US5851299A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Passive shield for CVD wafer processing which provides frontside edge exclusion and prevents backside depositions
Assignee: Applied Materials Inc
•
Filing: 1994-03-25
•
Granted: 1998-12-22
•
Expires: 2014-03-25
Abstract
Abstract An improved apparatus for CVD processing is described wherein a wafer mounted on a vertically movable susceptor beneath a gas outlet or showerhead is raised into contact with a shield ring which normally rests on a ring support in the chamber. The shield ring engages the frontside edge of the wafer, lifting the shield ring off its support, when the susceptor and the wafer are raised to a deposition position in the chamber. The shield ring, by engaging the frontside edge of the wafer, shields the edge of the top surface of the wafer, as well as the end edge and the backside of the wafer, during the deposition. Matching tapered edges, respectively, on the susceptor and the shield ring permit alignment of the shield ring with respect to the susceptor, and alignment of the wafer to the susceptor and the shield ring. Alignment means are also disclosed to circularly align the shield ring to its support in the chamber. Multi-unit shield rings permit the use of wider shield rings and prevent cracking of the shield ring due to thermal stresses caused by temperature differences near and away from the wafer during processing. These shield rings may also have tapered edges to ensure alignment of the rings with respect to each other.
Inventors
- 👤 David Cheng
- 👤 Mei Chang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:23
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/44; C23C16/455; C23C16/45519; C23C16/45521; H; H10; H10P; H10P14/00; H10P14/40; C23C16/04; C23C16/042; C23C16/458; C23C16/4582; C23C16/4583; C23C16/4585
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
80 words
In a vacuum processing system, apparatus for shielding a portion of a workpiece that is supported within the system comprising: a workpiece support having a top surface for supporting the workpiece within the system; a shield for engaging a portion of said workpiece and for preventing deposition of materials upon said engaged portion of said workpiece; and a movable shaft, connected to said workpiece support, for moving said workpiece support to engage said portion of said workpiece with said shield.
Claim 2
Dependent Claim
80 words
In a vacuum processing system, apparatus for shielding a portion of a workpiece that is supported within the system comprising: a workpiece support having a top surface for supporting the workpiece within the system; a shield for engaging a portion of said workpiece and for preventing deposition of materials upon said engaged portion of said workpiece; and a movable shaft, connected to said workpiece support, for moving said workpiece support to engage said portion of said workpiece with said shield.
Claim 3
Dependent Claim
26 words
The apparatus of claim 1 wherein said workpiece support further comprises an outer edge that is inwardly tapered from a bottom surface to said top surface.
Claim 4
Dependent Claim
42 words
The apparatus of claim 2 wherein said shield further comprises: an inner edge that is outwardly tapered from a top surface to a bottom surface; and a lip extending inwardly from said inner edge to engage a top edge of said workpiece.
Claim 5
Dependent Claim
60 words
The apparatus of claim 3 wherein said tapered edge of said workpiece support is of a smaller dimension than said tapered inner edge of said shield and of like angle, whereby said shield may be moved into alignment with said workpiece support by contact between said respective tapered edges as said workpiece is moved into a engagement with said shield.
Claim 6
Dependent Claim
27 words
The apparatus of claim 4 wherein top surface of said workpiece support is circular and has a diameter that is about the same diameter as the workpiece.
Claim 7
Dependent Claim
13 words
The apparatus of claim 5 wherein said shield has an annular plan form.
Claim 8
Dependent Claim
45 words
The apparatus of claim 1 wherein said shield is supported proximate said workpiece support by a shield support such that said shield and said portion of said workpiece that engages said shield are spaced apart when said movable shaft disengages the workpiece from said shield.
Claim 9
Dependent Claim
25 words
The apparatus of claim 7 further comprising alignment means, connected to said shield and said shield support, for aligning said shield with the shield support.
Claim 10
Dependent Claim
36 words
The apparatus of claim 8 wherein said alignment means comprises a slot attached to a bottom surface of said shield and a pin, for engaging said slot, attached to an upper surface of said shield support.
Claim 11
Dependent Claim
54 words
The apparatus of claim 7 wherein said shield has a tapered outer edge that corresponds to a tapered inner edge of said shield support such that when the shield is engaged by said workpiece and disengaged from said shield support the corresponding tapered edges of said shield and said shield support form a passageway.
Claim 12
Dependent Claim
13 words
The apparatus of claim 1 wherein said shield further comprises a plurality units.
Claim 13
Dependent Claim
36 words
The apparatus of claim 1 wherein said shield comprises two units, an inner unit adjacent to said workpiece support, and an outer unit having an inner edge that engages an outer edge of said inner unit.
Claim 14
Dependent Claim
71 words
The apparatus of claim 12 wherein said workpiece support further comprises an outer edge that is inwardly tapered from a bottom surface to said top surface and said inner edge of said inner unit further comprises an inner edge that is outwardly tapered from a top surface to a bottom surface at an angle that is substantially similar to an angle of taper of said outer edge of said workpiece support.
Claim 15
Dependent Claim
29 words
The apparatus of claim 13 wherein said inner unit of said shield contains a lip extending inwardly from said inner edge to engage a top edge of said workpiece.
Claim 16
Dependent Claim
29 words
The apparatus of claim 13 wherein said outer edge of said inner unit is tapered to match an angle of taper of said inner edge of said outer unit.
Claim 17
Dependent Claim
19 words
The apparatus of claim 12 wherein said outer unit is supported proximate said inner unit by a shield support.
Claim 18
Dependent Claim
15 words
The apparatus of claim 12 wherein said inner and outer units have annular plan forms.
Claim 19
Dependent Claim
195 words
A vacuum deposition apparatus for processing a semiconductor wafer which comprises: a vacuum deposition chamber; a susceptor in said chamber for supporting said semiconductor wafer, said susceptor having an outer edge extending from a bottom surface to a top surface; a process gas inlet located in said vacuum deposition chamber above the top surface of the susceptor; a non-reactive gas inlet for providing a non-reactive gas to a space within said chamber that is below said top surface of said susceptor; and a shield mounted in said chamber engagable by a front side edge of said semiconductor wafer to shield said front side edge of said semiconductor wafer during processing to prevent deposition on said front side edge of said semiconductor wafer, said shield having an inner edge extending from the bottom surface of said shield to the bottom surface of a lip on said shield, wherein said lip extends inwardly to engage the front side edge of said semiconductor wafer and said inner edge of said shield and said outer edge of said susceptor define a cavity, coupled to said space, for retaining said non-reactive gas proximate a circumferencial edge of the semiconductor wafer.
Claim 20
Dependent Claim
195 words
A vacuum deposition apparatus for processing a semiconductor wafer which comprises: a vacuum deposition chamber; a susceptor in said chamber for supporting said semiconductor wafer, said susceptor having an outer edge extending from a bottom surface to a top surface; a process gas inlet located in said vacuum deposition chamber above the top surface of the susceptor; a non-reactive gas inlet for providing a non-reactive gas to a space within said chamber that is below said top surface of said susceptor; and a shield mounted in said chamber engagable by a front side edge of said semiconductor wafer to shield said front side edge of said semiconductor wafer during processing to prevent deposition on said front side edge of said semiconductor wafer, said shield having an inner edge extending from the bottom surface of said shield to the bottom surface of a lip on said shield, wherein said lip extends inwardly to engage the front side edge of said semiconductor wafer and said inner edge of said shield and said outer edge of said susceptor define a cavity, coupled to said space, for retaining said non-reactive gas proximate a circumferencial edge of the semiconductor wafer.
Claim 21
Dependent Claim
23 words
The apparatus of claim 18 wherein said outer edge of said susceptor is inwardly tapered from said bottom surface to said top surface.
Claim 22
Dependent Claim
23 words
The apparatus of claim 19 wherein said inner edge of said shield is outwardly tapered from a top surface to a bottom surface.
Claim 23
Dependent Claim
59 words
The apparatus of claim 20 wherein said tapered edge of said susceptor is of a smaller dimension than said tapered inner edge of said shield and of like angle, whereby said shield may be moved into alignment with said susceptor by contact between said respective tapered edges as said semiconductor wafer is moved into a engagement with said shield.
Claim 24
Dependent Claim
28 words
The apparatus of claim 21 wherein said top surface of said susceptor is circular and has a diameter that is about the same diameter as the semiconductor wafer.
Claim 25
Dependent Claim
13 words
The apparatus of claim 22 wherein said shield has an annular plan form.
Claim 26
Dependent Claim
64 words
The apparatus of claim 18 wherein said shield is supported proximate said susceptor by a shield support and said susceptor is coupled to a moveable shaft that moves said susceptor vertically to engage said shield, such that said shield and said portion of said semiconductor wafer that engages said shield are spaced apart when a movable shaft disengages the semiconductor wafer from said shield.
Claim 27
Dependent Claim
25 words
The apparatus of claim 24 further comprising alignment means, connected to said shield and said shield support, for aligning said shield with the shield support.
Claim 28
Dependent Claim
36 words
The apparatus of claim 25 wherein said alignment means comprises a slot attached to a bottom surface of said shield and a pin, for engaging said slot, attached to an upper surface of said shield support.
Claim 29
Dependent Claim
55 words
The apparatus of claim 24 wherein said shield has a tapered outer edge that corresponds to a tapered inner edge of said shield support such that when the shield is engaged by said semiconductor wafer and disengaged from said shield support the corresponding tapered edges of said shield and said shield support form said cavity.
Claim 30
Dependent Claim
13 words
The apparatus of claim 18 wherein said shield further comprises a plurality units.
Claim 31
Dependent Claim
35 words
The apparatus of claim 28 wherein said shield comprises two units, an inner unit adjacent to said susceptor, and an outer unit having an inner edge that engages an outer edge of said inner unit.
Claim 32
Dependent Claim
67 words
The apparatus of claim 29 wherein said outer edge of said susceptor is inwardly tapered from said bottom surface to said top surface and said inner edge of said inner unit further comprises an inner edge that is outwardly tapered from a top surface to a bottom surface at an angle that is substantially similar to an angle of taper of said outer edge of said susceptor.
Claim 33
Dependent Claim
30 words
The apparatus of claim 30 wherein said inner unit of said shield contains a lip extending inwardly from said inner edge to engage a top edge of said semiconductor wafer.
Claim 34
Dependent Claim
29 words
The apparatus of claim 30 wherein said outer edge of said inner unit is tapered to match an angle of taper of said inner edge of said outer unit.
Claim 35
Dependent Claim
19 words
The apparatus of claim 29 wherein said outer unit is supported proximate said inner unit by a shield support.
Claim 36
Dependent Claim
15 words
The apparatus of claim 29 wherein said inner and outer units have annular plan forms.
References Cited (Backward Citations)
GB2196019A
Cited
US4842683A
Cited
US4951601A
Cited
US4963713A
Cited
US5262029A
Cited
US4962727A
Cited
US5033407A
Cited
EP0383491A2
Cited
US4978412A
Cited
US4932358A
Cited
JPH0313577A
Cited
US4963393A
Cited
US4990374A
Cited
EP0434227A1
Cited
US5013400A
Cited
EP0448346A1
Cited
EP0467623A2
Cited
US5230741A
Cited
US5238499A
Cited
US5374594A
Cited
US5620525A
Cited
US5304248A
Cited
EP0606751A1
Cited
EP0619381A1
Cited
JP3013577U
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-12-21 | 2002-06-22 | 2002-12-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-12-21 | 2006-06-22 | 2006-12-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-12-21 | 2010-06-22 | 2010-12-22 | $7700.00 | Window Closed / Lapsed |