U.S. patent application number 14/657875 was filed with the patent office on 2015-07-02 for methods and apparatus toward preventing esc bonding adhesive erosion.
The applicant listed for this patent is Applied Materials, Inc.. Invention is credited to Sumanth BANDA, Xing LIN, Jennifer Y. SUN.
Application Number | 20150183187 14/657875 |
Document ID | / |
Family ID | 49477073 |
Filed Date | 2015-07-02 |
United States Patent
Application |
20150183187 |
Kind Code |
A1 |
LIN; Xing ; et al. |
July 2, 2015 |
METHODS AND APPARATUS TOWARD PREVENTING ESC BONDING ADHESIVE
EROSION
Abstract
Embodiments of the present invention provide chamber components
having a protective element for shielding bonding material from
processing environments in a processing environment. The protective
element may include protective seals, protective structures,
erosion resistive filers, or combinations thereof. Embodiments of
the present invention reduce erosion of bonding material used in a
processing chamber, thus, improving processing quality and reducing
maintenance costs.
Inventors: |
LIN; Xing; (San Jose,
CA) ; SUN; Jennifer Y.; (Mountain View, CA) ;
BANDA; Sumanth; (San Jose, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Applied Materials, Inc. |
Santa Clara |
CA |
US |
|
|
Family ID: |
49477073 |
Appl. No.: |
14/657875 |
Filed: |
March 13, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13651967 |
Oct 15, 2012 |
8982530 |
|
|
14657875 |
|
|
|
|
61638908 |
Apr 26, 2012 |
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Current U.S.
Class: |
428/76 ;
428/448 |
Current CPC
Class: |
H01L 21/6833 20130101;
B32B 3/04 20130101; B32B 7/12 20130101; B32B 3/08 20130101; Y10T
428/239 20150115; Y10T 428/23 20150115; Y10T 428/31504
20150401 |
International
Class: |
B32B 7/12 20060101
B32B007/12; B32B 3/04 20060101 B32B003/04; B32B 3/08 20060101
B32B003/08 |
Claims
1. An apparatus use in a processing chamber, comprising: a first
component having a first surface; a second component having a
second surface, wherein the second surface faces the first surface
of the first component; a bonding material disposed between the
first surface and the second surface and joining the first
component and the second component; and a protective element
disposed for preventing the bonding material from erosion in the
processing chamber, wherein the protective element comprising a
silicon filler disposed in the bonding material.
2. The apparatus of claim 1, further comprising a protective sea
surrounding the bonding material.
3. The apparatus of claim 2, wherein the protective seal is
disposed in a recess formed at an interface between the first
component and the second component.
4. The apparatus of claim 3, wherein the recess is defined by a
step formed in an outer region of the first component, and the step
facing the second component.
5. The apparatus of claim 3, wherein the recess is defined by a
first step formed in an outer region of the first component and a
second step formed in an outer region of the second component.
6. An apparatus for use in a processing chamber, comprising: a
first component having a first surface; a second component having a
second surface, wherein the second surface faces the first surface
of the first component; a bonding material disposed between the
first surface and the second surface and joining the first
component and the second component; a protective structure
extending from the first surface if the first component covering
the bonding material, the protective structure integral with the
first component.
7. The apparatus of claim 6, wherein the protective structure
comprises a continuous Up extending from the first component and
overlapping an interface between the first component and the second
component in which the bonding material is disposed.
8. The apparatus of claim wherein the protective structure further
comprises a groove formed in the second component for receiving the
continuous lip.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of co-pending U.S. patent
application Ser. No. 13/651,967, filed Oct. 15, 2012, and which
claims benefit of U.S. Provisional Patent Application Ser. No.
61/638,908, filed Apr. 26, 2012, each of which is incorporated
herein by reference,
BACKGROUND
[0002] 1. Field of the Invention
[0003] Embodiments of the present invention relate to composite
structures joined by bonding materials with enhancing thermal
and/or chemical stabilities. Particularly, embodiments of the
present invention relate to an electrostatic chuck having two or
more components joined by a bonding material.
[0004] 2. Description of the Related Art
[0005] Semiconductor processing chambers often include parts that
are formed by bonding two or more components together with bonding
materials to achieve desired properties. For example, electrostatic
chucks, used for supporting and securing substrates during
processing, usually include a dielectric puck bonded to a metallic
base by a thermal conductive bonding material. The bonding
materials provide secured connection between different components
while providing thermal conductivity and/or electrical insulation.
However, the bonding materials can have negative impact on
processing, especially when the processes are performed at elevated
temperatures or in a hash chemical environment. For example, when
exposed to a plasma, a bonding material in an electrostatic chuck
may erode and generate particles causing particle contamination in
the processing chamber.
[0006] Embodiments of the present invention provide apparatus and
methods for preventing bonding material erosion and particle
generation.
SUMMARY
[0007] Embodiments of the present invention provide apparatus and
methods for protecting bonding material used in joining chamber
components, such as an electrostatic chuck, from processing
environments in a processing environment.
[0008] One embodiment of the present invention provides an
apparatus for using in a processing chamber. The apparatus includes
a first component, a second component and a bonding material
joining the first component and the second component. The apparatus
further includes a protective element for preventing the bonding
material from erosion in the processing chamber.
[0009] Another embodiment of the present invention provides an
electrostatic chuck for a processing chamber. The electrostatic
chuck comprises a chuck body having an upper surface configured to
support a substrate thereon and a lower surface opposing the upper
surface, a chuck base having an upper surface facing the lower
surface of the chuck body, and a bonding material joining the lower
surface of the chuck body and the upper surface of the chuck base.
The electrostatic chuck further includes a protective element for
preventing the bonding material from erosion caused by environment
in the processing chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] 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,
[0011] FIG. 1A is a sectional side view of an electrostatic chuck
having protective seals according to one embodiment of the present
invention.
[0012] FIG. 1B is an enlarged partial sectional view of the
electrostatic chuck of FIG. 1A.
[0013] FIG. 1C is an enlarged partial sectional view of an
electrostatic chuck according to another embodiment of the present
invention.
[0014] FIG. 1D is an enlarged partial sectional view of an
electrostatic chuck according to another embodiment of the present
invention.
[0015] FIG. 1E is a top view of the electrostatic chuck of FIG. 1A
with chuck body removed.
[0016] FIG. 2A is a sectional side view of an electrostatic chuck
having a protective structure according to one embodiment of the
present invention.
[0017] FIG. 2B is an enlarged partial sectional view of an
electrostatic chuck having a protective structure according to
another embodiment of the present invention.
[0018] FIG. 2C is an enlarged partial sectional view of an
electrostatic chuck having a protective structure according to
another embodiment of the present invention.
[0019] FIG. 3 is a sectional side view of a plasma processing
chamber having an electrostatic chuck according to embodiments of
the present invention.
[0020] To facilitate understanding, identical reference numerals
have been used, where possible, to designate identical elements
that are common to the figures. It is also contemplated that
elements and features oaf one embodiment may be beneficially
incorporated on other embodiments without further recitation,
DETAILED DESCRIPTION
[0021] Embodiments of the present invention provide apparatus and
methods for protecting bonding material used in joining chamber
components, such as an electrostatic chuck, from processing
environments in a processing environment. In one embodiment, a
protective seal is disposed to surround an edge of the bonding
material from exposure to processing environment. In another
embodiment, a protective structure is formed around a bonding
material in a chamber component to prevent direct exposure of the
bonding material to the processing environment. According to
another embodiment of the present invention, a bonding material
comprising a silicon filler and a polymer adhesive base is used in
joining chamber components with reduced particle generation.
Embodiments of the present invention reduce erosion of bonding
material used in a processing chamber, thus, improving processing
quality and reducing maintenance costs.
[0022] FIG. 1A is a sectional side view of an electrostatic chuck
100 according to one embodiment of the present invention. The
electrostatic chuck 100 may be movably or fixedly positioned in a
substrate processing chamber for supporting a substrate during
processing. The electrostatic chuck 100 includes a chuck body 110
secured to a chuck base 120 by a bonding material 130. A protective
seal 140 is disposed around the bonding material 130 to protect the
bonding material 130 from a processing environment.
[0023] The chuck body 110 has a substantially planar upper surface
112 for supporting a substrate 102 thereon. The chuck body 110 also
has a substantially planar lower surface 114 for receiving the
bonding material 130 and coupling to the chuck base 120. The chuck
body 110 may be formed from a dielectric material, in one
embodiment, the chuck body 110 may be formed from a ceramic, such
as aluminum oxide. An electrode 118 may be embedded in the chuck
body 110. The electrode 118 may be a thin metal plate or a metal
mesh. The electrode 118 may be large enough to encompass
substantially the entire area of the substrate 102. The electrode
118 may be coupled to a power source, such as a DC voltage source,
to produce electrostatic chucking force to attract and secure the
substrate 120 on the upper surface 112. Optionally, the electrode
118 may also be coupled to a RF power source for generating
capacitively coupled plasma in a processing chamber.
[0024] The chuck body 110 may have three or more through holes 116
to allow lift pins 104 passing through. The chuck body 110 may be
shaped according to the shape of the substrate 102 being processed.
For example, the chuck body 110 may be a circular disk for
supporting a circular substrate, such as a semiconductor substrate.
The chuck body 110 may also be a rectangular plate for supporting
rectangular substrates, such as glass substrates for forming liquid
crystalline display devices.
[0025] The chuck base 120 has an upper surface 122 for receiving
the bonding material 130 and the chuck body 110. The upper surface
122 may be substantially planar. The chuck base 120 may be formed
from a thermal conductive material, such as a metal, to provide
temperature control to the chuck body 110. In one embodiment, the
chuck base 120 is formed from aluminum. The chuck base 120 may have
cooling channels 123 formed therein. The cooling channels 123 may
be connected to a cooling fluid source (not shown) and have cooling
fluid circulated therein. The chuck base 120 may also have one or
more heating elements 124 formed therein for providing heating to
the chuck body 110. The one or more heating elements 124 may form
multiple heating zones to obtain desired heating effect. According
to embodiments of the present application, the one or more heating
elements 124 may form four independently controlled heating zones.
The chuck base 120 may have lift pin openings 126 formed
therethrough and aligned with the through holes 116 in the chuck
body 110 for receiving lift pins 104. In one embodiment, casing
elements 132, 134, 138 may be disposed in the lift pin openings 126
for guiding the lift pins 104. The casing elements 132, 134, 138
may be formed from a dielectric material, such as VESPEL.RTM.
polymer or polyether ether ketone (PEEK), to provide electrical
isolation between the lift pins 104 and the chuck base 120.
[0026] The bonding material 130 is disposed between the lower
surface 114 of the chuck body 110 and the upper surface 122 of the
chuck base 120 to join the chuck body 110 and the chuck base 120
together. The bonding material 130 may be in the form of a sheet
shaped similar to the chuck body 110 and the chuck base 120. In one
embodiment, the sheet of bonding material 130 may include three or
more lift pin holes 136 corresponding to the through holes 116 for
the lift pins 104. Alternatively, the bonding material 130 may be
liquid based.
[0027] The bonding material 130 is configured to provide secure
joint between dissimilar materials, such as the ceramic chuck body
110 and the metallic chuck base 120. The bonding material 130 also
provides thermal conduction between the joined components. In one
embodiment, the bonding material 130 may be a polymer based bonding
adhesive with filler materials to provide thermal conductivity. The
bonding material 130 may be a polymer based bonding adhesive with
erosion resistive fillers. In one embodiment, the filler material
includes silicon and the polymer base material includes Silicone.
The concentration of filler material in silicone base Is controlled
to achieve a thermal conductivity of 1 W/mk.
[0028] Fillers in conventional bonding material may be eroded in an
etching chemistry, such as a processing environment including
NF.sub.3 or NF.sub.3 and O.sub.2, generating white particles and
causing contamination. Compared to bonding materials with
traditional fillers, the bonding material 130 with silicone base
and silicon filler does not causing particle contamination in a
processing chemistry including NF.sub.2 or NF.sub.3 and O.sub.2,
thus greatly reducing particle contamination. For example, in
NF.sub.3 chemistry, the base polymer Silicone is attacked and the
Silicone volatilizes, leaving the traditional fillers, such as
alumina (Al.sub.2O.sub.3) fillers, behind causing particle
problems. When silicon fillers are used, both the silicon filler
and the silicone base volatilize under the NF3 attack without
generating any particles. The bonding material 130 comprising
silicon fillers may be used alone or in combination with the
protective seal 140.
[0029] In one embodiment, the protective seal 140 circum scribes
the bonding material 130 to prevent interaction between the bonding
material 130 and the processing environment. In one embodiment, a
recess 144 may be formed between the chuck body 110 and the chuck
base 120 to hold the protective seal 140 in position. Optionally, a
protective seal 142 may be disposed around each lift pin holes 136
in the bonding material 130 to prevent the bonding material 130
from being exposed to environment in the lift pin holes 136.
[0030] The protective seals 140, 142 may be formed from materials
maintain a seal between the chuck body 110 and the chuck base 120
when exposed to the processing environment. The protective seals
140, 142 may be formed from an elastomer, such as a
perfluoroelastomer. For operating in an etching chemistry including
NF.sub.3 or NF.sub.3 and O.sub.2, the protective seals 140, 142 may
be formed by one of but not limited to KALREZ.RTM. 8575
perfluoroelastomer, DUPRA.RTM. 192 perfluoroelastomer, KALREZ.RTM.
8085 perfluoroelastomer, CHEMRAZ.RTM. XPE elastomer. Other
materials, such as L7505, SC513 (Chemraz 513), L8015r1 G758
(Perlast), L8010, are also suitable for protective seals. The
protective seals 140, 142 may be in the form of an O-ring, gasket,
cup seal or have another suitable profile. The protective seals
140, 142 may optionally be spring loaded.
[0031] As shown in FIG. 1B, the recess 144 in the electrostatic
chuck 100 may be defined by a step formed in the chuck base 120 and
the lower surface 114 of the chuck body 110. Since only the chuck
base 120 is machined to form the recess 144, this configuration is
simple to implement. FIG. 1E is a top view of the chuck base 120 of
the electrostatic chuck 100 with the chuck body 110 removed with
the protective seals 140, 142 visible.
[0032] Alternatively, a recess for the protective seal 140 may be
formed in both the chuck body 110 and the chuck base 120, or on the
chuck body 110 only.
[0033] FIG. 1C is an enlarged partial sectional view of an
electrostatic chuck 100C according to another embodiment of the
present invention. The electrostatic chuck 100C is similar to the
electrostatic chuck 100 of FIG. 1A except that the protective seal
140 is secured in a recess 144C defined by a step 115C formed on
the lower surface 114 of the chuck body 110 and a step 128C formed
on the upper surface 122 of the chuck base 120. This configuration
ensures that the bonding material 130 is covered by a middle
portion of the protective seal 140.
[0034] FIG. 1D is an enlarged partial sectional view of an
electrostatic chuck 1000 according to another embodiment of the
present invention. The electrostatic chuck 100D is similar to the
electrostatic chuck 100 of FIG. 1A except that the protective seal
140 is secured in a recess 144D defined by a step 1150 formed on
the lower surface 114 of the chuck body 110 and the upper surface
122 of the chuck base 120. Only the chuck body 110 is machined to
form the recess 144d.
[0035] In addition or alternative to using a protective seal to
prevent erosion to bonding materials, embodiments of the present
invention also provide electrostatic chucks having shielding
features within the chuck body and/or chuck base for protecting the
bonding materials.
[0036] FIG. 2A is a sectional side view of an electrostatic chuck
200 having a bonding material protective structure, i.e., a
shielding feature, according to one embodiment of the present
invention. The electrostatic chuck 200 may be movably or fixedly
positioned in a substrate processing chamber for supporting a
substrate during processing. Similar to the electrostatic chuck
100, the electrostatic chuck 200 includes a chuck body 210 secured
to a chuck base 220 by a bonding material 230 that is the same as
the bonding material 130. A protective structure 216 may be formed
in the chuck body 210 and/or the chuck base 220 to shield the
bonding material 230 from a processing environment
[0037] The chuck body 210 has an upper surface 212 for supporting a
substrate 102 thereon and a substantially planar lower surface 214
for receiving the bonding material 230. The chuck body 210 may be
formed from a dielectric material. An electrode 218 may be embedded
in the chuck body 210.
[0038] The chuck base 220 has an upper surface 222 for receiving
the bonding material 230 and the chuck body 210. The chuck base 220
may have cooling channels 223 formed therein and heating elements
224 embedded therein for temperature control.
[0039] The bonding material 230 is disposed between the lower
surface 214 of the chuck body 210 and the upper surface 222 of the
chuck base 220 to join the chuck body 210 and the chuck base 220
together. The lower surface 214 of the chuck body 210 and the upper
surface 222 of the chuck base 220 may be smaller than outer edges
of the chuck body 210 and the chuck base 220 so that the bonding
material 230 may be surrounded by the protective structure 216
formed by the chuck body 210 and/or the chuck base 220.
[0040] According to the embodiment shown in FIG. 2A, the chuck base
220 has a step 228 dropping down from the upper surface 222. The
protective structure 216 is in the form of a lip that extends
downward from the lower surface 214 of the chuck body 210. The lip
may be continuous. When the chuck body 210 is secured to the chuck
base 220, the protective structure 216 in the form of a lip 216
extends above the step 228 and covers the interface between the
lower surface 214 of the chuck body 210 and the upper surface of
the chuck base 220, thus laterally surrounding the bonding material
230 and shielding the bonding material 230 from line of sight
exposure to the environment within the chamber. Without using a
protective seal, the protective structure 216 of the electrostatic
chuck 200 eliminates the needs to maintain and replace the
protective seals, thus, reducing operation cost. In one embodiment,
a continuous hp 217 may also be formed around each lift pin
passages 219 to prevent the bonding material 230 from being exposed
to the processing environment.
[0041] Even though the protective structure 216 is shown in FIG. 2A
to be in a form of a lip from the chuck body 210, any suitable
structures may be used to shield the bonding material 230. For
example, FIG. 2B is an enlarged partial sectional view of an
electrostatic chuck 200B having a protective structure in the form
of a protective lip 228B extending upwardly from chuck base 220 and
surrounding an outer edge 216B of the chuck body 210. In an
electrostatic chuck 200C shown in FIG. 2C, the chuck base 220 has a
groove 229 configured to receive a lip 215C from the chuck body
210. The groove 229 and the lip 215C form a maze to isolate the
bonding material 230 from the processing environment surrounding
the electrostatic chuck 2000.
[0042] According to embodiments of the present invention, one or
more protective elements, such as protective seals, protective
structures, or erosion resistive fillers may be used alone or in
combination to prevent bonding material from erosion in a
processing environment.
[0043] Electrostatic chucks according to embodiments of the present
invention may be used in various processing chambers, such as in
plasma etching chambers, chemical vapor deposition chambers, plasma
enhanced deposition chambers, atomic layer deposition chambers, ion
implantation chamber, for supporting substrates during
processing.
[0044] FIG. 3 is a sectional side view of a plasma processing
chamber 300 having the electrostatic chuck 100 disposed therein.
The electrostatic chuck 100 may be used to support a variety of
substrates, such as semiconductor substrates and reticles, and
accommodating a variety of substrate sizes. Alternatively, any
electrostatic chuck described above may he used in position of the
electrostatic chuck 100.
[0045] The plasma processing chamber 300 includes a bottom 322,
sidewalls 326 and a chamber lid 343 disposed over the sidewalls 326
defining a processing volume 341. The plasma processing chamber 300
further includes a liner 323 disposed in the processing volume 341
to prevent the sidewalls 326 from damage and contamination from the
processing chemistry and/or processing by-products. A slit valve
door opening 335 is formed through the sidewall 326 and the liner
323 to allow passage of the substrates and substrate transfer
mechanism. A slit valve door 324 selectively open and close the
slit valve door opening 335.
[0046] The electrostatic chuck 100 is disposed in the processing
volume 341. A lift 327 is configured to raise and lower lift pins
not shown) relative to the electrostatic chuck 100 during
processing and loading/unloading the substrate 102. The
electrostatic chuck 100 may be coupled to a bias power source 321
for generating chucking force to secure the substrate 102 on the
electrostatic chuck 100.
[0047] One or more processing gases may be supplied to the
processing volume 341 from a gas source 303 via an inlet 344. A
vacuum pump 330 is fluid communication with the processing volume
341. The vacuum pump 330 may be used to pump the processing volume
341 and maintain a low pressure environment through a plenum
336.
[0048] The plasma processing chamber 300 includes an antenna
assembly 370 disposed outside the chamber lid 343. The antenna
assembly 370 may be .degree. Wed to a radio-frequency (RE) plasma
power source 374 through a matching network 373. During processing,
the antenna assembly 370 is energized with RE power provided by the
power source 374 to ignite a plasma of processing gases within the
processing volume 341 and to maintain the plasma during processing
of the substrate 102.
[0049] The plasma processing chamber 300 may be used for various
plasma processes. In one embodiment, the plasma processing chamber
300 may be used to perform drying etching with one or more etching
agents. For example, the plasma processing chamber 300 may be used
for ignition of plasma from a precursor including C.sub.AF.sub.y
(where x and y can be different allowed combinations), O.sub.2,
NE.sub.3, or combinations thereof. Embodiments of the present
invention may also be used in etching chromium for photomask
applications, etching a profile, such as a deep trench and through
silicon vias (TSV) in a silicon substrate having oxide and metal
layers disposed on the substrate.
[0050] Even though electrostatic chucks joined by bonding materials
are described above, embodiments of the present invention may be
used in any composite structures joined by bonding materials to
protect the bonding material from operating environment. For
example, embodiments of the present invention may be applied to gas
distribution showerheads having two or more components joined by a
bonding material.
[0051] While the foregoing is directed to embodiments of the
present invention, other and further embodiments of the invention
may be devised without departing from the basic scope thereof, and
the scope thereof is determined by the claims that follow.
* * * * *