U.S. patent application number 09/755545 was filed with the patent office on 2002-07-11 for physical vapor deposition apparatus with modified shutter disk and cover ring.
Invention is credited to Gonzalez, Jose Luis, Groshong, Gary W., Hixson, Robert B., Monfort, Jason L..
Application Number | 20020088771 09/755545 |
Document ID | / |
Family ID | 25039599 |
Filed Date | 2002-07-11 |
United States Patent
Application |
20020088771 |
Kind Code |
A1 |
Hixson, Robert B. ; et
al. |
July 11, 2002 |
PHYSICAL VAPOR DEPOSITION APPARATUS WITH MODIFIED SHUTTER DISK AND
COVER RING
Abstract
Physical vapor deposition (PVD) system comprises a chamber, an
upper shield and a lower shield mounted within the chamber, a cover
ring having one or more tabs extending radially inwardly therefrom.
The PVD system further includes a shutter disk having one or more
notched areas formed in the periphery thereof to receive
non-contactingly the one or more tabs of the cover ring. The cover
ring has two or more recesses formed in an upper side thereof with
a guide pin extending from the center of the recesses. The lower
shield has two or more cups with a hole therein to be engaged with
the guide pin of the cover ring to keep the lower shield from
rotating with respect to the cover ring. The cups of the lower
shield are inserted into the recesses of the cover ring. These
improvements enable a standard shutter arm assembly and a shutter
disk to be utilized in a two-tab block-out scheme.
Inventors: |
Hixson, Robert B.;
(Portland, OR) ; Monfort, Jason L.; (Hillsboro,
OR) ; Groshong, Gary W.; (Brentwood, CA) ;
Gonzalez, Jose Luis; (Oakland, CA) |
Correspondence
Address: |
MARGER JOHNSON & MCCOLLOM PC
1030 SW MORRISON STREET
PORTLAND
OR
97205
US
|
Family ID: |
25039599 |
Appl. No.: |
09/755545 |
Filed: |
January 5, 2001 |
Current U.S.
Class: |
216/67 |
Current CPC
Class: |
H01L 21/68728 20130101;
H01J 37/32623 20130101; H01L 21/68785 20130101; H01L 21/68721
20130101 |
Class at
Publication: |
216/67 |
International
Class: |
B44C 001/22 |
Claims
What is claimed is:
1. A physical vapor deposition (PVD) chamber for tabbed block-out
scheme, comprising: a cover ring having one or more tabs extending
radially inwardly therefrom, and a shutter disk having one or more
peripheral notched areas formed therein configured to receive the
one or more tabs to keep a distance between the tab and the shutter
disk.
2. The apparatus of claim 1, wherein the distance is approximately
0.1 to approximately 0.3 inches.
3. The apparatus of claim 1, wherein the cover ring includes two or
more recesses formed in an upper side thereof with a guide pin
extending from the center of the recesses to fix the cover ring and
the tabs, and the shutter disk and notched areas in angular
registration.
4. The apparatus of claim 3, wherein the lower shield includes two
or more annular cups extending toward the cover ring and positioned
to receive the guide pin, the depth of the recesses being
approximately 0.9 inches to receive the cups.
5. A physical vapor deposition (PVD) system for tabbed block-out
scheme, comprising: a chamber; an upper shield and a lower shield
mounted within the chamber; a cover ring having one or more tabs
extending radially inwardly therefrom; and a shutter disk having
one or more notched areas formed on a periphery thereof to receive
the one or more tabs of the cover ring so that the cover ring
including the one or more tabs and the shutter disk do not contact
each other.
6. The PVD system of claim 5, wherein the cover ring includes: two
or more recesses formed in an upper side thereof with a guide pin
extending from the center of the recesses; and the lower shield
having two or more cups, each with a hole positioned therein to be
engaged with the guide pin of the cover ring to keep the lower
shield from rotating with respect to the cover ring, the cups of
the lower shield protruding toward the cover ring to be inserted
into the recesses of the cover ring.
7. The PVD system of claim 6, further comprising: a wafer pedestal
mounted within the chamber; means for positioning the shutter disk
to place the shutter disk on the wafer pedestal; and means for
vertically adjusting the height of wafer pedestal.
8. A method of using a physical vapor deposition (PVD) apparatus
for tabbed block-out scheme, the PVD device comprising a chamber;
an upper shield and a lower shield mounted within the chamber; a
cover ring having one or more tabs extending radially inwardly
therefrom; a wafer pedestal mounted within the chamber beneath the
lower shield; means for positioning a shutter disk to place the
shutter disk on the wafer pedestal; and means for vertically
adjusting the height of wafer pedestal, the method comprising:
forming notched areas in the periphery of the shutter disk
complementary to the one or more tabs of the cover ring to keep a
distance between the tab and the shutter disk; placing the shutter
disk on a wafer pedestal; moving the shutter disk into a pasting
position on the wafer pedestal, the notched areas of the shutter
disk corresponding with the tab for alignment therebetween such
that pasting can be performed in the chamber; and performing a
pasting process with the shutter disk on the pasting position.
9. The method of claim 8, which includes: forming two or more
recesses in an upper side of the cover ring with a guide pin
extending from the center of the recesses; forming in the lower
shield two or more cups with a hole therein to be engaged with the
guide pin of the cover ring to keep the lower shield from rotating
with respect to the cover ring; and inserting the cups of the lower
shield into the recesses of the cover ring.
10. The method of claim 9, wherein the depth of the recesses is
approximately 0.9 inches to receive the cups.
11. The method of claim 8, including arranging the tabs and notched
areas so that the cover ring including the one or more tabs and the
shutter disk do not contact each other,
12. The method of claim 8, wherein the distance is approximately
0.1 to approximately 0.3 inches.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates generally to the field of fabrication
of semiconductor devices and, more particularly, to a
physical-vapor deposition (PVD) apparatus and method of using the
apparatus.
[0003] 2. Description of the Related Art
[0004] Sputtering, a type of physical vapor deposition, is widely
used in semiconductor manufacturing to deposit thin metal or
insulating films on semiconductor wafers.
[0005] Conventional sputtering apparatus 11 shown in FIG. 1
includes a process chamber 10 enclosing a target 12 affixed to the
top thereof and a wafer pedestal 14 where a semiconductor wafer 16
rests during deposition. The target 12 is formed of a deposition
material to be deposited. A lower shield 18 and an upper shield 20
are positioned within the chamber 10 such that they are
electrically insulated from the chamber 10 and able to take on a
floating electrical potential associated with the potential of the
plasma of a gas, e.g. argon, generated within the chamber 10.
Additionally, a cover ring 22 is engaged with the lower shield 18
to keep any deposition material from being deposited on the
peripheral margin of the wafer 16.
[0006] During sputter deposition, the target 12 is bombarded by
plasma ions within the chamber 10 by applying an appropriate
voltage to the target 12, which causes particles of target material
to be ejected from the target 12 toward the wafer 16. These
particles deposit on the wafer 16 to form a desired film. During
the deposition, however, particles of target can also deposit on
the interior surfaces of the lower and upper shields 18 and 20.
Also, a portion of the particles returns to the target 12
itself.
[0007] For these reasons, after a number of wafers are processed,
the sputtering shields become coated with highly stressed, brittle
barrier metal films, e.g., of TiN. Without proper treatment, these
films can delaminate, flake off, and shower the substrate with
particles.
[0008] Thus, it is necessary to coat the shields occasionally with
metal such as titanium to prevent such particulation. This process
is called "pasting." A pasting material, such as titanium, is
sputtered around the interior of the shields 18 and 20 along with
the target 12. The layer of pasting material deposited onto the
interior of the shields 18 and 20 forms a barrier to cracking and
flaking between the layers of the high stress material. The pasting
material such as titanium acts as a glue layer to secure the
already-deposited films and to provide an adherent surface for any
additional material particulate. The pasting material deposited on
the target 12 must be cleaned before a normal sputtering process
begins.
[0009] Conventionally, a standard shutter disk 24 and a shutter arm
assembly 26 are used during pasting and cleaning of the target 12.
Typically, the shutter disk 24 is housed in an enclosure 30
attached to the side of the process chamber 10. The shutter disk 24
is positioned between the pedestal 14 and the target 12 to isolate
the target 12, and to protect other areas of the chamber 10 from
subsequent cleaning of the target 12 and the pasting material. The
shutter disk 24 is mounted on a rotating arm 32, i.e., an actuator
arm, which is located outside the shield 18 and within the process
chamber 10. When signaled to do so, the shutter arm assembly 26
rotates the disk 24 into the process chamber 10, overlying the
wafer pedestal 14. The shutter disk 24 can then be raised into a
pasting process position (at the same level as the wafer 16) by a
wafer lift 34. Thus, cleaning of the target (sputtering away any
contaminants present on the surface of target 12 onto the disk 24)
or pasting without contaminating the surface of wafer pedestal 14
is possible because the wafer pedestal surface is protected by the
shutter disk 24. When cleaning or pasting is completed, the shutter
disk 24 returns to the storage position.
[0010] In semiconductor manufacturing, it is important to align a
subsequent layer to a previous underlying layer. For this reason,
alignment marks 37 (FIG. 2B) are typically formed on a wafer or on
a reticle for alignment between various layers. The alignment marks
are typically formed by etching a depth into a wafer. The alignment
of one layer to the next is typically accomplished using a stepper.
The stepper uses a laser beam to detect the position of the
alignment marks on the wafer. It becomes difficult to maintain
these alignment marks, especially in the back end of the
manufacturing process, as the deposition over the marks makes the
marks indistinguishable.
[0011] Recently, to protect the alignment marks from being damaged
or contaminated by deposition, a two-tabbed alignment block-out
scheme has been introduced. One of the process chambers
incorporating the two-tabbed alignment block-out scheme is Endura
Model (model number ENDURA .RTM. HP PVD .TM.), available
commercially from Applied Materials, Inc.
[0012] As illustrated in FIG. 2A, a cover ring 22' has two tabs 35
protruding therefrom so that it can cover or protect alignment
marks 37 of FIG. 2B on a semiconductor wafer 16' during regular
deposition steps. Alignment marks 37 positioned beneath the tabs 35
can be protected. As a result, the alignment marks 37 can be better
maintained during deposition, and of course better alignment is
possible with well-maintained alignment marks 37.
[0013] As shown in FIG. 2C, which is a cross-sectional view of a
conventional cover ring taken in line 2C-2C of FIG. 2A, pins 38 are
formed in the bottom of the cover ring 22' in accordance with the
two-tabbed alignment block-out scheme.
[0014] As illustrated in FIG. 2D, the cover ring 22' is engaged
with the lower shield 18. The pins 38 extending down from the
bottom of the cover ring 22' are engaged in the holes 42 in a cup
19 formed under the lower shield 18. This keeps the cover ring 22'
from rotating so that the cover ring 22' with tabs 35 can be
precisely fixed in place with respect to alignment marks 37 formed
on a wafer 16.
[0015] However, conventional tabbed alignment block-out hardware
with the cover ring 22' and the lower shield 18 cannot use a
standard shutter disk and shutter arm assembly because the pins 38
of the cover ring 22' would interfere with the shutter disk 24 as
indicated at 27 of FIG. 1. Particularly, if an actuator arm 25 were
to attempt to put the shutter disk 24 onto the wafer pedestal 14,
the shutter blade 32 would run into the pins 38 extending down from
the lower shield 18.
[0016] Thus, there would be a clearance problem underneath the
lower shield 18 if the shutter disk 24 were used with the
two-tabbed block-out scheme.
[0017] Further, because the shutter disk 24 has to be sufficiently
thick (to withstand various processing conditions), it can be
inadvertently adhered to the tabs 35 by deposition during the
pasting or the cleaning steps as illustrated in FIG. 3. Therefore,
production wafers instead have been used for pasting by
transferring the production wafers into the chamber and pasting on
the wafers to avoid the clearance and gluing problems.
[0018] Unfortunately, using expensive production wafers each time
to paste the chamber (which is required before each production lot)
is costly and time consuming. Particularly, this is true because
operator intervention is necessary to place an extra wafer in each
production lot, leading to otherwise unnecessary exposure to
mis-processing and it takes a long time to transfer the wafer to
the chamber to be pasted. Also, because pasting is required quite
often for the PVD chamber, a large number of production wafers can
be wasted. Alternatively to using a wafer for pasting, an
additional chamber having a metal disk for shuttering can be
attached to the main chamber body and a robot arm can be used to
pick up the disk and to transfer it to the chamber for pasting or
cleaning of the target.
[0019] However, these prior art methods for cleaning targets or
pasting deposition chambers significantly reduce throughput because
they require significant non-productive down-time to transfer paste
wafers from another location into the chamber for pasting. Also, in
addition to the down time to transfer the metal disk to the pasting
or the cleaning position, the metal disk for shuttering can stress
the robot arm joints, thereby wearing out the robot arm
assembly.
[0020] Accordingly, a need remains for a new sputtering apparatus
that allows the use of a shutter and shutter arm assembly that do
not require long down time to transfer a wafer or a shutter disk
into the pasting or cleaning position, thereby improving the
throughput without problems noted above.
SUMMARY OF THE INVENTION
[0021] The present invention provides a new sputtering apparatus
that allow the use of a shutter disk and shutter arm assembly for
pasting in a two-tab blockout scheme, thereby improving
productivity and reducing waste of production wafers.
[0022] According to the present invention, physical vapor
deposition (PVD) system comprises
[0023] a chamber, an upper shield and a lower shield mounted within
the chamber, a cover ring having one or more tabs extending
radially inwardly therefrom. The PVD) system further includes a
shutter disk having one or more notched areas formed in the
periphery thereof to receive the one or more tabs of the cover
ring. The cover ring has two or more recesses formed in an upper
side thereof with a guide pin extending from the center of the
recesses. The lower shield has two or more cups with a hole therein
to be engaged with the guide pin of the cover ring to keep the
lower shield from rotating with respect to the cover ring. The cups
of the lower shield are inserted into the recesses of the cover
ring. A wafer pedestal is mounted within the chamber. Additionally,
the PVD system includes means for rotating the shutter disk to
place the shutter disk on the wafer pedestal; and means for
vertically adjusting the height of wafer pedestal.
[0024] With the shutter disk having notched areas and the modified
cover ring, the present invention allows use of the shutter disk
and shutter arm assembly without a clearance problem underneath the
lower shield and without a gluing problem in a tabbed alignment
block-out scheme. Thus, the present invention can be fully
automated and significantly improve productivity.
[0025] The foregoing and other objects, features and advantages of
the invention will become more readily apparent from the following
detailed description of a preferred embodiment of the invention
that proceeds with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is a schematic diagram of a conventional physical
vapor deposition (PVD) apparatus with a conventional shutter and
shutter assembly.
[0027] FIG. 2A is a perspective view of a cover ring and a lower
shield used in a conventional two-tabbed block-out scheme.
[0028] FIG. 2B is a cross-sectional view of a conventional cover
ring of FIG. 2A overlying alignment marks formed on a process
wafer.
[0029] FIG. 2C is a cross-sectional view of a conventional cover
ring taken in line 2C-2C of FIG. 2A.
[0030] FIG. 2D is a schematic diagram illustrating a clearance
problem underneath the lower shield in accordance with the prior
art.
[0031] FIG. 3 is a cross-sectional view illustrating gluing between
a conventional shutter disk and tabs from the conventional
two-tabbed block-out scheme.
[0032] FIG. 4 is a plan view of a shutter disk in accordance with
the present invention.
[0033] FIG. 5A is a top plan view of a cover ring in accordance
with the present invention with cups formed on an upper side of the
cover ring.
[0034] FIG. 5B is an inverted cross-sectional view taken along line
5B-5B of FIG. 5A.
[0035] FIG. 5C is a cross-sectional view taken along line 5C-5C of
FIG. 5A
[0036] FIG. 6A is a top plan view showing a lower shield in
accordance with one embodiment of the present invention.
[0037] FIG. 6B is a cross-sectional view taken along line 6B-6B of
FIG. 6A.
[0038] FIG. 6C is a schematic illustrating the concept of the
present invention to eliminate the clearance problem underneath the
lower shield of the prior art.
[0039] FIG. 7A is a plan view of the present invention illustrating
lateral movement of a shutter arm assembly to reposition the
shutter disk from an enclosure onto a wafer pedestal.
[0040] FIG. 7B is a cross-sectional view taken along lines 7B-7B in
FIG. 8A with the shutter disk in a pasting position.
[0041] FIG. 8A is a top view of a PVD chamber according to the
present invention with the shutter disk in a stored position.
[0042] FIG. 8B is a top view of a PVD chamber according to the
present invention with the shutter disk in the pasting
position.
DETAILED DESCRIPTION
[0043] In the following description, numerous specific details are
set forth to provide a thorough understanding of the present
invention. However, one having ordinary skill in the art should
recognize that the invention can be practiced without these
specific details. In some instances, well-known process steps,
device structures, and techniques have not been shown in detail to
avoid obscuring the present invention.
[0044] The invention can be implemented as a modification to a
conventional PVD system shown in FIG. 1, as shown in FIGS. 4 to 8B.
Common elements are indicated by the similar reference numerals. A
physical vapor deposition (PVD) system of the present invention
comprises a chamber 10', an upper shield 20' and a lower shield 48
mounted within the chamber 10', and a cover ring 42 having one or
more tabs 40 extending radially inwardly therefrom. The cover ring
42 includes two or more recesses 44 formed in an upper side thereof
with guide pins 45, 46 extending from the center of the recesses
44. The lower shield 48 has two or more cups 50 with a hole 51
therein to be engaged with the guide pins 45, 46 of the cover ring
42 to keep the lower shield 48 from rotating with respect to the
cover ring 42, the cups 50 of the lower shield 48 being inserted
into the recesses 44 of the cover ring 42.
[0045] Importantly, one or more notched areas 39 are formed in the
periphery of the shutter disk 36 to receive one or more tabs 40 of
the cover ring 42. Thus, with the features described above, the
cover ring 42 and the tabs 40, and the shutter disk 36 and notched
areas 39 can be fixed in angular registration.
[0046] As is known in the art, a wafer pedestal 14' is mounted
within the chamber 10' and the means 26' for rotating the shutter
disk is provided to place the shutter disk on the wafer pedestal.
Also, means 34 for vertically adjusting the height of wafer
pedestal is provided.
[0047] The preferred embodiment of the present invention comprises
a shutter disk 36 that is shown in FIG. 4 and FIG. 8B. As described
above, the shutter disk 36 includes notched areas 39 to solve the
problems of the prior art. FIGS. 5A-5C show a cover ring 42
according to one embodiment of the present invention. The cover
ring 42 has one or more tabs 40 extending radially inwardly
therefrom on the edge or periphery thereof in accordance with a
two-tabbed block-out scheme, as shown in FIGS. 8A-8B. The notched
areas 39 of the shutter disk 36 receive one or more tabs 40 of the
cover ring 42 to keep a lateral distance 43 between the tab 40 and
the shutter disk 36, when the shutter disk 36 is in a pasting
position as illustrated in FIG. 8B. Preferably, the distance 43 is
approximately 0.3 centimeters to approximately 0.8 centimeters
(approximately 0.1 inch to approximately 0.3 inches). Therefore,
the cover ring 42 including the one or more tabs 42 and the shutter
disk 36 do not contact each other but should be spaced sufficiently
apart to avoid gluing. Consequently, in the present invention,
because the sufficient distance is maintained between the cover
ring 42 and the shutter disk 36, an inadvertent gluing problem
between the shutter disk 36 and the tabs 40, shown in the prior
art, can be prevented.
[0048] The use of clamp ring is thus not recommended for the
purpose of the present invention because the clamp ring restrains
the wafer by clamping or contacting the wafer. Thus, it is not
suitable for a pasting process under two-tab block-out scheme,
where the cover ring having tabs and the shutter disk should not
contact each other.
[0049] Although the present invention is described and illustrated
with the cover ring 42 having two tabs 40 and the shutter disk 36
having two notched areas 39, the shutter disk 36 and the cover ring
42 could be further modified to allow for different orientations or
numbers of tabs on the cover ring 42.
[0050] For the reasons described above, with a shutter disk having
notched areas, one of the problems of the prior art, a gluing
problem between the tabs and the shutter disk, can be avoided.
Thus, the novel shutter disk design of the present invention allows
the shutter disk and shutter arm assembly to be used with a tabbed
alignment block-out scheme.
[0051] FIGS. 5A-5C and 6A-6C illustrate preferred embodiments of
the present invention to avoid the clearance problem underneath the
lower shield 18 indicated at 27 of FIG. 1, in which the shutter arm
assembly 26, particularly, shutter blade 32, would run into the
pins 38 extending down from the lower shield 18 if the shutter disk
24 were used with the two-tabbed block out scheme in conventional
apparatus.
[0052] As discussed above, the annular cover ring 42, shown in FIG.
5A, of the present invention includes one or more tabs 40 extending
radially inwardly therefrom. FIG. 5B is an upside-down
cross-sectional view taken along line 5B-5B of FIG. 5A to show the
tabs 40 of the cover ring 42 to protect alignment marks formed on a
semiconductor wafer in accordance with the two-tabbed block-out
scheme.
[0053] To further illustrate the present invention, FIG. 5C shows a
cross-sectional view taken along line 5C-5C of FIG. 5A. In
particular, the cover ring 42 includes two (or more) recesses 44 on
an upper side of the cover ring 42 with guide pins 45, 46 extending
from the center of the recesses 44. The recesses 44 are formed by a
cylindrical wall molded into ears on the periphery of the cover
ring 42. The recesses 44 are sized to receive cups 50. A suitable
diameter of recesses 44 is approximately 1.0 inch (2.5
centimeters). The guide pins 45, 46 are removably mounted, e.g.
screwed, into holes 41 of the cover ring 42. The lengths of the
guide pins 45, 46 are approximately 5.1 centimeters and 3.2
centimeters, respectively.
[0054] FIG. 6A shows a lower shield 48 in accordance with one
embodiment of the present invention. FIG. 6B is a cross-sectional
view of the lower shield 48 taken along line 6B-6B of FIG. 6A. The
lower shield 48 includes two or more annular cups 50 having a hole
51 to receive and engage the guide pins 45, 46 of the cover ring 42
in the recesses 44, as illustrated in FIG. 6C. This keeps the lower
shield 48 from rotating with respect to the cover ring 42. The cups
50 of the lower shield 48 are inserted into the recesses 44. (See
FIG. 7B) The height of cups 50 is sufficient so that the rotation
of the cover ring 42 with respect to the lower shield 48 can be
prevented. The depth 49 of the cover ring 42 is approximately 0.9
inches (2.5 centimeters). These features are important for
precisely aligning the tabs 42 and the alignment marks 37.
[0055] Importantly, as indicated in FIG. 6C, when the cover ring 42
is engaged with the lower shield 48, because the cover ring 42 has
recesses 44 on the upper side thereof and the guide pin 46 extends
from the bottom of the recesses 44, the pin 46 does not protrude
from the bottom of the lower shield 51 compared to the prior art
shown in FIGS. 2A, 2C and 2D. Thus, it is possible to give fall
clearance when an actuator arm attempts to place the shutter disk
36 into the pasting position. See FIG. 7B, which illustrates this
vertical clearance.
[0056] Positions of the guide pins 45, 46 and cups 50 can be
modified to allow for different orientations or numbers of tabs on
the cover ring 42. These may be necessary for alternate
implementations of the alignment scheme. Additional modifications
of the position and configuration of the cup 50 could be made and
still allow for shutter disk and shutter arm assembly operation
within the spirit and scope of the invention.
[0057] FIG. 7A illustrates the movement of a shutter arm assembly
to place the shutter disk 36 from an enclosure 30' onto a wafer
pedestal 14'. In detail, the shutter disk 36 rests on a shutter
blade 32' within the enclosure 30'. The shutter disk 36 is pivoted
(rotated) about pivot 80 into a process chamber 10', overlying the
wafer pedestal 14' as indicated in the dotted line (B
position).
[0058] As shown in FIG. 7B, the shutter blade 32' is attached to
the top of an actuator arm 25', forming a shutter arm assembly 26'.
As the lift hoop 67 rises, lift hoop fingers 65 pick up the shutter
disk 36 from the shutter blade 32' to raise the shutter disk 36 by
a wafer lift 34'. (65, 67 not shown in FIG. 7A, but shown in FIG.
7B) Finally, the wafer pedestal 14' and the shutter disk 36 are
raised to the pasting position shown in FIG. 7B and 8B. Once the
cleaning or pasting process has been completed, the shutter disk 36
is pivoted (rotated) back into the enclosure 30' using the shutter
blade 32'. This lateral travel must be below the lower shield/cover
ring assembly and above the wafer pedestal 14'.
[0059] As discussed, FIG. 7B shows a cross-sectional view of the
present invention PVD chamber with the shutter disk 36 in the
pasting position. Then, a pasting process is performed with the
shutter disk 36 on the pasting position. As a result, the metal
such as Ti for a glue layer--to secure the material layer such as
titanium nitride already deposited and to provide an adherent
surface for additional deposition--can be deposited onto the
exposed surface of the process chamber 10'. A target 12' can be
cleaned without contaminating the wafer pedestal 14'.
[0060] Referring to FIG. 8A, a top view of a present invention PVD
chamber 10' is shown with the shutter disk in a "stored" position.
At this time, the shutter disk 36 is housed in the enclosure 30'
until there is a signal to rotate the shutter disk 36 into the
process chamber 10' for a pasting process. Thus, the shutter disk
36 is not shown yet but the cover ring 42 with the tabs 40. In
addition, the lower shield 48 is engaged with the cover ring 42.
Also, the upper shield 20' is associated with the lower shield 48
to confine the ion bombardment to the target 12'.
[0061] FIG. 8B shows a top view of the PVD chamber 10' with the
shutter disk 36 in a "pasting" position corresponding to FIG. 7B.
As described above, the shutter disk 36 having notched areas 39 on
the periphery thereof is placed complementary to the tabs 40 of the
cover ring 42.
[0062] In conclusion, with the shutter disk 36 with notched areas
39 and the modified cover ring 42 with cups 50 formed on the upper
portion of the lower shield 48, the present invention allows use of
the shutter disk 36 and shutter arm assembly 26' without a
clearance problem underneath the lower shield 48 and without a
gluing problem in a tabbed alignment block-out scheme. Thus, the
present invention can be fully automated, as opposed to requiring
human intervention with the wafer-based pasting as in the prior
art.
[0063] Importantly, because the shutter disk 36 is located
immediately adjacent to the process chamber 10', the present
invention represents a highly productive method, when contrasted
with the prior art.
[0064] Although described in the context of sputtering apparatus,
the present invention can be applied to any type of physical vapor
deposition chamber using the tab block-out scheme described
above.
[0065] Having described and illustrated the principles of the
invention in a preferred embodiment thereof, it should be apparent
that the invention can be modified in arrangement and detail
without departing from such principles. We claim all modifications
and variation coming within the spirit and scope of the following
claims.
* * * * *