45 wt % water, wherein the composition is substantially free of hydroxylamine and of fluoride ions, and the composition is capable of removing residue from a metal or metal alloy substrate or a metal or metal alloy substrate layer, while maintaining an acceptably low etch rate with respect to the metal or metal alloy substrate or substrate layer.

15. The substantially hydroxylamine-free composition of claim 14, wherein the composition is substantially free from corrosion inhibitors.

16. The substantially hydroxylamine-free composition of claim 14, wherein the two-carbon atom linkage alkanolamine compound has a boiling point of at least about 185.degree. C. and a flash point of at least about 95.degree. C.

17. The substantially hydroxylamine-free composition of claim 16, wherein the two-carbon atom linkage alkanolamine compound is 2-(2-aminoethoxy)-ethanol, or both.

18. The substantially hydroxylamine-free composition of claim 14, further comprising a polar organic solvent in an amount from about 5 wt % to about 15 wt %.

19. The substantially hydroxylamine-free composition of claim 14, wherein the composition is substantially free from polar organic solvents.

20. A resist and etching residue remover composition comprising: from about 5 wt % to about 30 wt % of N,N-diethylhydroxylamine; and from about 20 wt % to about 80 wt % of a two-carbon atom linkage alkanolamine compound having the formula ##STR00013## wherein R.sub.1, R.sub.1', R.sub.2, R.sub.2', and R.sub.3 are, independently in each case, hydrogen or a linear, branched, or cyclic hydrocarbon containing from 1 to 7 carbon atoms, wherein Z is a group having the formula -(-Q-CR.sub.1R.sub.1'--CR.sub.2R.sub.2')m-, such that m is a whole number from 0 to 3, R.sub.1, R.sub.1', R.sub.2, and R.sub.2' are independently defined in each repeat unit, if m>1, within the parameters set forth for these moieties above, and Q is independently defined in each repeat unit, if m>1, each Q being independently either --O-- or --NR.sub.3--, and wherein X and Y are, independently in each case, hydrogen, a C.sub.1 C.sub.7 linear, branched, or cyclic hydrocarbon, or a group having the formula --CR.sub.1R.sub.1'--CR.sub.2 R.sub.2'-Z-F, with F being either --O--R.sub.3 or --NR.sub.3R.sub.4, where R.sub.4 is defined similarly to R.sub.1, R.sub.1', R.sub.2, R.sub.2', and R.sub.3 above, and with Z, R.sub.1, R.sub.1', R.sub.2, R.sub.2', and R.sub.3 defined as above, or wherein X and Y are linked together form a nitrogen-containing heterocyclic C.sub.4 C.sub.7 ring, wherein the composition is substantially free of water and of fluoride ions, and the composition is capable of removing residue from a metal or metal alloy substrate or a metal or metal alloy substrate layer, while maintaining an acceptably low etch rate with respect to the metal or metal alloy substrate or substrate layer.

Description

FIELD OF THE INVENTION

The present invention is directed to resist and etching residue removing compositions containing at least one nucleophilic amine compound possessing reduction and oxidation potentials, a two-carbon atom linkage alkanolamine compound, and optionally water and/or one or more corrosion inhibitors. The compositions are useful in processes for removing resists and etching residue from micro-circuitry during fabrication.

BACKGROUND OF THE INVENTION

During the fabrication of microcircuits, the precise positioning of a number of appropriately doped regions on a slice of semiconductor is required followed by the positioning of one or more interconnection patterns on the semiconductor. Positive-type resists have been extensively used as masking materials to delineate patterns onto a substrate so that the patterns can be subsequently etched or otherwise defined into the substrate. The final steps in preparing the substrate then involve removing the unexposed resist material and any etching residue from the substrate. Increasingly, however, plasma etching, reactive ion etching or ion milling is used to define the pattern in a substrate which renders the resist mask substantially impossible to remove by stripping agents heretofore commonly used for such or similar purposes containing one or more of the following solvents: halogenated hydrocarbons such as, for example, methylene chloride or tetrachloroethylene; amines and their derivatives such as, for example, dimethylformamide, dimethylacetamide, pyrrolidone, diethanolamine, and triethanolamine; glycol ethers, such as, for example, ethylene glycol monoethyl ether, 2-butoxyethanol, and 2-(butoxy-ethoxy)ethanol; and an alkylsulfone, such as, for example, dimethylsulfone.

Additionally, during such etching processing, an organometallic by-product compound can be formed on the sidewall of the substrate material. The above-mentioned solvents are also ineffective in removing such organometallic polymers. A recently developed technique effective for photoresist removal is plasma oxidation, also known as plasma ashing. However, while this process is effective for removing a photoresist, it is not effective for removing the organometallic polymer formed on the sidewall of the substrate during the etching process.

Further, polyimides are increasingly used in microelectronics as fabrication aids, passivants, and inter-level insulators. The use of a polyimide as a fabrication aid includes application of the polyimide as a photoresist, planarization layer in a multi-level photoresist scheme and as an ion implant mask. In these applications, the polymer is applied to a wafer or substrate, subsequently cured or patterned by a suitable method and removed after use. Many conventional strippers are not sufficiently effective in removing the polyimide layer once the polyimide has been subjected to a severe curing operation. The removal of such polyimides is normally accomplished by boiling the substrate in hydrazine or in oxygen plasma.

Accordingly, a composition suitable for stripping a resist so as to remove the resist rapidly and completely would provide substantial advantages over conventional strippers. Further, a composition capable of removing both the resist and organometallic by-products would provide even a greater advantage. As apparent, if an etching residue is not completely removed from the substrate, the residue can interfere with subsequent processes involving the substrate.

In addition to removing completely the resist material, particularly with the introduction of submicron process techniques to form wafers, there is a demand for cleaning technology for removing etching residue remaining following resist removal. The requirement for a cleaning solution to remove all types of residue generated as a result of plasma etching of various types of metals, such as aluminum, aluminum/silicon/copper, titanium, titanium nitride, titanium/tungsten, tungsten, copper, silicon oxide, polysilicon crystal, etc., presents a need for more effective cleaning chemistry in the processing area.

More specifically, during the fabrication of microcircuits, the substrate surface can be aluminum, titanium, silicon oxide or polysilicon and patterns are delineated thereon by chemical etching. Increasingly, plasma etching, reactive ion etching or ion milling are used, and such etching processes produce undesirable by-products from the interaction of the plasma gases, reacted species and the photoresist. The composition of such by-products is generally made up of the etched substrates, underlying substrate, photoresist and etching gases. The formation of such by-products is influenced by the type of etching equipment, process conditions and substrates utilized. These by-products are generally referred to as "sidewall polymer," "veil", "fences", "rabbit ears" or "goat horns", and cannot be removed completely by either oxygen plasma or conventional solvents, such as N-methyl-2-pyrrolidone, diethyleneglycol monobutyl ether, dimethylacetamide, or the like, which are conventionally used to remove resists. It is critical that all of the etching residue and the like be removed to provide a wafer having sufficient integrity for subsequent use of the wafer in microcircuitry.

Examples of alkaline/solvent mixtures useful as photoresist strippers, but not necessarily cleaners, known for use in stripping applications include dimethylacetamide or dimethylformamide and alkanolamines as described in U.S. Pat. Nos. 4,770,713 and 4,403,029; 2-pyrrolidone, dialkylsulf one and alkanolamines as described in U.S. Pat. Nos. 4,428,871, 4,401,747, and 4,395,479; and 2-pyrrolidone and tetramethylammonium hydroxide as described in U.S. Pat. No. 4,744,834. Such stripping compositions, however, have only proven successful in cleaning "sidewall polymer" from the contact openings and metal line etching in simple microcircuit manufacturing involving a single layer of metal when the metal structure involves mainly Al--Si or Al--Si--Cu and the "sidewall polymer" residue contains only an organometallic compound with aluminum. The cleaning mechanism involving such materials has been studied by EKC Technology, Inc. and Intel Corp., as presented at the K.T.I. Conference in 1989 in the presentation entitled "Metal Corrosion in Wet Resist Stripping Process," by P. L. Pai, C. H. Ting, W. N. Lee and R. Kuroda. Due to the corrosive nature of such strippers as above described, the "sidewall polymer" is removed either by attacking the organoaluminum compound or the metal surface itself and causing the "sidewall polymer" residue to be lifted off. Further, in addition to the use of the stripping composition, mechanical scrubbing, such as ultrasonic vibration, is required to achieve complete removal of the "sidewall polymer."

The most current submicron processing techniques utilized in the industry involving multi-levels of metal and multi-level of interconnecting processes usually incorporate metal materials including TiN, TiW, Ti, TiSi, W, WSi, and the like. The use of such materials results in the generation of new organometallic material by-products during plasma etching, whether formed intentionally or unintentionally, which renders the cleaning incomplete when utilizing existing commercially available stripping and cleaning products. Such findings were described at the SPIE Symposium on Microlithography in 1991 in a presentation entitled "Plasma Etching and Reactive Ion Etching" by John W. Coburn. In particular, it has been found that the residue remaining on the substrate surface after removal of a resist by plasma ashing has changed from the organometallic to the corresponding oxide, such as TiO.sub.2, which is chemically inert to mild alkaline strippers. The effect of such poor cleaning results in low device yield, low device reliability, and low device performance.

Therefore, conventional stripping compositions--are ineffective in removing sidewall organometallic and other metal oxide residue which is present following use of the current technology to remove resists. Even plasma ashing, which has been found effective for removing photoresists, is not effective for removing the sidewall organometallic polymer and some other of the metal oxide residues formed during etching processes.

Additionally, because many of the toxic components of such compositions are highly volatile and subject to unduly high evaporation rates, the compositions require special human and environmental safety precautions to be taken during storage and use of said compositions.

The resists may in some locations be altered, for example by etching, into various compounds, which incorporate the altered resist, as well as some usually altered substrate. For example, oxygen plasma oxidation is often used for removal of resists or other polymeric materials after their use, during the fabrication process has been completed. Such high energy processes typically result in the formation of organometallic and other residues, for example metal oxides, on sidewalls of the structures being formed in the fabrication process. Other etching, including the use of directed energy and/or chemical etching, leave different types of residue, for example organometallic compounds and/or metal fluorides. Finally, direct layer deposition using convertible organometallic compounds, which may or may not require etching to form a pattern, may leave yet other types of residues. These residues must be removed without substantially altering the underlying substrate.

U.S. Pat. No. 6,372,050 teaches a composition for cleaning residue from a substrate that contains 5 to 50% of a solvent selected from a particular group that includes M-methyl-2-pyrrolidone (NMP), dimethyl sulfoxide (DMSO), N,N-dimethylacetamide, and many others; 10 to 90% of an alkanolamine selected from diethyleneglycolamine (DGA), monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), AEEA, and mixtures thereof; from 0.1 to 10% of a carboxylic acid selected from formic acid, acetic acid, phthalic acid, salicylic acid, oxalic acid, and many others; and 1 to 40% water.

A variety of metal and other layers are commonly employed in integrated circuit fabrication, including aluminum, aluminum/silicon/copper, copper, titanium, titanium nitride, titanium/tungsten, tungsten, silicon oxide, polysilicon crystal, and the like. The use of such different layers results in the formation of different organometallic residues in the high energy processes. Further, there is almost always at least two, but in some cases there may be more than two substrate types on an outer layer to be cleaned. A cleaning composition is often designed to be compatible with a single substrate exposed to the cleaning composition.

A variety of residue removal compositions and processes suitable for integrated circuit fabrication have been developed and marketed by EKC Technology, Inc. (hereinafter "EKC"), the assignee of the present application. Some of these compositions and processes are also useful for removing photoresist, polyimide, or other polymeric layers from substrates in integrated circuit fabrication, and EKC has also developed a variety of compositions and processes specifically for removing such polymeric layers from substrates in integrated circuit fabrication. Additionally, EKC has developed a variety of compositions and processes to selectively remove specific substrate compositions from a substrate surface at a controlled rate. Such compositions and processes are disclosed in the following commonly assigned issued patents:

U.S. Pat. No. 6,367,486 to Lee et al., which issued on Apr. 9, 2002, entitled Ethylenediaminetetraacetic acid or its ammonium salt semiconductor process residue removal process;

U.S. Pat. No. 6,313,039 to Small et al., which issued on Nov. 6, 2001, entitled Chemical mechanical polishing composition and process;

U.S. Pat. No. 6,276,372 to Lee, which issued on Aug. 21, 2001, entitled Process using hydroxylamine-gallic acid composition;

U.S. Pat. No. 6,251,150 to Small et al., which issued on Jun. 26, 2001, entitled Slurry composition and method of chemical mechanical polishing using same;

U.S. Pat. No. 6,248,704 to Small et al., which issued on Jun. 19, 2001, entitled Compositions for cleaning organic and plasma etched residues for semiconductors devices;

U.S. Pat. No. 6,242,400 to Lee, which issued on Jun. 5, 2001, entitled Method of stripping resists from substrates using hydroxylamine and alkanolamine;

U.S. Pat. No. 6,235,693 to Cheng et al., which issued on May 22, 2001, entitled Lactam compositions for cleaning organic and plasma etched residues for semiconductor devices;

U.S. Pat. Nos. 6,187,730 and 6,221,818, both to Lee, which issued on Feb. 13, 2001 and on Apr. 24, 2001, respectively, entitled Hydroxylamine-gallic compound composition and process;

U.S. Pat. No. 6,156,661 to Small, which issued on Dec. 5, 2000, entitled Post clean treatment;

U.S. Pat. No. 6,140,287 to Lee, which issued on Oct. 31, 2000, entitled Cleaning compositions for removing etching residue and method of using;

U.S. Pat. No. 6,121,217 to Lee, which issued on Sep. 19, 2000, entitled Alkanolamine semiconductor process residue removal composition and process;

U.S. Pat. No. 6,117,783 to Small et al., which issued on Sep. 12, 2000, entitled Chemical mechanical polishing composition and process;

U.S. Pat. No. 6,110,881 to Lee et al., which issued on Aug. 29, 2000, entitled Cleaning solutions including nucleophilic amine compound having reduction and oxidation potentials;

U.S. Pat. No. 6,000,411 to Lee, which issued on Dec. 14, 1999, entitled Cleaning compositions for removing etching residue and method of using;

U.S. Pat. No. 5,981,454 to Small, which issued on Nov. 9, 1999, entitled Post clean treatment composition comprising an organic acid and hydroxylamine;

U.S. Pat. No. 5,911,835 to Lee et al., which issued on Jun. 15, 1999, entitled Method of removing etching residue;

U.S. Pat. No. 5,902,780 to Lee, which issued on May 11, 1999, entitled Cleaning compositions for removing etching residue and method of using;

U.S. Pat. No. 5,891,205 to Picardi et al., which issued on Apr. 6, 1999, entitled Chemical mechanical polishing composition;

U.S. Pat. No. 5,672,577 to Lee, which issued on Sep. 30, 1997, entitled Cleaning compositions for removing etching residue with hydroxylamine, alkanolamine, and chelating agent;

U.S. Pat. No. 5,482,566 to Lee, which issued on Jan. 9, 1996, entitled Method for removing etching residue using a hydroxylamine-containing composition;

U.S. Pat. No. 5,399,464 to Lee, which issued on Mar. 21, 1995, entitled Triamine positive photoresist stripping composition and post-ion implantation baking;

U.S. Pat. No. 5,381,807 to Lee, which issued on Jan. 17, 1995, entitled Method of stripping resists from substrates using hydroxylamine and alkanolamine;

U.S. Pat. No. 5,334,332 to Lee, which issued on Aug. 2, 1994, entitled Cleaning compositions for removing etching residue and method of using;

U.S. Pat. No. 5,279,771 to Lee, which issued on Jan. 18, 1994, entitled Stripping compositions comprising hydroxylamine and alkanolamine;

U.S. Pat. No. 4,824,763 to Lee, which issued on Apr. 25, 1989, entitled Triamine positive photoresist stripping composition and prebaking process; and

U.S. Pat. No. 4,395,348 to Lee, which issued on Jul. 26, 1983, entitled Photoresist stripping composition and method;

the entire disclosures of all of which are incorporated herein for all purposes by express reference thereto. These compositions have achieved substantial success in integrated circuit fabrication applications.

U.S. Pat. No. 5,997,658 describes a remover for photoresist and etching residue that contains water, an amine, and a corrosion inhibitor including benzotriazole, gallic acid, or both.

As a result of a continuous effort to decrease critical dimension size in the integrated circuit industry, such as in the fabrication of sub-micron size devices, etching residue removal and substrate compatibility with chemicals employed in wet processing is becoming more and more critical for obtaining acceptable yield in very large scale integration (VLSI) and ultra large scale integration (ULSI) processes. The effectiveness of residue removal by etching, to a large extent, depends on the composition of the surfaces or materials to be etched and the composition of the etchant, as well as many other variables too numerous to mention. The composition of such etching residue is generally made up primarily of the etched substrates, underlying substrate, etched and/or ashed photoresist, and etching gases. The substrate compatibility of the wafers with wet chemicals is highly dependent on the processing of the polysilicon, multilevel interconnection dielectric layers, and metallization in thin film deposition, etching and post-etch treatment of the wafers. Processing conditions are often quite different from one fabrication process to another, making it difficult to apply a particular composition to obtain both effective residue removal and substrate compatibility. For example, some compositions have produced corrosion on certain metal substrates, such as those including a titanium metal layer. Titanium has become more widely used in semiconductor manufacturing processes. It is employed both as a barrier layer to prevent electromigration of certain atoms and as an antireflector or refractory metal layer on top of other metals. Used in such a capacity, the layer is often very thin, and corrosion or etching during cleaning operations may compromise the purpose of the layer.

Hydroxylamine (HA) formulations have been found to be useful in the removal of substrate, for example as an etchant used in chemical-mechanical etching processes, as described in U.S. Pat. Nos. 6,313,039; 6,251,150; and 6,117,783.

Hydroxylamine formulations have also been useful in removing photoresists, such as is found in U.S. Pat. Nos. 5,279,771 and 5,381,807, which describe formulations containing hydroxylamine, an alkanolamine, and optionally a polar organic solvent. Hydroxylamine formulations have also been useful in removing etching residue, such as is found in U.S. Pat. No. 5,334,332, which describes a formulation containing hydroxylamine, an alkanolamine, water, and a chelating agent. Hydroxylamine-containing formulations designed to remove residues are known to be aggressive to metals, particularly to titanium film and under more aggressive process conditions to aluminum film.

As a result, various formulations have been developed to control the corrosion. The attack of titanium can be moderated by using different chelator, e.g., such as disclosed in U.S. Pat. No. 6,276,372, and /or by selecting a class of alkanolamine with 2-carbon linkage(s), which is disclosed, e.g., in U.S. Pat. No. 6,121,217. For example, other formulations include those disclosed in: U.S. Pat. Nos. 6,276,372, 6,221,818, and 6,187,730, which each describe a hydroxylamine formulation with a gallic compound (as opposed to catechol) and an alcohol amine; U.S. Pat. No. 6,242,400, which describes a hydroxylamine formulation with an alcohol amine and a polar organic solvent; U.S. Pat. Nos. 6,156,661 and 5,981,454, which each describe a buffered hydroxylamine formulation with an organic acid; U.S. Pat. Nos. 6,140,287 and 6,000,411, which each describe a hydroxylamine formulation with an alkanolamine and a chelating agent; U.S. Pat. No. 6,121,217, which describes a hydroxylamine formulation with an alkanolamine and gallic acid or catechol; U.S. Pat. No. 6,110,881, which describes a hydroxylamine formulation with an organic solvent, water, and a chelating agent; U.S. Pat. No. 5,911,835, which describes a nucleophilic amine compound formulation with an organic solvent, water, and a chelating agent; and U.S. Pat. Nos. 5,902,780, 5,672,577, and 5,482,566, which each describe a hydroxylamine formulation with an alkanolamine, water, and a dihydroxybenzene chelating agent.

U.S. Pat. No. 5,997,658 to Peters et al. describes a hydroxlamine-free photoresist stripping and cleaning composition, for use particularly of copper or titanium substrates, having about 70 to 85% by weight of an alkanolamine, about 0.5 to 2.5% by weight of benzotriazole, about 0.5 to 2.5% by weight of gallic acid and the remainder being water. Alkanolamines include N-methylethanolamine (NMEA), monoethanolamine (MEA), diethanolamine, mono-, di-, and tri-isopropanolamine, 2-(2-aminoethylamino)-ethanol, 2-(2-aminoethoxy)-ethanol, triethanolamine, and the like. The preferred alkanolamine is N-methylethanolamine (MEA).

Additionally, U.S. Pat. No. 5,928,430 to Ward et al., entitled Aqueous stripping and cleaning compositions containing hydroxylamine and use thereof, describes an aqueous stripping composition comprising a mixture of about 55% to 70% by weight of a polar amine solvent, about 22.5 to 15% by weight of a basic amine, especially hydroxylamine, gallic acid as a corrosion inhibitor, and water. U.S. Pat. No. 5,419,779 to Ward describes a stripping composition containing water, 22.5 to 15% by weight of hydroxylamine, 55% to 70% monoethanolamine, and preferably up to about 10% by weight of a corrosion inhibitor, particularly one selected from the group consisting of catechol, pyrogallol, anthranilic, acid, gallic acid, and gallic ester.

Other cleaning-type compositions exist, for example as found in U.S. Pat. No. 6,261,745 to Tanabe et al., entitled Post-ashing treating liquid compositions and a process for treatment therewith, which describes a post-ashing treating liquid composition comprising a salt of hydrofluoric acid with a base free from metal ions, a water-soluble organic solvent, water, and an acetylene alcohol/alkylene oxide adduct.

Other prior art, e.g., U.S. Pat. Nos. 6,372,050, 6,326,130, 6,268,323, 6,261,745, 5,997,658, 5,417,877, and 4,617,251, inter alia, have demonstrated the corrosion of the aluminum metal film caused by various amines and other compounds in photoresist stripper formulations.

However, further development of integrated circuits and their fabrication processes have created a need for improvement in residue removal compositions and processes.

OBJECTS OF THE INVENTION

The cleaning and substrate etching characteristics of a formulation will change as the amounts of the components change. Some manufacturers provide replenishing solutions that contain one or more components that are lost over time while storing the residue remover at operating temperature. Since low-boiling-temperature organics are preferentially lost and these low-boiling-temperature organics have lower flash points than high-boiling-temperature organics, this replenishing formulation typically has a very low flash point. During the process of adding the replenishing solutions, the system may have localized areas where the temperature exceeds the flash point of the liquid, which can result in dangerous conditions. Advantageously, for certain embodiments of this invention, replenishing solutions consist essentially of water and, optionally, a hydroxylamine derivative. The replenishing solutions are preferably substantially free of alkanolamines and polar organic solvents, and optionally chelating agents and/or corrosion inhibitors.

The etch rates of most residue remover formulations increases with increasing process temperature. Some manufacturers suggest using formulations at low temperatures, such as at 30.degree. C., to provide low etch rates at "normal" operating temperatures. Lower temperatures do not provide adequate removal of tougher residues, which may include polymeric material, within an feasible processing time.

It is possible to use highly reactive components in residue removers, which allows elimination of many solvents and other organics. Fluoride-containing compositions can be used for oxide etch residue. This allows higher flashpoints for mixtures, in some cases exceeding 105.degree. C. However, aluminum and titanium etch rates, at ambient temperatures, of 3 to 6 .ANG./minute are found in commercial inhibited formulations. Therefore, higher temperatures are not practicable for such formulations.

Finally, there may be more than one substrate exposed to a cleaner. Many cleaner formulations exhibit reduced etching activity for one substrate but poor etching activity with other substrate(s). Different etch rates will often produce undesired results.

Accordingly, one object of the invention is to provide a family of photoresist and residue removing compositions which overcomes the above and other stated problems with the prior art.

Another object of the present invention is to provide a resist and etching residue removing composition containing at least one nucleophilic amine compound which possesses oxidation and reduction potentials and one or more corrosion inhibitors; and a method of using the composition to completely remove a resist and clean a microcircuitry substrate.

A further object of the present invention is to provide a resist and etching residue removing composition having long term stability by providing a composition comprising at least one nucleophilic amine compound possessing reduction and oxidation potentials and at least one corrosion inhibitor.

A further object of the present invention is to provide a resist and etching residue removing composition including at least one nucleophilic amine compound possessing reduction and oxidation potentials, at least one solvent which is miscible with the nucleophilic amine compound, and optionally water, wherein the nucleophilic amine and the organic solvent are maintained separately and combined just prior to use and which is disposable after use due to having a short active life cycle. This composition, once formed by combining the components as identified above, can advantageously be reactivated by combining a corrosion inhibitor therewith.

A further object of the present invention is to provide a composition for removing residue formed during etching and resist removal processes from a substrate without adversely damaging the substrate surface or hindering subsequent operation or process steps involving the substrate.

Another object of this invention is to provide an improved composition for residue removal and process using such a composition suitable for meeting current semiconductor fabrication requirements.

It is another object of the invention to provide a process which is suitable for meeting the above objects.

The attainment of the foregoing and related objects, advantages, and features of the invention should be more readily apparent to those skilled in the art, after review of the following more detailed description of the invention, taken together with the examples and claims, as described herein.

SUMMARY OF THE INVENTION

The present invention is directed to a resist and etching residue removing composition comprising at least one nucleophilic amine compound having oxidation and reduction potentials, at least one organic solvent which is miscible with the nucleophilic amine compound, water and, optionally, one or more corrosion inhibitors. The water can be added to the composition by itself or as a carrier for the nucleophilic amine compound, i.e., the nucleophilic amine being present in aqueous solution.

Related application, U.S. Ser. No. 610,044 filed Nov. 5, 1990, which is incorporated herein by reference and which corresponds to published European Patent Application No. 485,161 A1, discloses hydroxylamine in combination with an alkanolamine which is miscible with the hydroxylamine as being useful to remove a resist from a substrate. It has now been found that compounds other than hydroxylamine and an alkanolamine are useful for removing resists, but in particular are also useful in removing etching residues from substrates. It has been found that nucleophilic amine compounds having oxidation and reduction potentials satisfactorily remove resists and etching residue from a substrate when combined with an organic solvent which is miscible with the nucleophilic amine compound and water. While the nucleophilic amine compound must have the potential for reduction and oxidation, it is not required that reduction and oxidation actually occur in the use of the composition. Examples of nucleophilic amine compounds useful in the present invention include hydroxylamines, hydrazines, certain specified amines, and their derivatives as further described below. The organic solvent is not required to be an amine, but the presence of an amine solvent is preferred.

Further, it has been found that when a corrosion inhibitor is present in a composition containing at least one nucleophilic amine compound having reduction and oxidation potentials that at least two additional surprising benefits are achieved, namely, (1) the corrosion inhibitor assists in cleaning by retaining etching residue in the cleaning solution and thereby avoiding resettling of the residue onto the substrate and (2) the corrosion inhibitor serves as a stabilizing agent to provide long term effectiveness to the composition. The presence of the corrosion inhibitor further provides the composition with long term activity and, therefore, a long shelf life. When a corrosion inhibitor is not present in the composition containing a nucleophilic amine compound, depending on the nature or presence of a two-carbon atom linkage alkanolamine compound, the solution may have only short term stability, e.g., generally an active life of about one week. Accordingly, when a corrosion inhibitor is not present, it is preferable to maintain the nucleophilic amine compound separately from any other compounds in the composition until just prior to use. After the components are combined and the solution used, the remaining solution can be disposed of, or, once the activity has decreased, the solution can be reactivated by the addition of a corrosion inhibitor. In one embodiment, the corrosion inhibitors include dihydroxybenzenes and their derivatives, as further described below.

The cleaning composition is especially useful in removing etching residue from substrates which contain metal elements other than aluminum such as titanium (Ti), tungsten (W), silicon (Si) and silicon oxide (SiO.sub.2). While the compositions of the invention are capable of removing resists from substrates, the compositions of the invention have been shown to have a surprising capacity for cleanly removing etching residue, in particular organometallic and metal oxide etching residue, from a substrate surface following removal of a resist therefrom. Currently in the industry, etching residue is extremely difficult to completely remove without damaging the substrate.

The cleaning compositions of the present invention are particularly suitable for removing organometallic and metal oxide residues from a substrate, in particular, during the fabrication of a submicron (i.e., less than 0.8 microns) integrated circuit without adversely affecting or hindering subsequent manufacturing operation or process steps involving the substrate. Further, the cleaning compositions of the invention are effective in removing organometallic residue outgasing which has been deposited on parts of the etching equipment utilized in the processing. This equipment can be made of polycarbonate, ceramic, aluminum, or a like material.

The method of removing a resist or etching residue from a substrate using the compositions of the present invention also is advantageous in that complex process steps and equipment are not required. The method of the invention involves contacting a substrate containing a resist or etching residue with the composition of the invention as described herein at a temperature and for a time sufficient to remove the particular resist or etching residue present.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows etched wafer residue following the use of plasma ashing to remove a resist from a silicon oxide dielectric layer which had been earlier plasma etched.

FIG. 2 shows the results of an analysis using ion mass spectrometry (LII4A) of the residue shown in FIG. 1. Such analysis indicates that the residue contains metal oxide and trace amounts of organic material.

FIGS. 3A and 3B show the results of a comparison test utilizing a cleaning composition of the present invention (FIG. 3A) and a stripping composition as described in U.S. Pat. No. 4,403,029 (FIG. 3B) in relation to a silicon oxide dielectric layer containing etching residue thereon which is present following removal of a resist by plasma ashing. By comparing FIG. 3A with FIG. 3B, it can be seen that all the organometallic residue was removed using the composition of the present invention while residue remained following use of the stripping composition described in U.S. Pat. No. 4,403,029.

FIGS. 4A and 4B show the results of a comparison test utilizing a cleaning composition of the present invention (FIG. 4A) and a stripping composition as described in U.S. Pat. No. 4,770,713 (FIG. 4B) in relation to a silicon dielectric layer which contained etching residue following removal of a resist therefrom by plasma ashing. As evident upon a comparison of FIG. 4A with FIG. 4B, the composition of the present invention removed all the organometallic residue while the other composition did not.

FIG. 5A shows a microcircuit pattern of polysilicon over silicon oxide containing etching residue which remained on the substrate following plasma etching. FIG. 5B shows the same microcircuit pattern following cleaning with a composition of the present invention. As evident from a comparison of FIG. 5A with FIG. 5B, it can be seen that the residue has been removed.

FIG. 6A shows residue which remained on a metal substrate after the removal of a photoresist from the substrate by plasma ashing. FIG. 6B shows the same substrate following cleaning with a composition of the present invention.

FIGS. 7A 7D show the results of comparison tests using a cleaning composition of the present invention (FIGS. 7A and 7B) and a N-methyl-2-pyrrolidone solvent alkanolamine base stripper (FIGS. 7C and 7D) in relation to openings on a silicon oxide dielectric layer. As shown in FIGS. 7A and 78, all the organometallic residue was removed using the composition of the present invention while, as evident from FIGS. 7C and 7D, residue remained on the substrate treated with the stripper.

FIG. 8A shows residue remaining on a wafer following etching and the removal of a photoresist therefrom. FIG. 8B shows the same wafer following cleaning with a composition of the present invention. All the residue on the wafer was removed.

FIG. 9 illustrates the results of Example 11 below wherein the stability of cleaning Compositions A, C and G were compared.

FIGS. 10, 11, and 12 each show a graphical chart representing the etch rate of a substrate (copper, aluminum, and titanium, respectively) based on the relative amounts of water and N,N-diethylhydroxylamine present.

DEFINITIONS

Unless otherwise specified, all percentages expressed herein should be understood to refer to percentages by weight. Also, the term "about," when used in reference to a range of values, should be understood to refer to either value in the range, or to both values in the range.

As used herein, the phrases "contains substantially no," "is substantially free from," or "substantially [something]-free," in reference to a composition means: for major components including alkanolamines or nucleophilic amines, polar organic solvents, non-hydroxyl-containing amines, water, organic solvents, hydroxylamine and hydroxylamine derivatives, the aforementioned phrases should be understood to mean that the composition contains less than 1.5%, preferably less than about 1%, more preferably less than about 0.1%, of the specific element mentioned thereafter; for minor components including chelating agents, corrosion inhibitors, HF and HF salts, surfactants, and the like, the aforementioned phrases should be understood to mean that the composition contains less than 0.2%, preferably less than about 0.1%, most preferably less than about 0.01%, of the specific element mention thereafter; and for trace contaminants such as metal ions, substantially free is defined in the specification, e.g., less than 10 ppm metals and metal ions.

Preferably, when one of the aforementioned phrases is used, the composition is completely free of any added element specifically mentioned thereafter, or at least does not contain the added element in an amount such that the element affects the efficacy, storability, usability regarding necessary safety concerns, or stability of the composition.

Unless otherwise specified, and wherever possible, a compound should generally not be characterized under more than one enumerated element of the composition according to the invention. If a compound is capable of being characterized under, for example, two enumerated embodiments of the composition, such a compound may be characterized herein only under either one of the two enumerated elements, but not under both. At times, the distinction may be made based on the content of the compound in the composition. For instance, catechol or gallic acid can act primarily as a corrosion inhibitor at "high" concentrations, e.g. about 0.5% to 20%, or primarily as a metal chelator at "low" concentrations, e.g., in the ppm to 0.5 wt % range.

As used herein, hydroxylamine and hydroxyamine derivatives are not considered organic, despite the organic substituents that may be present on substituted hydroxylamine.

As used herein, an "acceptably low etch rate," when referring to etching of a substrate layer by a composition, should be understood to mean that the composition causes not more than about 5 .ANG./min etching of the substrate layer, alternately not more than about 3 .ANG./min etching of the substrate layer, for example not more than about 1 .ANG./min etching of the substrate layer, upon contact under given conditions for an enumerated period of time.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The cleaning and stripping composition of the present invention for removing etching residue and resists from a substrate contains at least one nucleophilic amine compound having oxidation and reduction potentials in a cleaning environment, at least one organic solvent which is miscible with the nucleophilic amine compound, water, and, optionally, one or more corrosion inhibitors. The water can be provided in the composition independently or in combination with the nucleophilic amine compound, for example the nucleophilic amine compound can be added as 50% aqueous solution.

In a composition according to the invention, the composition preferably contains a corrosion inhibitor. The corrosion inhibitor serves to provide long term stability and activity to the composition. The composition, therefore, has the desirable commercial attribute of having a long shelf life.

Alternatively, the composition can be provided including at least one nucleophilic amine compound having reduction and oxidation potentials, an organic solvent and water. This composition, however, only has short term effectiveness and so it is preferable that the nucleophilic amine compound and organic solvent are maintained separate until just prior to use. As stated above, the water can be present in combination with the nucleophilic amine compound. In this case the nucleophilic amine compound in aqueous solution will be maintained separate from the organic solvent until just prior to use. The components are then combined and the composition used as needed. Generally, the composition without a corrosion inhibitor will have an effective active life for approximately one week. Any unused portion of the composition can then be simply disposed of or, alternatively, the unused portion can be reactivated by the addition of a corrosion inhibitor to the solution.

The composition of the invention can be used as a stripping composition to remove a resist or a cleaning composition to remove etching residue from a substrate. The ability to remove etching residue effectively is in particular surprising in view of the difficulty experienced in the art to produce an effective etching residue removing solution.

The cleaning compositions of the present invention are suitable for removing etching residue, such as organometallic and metal oxide residue, formed on a substrate, in particular residue formed during plasma etching processes. The substrate can include copper and non-copper metal elements such as titanium, tungsten, aluminum, silicon, and silicon oxide. The extent and type of residue remaining following etching is determined by the etching equipment utilized, process conditions and substrates utilized.

Compounds suitable for use as the nucleophilic amine compound having oxidation and reduction potentials include certain amines, hydroxylamines, hydrazines and their derivatives as set forth below. The nucleophilic amine compound used in the present invention does not have to actually take part in oxidation or reduction during a cleaning or stripping process. The nucleophilic amine compound must only possess oxidation and reduction qualities in a cleaning or stripping environment. Suitable nucleophilic amine compounds useful in the present invention include, but are not limited to, compounds having the following formulae, and quaternary ammonium salts thereo