U.S. patent application number 09/811120 was filed with the patent office on 2003-03-27 for disk carrier.
Invention is credited to Nguyen, Tin.
Application Number | 20030057089 09/811120 |
Document ID | / |
Family ID | 27400414 |
Filed Date | 2003-03-27 |
United States Patent
Application |
20030057089 |
Kind Code |
A1 |
Nguyen, Tin |
March 27, 2003 |
DISK CARRIER
Abstract
A first disk carrier constructed in accordance with the
invention is substantially circular, and has a size and shape such
that it can be placed in an opening in a second, larger disk
carrier. In one embodiment, the second, large disk carrier is a
conventional disk carrier, e.g. used to hold a substrate during a
magnetic disk manufacturing process. The first disk carrier is
circular, and has a diameter equal (or substantially equal) to
common substrates currently being manufactured. Therefore, the
first disk carrier fits in and can be held by the second disk
carrier. The first disk carrier has one or more openings for
holding one or more substrates that have a diameter substantially
less than the diameter of the opening of the second disk
carrier.
Inventors: |
Nguyen, Tin; (San Jose,
CA) |
Correspondence
Address: |
Kenneth Leeds
P.O. Box 2819
Sunnyvale
CA
94087-0819
US
|
Family ID: |
27400414 |
Appl. No.: |
09/811120 |
Filed: |
March 17, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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60251097 |
Dec 1, 2000 |
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60264235 |
Jan 24, 2001 |
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Current U.S.
Class: |
204/298.15 ;
118/728; 118/729; 204/192.1; 204/192.12; 204/298.25; 414/222.01;
414/225.01; 414/935; 414/936; 414/937; 414/938; 414/941;
G9B/17.055 |
Current CPC
Class: |
C23C 14/568 20130101;
C23C 14/50 20130101; G11B 17/226 20130101 |
Class at
Publication: |
204/298.15 ;
204/298.25; 204/192.1; 204/192.12; 118/728; 118/729; 414/222.01;
414/935; 414/936; 414/937; 414/938; 414/941; 414/225.01 |
International
Class: |
C23C 014/50; B65H
001/00; B65G 049/07 |
Claims
I claim:
1. A method comprising: loading one or more substrates into a first
substrate carrier, said first substrate carrier comprising one or
more openings, each of said one or more openings accommodating one
of said substrates, said first substrate carrier having an exterior
such that said first carrier can be loaded into an opening in a
second substrate carrier.
2. Method of claim 1 further comprising loading said first
substrate carrier into said opening of said second substrate
carrier.
3. Method of claim 2 further comprising depositing material on said
one or more substrates after said loading of said one or more
substrates into said first substrate carrier and said loading of
said first substrate carrier into said opening of said second
substrate carrier.
4. Method of claim 2 wherein said loading of said one or more
substrates into said first substrate carrier is accomplished prior
to said loading of said first substrate carrier into said opening
of said second substrate carrier.
5. Method of claim 2 wherein said loading of said first substrate
carrier into said opening of said second substrate carrier is
accomplished prior to said loading of said one or more substrates
into said first substrate carrier.
6. Method of claim 1 wherein said first substrate carrier comprises
a plurality of openings for holding substrates, said method further
comprising loading a plurality of substrates into said first
substrate carrier.
5. Method of claim 1 wherein said one or more substrates are
substantially disk-shaped and said first substrate carrier has a
substantially circular exterior for mating with said opening in
said second substrate carrier.
6. Method of claim 5 further comprising loading of said first
substrate carrier into said opening of said second substrate
carrier, said opening of said second substrate carrier being
substantially circular.
7. Method of claim 1 wherein said opening of said second substrate
carrier accommodates a substantially disk-shaped substrate.
8. Method of claim 1 further comprising: loading said first
substrate carrier into said opening in said second substrate
carrier; and depositing material onto said one or more substrates
while said one or more substrates are being held by said first
substrate carrier and said first substrate carrier is being held by
said second substrate carrier.
9. Method of claim 8 further comprising removing said one or more
substrates from said first substrate carrier after said
depositing.
10. Method of claim 8 further comprising unloading said first
substrate carrier from said opening in said second substrate
carrier after said depositing.
11. Method of claim 10 further comprising loading said first
substrate carrier into a cassette after said depositing.
12. Method comprising loading a first substrate carrier into an
opening of a second substrate carrier, said first substrate carrier
comprising one or more openings for receiving substrates.
13. Method of claim 12 wherein each of said one or more openings
receives and holds a substrate.
14. Method of claim 13 wherein said substrates are disk-shaped, and
said opening of said second substrate carrier is shaped to
accommodate a disk-shaped substrate.
15. Method of claim 14 further comprising depositing material on
said substrate after said loading of said first substrate carrier
into said opening of said second substrate carrier.
16. Method of claim 12 wherein said first substrate carrier has a
substantially circular exterior for mating with said second
substrate carrier.
17. Method comprising: loading one or more substrates into a first
substrate carrier, said first substrate carrier having an exterior
shaped to be received by an opening in a second substrate carrier;
and loading said first substrate carrier into a cassette.
18. Method of claim 17 further comprising removing said first
substrate carrier from said cassette and loading said first
substrate carrier into said opening in said second opening.
19. Method of claim 17 wherein said first substrate carrier has a
substantially circular exterior and said opening in said second
substrate carrier accommodates said substantially circular exterior
of said first substrate carrier.
20. Method comprising: providing a cassette, said cassette
containing at least one substrate carrier said substrate carrier
comprising at least one opening, said opening containing a
substrate; and removing said at least one substrate carrier from
said cassette.
21. Method of claim 20 further comprising loading said at least one
substrate carrier into an opening within a second substrate carrier
after said removing.
22. Method of claim 20 wherein said at least one substrate carrier
has an exterior shaped for mating with a second substrate
carrier.
23. Method of claim 20 wherein said at least one substrate carrier
has a substantially circular exterior.
24. A method comprising: providing a first substrate carrier having
one or more openings, at least one of said one or more of said
openings holding a substrate, said first substrate carrier being
held by a second substrate carrier; and depositing material onto
said substrate.
25. Method of claim 24 wherein said first substrate carrier has a
substantially circular exterior for mating with an opening within
said second substrate carrier
26. Method of claim 24 wherein said depositing comprises sputtering
said material onto said substrate.
27. Method comprising: providing a first substrate carrier having
one or more openings, at least one of said one or more of said
openings holding a substrate, said first substrate carrier being
held by a second substrate carrier; and unloading said first
substrate carrier from said second substrate carrier.
28. Method of claim 27 wherein said first substrate carrier has a
substantially circular exterior for mating with an opening in said
second substrate carrier.
29. Method of claim 27 further comprising depositing material on
said substrate prior to said unloading.
30. Method comprising: providing a first substrate carrier having
one or more openings, at least one of said one or more of said
openings holding a substrate, said first substrate carrier being
held by a second substrate carrier; and unloading said one or more
substrates from said first substrate carrier.
31. Method of claim 30 wherein said first substrate carrier has a
substantially circular exterior for mating with an opening in said
second substrate carrier.
32. Method of claim 30 wherein said providing comprises providing
at least one substrate in at least one of said one or more
openings, said method further comprising depositing material on
said at least one substrate prior to said unloading.
33. Method comprising: providing a first substrate carrier, said
first substrate carrier comprising at least a first opening for
holding a substrate and at least a second opening for receiving a
tool; providing a tool having a member for being received by and
mating with said second opening; and causing said member to mate
with said second opening so that said first substrate carrier is
held by said tool.
34. Method of claim 33 wherein said tool removes said first
substrate carrier from a cassette.
35. Method of claim 33 wherein said tool places said first
substrate carrier into a cassette.
36. Method of claim 33 wherein said tool places said first
substrate carrier in a second substrate carrier.
37. Method of claim 36 wherein said first substrate carrier has a
substantially circular exterior and said second substrate carrier
has an opening for receiving a substantially disk-shaped
structure.
38. Method of claim 33 wherein said tool removes said first
substrate carrier from a second substrate carrier.
38. Method of claim 38 wherein said first substrate carrier has a
substantially circular exterior and said second substrate carrier
has an opening for receiving and holding a substantially
disk-shaped structure, said opening in said second substrate
carrier holding said first substrate carrier, said tool removing
said first substrate carrier from said opening in said second
substrate carrier.
39. Apparatus comprising: a first substrate carrier having at least
one opening for holding a substrate and an exterior for being held
by a second substrate carrier.
40. Apparatus of claim 39 further comprising said second substrate
carrier, said first substrate carrier being held within said
opening within said second substrate carrier.
41. Apparatus of claim 39 wherein said first substrate carrier is
held by a cassette.
42. Apparatus of claim 39 wherein said first substrate carrier is
within deposition apparatus.
43. Apparatus of claim 39 wherein said first substrate carrier has
a substantially circular exterior.
44. Apparatus of claim 39 wherein said first substrate carrier has
a second opening for mating with a tool, said apparatus further
comprising a tool having comprising a member shaped for mating with
said second opening.
45. Method comprising loading a first holder into a cassette, said
first holder having one or more openings for receiving a substrate,
said first holder having an exterior for being received by a second
holder.
46. Method comprising unloading a first holder from a cassette,
said first holder having one or more openings for receiving a
substrate, said first holder having an exterior for being received
by a second holder.
47. In apparatus comprising a first holder having one or more
openings, each opening for holding a substrate, said apparatus
permitting deposition of material on a first number of substrates
simultaneously when a substrate is provided in each of said
openings of said first holder, a method comprising providing a
second holder in at least one of said openings in said first
holder, said second holder comprising a plurality of openings for
holding substrates, wherein said second holder permits an increase
in the number of substrates upon which material can be deposited
simultaneously.
48. Method of claim 47 wherein said apparatus is static sputtering
apparatus, said apparatus permitting material to be deposited on
only one substrate at a time when a substrate is provided in each
of said one or more openings of said first carrier, said apparatus
permitting material to be deposited on a plurality of substrates at
a time when said second carrier is placed within an opening of said
first carrier.
49. Deposition apparatus comprising: a first holder having one or
more openings, each opening for holding a substrate, said apparatus
permitting deposition of material on a first number of substrates
simultaneously when a substrate is provided in each of said
openings of said first holder; and a second holder provided in at
least one of said openings in said first holder, said second holder
comprising a plurality of openings for holding substrates, wherein
said second holder permits an increase in the number of substrates
upon which material can be deposited simultaneously.
50. Apparatus of claim 49 wherein said apparatus is static
sputtering apparatus, said apparatus permitting material to be
deposited on one substrate at a time when only one substrate is
provided in said one or more openings of said first carrier, said
apparatus permitting material to be deposited on a plurality of
substrates at a time when said second carrier is placed within said
first carrier.
Description
[0001] This application claims priority based on provisional patent
application serial No. 60/251,097, filed Dec. 1, 2000 and serial
No. 60/264,235, filed Jan. 24, 2001. These applications are
incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] This invention pertains to structures for holding disks
during sputtering. This invention also pertains to methods and
apparatuses for manufacturing magnetic disks.
[0003] Magnetic disks are typically manufactured by sputtering an
underlayer, a magnetic alloy film and a protective overcoat, in
that order, on a disk-shaped substrate. An example of such a
process is described in U.S. patent application Ser. No.
08/984,753, filed by Bertero et al. on Dec. 4, 1997, incorporated
herein by reference.
[0004] During sputtering, the following steps are typically
performed:
[0005] 1. A disk-shaped substrate is placed in a "disk carrier".
(The substrate can be glass, glass ceramic, aluminum plated with a
nickel-phosphorus alloy, or other appropriate material. The
nickel-phosphorus alloy is sometimes referred to as "NiP".)
[0006] 2. In some (but not all) manufacturing processes, the disk
carrier carries the substrate past a heating element for heating
the substrate.
[0007] 3. The disk carrier carries the substrate through sputtering
apparatus, past several sets of sputtering targets.
[0008] 4. The substrates are then removed from the disk
carrier.
[0009] Various types of disk carriers are known in the art. For
examples of disk carriers used during low temperature sputtering
processes see U.S. Pat. Nos. 5,244,555; 5,296,118; and 4,595,481,
each assigned to Komag, Inc. and incorporated herein by reference.
These disk carriers include a vertical plate with a substantially
circular opening for receiving a disk-shaped substrate. A groove is
provided in the bottom of the circular opening for receiving and
holding the outer edge of the substrate. During low temperature
sputtering processes, the substrate is placed within the carrier
and carried past a set of sputtering targets. The substrate is
typically not carried past a heating element prior to sputtering.
Therefore, the carrier need not accommodate much thermal expansion
of the substrate relative to the carrier.
[0010] U.S. patent application Ser. No. 09/428,301, filed Oct. 27,
1999 and assigned to Komag, Inc., teaches and claims several types
of disk carriers used in a high temperature sputtering process.
(The '301 application is incorporated herein by reference.) The
'301 carriers also include a vertical plate with a circular opening
for receiving a substrate. For example, in '301 FIGS. 2A to 2E
(FIGS. 1A to 1E of the present application), the '301 application
shows an embodiment of a disk carrier 100 comprising a vertical
plate 102 having a substantially circular opening 104 for receiving
a disk-shaped substrate 106. During a high temperature sputtering
process, carrier 100 carries substrate 106 past a heating element
prior to sputtering. Because substrate 106 has a much lower thermal
mass than carrier 100, the temperature of substrate 106 can exceed
the temperature of carrier 100 by 200.degree. C. or more.
Accordingly, carrier 100 has the following characteristics.
[0011] 1. Opening 104 has a size and shape such that it can hold
substrate 106 when substrate 106 and carrier 100 are both at room
temperature.
[0012] 2. Opening 104 can hold substrate 106 when substrate 106 is
at an elevated temperature with respect to carrier 100 without
having carrier 100 pressing against substrate 106 so as to cause
substrate 106 to bend or bow.
[0013] Substrate 106 is disk-shaped and has a diameter of 95.025 mm
(e.g. a radius of about 47.513 mm) at room temperature, a thickness
of 0.80 mm at room temperature, a diameter of 95.572 mm at
300.degree. C. and a thickness of 0.890 at 300.degree. C. Substrate
106 has a central aperture 107 formed therein. Substrate 106
typically comprises an aluminum alloy plated with a NiP.
[0014] Opening 104 of carrier 100 comprises an upper circular
portion 104u and a lower circular portion 104l. Upper circular
portion 104u has a radius R1 equal to about 48.82 mm about a center
C. (Radius R1 is greater than the room temperature substrate
radius.)
[0015] Lower portion 104l of opening 104 extends about an arc of
approximately 176.degree.. Within lower circular portion 104l is a
groove 108 (FIGS. 1C to 1E) for receiving an outer edge 106a of
substrate 106. Groove 108 extends continuously along the length of
circular portion 104l. Groove 108 includes side walls 108a, 108b
(FIG. 1E) which form an angle .alpha.1 of about 100.degree. and a
floor 108c having a width W1 of about 0.25 mm. The distance D1
(FIG. 1A) between the center C of opening 104 and the top 108t of
groove 108 is typically between 47.424 and 47.454 mm (i.e. less
than the substrate radius). The distance between the center C of
opening 104 and floor 108c of groove 108 is typically between
47.907 and 47.937 mm (i.e. greater than the substrate radius).
Groove 108 terminates when it reaches points 109a, 109b (FIG. 1A).
Points 109a, 109b are about 2.degree. below the horizontal diameter
of opening 104.
[0016] At room temperature substrate 106 has a radius of 47.513 mm
and a thickness of 0.800 mm. Thus, when substrate 106 is at room
temperature and rests in groove 108, edge 106a of substrate 106 is
a distance D2 of about 0.12 mm from floor 108c of groove 108 (FIG.
1E'). At a substrate temperature of 300.degree. C., edge 106a is
about 0.16 mm from floor 108c. Substrate 106 is adequately
supported by groove 108 when substrate 106 is at room temperature
(about 20.degree. C.). However, because the radius of floor 108c of
groove 108 is greater than the substrate radius at room
temperature, carrier 100 can accommodate thermal expansion of
substrate 106 without causing substrate 106 to bow outwardly.
During some high temperature processes, substrate 106 is heated to
a temperature of about 200.degree. C. before sputtering.
[0017] Above points 109a, 109b, groove 108 terminates, and a recess
112 having a depth D4 of about 6.35 mm (FIG. 1D) is formed in a
side 114 of carrier 100. (Carrier 100 has a width D5 of about 11
mm.) The walls of recess 112 include first and second portions
112a, 112b (FIG. 1A) which extend in a linear direction, and a
third, curved portion 112c. Recess 112 permits loading and removal
of substrate 106 from side 114 of carrier 100. (However, it is not
feasible to load substrate 106 from the other side 117 of carrier
100.) Curved portion 112c of the wall of recess 112 is circular,
and has a radius R2 of about 53.80 mm from a point C' that is a
distance D3 about 4.44 mm above center point C. Linear walls 112a
and 112b are a distance D4 of about 52.10 mm from point C'.
[0018] A bevel 116 is formed on side 114 of carrier 100 to
facilitate exposure of substrate 106 to plasma to during
sputtering. Similarly, a bevel 118 is formed on side 117 of carrier
100, also to facilitate exposure of plasma to substrate 106 during
sputtering. Bevels 116 and 118 form an angle .gamma.1 of 26.degree.
(FIG. 1E) with the side of carrier 100. Bevels 116 and 118 are
circular, with a radius R3 of about 57.16 mm from center C (FIG.
1A).
[0019] FIG. 1C is an expanded view of a portion P1 of FIG. 1A where
groove 108 terminates. As can be seen, below wall 112a, a wall 112d
that curves downward and to the right toward opening 104 bounds
recess 112. The radius of curvature R4 of wall 112 is about 4
mm.
[0020] The '301 application teaches and claims several other types
of substrate carriers, e.g. as shown in '301 FIGS. 3A to 3C and 4A
to 4D. The embodiment of '301 FIGS. 3A to 3C permits a substrate to
be loaded and unloaded from either side of the disk carrier. The
embodiment of '301 FIGS. 4A to 4D has a groove that is shallower at
the lowest point of the opening (e.g. near point 109c) than away
from the lowest point of the opening (e.g. near points 109a, 109b).
This makes it easier for the carrier to hold the substrate when the
substrate is at room temperature without having the substrate fall
out of the opening. As mentioned above, the '301 application is
incorporated herein by reference.
[0021] Magnetic disks come in standard sizes. One of the most
prevalent sizes is 95 mm diameter disks. Accordingly, the
substrates used to manufacture such disks are about 95 mm (e.g.
95.025 mm) in diameter, and substrate carriers used to manufacture
such disks have openings designed to accommodate such
substrates.
[0022] Recently, smaller disk sizes have been introduced. For
example, disks are being designed that are about 27 mm in diameter.
Normally, this would require retooling the manufacturing apparatus
to accommodate the new substrate sizes. For example, one would have
to design and build completely new substrate carriers. Such
retooling is expensive and difficult. It would be desirable to be
able to accommodate this smaller substrate size with a minimum of
effort.
SUMMARY
[0023] A first substrate carrier in accordance with the invention
holds one or more of substrates (e.g. five substrates) during a
deposition process (e.g. a sputtering process). In one embodiment,
the substrates have a smaller diameter than substrates now
prevalent (e.g. smaller than 95 mm).
[0024] In one embodiment, the first substrate carrier fits within
an opening in a second substrate carrier. The opening of the second
carrier is substantially circular, and has a size and shape such
that it can accommodate a substrate such as (for example) a 95 mm
diameter substrate. The second substrate carrier can be a carrier
in accordance with the '301 application or the above-incorporated
Komag patents. The second carrier can also be in accordance with
another carrier design. However, during a method in accordance with
this invention, instead of simply carrying a substrate, the second
carrier carries the first substrate carrier, and the first
substrate carrier holds one or more substrates.
[0025] In one embodiment, the second carrier comprises one opening
for receiving either a substrate or the first carrier. In another
embodiment, the second carrier can have more than one opening for
receiving either substrates or carriers.
[0026] The first and second substrate carriers can be designed for
low temperature sputtering processes. Alternatively, the first and
second carriers can be designed for high temperature sputtering
processes.
[0027] In one embodiment, the first and second carriers can be used
in conjunction with a sputtering process. In another embodiment,
the first and second carriers can be used in conjunction with other
kinds of deposition processes, e.g. chemical vapor deposition,
plasma-enhanced chemical vapor deposition, cathodic arc deposition
or ion beam deposition.
[0028] In one embodiment, the substrates are used during magnetic
disk manufacturing. Such substrates can be metallic (e.g. an
aluminum alloy plated with NiP), glass, glass ceramic or other
material. In other embodiments, the substrates are used during
other types of manufacturing processes, e.g. integrated circuit
manufacturing.
[0029] In one embodiment, the carriers are used in conjunction with
in-line sputtering apparatus. Alternatively, the carriers can be
used in conjunction with static sputtering apparatus.
[0030] In static sputtering apparatus, in the prior art, a
substrate carrier holds up to two substrates and material is only
sputtered onto one substrate at a time. In the present invention,
without modifying the original carrier, the sputtering apparatus
can now sputter material from a sputtering target onto several
substrates simultaneously, e.g. five substrates at a time. Thus, a
carrier in accordance with the present invention has the advantage
of permitting one to deposit layers on several substrates
simultaneously to thereby increase throughput when using such a
carrier. In other words, throughput is increased by permitting
deposition on more substrates simultaneously than the sputtering
apparatus and carrier previously accommodated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1A shows a first side of a disk carrier constructed in
accordance with a first embodiment described in copending
application Ser. No. 09/428,301.
[0032] FIG. 1A' shows the disk carrier of FIG. 1A carrying a
substrate.
[0033] FIG. 1B shows a second side of the disk carrier of FIG.
1A.
[0034] FIG. 1C is an expanded view of a portion P1 of the disk
carrier of FIG. 1A.
[0035] FIG. 1D is a cross section view of the disk carrier of FIG.
1A along lines D-D.
[0036] FIG. 1E is an expanded view of a portion P2 of FIG. 1D.
[0037] FIG. 1E' illustrates portion P2 when the disk carrier is
holding a substrate.
[0038] FIG. 2A is a perspective view of a disk carrier constructed
in accordance with the present invention.
[0039] FIG. 2B is a side view of the disk carrier of FIG. 2A.
[0040] FIG. 2C illustrates in cross section the disk carrier of
FIGS. 2A and 2B.
[0041] FIGS. 2D-1, 2D-2 and 2D-3 are magnified cross section
illustrations of portions of the disk carrier shown in FIGS. 2A to
2C.
[0042] FIG. 2E illustrates a groove in an opening within the disk
carrier of FIGS. 2A to 2D.
[0043] FIGS. 3A is a top view of a tool for placing the carrier of
FIG. 2 in and removing the carrier of FIG. 2 from the carrier of
FIG. 1.
[0044] FIG. 3B is a side view of the tool of FIG. 3A.
[0045] FIG. 3C is a front view of the tool of FIGS. 3A and 3B.
DETAILED DESCRIPTION
[0046] FIGS. 2A to 2E illustrate a disk carrier 200 constructed in
accordance with the present invention. Disk carrier 200 is
substantially circular, and has a diameter D20 of about 95 mm.
Carrier 200 comprises five substantially identical circular
openings 202-1 to 202-5 for holding disk substrates. (Of course, in
other embodiments, carrier 200 can have more or fewer than five
openings 202.) In one embodiment, these disk substrates (not shown)
are disk shaped, have an outer diameter of about 27.400.+-.0.050
mm, an inner diameter of about 7.012.+-.0.012 mm, and a thickness
of about 0.250.+-.0.020 mm, but other size substrates (and thus
other size openings) can be used. Carrier 200 is used to hold disk
substrates during sputtering. In particular, during use, a
substrate is loaded into each of openings 202-1 to 202-5, and
carrier 200 carries these substrates past sputtering targets where
the various magnetic disk layers are deposited on the substrates to
manufacture magnetic disks. (As mentioned above, these layers
typically include one or more underlayers, one or more magnetic
alloy layers and one or more protective overcoats. Also as
mentioned above, one example of such a manufacturing process is
discussed in the above-incorporated Bertero application.)
Thereafter, the substrates are removed from carrier 200, e.g. by
placing the substrates in a cassette.
[0047] As shown in FIGS. 2C and 2E, the lower portion 202l of each
opening 202 comprises a groove 204 for receiving and holding the
outer edge of a substrate. Grooves 204 have the characteristic that
the bottom 204b of groove 204 extends about an arc that has a
radius that is greater than the radius of the substrate that is to
be loaded therein. In one embodiment, this arc extends about a
center point G (FIG. 2E), and has a radius R20 of about 13.722 mm.
The top 204t of groove 204 extends about an arc centered at point
G, and has a radius R21 of 13.222 mm. In contrast the substrates to
be loaded into groove 204 have a radius of 13.700.+-.0.025 mm.
Because of this, if the substrate expands due to thermal expansion,
openings 202 will still be able to hold the substrate, without
having the substrate bow or bend. (Again, it is noted that the
dimensions set forth herein are merely exemplary, and other
dimensions can be used.)
[0048] Openings 202 contain an upper circular portion 202u (FIG.
2E). Portion 202u extends along an arc having a radius R23 of
14.261 mm about a center point H. Center point H is a distance D22
of about 1.42 mm above center point G. Because of the fact that
radius R23 is greater than the radius of the substrates, and
because center point H of upper portion 202u is above center point
G of lower portion 202l, one can easily load substrates into groove
204 from either side of carrier 200.
[0049] Grooves 204 have inner walls 204-w1, 204-w2 that form an
angle .alpha.2 of about 30.degree.. The outer walls 206-w1, 206-w2
of carrier 200 near grooves 204 form a bevel, and extend at an
angle .gamma.2 of about 90.degree. relative to each other. This
bevel facilitates exposure of the substrate loaded in carrier 200
to plasma within the sputtering chamber. The outer edge 206e of
walls 206-w1, 206-w2 extends about an arc having a radius R24 of
about 14.30 mm from center point G.
[0050] As mentioned above, prior art substrates 106 were about 95
mm in diameter, and were loaded into disk carriers, such as carrier
100 of FIGS. 1A to 1E. Carrier 100 has an opening 104 for holding
such substrates. In accordance with the present invention, carrier
200 is loaded into opening 104 of carrier 100. Since carrier 200
has a diameter of 95 mm, it readily fits within opening 104. Thus,
one can use currently existing tooling (geared toward manufacturing
95 mm disks) to manufacture smaller disks (e.g. disks that are 27.4
mm in diameter). As seen in FIGS. 2C, 2D-1 and 2D-3, a lip 210
extends from the outer circumference of carrier 200. The width W5
of lip 210 can be 1.20 mm. The height H1 of lip 210 can be 2 mm. In
one embodiment, lip 210 can be inserted into groove 108 of carrier
100.
[0051] While carrier 100 is typically designed to accommodate
thermal expansion of a substrate, carrier 200 does not typically
substantially expand relative to carrier 100. In one embodiment,
this can be because carrier 100 and 200 are used in a low
temperature sputtering process. In another embodiment, this can be
because the thermal mass of carrier 100 is such that it does not
increase very much in temperature relative to carrier 100 during
use. Thus, it is not necessary to use carrier 200 in conjunction
with a carrier that accommodates much if any thermal expansion of
carrier 200. However, in alternative embodiments, one can provide a
carrier 200 that does expand relative to carrier 100 during use. In
such an embodiment, carrier 100 is typically designed to
accommodate such expansion.
[0052] Also shown in FIGS. 2A, 2B and 2C is a central opening 220.
This opening has a U-shaped bottom region 220a and a flat top 220b.
A flat metal member 222 extends across the top of central opening
220, and a bottom edge 222a of flat member 222 includes an
indentation 222b for receiving a tool 300 that is used to lift
carrier 200 in and out of carrier 100. Tool 300 is shown in FIGS.
3A to 3C, and is designed to place carrier 200 in opening 104 prior
to sputtering, and to remove carrier 200 from opening 104 after
sputtering.
[0053] Referring to FIG. 3, tool 300 includes an arm 302 affixed to
an end piece 304. End piece 304 is designed to mate with the
structures in opening 220. In particular, End piece 302 has the
shape of a generalized cylinder with a notch 306 cut therein. Notch
306 has a width W6 that can be about 1.3 mils wide and a depth D6
about 3.0 mils deep, and is designed to mate with flat member 222
of FIGS. 2A and 2B. The unique shape of opening 220, member 222 and
end piece 304 enable one to ensure that carrier 200 is right side
up when carrier 200 is grabbed by tool 300. This prevents
substrates from falling out of carrier 200 during handling.
[0054] Arm 302 is at an angle .theta. (FIG. 3C) with respect to the
axis A of end piece 304 to facilitate placing carrier 200 in and
out of a cassette (e.g. before and after sputtering).
[0055] Referring back to FIGS. 2A and 2B, carrier 100 contains five
relatively small holes 250-1, 250-2, 250-3, 250-4 and 250-5. These
holes are primarily for purposes of machining, and will not be
discussed in further detail.
[0056] As mentioned above, carrier 200 can be placed within and
removed from carrier 100. Carrier 200 has a substantially circular
exterior so that carrier 200 can fit within a substantially
circular opening in another carrier, which other carrier has been
designed to carry larger substrates (e.g. 95 mm diameter
substrates). In one embodiment, carrier 200 can be used as follows.
First, a set of smaller diameter substrates are placed within
openings 202 of carrier 200. This can be done either manually or
using robotic automation. Thereafter, tool 300 can be used to pick
up carrier 200 and place it in a cassette. Since carrier 200
typically has a diameter that is about the same as the diameter of
common magnetic disk substrates, a conventional cassette can be
used to hold and transport a set of carriers 200. (Cassettes are,
of course, well-known in the art. See, for example, U.S. Pat. No.
5,657,617, assigned to Komag, Inc. and incorporated herein by
reference.)
[0057] Thereafter, carriers 200 can be taken out of the cassette
and placed within the opening of a carrier such as carrier 100.
This can be accomplished with a tool having the design of tool 300.
The asymmetric shape of tool 300 facilitates such maneuvering. In
particular, since tool 300 only fits into opening 220 in one way,
it is not generally possible to accidentally orient carrier 200
such that it is upside down.
[0058] After carrier 200 is placed within carrier 100, the two
carriers 100, 200 carry the substrates (optionally) past a heating
element, and past various sets of sputtering targets. Thereafter,
carrier 200 can be unloaded from carrier 100 and placed in a
cassette along with other carriers of like design. Again, this can
be accomplished using the same or a different tool having the
design of tool 300. The disks can be unloaded from carrier 200
later on, either manually or with robotic automation.
[0059] While the invention has been described with respect to
specific embodiments, those skilled in the art will appreciate that
changes can be made in form and detail without departing from the
spirit and scope of the invention. For example, the dimensions and
sizes set forth above are merely exemplary, and other size
structures can be used. Also, a substrate carrier can be used
during different types of deposition processes, e.g. CVD, PECVD,
ion beam deposition, cathodic arc deposition, and other deposition
processes. The openings within carrier 200 (and the substrates
carried therein) need not be substantially circular. (For example,
the openings within carrier 200 and the substrates therein can be
rectangular.) Further, the opening within carrier 100 (and the
exterior of carrier 200) need not be circular. (The opening within
carrier 100 and the exterior of carrier 200 can be rectangular.)
The disk carrier can be made of any appropriate solid material. The
substrates can have either chamfered edges or unchamfered edges.
(See PCT patent application PCT/US00/21301, incorporated herein by
reference.)
[0060] One can use means other than tool 300 to move carrier 200 in
and out of carrier 100 or in and out of a cassette.
[0061] Substrates can be loaded into carrier 100 before carrier 100
is loaded into carrier 200. Alternatively, substrates can be loaded
into carrier 100 after carrier 100 is loaded into carrier 200.
[0062] Substrates can be removed from carrier 100 after carrier 100
is removed from carrier 200. Alternatively, substrates can be
removed from carrier 100 before carrier 100 is removed from carrier
200. In yet another embodiment, carrier 200 need not be removed
from carrier 100.
[0063] In an embodiment in which carriers 100 and 200 are used for
sputtering, the various layers can be sputtered on only one side of
the substrate. Alternatively, the various layers can be sputtered
on both sides of the substrate. (In such an embodiment, the carrier
typically carries the substrates between several pairs of
sputtering targets, each pair of sputtering targets being used to
deposit material onto the substrate.) As mentioned above, prior to
deposition, the carriers can optionally carry the substrates past
one or more heating elements. (Two heating elements can be
provided, one on either side of the substrates.) Accordingly, all
such changes come within the invention.
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