Lid assembly for front end of line fabrication Number:7,520,957 from the United States Patent and Trademark Office (PTO) owispatent A lid assembly for semiconductor processing is provided. In at least one embodiment, the lid assembly includes a first electrode comprising an expanding section that has a gradually increasing inner diameter. The lid assembly also includes a second electrode disposed opposite the first electrode. A plasma cavity is defined between the inner diameter of the expanding section of the first electrode and a first surface of the second electrode.<H fabrication, assembly, Lid, assembly, fo, 7520957.html, Patent, pto, 7520957

Title: Lid assembly for front end of line fabrication

Abstract: A lid assembly for semiconductor processing is provided. In at least one embodiment, the lid assembly includes a first electrode comprising an expanding section that has a gradually increasing inner diameter. The lid assembly also includes a second electrode disposed opposite the first electrode. A plasma cavity is defined between the inner diameter of the expanding section of the first electrode and a first surface of the second electrode.

Patent Number: 7,520,957 Issued on 04/21/2009 to Kao, et al.

Inventors: Kao; Chien-Teh (Sunnyvale, CA), Chou; Jing-Pei (Connie) (Sunnyvale, CA), Lai; Chiukin (Steven) (Sunnyvale, CA), Umotoy; Sal (Antioch, CA), Huston; Joel M. (San Jose, CA), Trinh; Son (Cupertino, CA), Chang; Mei (Saragoga, CA), Yuan; Xiaoxiong (John) (Cupertino, CA), Chang; Yu (San Jose, CA), Lu; Xinliang (Sunnyvale, CA), Wang; Wei W. (Cupertino, CA), Phan; See-Eng (San Jose, CA)
Assignee: Applied Materials, Inc. (Santa Clara, CA)

Appl. No.: 11/137,199

Filed: May 24, 2005

Related U.S. Patent Documents


Application Number	Filing Date	Patent Number	Issue Date
11063645	Feb., 2005
60547839	Feb., 2004

Current U.S. Class: 156/345.43 ; 118/723DC; 118/723E; 118/723ER; 118/723IR; 118/723R; 156/345.35; 156/345.45

Current International Class: H01L 21/00 (20060101); C23C 16/00 (20060101)

Field of Search: 156/345.34,345.35,345.43,345.45 118/723ER,723IR,723ME,723R,723DC,723E

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Other References

SM. Sze, VLSI Technology, McGraw-Hill Book Company, 3 pages. cited by other .
Ogawa, Hiroki, et al., Dry Cleaning Technology for Removal of Silicon Native Oxide Employing Hot NH.sub.3/NF.sub.3 Exposure, Jpn. J. Appl. Phys. vol. 41 (2002) pp. 5349-5358, Part 1, No. 8, Aug. 2002. cited by other .
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Primary Examiner: Kackar; Ram N.
Attorney, Agent or Firm: Patterson & Sheridan, LLP

Parent Case Text

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No. 11/063,645, filed on Feb. 22, 2005, which claims benefit of U.S. provisional patent application Ser. No. 60/547,839, filed Feb. 26, 2004, which are herein incorporated by reference. This application is also related to U.S. patent application Ser. No. 11/137,609, filed May 24, 2005, now issued as U.S. Pat. No. 7,396,480; U.S. patent application Ser. No. 11/266,167 , filed Nov. 3, 2005; U.S. patent application Ser. No. 11/622,437, filed Jan. 11, 2007; U.S. patent application Ser. No. 11/962,791, filed Dec. 21, 2007; and U.S. patent application Ser. No. 12/134,715, filed Jun. 6, 2008.

Claims

The invention claimed is:

1. A lid assembly for semiconductor processing, comprising: a first electrode comprising an expanding section that has a gradually increasing inner diameter; a second electrode disposed opposite the first, wherein a plasma cavity is defined between the inner diameter of the expanding section of the first electrode and a first surface of the second electrode and wherein the second electrode comprises a plurality of gas passages that are in fluid communication with the plasma cavity; and an isolation ring disposed about an outer diameter of the expanding section, wherein the isolation ring and the expanding section of the first electrode fit within a recess formed in the first surface of the second electrode.

2. A lid assembly for semiconductor processing, comprising: a first electrode comprising an expanding section having a gradually increasing inner diameter; and a second electrode disposed opposite the first electrode, wherein the second electrode comprises a plurality of gas passages formed there through and wherein a plasma cavity is defined between the inner diameter of the expanding section of the first electrode and a first surface of the second electrode; and a perforated plate disposed opposite a second surface of the second electrode, wherein the perforations of the perforated plate are in fluid communication with the plurality of gas passages of the second electrode, wherein; the second electrode and the perforated plate each comprise a notched outer diameter, and the notched outer diameter of the second electrode is adapted to mount on the notched outer diameter of the perforated plate; the said lid assembly further comprising an isolation ring disposed about an outer diameter of the expanding section, wherein the isolation ring and the expanding section of the first electrode fit within a recess formed in the first surface of the second electrode.

3. The lid assembly of claim 2, wherein the perforated plate includes a fluid channel embedded in an outer diameter thereof for conveying a heating medium to heat the perforated plate.

4. The lid assembly of claim 2, wherein the perforated plate convectively heats the second electrode.

5. A lid assembly for semiconductor processing, comprising: a first electrode comprising an expanding section having a gradually increasing inner diameter; a second electrode disposed opposite the first electrode, wherein the second electrode comprises a plurality of gas passages formed there through and wherein a plasma cavity is defined between the inner diameter of the expanding section of the first electrode and a first surface of the second electrode; a first perforated plate disposed opposite a second surface of the second electrode; and a second perforated plate disposed between the second electrode and the first perforated plate, wherein; the second electrode and the first perforated plate each comprise a notched outer diameter, the notched outer diameter of the second electrode is adapted to mount on the notched outer diameter of the first perforated plate; and at least a portion of the second perforated plate is adapted to mount to the second surface of the second electrode; the said lid assembly, further comprising an isolation ring disposed about an outer diameter of the expanding section, wherein the isolation ring and the expanding section of the first electrode fit within a recess formed in the first surface of the second electrode.

6. The lid assembly of claim 5, wherein the first perforated plate includes a fluid channel embedded in an outer diameter thereof for conveying a heating medium to heat the first perforated plate.

7. The lid assembly of claim 5, wherein the expanding section of the first electrode is connected to a RF power source and adapted to confine a plasma of reactive gases within the plasma cavity.

8. The lid assembly of claim 5, wherein the perforations of the first and second perforated plates are in fluid communication with the gas passages of the second electrode.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the present invention generally relate to semiconductor processing equipment. More particularly, embodiments of the present invention relate to a chemical vapor deposition (CVD) system for semiconductor fabrication and in situ dry cleaning methods using the same.

2. Description of the Related Art

A native oxide typically forms when a substrate surface is exposed to oxygen. Oxygen exposure occurs when the substrate is moved between processing chambers at atmospheric conditions, or when a small amount of oxygen remaining in a vacuum chamber contacts the substrate surface. Native oxides may also result if the substrate surface is contaminated during etching. Native oxides typically form an undesirable film on the substrate surface. Native oxide films are usually very thin, such as between 5 and 20 angstroms, but thick enough to cause difficulties in subsequent fabrication processes.

Such difficulties usually affect the electrical properties of semiconductor devices formed on the substrate. For example, a particular problem arises when native silicon oxide films are formed on exposed silicon containing layers, especially during processing of Metal Oxide Silicon Field Effect Transistor ("MOSFET") structures. Silicon oxide films are electrically insulating and are undesirable at interfaces with contact electrodes or interconnecting electrical pathways because they cause high electrical contact resistance. In MOSFET structures, the electrodes and interconnecting pathways include silicide layers formed by depositing a refractory metal on bare silicon and annealing the layer to produce the metal suicide layer. Native silicon oxide films at the interface between the substrate and the metal reduce the compositional uniformity of the silicide layer by impeding the diffusional chemical reaction that forms the metal silicide. This results in lower substrate yields and increased failure rates due to overheating at the electrical contacts. The native silicon oxide film can also prevent adhesion of other CVD or sputtered layers which are subsequently deposited on the substrate.

Sputter etch processes have been tried to reduce contaminants in large features or in small features having aspect ratios smaller than about 4:1. However, sputter etch processes can damage delicate silicon layers by physical bombardment. In response, wet etch processes using hydrofluoric (HF) acid and deionized water, for example, have also been tried. Wet etch processes such as this, however, are disadvantageous in today's smaller devices where the aspect ratio exceeds 4:1, and especially where the aspect ratio exceeds 10:1. Particularly, the wet solution cannot penetrate into those sizes of vias, contacts, or other features formed within the substrate surface. As a result, the removal of the native oxide film is incomplete. Similarly, a wet etch solution, if successful in penetrating a feature of that size, is even more difficult to remove from the feature once etching is complete.

Another approach for eliminating native oxide films is a dry etch process, such as one utilizing fluorine-containing gases. One disadvantage to using fluorine-containing gases, however, is that fluorine is typically left behind on the substrate surface. Fluorine atoms or fluorine radicals left behind on the substrate surface can be detrimental. For example, the fluorine atoms left behind can continue to etch the substrate causing voids therein.

A more recent approach to remove native oxide films has been to form a fluorine/silicon-containing salt on the substrate surface that is subsequently removed by thermal anneal. In this approach, a thin layer of the salt is formed by reacting a fluorine-containing gas with the silicon oxide surface. The salt is then heated to an elevated temperature sufficient to dissociate the salt into volatile by-products which are then removed from the processing chamber. The formation of a reactive fluorine-containing gas is usually assisted by thermal addition or by plasma energy. The salt is usually formed at a reduced temperature that requires cooling of the substrate surface. This sequence of cooling followed by heating is usually accomplished by transferring the substrate from a cooling chamber where the substrate is cooled to a separate anneal chamber or furnace where the substrate is heated.

For various reasons, this reactive fluorine processing sequence is not desirable. Namely, wafer throughput is greatly diminished because of the time involved to transfer the wafer. Also, the wafer is highly susceptible to further oxidation or other contamination during the transfer. Moreover, the cost of ownership is doubled because two separate chambers are needed to complete the oxide removal process.

There is a need, therefore, for a processing chamber capable of remote plasma generation, heating and cooling, and thereby capable of performing a single dry etch process in a single chamber (i.e. in-situ).

SUMMARY OF THE INVENTION

A lid assembly for semiconductor processing is provided. In at least one embodiment, the lid assembly includes a first electrode comprising an expanding section that has a gradually increasing inner diameter. The lid assembly also includes a second electrode disposed opposite the first electrode. A plasma cavity is defined between the inner diameter of the expanding section of the first electrode and a first surface of the second electrode.

In at least one other embodiment, the lid assembly includes a first electrode comprising an expanding section having an inner diameter gradually increasing inner diameter. The lid assembly also includes a second electrode disposed opposite the first electrode. The second electrode includes a plurality of gas passages formed therethrough and a plasma cavity is defined between the inner diameter of the expanding section of the first electrode and a first surface of the second electrode. The lid assembly further includes a perforated plate disposed opposite a second surface of the second electrode. The perforations of the perforated plate are in fluid communication with the plurality of gas passages of the second electrode. The second electrode and the perforated plate each include a notched outer diameter, and the notched outer diameter of the second electrode is adapted to mount on the notched outer diameter of the perforated plate.

In at least one other embodiment, the lid assembly includes a first electrode having an expanding section that includes a gradually increasing inner diameter. A second electrode is disposed opposite the first electrode. The second electrode includes a plurality of gas passages formed therethrough, and a plasma cavity is defined between the inner diameter of the expanding section of the first electrode and a first surface of the second electrode. A first perforated plate is disposed opposite a second surface of the second electrode, and a second perforated plate is disposed between the second electrode and the first perforated plate. The second electrode and the first perforated plate each include a notched outer diameter. The notched outer diameter of the second electrode is adapted to mount on the notched outer diameter of the first perforated plate. At least a portion of the second perforated plate is adapted to mount to the second surface of the second electrode.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

FIG. 1A shows a partial cross sectional view of an illustrative processing chamber 100 for heating, cooling, and etching.

FIG. 1B shows an enlarged schematic view of an illustrative liner disposed within the processing chamber of FIG. 1A.

FIG. 2A shows an enlarged cross sectional view of an illustrative lid assembly that can be disposed at an upper end of the chamber body shown in FIG. 1A.

FIGS. 2B and 2C show enlarged schematic views of the gas distribution plate of FIG. 2A.

FIG. 3A shows a partial cross sectional view of an illustrative support assembly, which is at least partially disposed within the chamber body 112 of FIG. 1A.

FIG. 3B shows an enlarged partial cross sectional view of the illustrative support member 300 of FIG. 3A.

FIG. 4A shows a schematic cross sectional view of another illustrative lid assembly 400.

FIG. 4B shows an enlarged schematic, partial cross sectional view of the upper electrode of FIG. 4A.

FIG. 4C shows a partial cross sectional view of the illustrative processing chamber 100 utilizing the lid assembly 400 of FIG. 4A.

FIGS. 5A-5H are sectional schematic views of a fabrication sequence for forming an illustrative active electronic device, such as a MOSFET structure.

FIG. 6 is a schematic diagram of an exemplary multi-chamber processing system adapted to perform multiple processing operations.

DETAILED DESCRIPTION

A processing chamber for any number of substrate processing techniques is provided. The chamber is particularly useful for performing a plasma assisted dry etch process that requires both heating and cooling of the substrate surface without breaking vacuum. For example, the processing chamber described herein is envisioned to be best suited for a front-end-of line (FEOL) clean chamber for removing oxides and other contaminants from a substrate surface.

A "substrate surface", as used herein, refers to any substrate surface upon which processing is performed. For example, a substrate surface may include silicon, silicon oxide, doped silicon, germanium, gallium arsenide, glass, sapphire, and any other materials such as metals, metal nitrides, metal alloys, and other conductive materials, depending on the application. A substrate surface may also include dielectric materials such as silicon dioxide, organosilicates, and carbon doped silicon oxides. The substrate itself is not limited to any particular size or shape. In one aspect, the term "substrate" refers to a round wafer having a 200 mm diameter or 300 mm diameter. In another aspect, the term "substrate" refers to any polygonal, squared, rectangular, curved or otherwise non-circular workpiece, such as a glass substrate used in the fabrication of flat panel displays, for example.

FIG. 1A is a partial cross sectional view showing an illustrative processing chamber 100. In one embodiment, the processing chamber 100 includes a chamber body 112, a lid assembly 200, and a support assembly 300. The lid assembly 200 is disposed at an upper end of the chamber body 112, and the support assembly 300 is at least partially disposed within the chamber body 112. The processing chamber 100 and the associated hardware are preferably formed from one or more process-compatible materials, such as aluminum, anodized aluminum, nickel plated aluminum, nickel plated aluminum 6061-T6, stainless steel, as well as combinations and alloys thereof, for example.

The chamber body 112 includes a slit valve opening 160 formed in a sidewall thereof to provide access to the interior of the processing chamber 100. The slit valve opening 160 is selectively opened and closed to allow access to the interior of the chamber body 112 by a wafer handling robot (not shown). Wafer handling robots are well known to those with skill in the art, and any suitable robot may be used. For example, an exemplary robotic transfer assembly has been described in a commonly assigned U.S. Pat. No. 4,951,601, entitled "Multi-chamber Integrated Process System," issued Aug. 28, 1990, the complete disclosure of which is incorporated herein by reference. In one embodiment, a wafer can be transported in and out of the processing chamber 100 through the slit valve opening 160 to an adjacent transfer chamber and/or load-lock chamber, or another chamber within a cluster tool. A cluster tool of a type that can be coupled to the processing chamber 100 is described in a commonly assigned U.S. Pat. No. 5,186,718, entitled "Staged-Vacuum Wafer Processing System and Method", issued Feb. 16, 1993, and is herein incorporated by reference.

In one or more embodiments, the chamber body 112 includes a channel 113 formed therein for flowing a heat transfer fluid therethrough. The heat transfer fluid can be a heating fluid or a coolant and is used to control the temperature of the chamber body 112 during processing and substrate transfer. The temperature of the chamber body 112 is important to prevent unwanted condensation of the gas or byproducts on the chamber walls. Exemplary heat transfer fluids include water, ethylene glycol, or a mixture thereof. An exemplary heat transfer fluid may also include nitrogen gas.

The chamber body 112 can further include a liner 133 that surrounds the support assembly 300. The liner 133 is preferably removable for servicing and cleaning. The liner 133 can be made of a metal such as aluminum, or a ceramic material. However, the liner 133 can be any process compatible material. The liner 133 can be bead blasted to increase the adhesion of any material deposited thereon, thereby preventing flaking of material which results in contamination of the processing chamber 100. In one or more embodiments, the liner 133 includes one or more apertures 135 and a pumping channel 129 formed therein that is in fluid communication with a vacuum system. The apertures 135 provide a flow path for gases into the pumping channel 129, which provides an egress for the gases within the processing chamber 100.

The vacuum system can include a vacuum pump 125 and a throttle valve 127 to regulate flow of gases through the processing chamber 100. The vacuum pump 125 is coupled to a vacuum port 131 disposed on the chamber body 112 and therefore, in fluid communication with the pumping channel 129 formed within the liner 133. The terms "gas" and "gases" are used interchangeably, unless otherwise noted, and refer to one or more precursors, reactants, catalysts, carrier, purge, cleaning, combinations thereof, as well as any other fluid introduced into the chamber body 112.

Considering the liner 133 in greater detail, FIG. 1B shows an enlarged schematic view of one embodiment of the liner 133. In this embodiment, the liner 133 includes an upper portion 133A and a lower portion 133B. An aperture 133C that aligns with the slit valve opening 160 disposed on a side wall of the chamber body 112 is formed within the liner 133 to allow entry and egress of substrates to/from the chamber body 112. Typically, the pumping channel 129 is formed within the upper portion 133A. The upper portion 133A also includes the one or more apertures 135 formed therethrough to provide passageways or flow paths for gases into the pumping channel 129.

Referring to FIGS. 1A and 1B, the apertures 135 allow the pumping channel 129 to be in fluid communication with a processing zone 140 within the chamber body 112. The processing zone 140 is defined by a lower surface of the lid assembly 200 and an upper surface of the support assembly 300, and is surrounded by the liner 133. The apertures 135 may be uniformly sized and evenly spaced about the liner 133. However, any number, position, size or shape of apertures may be used, and each of those design parameters can vary depending on the desired flow pattern of gas across the substrate receiving surface as is discussed in more detail below. In addition, the size, number and position of the apertures 135 are configured to achieve uniform flow of gases exiting the processing chamber 100. Further, the aperture size and location may be configured to provide rapid or high capacity pumping to facilitate a rapid exhaust of gas from the chamber 100. For example, the number and size of apertures 135 in close proximity to the vacuum port 131 may be smaller than the size of apertures 135 positioned farther away from the vacuum port 131.

Still referring to FIGS. 1A and 1B, the lower portion 133B of the liner 133 includes a flow path or vacuum channel 129A disposed therein. The vacuum channel 129A is in fluid communication with the vacuum system described above. The vacuum channel 129A is also in fluid communication with the pumping channel 129 via a recess or port 129B formed in an outer diameter of the liner 133. Generally, two gas ports 129B (only one shown in this view) are formed in an outer diameter of the liner 133 between the upper portion 133A and the lower portion 133B. The gas ports 129B provide a flow path between the pumping channel 129 and the vacuum channel 129A. The size and location of each port 129B is a matter of design, and are determined by the stoichiometry of a desired film, the geometry of the device being formed, the volume capacity of the processing chamber 100 as well as the capabilities of the vacuum system coupled thereto. Typically, the ports 129B are arranged opposite one another or 180 degrees apart about the outer diameter of the liner 133.

In operation, one or more gases exiting the processing chamber 100 flow through the apertures 135 formed through the upper portion 133A of the liner 133 into the pumping channel 129. The gas then flows within the pumping channel 129 and through the ports 129B into the vacuum channel 129A. The gas exits the vacuum channel 129A through the vacuum port 131 into the vacuum pump 125.

Considering the lid assembly 200 in more detail, FIG. 2A shows an enlarged cross sectional view of an illustrative lid assembly 200 that can be disposed at an upper end of the chamber body 112 shown in FIG. 1A. Referring to FIGS. 1A and 2A, the lid assembly 200 includes a number of components stacked on top of one another, as shown in FIG. 1A. In one or more embodiments, the lid assembly 200 includes a lid rim 210, gas delivery assembly 220, and a top plate 250. The gas delivery assembly 220 is coupled to an upper surface of the lid rim 210 and is arranged to make minimum thermal contact therewith. The components of the lid assembly 200 are preferably constructed of a material having a high thermal conductivity and low thermal resistance, such as an aluminum alloy with a highly finished surface for example. Preferably, the thermal resistance of the components is less than about 5.times.10.sup.-4 m.sup.2 K/W. The lid rim 210 is designed to hold the weight of the components making up the lid assembly 200 and is coupled to an upper surface of the chamber body 112 via a hinge assembly (not shown in this view) to provide access to the internal chamber components, such as the support assembly 300 for example.

Referring to FIGS. 2B and 2C, the gas delivery assembly 220 can include a distribution plate or showerhead 225. FIG. 2B shows an enlarged schematic view of one embodiment of an illustrative gas distribution plate 225 and FIG. 2C shows a partial cross sectional view. In one or more embodiments, the distribution plate 225 is substantially disc-shaped and includes a plurality of apertures 225A or passageways to distribute the flow of gases therethrough. The apertures 225A of the distribution plate 225 prevent the gases flowing through the lid assembly 200 from impinging directly on the substrate surface below by slowing and re-directing the velocity profile of the flowing gases. The apertures 225A of the distribution plate 225 also evenly distribute the flow of the gas exiting the lid assembly 200, thereby providing an even distribution of the gas across the surface of the substrate.

Referring to FIGS. 2A, 2B and 2C, the distribution plate 225 further includes an annular mounting flange 222 formed at a perimeter thereof, which is sized to rest on the lid rim 210. Accordingly, the distribution plate 225 makes minimal contact with the lid assembly 200. Preferably, an o-ring type seal 224, such as an elastomeric o-ring, is at least partially disposed within the annular mounting flange 222 to ensure a fluid-tight contact with the lid rim 210.

The gas delivery assembly 220 can further include a blocker assembly 230 disposed adjacent the distribution plate 225. The blocker assembly 230 provides an even distribution of gas to the backside of the distribution plate 225. Preferably, the blocker assembly 230 is made of an aluminum alloy and is removably coupled to the distribution plate 225 to ensure good thermal contact. For example, the blocker assembly 230 can be coupled to the distribution plate 225 using a bolt 221 or similar fastener. Preferably, the blocker assembly 230 makes no thermal contact with the lid rim 210 as shown in FIGS. 2A.

In one or more embodiments, the blocker assembly 230 includes a first blocker plate 233 mounted to a second blocker plate 235. The second blocker plate 235 includes a passage 259 formed therethrough. Preferably, the passage 259 is centrally located through the second blocker plate 235 such that the passage 259 is in fluid communication with a first cavity or volume 261 defined by a lower surface of the top plate 250 and an upper surface of the second blocker plate 235. The passage 259 is also in fluid communication with a second cavity or volume 262 defined by a lower surface of the second blocker plate 235 and an upper surface of the first blocker plate 233. The passage 259 is also in fluid communication with a third cavity or volume 263 defined by a lower surface of the first blocker plate 233 and an upper surface of the distribution plate 225. The passage 259 is coupled to a gas inlet 223. The gas inlet 223 is coupled to the top plate 250 at a first end thereof. Although not shown, the gas inlet 223 is coupled at a second end thereof to one or more upstream gas sources and/or other gas delivery components, such as gas mixers.

The first blocker plate 233 includes a plurality of passageways 233A formed therein that are adapted to disperse the gases flowing from the passage 259 to the gas distribution plate 225. Although the passageways 233A are shown as being circular or rounded, the passageways 233A can be square, rectangular, or any other shape. The passageways 233A can be sized and positioned about the blocker plate 233 to provide a controlled and even flow distribution across the surface of the substrate. As described above, the first blocker plate 233 can easily be removed from the second blocker plate 235 and from the distribution plate 225 to facilitate cleaning or replacement of those components.

In use, one or more process gases are introduced into the gas delivery assembly 220 via the gas inlet 223. The process gas flows into the first volume 261 and through the passage 259 of the second blocker plate 235 into the second volume 262. The process gas is then distributed through the holes 233A of the first blocker plate 233 into the third volume 263 and further distributed through the holes 225A of the distribution plate 225 until the gas meets the exposed surfaces of the substrate disposed within the chamber body 112.

A gas supply panel (not shown) is typically used to provide the one or more gases to the processing chamber 100. The particular gas or gases that are used depend upon the process or processes to be performed within the chamber 100. Illustrative gases can include, but are not limited to one or more precursors, reductants, catalysts, carriers, purge, cleaning, or any mixture or combination thereof. Typically, the one or more gases introduced to the processing chamber 100 flow through the inlet 223 into the lid assembly 200 and then into the chamber body 112 through the gas delivery assembly 220. An electronically operated valve and/or flow control mechanism (not shown) may be used to control the flow of gas from the gas supply into the processing chamber 100. Depending on the process, any number of gases can be delivered to the processing chamber 100, and can be mixed either in the processing chamber 100 or before the gases are delivered to the processing chamber 100, such as within a gas mixture (not shown), for example.

Still referring to FIGS. 1A and 2A, the lid assembly 200 can further include an electrode 240 to generate a plasma of reactive species within the lid assembly 200. In one embodiment, the electrode 240 is supported on the top plate 250 and is electrically isolated therefrom. For example, an isolator filler ring 241 can be disposed about a lower portion of the electrode 240 separating the electrode 240 from the top plate 250 as shown in FIG. 2A. An annular isolator 242 can also be disposed about an outer surface of the isolator filler ring 241. An annular insulator 243 can then be disposed about an upper portion of the electrode 240 so that the electrode 240 is electrically isolated from the top plate 250 and all the other components of the lid assembly 200. Each of these rings 241, 242, 243 can be made from aluminum oxide or any other insulative, process compatible material.

In one or more embodiments, the electrode 240 is coupled to a power source (not shown) while the gas delivery assembly 220 is connected to ground (i.e. the gas delivery assembly 220 serves as an electrode). Accordingly, a plasma of one or more process gases can be generated in the volumes 261, 262 and/or 263 between the electrode 240 ("first electrode") and the gas delivery assembly 220 ("second electrode"). For example, the plasma can be struck and contained between the electrode 240 and the blocker assembly 230. Alternatively, the plasma can be struck and contained between the electrode 240 and the distribution plate 225, in the absence of the blocker assembly 230. In either embodiment, the plasma is well confined or contained within the lid assembly 200. Accordingly, the plasma is a "remote plasma" since no active plasma is in direct contact with the substrate disposed within the chamber body 112. As a result, plasma damage to the substrate is avoided because the plasma is sufficiently separated from the substrate surface.

Any power source capable of activating the gases into reactive species and maintaining the plasma of reactive species may be used. For example, radio frequency (RF), direct current (DC), or microwave (MW) based power discharge techniques may be used. The activation may also be generated by a thermally based technique, a gas breakdown technique, a high intensity light source (e.g., UV energy), or exposure to an x-ray source. Alternatively, a remote activation source may be used, such as a remote plasma generator, to generate a plasma of reactive species which are then delivered into the chamber 100. Exemplary remote plasma generators are available from vendors such as MKS Instruments, Inc. and Advanced Energy Industries, Inc. Preferably, an RF power supply is coupled to the electrode 240.

Referring to FIG. 2A, the gas delivery assembly 220 can be heated depending on the process gases and operations to be performed within the processing chamber 100. In one embodiment, a heating element 270, such as a resistive heater for example, can be coupled to the distribution plate 225. In one embodiment, the heating element 270 is a tubular member and is pressed into an upper surface of the distribution plate 225 as shown in more detail in FIGS. 2B and 2C.

Referring to FIGS. 2B and 2C, the upper surface of the distribution plate 225 includes a groove or recessed channel having a width slightly smaller than the outer diameter of the heating element 270, such that the heating element 270 is held within the groove using an interference fit. The heating element 270 regulates the temperature of the gas delivery assembly 220 since the components of the delivery assembly 220, including the distribution plate 225 and the blocker assembly 230, are each conductively coupled to one another. Regulation of the temperature may be facilitated by a thermocouple 272 coupled to the distribution plate 225. The thermocouple 272 may be used in a feedback loop to control electric current applied to the heating element 270 from a power supply, such that the gas delivery assembly 220 temperature can be maintained or controlled at a desired temperature or within a desired temperature range. Control of the gas delivery assembly 220 temperature is facilitated because as described above, the gas delivery assembly 220 makes minimal thermal contact with the other components of the lid assembly 200, and as such, thermal conductivity is limited.

In one or more embodiments, the lid assembly 200 can include one or more fluid channel 202 formed therein for flowing a heat transfer medium to provide temperature control of the gas delivery assembly 220. In one embodiment, the fluid channel 202 can be formed within the lid rim 210, as shown in FIG. 2A. Alternatively, the fluid channel 202 can be formed within any component of the lid assembly 200 to provide an uniform heat transfer to the gas delivery assembly 220. The fluid channel 202 can contain either a heating or cooling medium to control temperature of the gas delivery assembly 220, depending on the process requirements within the chamber 100. Any heat transfer medium may be used, such as nitrogen, water, ethylene glycol, or mixtures thereof, for example.

In one or more embodiments, the gas delivery assembly 220 can be heated using one or more heat lamps (not shown). Typically, the heat lamps are arranged about an upper surface of the distribution plate 225 to heat the distribution plate 225 by radiation.

FIG. 3A shows a partial cross sectional view of an illustrative support assembly 300. The support assembly 300 can be at least partially disposed within the chamber body 112. The support assembly 300 can include a support member 310 to support a substrate (not shown in this view) for processing within the chamber body 112. The support member 310 can be coupled to a lift mechanism 330 through a shaft 314 which extends through a centrally-located opening 114 formed in a bottom surface of the chamber body 112. The lift mechanism 330 can be flexibly sealed to the chamber body 112 by a bellows 333 that prevents vacuum leakage from around the shaft 314. The lift mechanism 330 allows the support member 310 to be moved vertically within the chamber body 112 between a process position and a lower, transfer position. The transfer position is slightly below the opening of the slit valve 160 formed in a sidewall of the chamber body 112.

FIG. 3B shows an enlarged partial cross sectional of the support assembly 300 shown in FIG. 3A. In one or more embodiments, the support member 310 has a flat, circular surface or a substantially flat, circular surface for supporting a substrate to be processed thereon. The support member 310 is preferably constructed of aluminum. The support member 310 can include a removable top plate 311 made of some other material, such as silicon or ceramic material, for example, to reduce backside contamination of the substrate.

In one or more embodiments, the support member 310 or the top plate 311 can include a plurality of extensions or dimples 311A arranged on the upper surface thereof. In FIG. 3B, the dimples 311A are shown on the upper surface of the top plate 311. It can be envisioned that the dimples 311A can be arranged on the upper surface of the support member 310 if a top plate 311 is not desired. The dimples 311A provide minimum contact between the lower surface of the substrate and the support surface of the support assembly 300 (i.e. either the support member 310 or the top plate 311).

In one or more embodiments, the substrate (not shown) may be secured to the support assembly 300 using a vacuum chuck. The top plate 311 can include a plurality of holes 312 in fluid communication with one or more grooves 316 formed in the support member 310. The grooves 316 are in fluid communication with a vacuum pump (not shown) via a vacuum conduit 313 disposed within the shaft 314 and the support member 310. Under certain conditions, the vacuum conduit 313 can be used to supply a purge gas to the surface of the support member 310 to prevent deposition when a substrate is not disposed on the support member 310. The vacuum conduit 313 can also pass a purge gas during processing to prevent a reactive gas or byproduct from contacting the backside of the substrate.

In one or more embodiments, the substrate (not shown) may be secured to the support member 310 using an electrostatic chuck. In one or more embodiments, the substrate can be held in place on the support member 310 by a mechanical clamp (not shown), such as a conventional clamp ring.

Preferably, the substrate is secured using an electrostatic chuck. An electrostatic chuck typically includes at least a dielectric material that surrounds an electrode (not shown), which may be located on an upper surface of the support member 310 or formed as an integral part of the support member 310. The dielectric portion of the chuck electrically insulates the chuck electrode from the substrate and from the remainder of the support assembly 300.

In one or more embodiments, the perimeter of the chuck dielectric can be is slightly smaller than the perimeter of the substrate. In other words, the substrate slightly overhangs the perimeter of the chuck dielectric so that the chuck dielectric will remain completely covered by the substrate even if the substrate is misaligned off center when positioned on the chuck. Assuring that the substrate completely covers the chuck dielectric ensures that the substrate shields the chuck from exposure to potentially corrosive or damaging substances within the chamber body 112.

The voltage for operating the electrostatic chuck can be supplied by a separate "chuck" power supply (not shown). One output terminal of the chucking power supply is connected to the chuck electrode. The other output terminal typically is connected to electrical ground, but alternatively may be connected to a metal body portion of the support assembly 300. In operation, the substrate is placed in contact with the dielectric portion, and a direct current voltage is placed on the electrode to create the electrostatic attractive force or bias to adhere the substrate on the upper surface of the support member 310.

Still referring to FIGS. 3A and 3B, the support member 310 can include one or more bores 323 formed therethrough to accommodate a lift pin 325. Each lift pin 325 is typically constructed of ceramic or ceramic-containing materials, and are used for substrate-handling and transport. Each lift pin 325 is slideably mounted within the bore 323. In one aspect, the bore 323 is lined with a ceramic sleeve to help freely slide the lift pin 325. The lift pin 325 is moveable within its respective bore 323 by engaging an annular lift ring 320 disposed within the chamber body 112. The lift ring 320 is movable such that the upper surface of the lift-pin 325 can be located above the substrate support surface of the support member 310 when the lift ring 320 is in an upper position. Conversely, the upper surface of the lift-pins 325 is located below the substrate support surface of the support member 310 when the lift ring 320 is in a lower position. Thus, part of each lift-pin 325 passes through its respective bore 323 in the support member 310 when the lift ring 320 moves from either the lower position to the upper position.

When activated, the lift pins 325 push against a lower surface of the substrate, lifting the substrate off the support member 310. Conversely, the lift pins 325 may be de-activated to lower the substrate, thereby resting the substrate on the support member 310. The lift pins 325 can include enlarged upper ends or conical heads to prevent the pins 325 from falling out from the support member 310. Other pin designs can also be utilized and are well known to those skilled in the art.

In one embodiment, one or more of the lift pins 325 include a coating or an attachment disposed thereon that is made of a non-skid or highly frictional material to prevent the substrate from sliding when supported thereon. A preferred material is a high temperature, polymeric material that does not scratch or otherwise damage the backside of the substrate which would create contaminants within the processing chamber 100. Preferably, the coating or attachment is KALREZ.TM. coating available from DuPont.

To drive the lift ring 320, an actuator, such as a conventional pneumatic cylinder or a stepper motor (not shown), is generally used. The stepper motor or cylinder drives the lift ring 320 in the up or down positions, which in turn drives the lift-pins 325 that raise or lower the substrate. In a specific embodiment, a substrate (not shown) is supported on the support member 310 by three lift-pins 325 (not shown in this view) dispersed approximately 120 degrees apart and projecting from the lift ring 320.

Referring again to FIG. 3A, the support assembly 300 can include an edge ring 305 disposed about the support member 310. The edge ring 305 can be made of a variety of materials such as ceramic, quartz, aluminum and steel, among others. In one or more embodiments, the edge ring 305 is an annular member that is adapted to cover an outer perimeter of the support member 310 and protect the support member 310 from deposition. The edge ring 305 can be positioned on or adjacent the support member 310 to form an annular purge gas channel 334 between the outer diameter of support member 310 and the inner diameter of the edge ring 305. The annular purge gas channel 334 can be in fluid communication with a purge gas conduit 335 formed through the support member 310 and the shaft 314. Preferably, the purge gas conduit 335 is in fluid communication with a purge gas supply (not shown) to provide a purge gas to the purge gas channel 334. Any suitable purge gas such as nitrogen, argon, or helium, may be used alone or in combination. In operation, the purge gas flows through the conduit 335, into the purge gas channel 334, and about an edge of the substrate disposed on the support member 310. Accordingly, the purge gas working in cooperation with the edge ring 305 prevents deposition at the edge and/or backside of the substrate.

Referring again to FIGS. 3A and 3B, the temperature of the support assembly 300 is controlled by a fluid circulated through a fluid channel 360 embedded in the body of the support member 310. In one or more embodiments, the fluid channel 360 is in fluid communication with a heat transfer conduit 361 disposed through the shaft 314 of the support assembly 300. Preferably, the fluid channel 360 is positioned about the support member 310 to provide a uniform heat transfer to the substrate receiving surface of the support member 310. The fluid channel 360 and heat transfer conduit 361 can flow heat transfer fluids to either heat or cool the support member 310. Any suitable heat transfer fluid may be used, such as water, nitrogen, ethylene glycol, or mixtures thereof. The support assembly 300 can further include an embedded thermocouple (not shown) for monitoring the temperature of the support surface of the support member 310. For example, a signal from the thermocouple may be used in a feedback loop to control the temperature or flowrate of the fluid circulated through the fluid channel 360.

Referring back to FIG. 3A, the support member 310 can be moved vertically within the chamber body 112 so that a distance between support member 310 and the lid assembly 200 can be controlled. A sensor (not shown) can provide information concerning the position of support member 310 within chamber 100. An example of a lifting mechanism for the support member 310 is described in detail in U.S. Pat. No. 5,951,776, issued Sep. 14, 1999 to Selyutin et al., entitled "Self-Aligning Lift Mechanism", which is hereby incorporated by reference in it entirety.

In operation, the support member 310 can be elevated to a close proximity of the lid assembly 200 to control the temperature of the substrate being processed. As such, the substrate can be heated via radiation emitted from the distribution plate 225 that is controlled by the heating element 270. Alternatively, the substrate can be lifted off the support member 310 to close proximity of the heated lid assembly 200 using the lift pins 325 activated by the lift ring 320.

After extended periods of use or at designated times for scheduled maintenance, certain components of the processing chamber 100 including those described above can be regularly inspected, replaced, or cleaned. These components are typically parts that are collectively known as the "process kit." Illustrative components of the process kit can include, but are not limited to the showerhead 225, the top plate 311, the edge ring 305, the liner 133, and the lift pins 325, for example. Any one or more of these components are typically removed from the chamber 100 and cleaned or replaced at regular intervals or according to an as-needed basis.

FIG. 4A shows a partial cross sectional view of another illustrative lid assembly 400. The lid assembly 400 includes at least two stacked components configured to form a plasma volume or cavity therebetween. In one or more embodiments, the lid assembly 400 includes a first electrode 410 ("upper electrode") disposed vertically above a second electrode 450 ("lower electrode") confining a plasma volume or cavity 425 therebetween. The first electrode 410 is connected to a power source 415, such as an RF power supply, and the second electrode 450 is connected to ground, forming a capacitance between the two electrodes 410, 450.

In one or more embodiments, the lid assembly 400 includes one or more gas inlets 412 (only one is shown) that are at least partially formed within an upper section 413 of the first electrode 410. The one or more process gases enter the lid assembly 400 via the one or more gas inlets 412. The one or more gas inlets 412 are in fluid communication with the plasma cavity 425 at a first end thereof and coupled to one or more upstream gas sources and/or other gas delivery components, such as gas mixers, at a second end thereof. The first end of the one or more gas inlets 412 can open into the plasma cavity 425 at the upper most point of the inner diameter 430 of the expanding section 420 as shown in FIG. 4A. Similarly, the first end of the one or more gas inlets 412 can open into the plasma cavity 425 at any height interval along the inner diameter 430 of the expanding section 420. Although not shown, two gas inlets 412 can be disposed at opposite sides of the expanding section 420 to create a swirling flow pattern or "vortex" flow into the expanding section 420 which helps mix the gases within the plasma cavity 425. A more detailed description of such a flow pattern and gas inlet arrangements is provided by U.S. patent application Ser. No. 20030079686, filed on Dec. 21, 2001, which is incorporated by reference herein.

In one or more embodiments, the first electrode 410 has an expanding section 420 that houses the plasma cavity 425. As shown in FIG. 4A, the expanding section 420 is in fluid communication with the gas inlet 412 as described above. In one or more embodiments, the expanding section 420 is an annular member that has an inner surface or diameter 430 that gradually increases from an upper portion 420A thereof to a lower portion 420B thereof. As such, the distance between the first electrode 410 and the second electrode 450 is variable. That varying distance helps control the formation and stability of the plasma generated within the plasma cavity 425.

In one or more embodiments, the expanding section 420 resembles a cone or "funnel," as is shown in FIGS. 4A and 4B. FIG. 4B shows an enlarged schematic, partial cross sectional view of the upper electrode of FIG. 4A. In one or more embodiments, the inner surface 430 of the expanding section 420 gradually slopes from the upper portion 420A to the lower portion 420B of the expanding section 420. The slope or angle of the inner diameter 430 can vary depending on process requirements and/or process limitations. The length or height of the expanding section 420 can also vary depending on specific process requirements and/or limitations. In one or more embodiments, the slope of the inner diameter 430, or the height of the expanding section 420, or both can vary depending on the volume of plasma needed for processing. For example, the slope of the inner diameter 430 can be at least 1:1, or at least 1.5:1 or at least 2:1 or at least 3:1 or at least 4:1 or at least 5:1 or at least 10:1. In one or more embodiments, the slope of the inner diameter 430 can range from a low of 2:1 to a high of 20:1.

In one or more embodiments, the expanding section 420 can be curved or arced although not shown in the figures. For example, the inner surface 430 of the expanding section 420 can be curved or arced to be either convexed or concaved. In one or more embodiments, the inner surface 430 of the expanding section 420 can have a plurality of sections that are each sloped, tapered, convexed, or concaved.

As mentioned above, the expanding section 420 of the first electrode 410 varies the vertical distance between the first electrode 410 and the second electrode 450 because of the gradually increasing inner surface 430 of the first electrode 410. That variable distance is directly related to the power level within the plasma cavity 425. Not wishing to be bound by theory, the variation in distance between the two electrodes 410, 450 allows the plasma to find the necessary power level to sustain itself within some portion of the plasma cavity 425 if not throughout the entire plasma cavity 425. The plasma within the plasma cavity 425 is therefore less dependent on pressure, allowing the plasma to be generated and sustained within a wider operating window. As such, a more repeatable and reliable plasma can be formed within the lid assembly 400.

The first electrode 410 can be constructed from any process compatible materials, such as aluminum, anodized aluminum, nickel plated aluminum, nickel plated aluminum 6061-T6, stainless steel as well as combinations and alloys thereof, for example. In one or more embodiments, the entire first electrode 410 or portions thereof are nickel coated to reduce unwanted particle formation. Preferably,