Title: Apparatus for surface modification of polymer, metal and ceramic materials using ion beam
Abstract: An apparatus for surface modification of a polymer, metal and ceramic material using an ion beam (IB) is disclosed, which is capable of supplying and controlling a voltage (220) applied to a material to be surface-modified so that an ion beam (IB) energy irradiated to the material is controlled, differentiating the degree of the vacuum of a reaction gas in a portion of a vacuum chamber in which the ion beam is irradiated from that in a portion in which the ion beam is generated, and also being applicable for both-side irradiating processing and continuous processing.
Patent Number: 6,841,789 Issued on 01/11/2005 to Koh, et al.
| Inventors:
|
Koh; Seok-Keun (Seoul, KR);
Jung; Hyung Jin (Seoul, KR);
Choi; Won Kook (Seoul, KR);
Cho; Jung (Seoul, KR)
|
| Assignee:
|
Korea Institute of Science and Technology (Seoul, KR)
|
| Appl. No.:
|
957896 |
| Filed:
|
September 21, 2001 |
Foreign Application Priority Data
| Dec 05, 1997[KR] | 1997-66184 |
| Current U.S. Class: |
250/492.3; 250/397; 250/398; 250/492.1; 250/492.2; 250/492.21; 250/492.22 |
| Intern'l Class: |
H01J 003/26 |
| Field of Search: |
250/492.1,492.2,492.21,492.22,492.3,397,398
|
References Cited [Referenced By]
| Foreign Patent Documents |
| 61163270 | Jul., 1986 | JP.
| |
| 62287068 | Dec., 1987 | JP.
| |
| 62287068 | Dec., 1987 | JP.
| |
| 61 163270 | Jul., 1988 | JP.
| |
| 01-195274 | Aug., 1989 | JP.
| |
| 01-195274 | Aug., 1989 | JP.
| |
| 04-099173 | Mar., 1992 | JP.
| |
| 04-099173 | Mar., 1992 | JP.
| |
| WO 96/33293 | Oct., 1996 | KR.
| |
| WO-96/33293 | Oct., 1996 | WO.
| |
Primary Examiner: Lee; John R.
Assistant Examiner: Vanore; David A.
Attorney, Agent or Firm: Darby & Darby
Parent Case Text
This is a divisional of application Ser. No. 09/555,832, filed Aug. 7,
2000, now U.S. Pat. No. 6,319,326, which is a national phase filing of
PCT/KR98/00403, filed Dec. 4, 1998. Each of these prior applications is
hereby incorporated herein by reference, in its entirety.
Claims
What is claimed is:
1. An apparatus for surface modification of a powdered material using an
ion beam, comprising:
a chamber;
a vacuum means for maintaining a vacuum within the chamber;
an ion source having an ion gun for generating an ion beam, which is
installed in an upper portion of the chamber;
a holder means for holding a powdered material to which an ion beam from
the ion source is irradiated and agitating the powdered material; and
a reaction gas supplying means for supplying a reaction gas to the powdered
material therethrough.
2. The apparatus according to claim 1, wherein two or more vacuum means are
provided, and further comprising a separating means for separating a
material reaction portion of the chamber in which the surface is modified
when the reaction gas is supplied to the material surface, from a portion
of the chamber in which the ion source is provided, and wherein the vacuum
level in the material reaction portion of the chamber is maintained to be
higher than that in the portion of the chamber in which the ion source is
provided.
Description
TECHNICAL FIELD
The present invention relates to an apparatus for surface modification of
polymer, metal and ceramic materials using an ion beam, and in particular
to an improved apparatus for surface modification of polymer, metal and
ceramic materials using an ion beam which is capable of controlling the
amount of a reaction gas and the energy of an ion beam, modifying the
surface of a powder material and implementing a continuous surface
modification of a material.
BACKGROUND ART
Conventional ion beam modification methods include methods based on a thin
film fabrication and methods based on a surface cleaning process.
As the thin film fabrication methods, there are proposed an ion
implantation using a high energy (tens of KeV to a few MeV), an ion beam
irradiation, an ion beam sputtering deposition which is implemented by
irradiating ionized particles from an ion source generating low energy (0
to a few KeV) particles onto a target for thereby generating a material to
be deposited, a multiple ion beam deposition, a process for assisting a
thin film fabrication, and an ion-assisted deposition.
In addition, as the surface cleaning methods, there are proposed a surface
cleaning which is generated by irradiating energized particles onto the
surface of a material and a reactive ion beam etching which is implemented
by supplying a reaction gas into a vacuum chamber.
In case of the thin film fabrication using an ion beam, the thin film is
fabricated by controlling the relative ratio of the particles between the
to-be deposited particles and the assisted ion beam particles. In the case
of the cleaning method using the ion beam, a reaction gas is ionized while
controlling the occurrence of a plasma and the amount of the reaction gas,
thereby implementing a quick surface cleaning, while the cleaning of the
conventional wet reaction requires a long time.
FIG. 1 is a schematic view illustrating an earlier-filed (Korean Patent
Applns. Nos. 2465/1996, 11994/1996, 11995/1996 and 11996/1196, the
disclosures of which are incorporated hereinto by reference) surface
modification apparatus which includes an ion source 10 having an ion gun
12 generating an ion beam IB and an assisted ion gun 14 generating an
assisted ion beam AB, an ion beam current measuring unit 40 and controller
42 for respectively measuring and controlling the amount of irradiated
energized ions, a sample holder 20 holding a sample material 22 the
surface of which is to be modified by ions, a reaction gas control
apparatus (not shown) having a reaction gas inlet 26 providing
therethrough a reaction gas to the sample material 22, a vacuum pump 28
generating a vacuum within an enclosing vacuum chamber 30 in order to
facilitate the generation of the ion beams IB, AB.
The apparatus may be implemented in the following ways. First, oxygen is
provided as a reaction gas around a polymer material, and argon ions are
irradiated onto the surface of the material, thereby generating a
hydrophilic functional group, in which an oxygen atom is chemically bonded
with a carbon ring, on the surface of the polymer material. In addition,
the argon ions are irradiated together with providing the oxygen to the
surface of an nitride AIN, thereby forming a bonding of the AION and a new
material on the surface without affecting the material itself.
Accordingly, various problems can be solved due to the variation of
inherent properties of surfaces. For example, the adhesion of another
material, adsorption, hydrophilic property with water, and surface
strength of the material may be changed. In the ion beam assisted
reaction, the particle energy having a lower energy band is generally used
compared to the earlier deposition methods, and the amount of the ion
irradiation is 10.sup.13 -10.sup.18 ions/cm.sup.2, and the amount of the
reaction gas is also characterized in that the partial pressure around the
material is higher than the total degree of vacuum in the vacuum chamber.
However, in the above-described ion beam irradiating apparatus, only the
surface modification by the reaction gas is considered as an important
matter. Therefore, the improvement of physical properties and the surface
modification characteristic cannot have been obtained by controlling the
amount of the reaction gas. Also, the energy of the ion beam applied to a
sample material has been controlled by only the ion beam.
DISCLOSURE OF THE INVENTION
Accordingly, it is an object of the present invention to provide an
apparatus for surface modification of polymer, metal and ceramic materials
using an ion beam which overcomes the aforementioned problems encountered
in the background art.
It is another object of the present invention to provide an apparatus which
is capable of controlling the amount of a reaction gas provided to the
surface being modified while irradiating a specific amount of ion beam
energy onto the surface of a material to be surface-modified, and
controlling the ion energy of an ion beam applied to the surface, thereby
forming a material on the surface which has a new chemical structure,
whereby the degree of the surface modification is controlled by
controlling the ion irradiation amount, the implanting amount of reaction
gases and the particle energy of energized particles.
It is another object of the present invention to provide an apparatus for
surface modification which can be applied to both-face irradiating type
and continuous batch type processes in actual manufacturing.
To achieve the above objects, there is provided an apparatus for surface
modification of polymer, metal and ceramic materials using an ion beam
according to the present invention which includes a chamber, a means for
maintaining a vacuum within the chamber, an ion source having an ion gun
for generating an ion beam, a holder on which a material to be
surface-modified may be placed to be irradiated by the ion beam from the
ion source, and a reaction gas supplying means for supplying a reaction
gas to the material surface therethrough, wherein a voltage is applied to
the holder while insulating the holder from the chamber, whereby an ion
energy of the ion beam which is irradiated to the material surface is
controlled.
To achieve the above objects, there is also provided an apparatus for
surface modification of polymer, metal and ceramic materials using an ion
beam according to the present invention which includes a chamber, a means
for maintaining a vacuum within the chamber, an ion source having an ion
gun for generating an ion beam, a holder on which a material to be
surface-modified may be placed to be irradiated by the ion beam from the
ion source, a reaction gas supplying means for supplying a reaction gas to
the material surface therethrough, and a separating means for separating a
material reaction portion of the chamber in which the surface is modified
when the reaction gas is supplied to the material surface, from a portion
of chamber in which the ion source is provided, wherein the vacuum level
in the material reaction portion of the chamber is maintained to be higher
than that in the portion of the chamber in which the ion source is
provided.
To achieve the above objects, there is further provided an apparatus for
surface modification of polymer, metal and ceramic materials using an ion
beam according to the present invention which includes a chamber, a vacuum
means for maintaining a vacuum within the chamber, an ion source having an
ion gun for generating an ion beam, which is installed in an upper portion
of the chamber, a holder for holding a powdered material to which an ion
beam from the ion source is irradiated while agitating the powdered
material, and a reaction gas supplying means for supplying a reaction gas
to the powdered material therethrough.
To achieve the above objects, there is still further provided an apparatus
for surface modification of polymer, metal and ceramic materials using an
ion beam according to the present invention which includes a chamber, a
vacuum means for maintaining a vacuum within the chamber, one or more ion
sources each having an ion gun and provided in an upper or lower portion
of the chamber, or in at least two respective opposing locations within
the chamber for generating respective ion beams and irradiating the ion
beams respectively to front and/or back, or opposing, surfaces of a
material to be surface-modified, a means for supplying the material to be
surface-modified, and a reaction gas supplying means for supplying a
reaction gas to respective surfaces of the material onto which the ion
beams generated from the ion sources are irradiated, wherein the material
is continuously supplied to a reaction region in the chamber over which
the ion beams are irradiated, and drawn off from the reaction region.
Here, the material to be surface-modified may be wound in a roll, one end
of the material being unwound at one side of the chamber to be supplied
into the reaction region, and the part of the material supplied into the
reaction region is surface-modified by irradiating the ion beams thereon,
and then the modified material is wound again in the other side of the
chamber. Also, the material may be supplied and drawn off as wafers.
Furthermore, a plurality of vacuum means may be provided in the chamber,
and such vacuum means are provided in due sequence so that the degree of
vacuum in the chamber is the highest in the reaction region when the
material to be surface-modified is supplied from the outside of the
reaction chamber to the reaction region and the material having been
surface-modified is drawn off to the outside of the chamber.
A Kaufman type ion source, a cold hollow cathode ion source, or a high
frequency ion source, etc. may be used as the ion source. Hereinafter, the
energized particles generated from the ion source are referred to as an
ion beam. The amount of the irradiated ions is preferably within the range
of 10.sup.13 to 10.sup.18 ions/cm.sup.2. The amount of the reaction gas
blown on the material to be modified surface is preferably 0 to 30 ml/min.
The partial pressure of the reaction gas in the reaction chamber is higher
than the partial pressure around the material to be modified surface. The
partial pressure of the reaction gas within the vacuum chamber is
10.sup.-1 to 10.sup.-7 torr.
Additional advantages, objects and features of the invention will become
more apparent from the description which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed
description given hereinbelow and the accompanying drawings which are
given by way of illustration only, and thus are not limitative of the
present invention, and wherein:
FIG. 1 is a schematic view illustrating an ion assisted reaction apparatus
using a reaction gas in the known art;
FIG. 2 is a schematic view illustrating an ion assisted reaction apparatus
according to the present invention which is capable of applying a voltage
to the surface of a material to be surface-modified;
FIG. 3 is a schematic view illustrating an ion assisted reaction apparatus
according to the present invention which is capable of controlling the
partial pressure of a reaction gas;
FIG. 4 is a schematic view illustrating an ion assisted reaction apparatus
according to the present invention which is capable of implementing the
modification of the surface of a powdered material;
FIG. 5 is a schematic perspective view illustrating an ion assisted
reaction apparatus according to the present invention which is capable of
modifying more than one side of a material;
FIG. 6 is a schematic view illustrating an ion assisted reaction apparatus
according to the present invention which is capable of implementing a
batch type continuous process;
FIG. 7 is a schematic view illustrating an ion assisted reaction apparatus
according to the present invention which is capable of continuously
modifying a surface of a material by introducing the material from outside
into a vacuum chamber; and
FIG. 8 is a schematic view illustrating an ion assisted reaction apparatus
according to the present invention which is capable of continuously
modifying the surface of a material which is provided in the form of a set
of wafers.
MODES FOR CARRYING OUT THE PREFERRED EMBODIMENTS
The present invention is directed to an apparatus for surface modification
using a low energy ion beam which is different from the known art which is
directed to a thin film fabrication and to a surface cleaning. The present
invention is directed to overcoming the limitations encountered in the
techniques disclosed in Korean Patent applications 2456/1996, 11994/1996,
11995/1996 and 11996/1996.
When an ion beam generated from the ion source is irradiated over the
surface of a polymer material while blowing a reaction gas thereover,
namely, oxygen or nitrogen gas onto the surface, a hydrophobic surface can
be changed into a hydrophilic surface. Also, in case of changing the
roughness of the surface of a deposited metal thin film by irradiating an
inert gases onto the surface simultaneously with depositing other thin
films (nitride or oxide) on the surface by blowing a reaction gas onto the
surface, the enhancement of the adhesive force between two thin films can
be obtained.
FIG. 2 is a schematic view illustrating an ion-assisted reaction apparatus
according to the present invention which is capable of applying a voltage
(i.e., bias) to a material to be surface-modified. According to the first
preferred embodiment of the present invention, when irradiating an ion
beam onto the surface of a metallic thin film, oxide thin film or organic
material 200 having curved surfaces, an attraction force or repulsion
force between the ions from the ion gun 210 and the surfaces of the
material is generated by applying a voltage from a voltage source 220 to
the material to be surface-modified simultaneously while Ar.sup.+ ions
from the ion gun are accelerated, so that a charge distortion may be
obtained to modify the composition and shape of the surface of the
material. That is, according to the present invention, there is provided a
holder 230 to which a voltage is applied, compared to the known art in
which a voltage is not applied to the holder. Furthermore, according to
the present invention, the holder 230 is electrically insulated from the
vacuum chamber and positive or negative voltages are applied thereto.
FIG. 3 is a schematic view illustrating an ion beam apparatus which is
capable of controlling a reaction gas partial pressure. In the known art,
it is difficult to control the amount of the reaction gas because the
reaction gas is blown over the surface of the material when supplying the
reaction gas around the holder. However, as shown in FIG. 3, in the
present invention, there are provided separating walls 300, 310 for
separating the material 320 to be surface-modified from the ion gun 340
generating an ion beam IB for thereby easily controlling the partial
pressure of the reaction gas around the material 320. The separating walls
300, 310 are installed within the chamber for the reason that when the
reaction gas blown around the surface of the material 320 is introduced
into the ion gun 340, the reaction gas may react with a filament hot-wire
provided in the ion gun 340 thereby damaging the filament hot-wire by an
oxidation or nitrification reaction therebetween. In addition, such
reaction between the reaction gas and the filament hot-wire may prevent
the formation of a plasma generated from the ion source. Namely, since the
degree of the vacuum around the material is lower than that at the side of
the ion source by 10.sup.-3, the reaction gas is not introduced toward the
ion source side and is discharged to the outside. When forming the
separating walls 300, 310 for thereby exposing only a predetermined
region, it is possible to modify only a predetermined surface, so that the
surface of the material 320 may be selectively modified, and it is
possible to prevent the introduction of a foreign material which may cause
the above-described problems. In addition, the partial pressure in the
vacuum chamber 330 between the portion 330a around the material and the
portions 330b or 330c around the ion source may be controlled by variously
installing vacuum pumps 350a, 350b, 350c providing different degrees of
vacuum.
FIG. 4 is a schematic view illustrating an ion-assisted reaction apparatus
for modifying powdered materials according to the present invention. In
the known art, the ion source is installed at a lower portion in the
ion-assisted deposition apparatus, and a material to be deposited is
placed thereabove, i.e., the target to be surface-modified is placed on
the opposite side of the ion source as in the ion sputtering method. In
this case, however, it is impossible to hold a material such as one
consisting of fine particles or a non-uniformly shaped material. However,
according to the present invention, a powdered material 420 may be
surface-modified by installing the ion source 400 in an upper portion of
the chamber 410 and agitating the powdered material 420. In order to
modify the surfaces of the powder, a holder 430 is provided in the vacuum
chamber 410 in order to hold the powdered material 420 to which an ion
beam IB from the ion source 400 is irradiated and to agitate the powdered
material 420 when driven by a motor 450. In the case of the blowing of the
reaction gas, a gas blowing unit 440 for supply a reaction gas to the
powdered material therethrough is installed around the powdered material
420 or in the holder 430, so that the amount of the reaction gas is
controlled.
FIG. 5 is a schematic view illustrating an apparatus which is capable of
modifying more than one side of a material. Namely, there is shown an
apparatus which with respect to the position of an ion source, is capable
of modifying the surfaces of a piece of cloth or the surfaces of a film.
As shown therein, two or more ion sources 510, 520 are provided in an
upper or lower portion of the chamber, or in at least two respectively
opposing locations within the chamber 500 for generating respective ion
beams IB and irradiating the ion beams respectively to front and/or back
or respectively opposing surfaces of a material 530 to be
surface-modified. Namely, it is possible to irradiate the ion beams at an
angle of 45.degree., 60.degree., 90.degree. to the surface-modified plane,
so that variously shaped materials such as spherical materials, curved
materials, etc. may be uniformly surface-modified.
FIG. 6 is a view illustrating an ion beam modification apparatus which is
capable of implementing a batch-type continuous process. Generally, the
apparatus is designed to continuously process the surfaces of a film, foil
or a sheet for the mass production. As shown therein, after forming a film
or textile materials having a long length i.e., a web wound into a roll, a
continuous surface modification is performed thereon. The above described
continuous surface modification apparatus also has an advantage of being
capable of controlling the speed of the film in order to control the
degree of the surface modification, by installing a device for winding the
film in a roll. The apparatus includes a chamber 600, a vacuum source 650
for maintaining a vacuum within the chamber, one or more ion sources 610,
620 each having an ion gun and provided in an upper or lower portion of
the chamber 600, or in at least two respectively opposing locations within
the chamber for generating respective ion beams and irradiating the ion
beams respectively to front and/or back or opposing surfaces of a material
630 to be surface-modified, a rollers 631, 632, 633, 634 for supplying the
material 630, and a reaction gas supply manifold 640a, 640b for supplying
a reaction gas to respective surfaces of the material onto which the ion
beams generated from the ion sources are irradiated, wherein the material
630 is continuously supplied to a reaction region in the chamber over
which the ion beams are irradiated, and drawn off from the reaction
region.
FIG. 7 is a view illustrating an ion beam modification apparatus which is
capable of continuously modifying a material introduced from the outside
atmosphere into the vacuum atmosphere within the chamber. Generally, the
ion source apparatus generating the ion beam produces a high quality of
ion beam only if a high degree of vacuum is maintained in the chamber. In
the first vacuum chamber 710 in which an initial vacuum is formed by a
first vacuum pump 712, a low degree of a vacuum is obtained, and then a
desired degree of vacuum is sequentially obtained in the sequential vacuum
chamber 700 by another vacuum pump 702. Because the first vacuum chamber
712 in which is generated an initial vacuum is provided to form only an
initial vacuum state, a vacuum chamber of large volume is unnecessary. If
the initial vacuum state is not able to be desirably formed, there can be
provided secondary or tertiary vacuum chambers 720 and secondary or
tertiary vacuum pump 722. When the desired vacuum is formed, the material
730 is transferred into the reaction area in which the ion beam IB from
the ion source 740 is irradiated and the surface modification is
performed. In the case of drawing off the modified material, the material
is drawn off via one or more chambers having a lower degree of vacuum in a
reverse order in sequence of obtaining a desired vacuum state, and then
the resultant material is stored in a desired manner.
FIG. 8 is a view illustrating an ion beam apparatus which is capable of
continuously modifying a material which is provided in a set form such as
in wafers, which can be used for forming an oxide material or for forming
a material having mechanical strength. This apparatus can be used to
modify surfaces with a plate shape, so it has useful applications such as
for surface modification of silicon wafers, metal plates and ceramic thick
films. In order to move the plate type materials, a container chamber 820
is attached at each side of an ion beam modification chamber and a belt
type conveyor system 830 is extended cross the ion beam modification
chamber. Firstly, a vertical movement rod supporting the holders 840 can
move upwardly and downwardly for changing the round-type holders 840 which
may contain a maximum of 6 articles (wafers, plates, etc.) at the same
time. Secondly, each holder 840 is rotated and connected with the batch
type conveyor system 830 for moving the articles into the ion beam
modification chamber. A holder rotation system 850 is driven by a stepping
motor which rotates with an angular rotation each 60.degree..
As described above, in the present invention, it is possible to enhance the
characteristic of the surface of the material by controlling the amount of
the reaction gas in the ion assisted reaction apparatus and the energy of
the ion beam irradiated to the material to be modified with respect to its
surface.
According to the present invention, it is possible to implement a surface
irradiating method or a continuous batch process which may be applicable
to an actual fabrication process.
Although the preferred embodiments of the present invention have been
disclosed for illustrative purposes, those skilled in the art will
appreciate that various modifications, additions and substitutions are
possible, without departing from the scope and spirit of the invention as
recited in the accompanying claims.
*
