Patent EP0467623A2 successfully refreshed from Google Patents.
EP0467623A2
Expired / Lapsed
EP
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Apparatus for and method of protection during substrate processing
Assignee: Novellus Systems Inc
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Filing: 1991-07-15
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Granted: —
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Expires: 2011-07-15
Abstract
Abstract A suitable inert gas such as argon or a mixture of inert and reactive gases such as argon and hydrogen is introduced onto the backside of wafers being processed in a CVD reactor during the deposition of tungsten or other metals, metal nitrides and silicides, to avoid deposition of material on the backside of the wafers being processed. Each process station (4b,4c,4d) includes a gas dispersion head (12b,c,d) disposed over a platen (14b,c,d). A vacuum chuck including a number of radial and circular vacuum grooves in the top surface of the platen is provided for holding the wafer in place. A platen heater is provided under the platen. Backside gas is heated in and about the bottom of the platen, and introduced through a circular groove in the peripheral region outside of the outermost vacuum groove of the vacuum chuck. Backside gas pressure is maintained in this peripheral region at a level greater than the CVD chamber pressure. In this manner, backside gas vents from beneath the edge of the wafer on the platen and prevents the process gas from contacting the wafer backside. If the process gas is also to be prevented from contacting the periphery of the wafer frontside, a shroud is urged against the platen to direct the backside gas into a cavity formed between the shroud and the platen. This cavity contains the wafer frontside periphery, so that backside gas venting from between the shroud and the wafer frontside periphery excludes the process gas.
Inventors
- 👤 Everhardus P. Van Den Ven
- 👤 Eliot K. Broadbent
- 👤 Jeffrey C. Benzing
- 👤 Barry L. Chin
- 👤 Christopher W. Burkhart
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 02:31
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/44; C23C16/455; C23C16/45519; C23C16/45521; C23C16/04; C23C16/458; C23C16/4582; C23C16/4583; C23C16/4585; C23C16/4586; C23C16/54; H; H10; H10P; H10P72/00; H10P72/04; H10P72/0402; H10P72/0431; H10P72/0434; H10P72/70; H10P72/76; H10P72/7604; H10P72/7612; H10P72/7618; H10P72/7621; H10P72/78
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
83 words
An apparatus for supporting a substrate in a process chamber, comprising: a platen mounted on a pedestal base, a lower surface of the platen and an interior section of the pedestal base forming an enclosed volume for receiving a pressurized gas, and an upper surface of the platen having an interior region and a peripheral region, a gas groove being disposed in the peripheral region; and a gas line integral with the gas groove and extending through the platen to the enclosed volume.
Claim 2
Independent Claim
79 words
An apparatus for supporting a substrate in a process chamber, comprising: a platen mounted on a pedestal base and having a vacuum groove in an interior region of an upper surface of the platen, and a gas groove in a peripheral region of the platen upper surface; a vacuum line integral with the vacuum groove for providing a vacuum to the vacuum groove; and a gas line integral with the gas groove for providing gas to the gas groove.
Claim 3
Independent Claim
30 words
An apparatus as claimed in 2 wherein a lower surface of the platen and an interior section of the pedestal base form an enclosed volume for receiving a pressurized gas.
Claim 4
Dependent Claim
36 words
An apparatus as claimed in claim 1 or 3 wherein a heating element is mounted on the lower platen surface within the enclosed volume, and the pedestal base comprises a base plate covering the heating element.
Claim 5
Dependent Claim
45 words
An apparatus as claimed in claim 1, 3 or 4 wherein the pedestal base comprises a substantially hollow cylindrical pedestal, the interior thereof forming part of the enclosed volume and an end thereof having an orifice for introducing the pressurized gas into the enclosed volume.
Claim 6
Independent Claim
16 words
An apparatus as claimed in any preceding claim wherein the gas line extends through the platen.
Claim 7
Independent Claim
22 words
An apparatus as claimed in any preceding claim wherein the platen is substantially circular and the gas groove comprises an annular groove.
Claim 8
Dependent Claim
39 words
An apparatus as claimed in claim 6 wherein the gas groove is annular and the gas line comprises a plurality of bores originating at a lower surface of the platen and intersecting the gas groove at respective annular positions.
Claim 9
Dependent Claim
66 words
An apparatus as claimed in claim 1, 3, 4 or 5 wherein the gas line comprises a plurality of bores originating from a platen lower surface within a first surface section thereof, and wherein at least the first surface section of the platen lower surface forms the enclosed volume with the interior section of the pedestal base, the bores being in commnunication with the enclosed volume.
Claim 10
Dependent Claim
40 words
An apparatus as claimed in claim 1 wherein the platen has a vacuum groove in the interior region of the platen upper surface and a vacuum line integral with the vacuum groove for providing a vacuum to the vacuum groove.
Claim 11
Dependent Claim
23 words
An apparatus as claimed in claim 2, 10, or any claim dependent on claim 2 wherein the vacuum line extends through the platen.
Claim 12
Dependent Claim
27 words
An apparatus as claimed in claim 11 wherein the platen is substantially circular and the vacuum groove comprises a network of integrated radial and annular groove sections.
Claim 13
Dependent Claim
39 words
An apparatus as claimed in claim 11 wherein the vacuum line comprises a vertical bore through the platen, the annular groove sections of the vacuum groove emanating from an intersection of the vertical bore with the upper platen surface.
Claim 14
Dependent Claim
49 words
An apparatus as claimed in claim 13 comprising a tube connected at one end to the vertical bore at an intersection of the vertical bore with a lower surface of the platen, the tube having a vacuum fixture connected at the opposite end for connection to a vacuum system.
Claim 15
Independent Claim
33 words
An apparatus as claimed in any preceding claim wherein the pressurized gas consists of an inert gas, a mixture of inert gases, or a mixture of an inert gas with a reactant gas.
Claim 16
Independent Claim
110 words
An apparatus as claimed in any preceding claim comprising: a shield having a first surface region encircling a second surface region, the first surface region being adapted to contact a continuous first portion of the platen peripheral region, and the second surface region being adapted to define a cavity in conjunction with a second portion of the platen peripheral region when the first shield surface region is in contact with the first platen peripheral region portion, the cavity being adapted to enclose a backside peripheral region, the edge, and a frontside peripheral region of a substrate when mounted on the platen; and means for urging the shield against the platen.
Claim 17
Dependent Claim
46 words
An apparatus as claimed in claim 16 wherein the shield is an annular member having an annularly relieved inside bottom portion, and wherein the second surface region corresponds to the annularly relieved portion and the first surface region corresponds to the bottom of the annular member.
Claim 18
Dependent Claim
16 words
An apparatus as claimed in claim 17 wherein the annularly relieved portion is an annular step.
Claim 19
Dependent Claim
95 words
An apparatus as claimed in claim 7 comprising: an annular shield having a generally planar bottom surface adapted to contact a portion of the platen upper surface peripheral region, a portion of the projecting radially toward the center thereof and raised from the plane of the bottom surface and adapted to define in conjunction a portion of the platen upper surface peripheral region a cavity for enclosing a backside peripheral region, an edge, and a frontside peripheral region of the substrate when mounted on the platen; and means for urging the shroud against the platen.
Claim 20
Independent Claim
160 words
An apparatus for supporting a substrate for processing in a deposition chamber, comprising: a platen having a substrate retainer for retaining a substrate on the platen, the substrate retainer being ineffective for sealing a periphery of the backside of a substrate against a peripheral surface region of the platen; a gas dispenser disposed in the platen peripheral surface region for introducing a backside gas over the platen peripheral surface region; a shield having a bottom including an enclosing contact portion for contacting an enclosing contact portion of the platen peripheral surface region, and a closed relieved portion enclosed by the contact portion, a width of the relieved portion corresponding to a substrate frontside periphery and a depth of the relieved portion corresponding to a substrate thickness; and a positioner for selectively lowering the shield into engagement with the platen along the shield enclosing contact portion and the platen enclosing contact portion, and raising the shield from engagement with the platen.
Claim 21
Dependent Claim
24 words
An apparatus as claimed in claim 20 wherein the platen and the shield are annular and the shield relieved portion is an annular step.
Claim 22
Dependent Claim
79 words
An apparatus as claimed in claim 21 wherein the outside diameter of the shield exceeds the outside diameter of the platen, thereby forming an annular overhang, and wherein the positioner comprises a moveable plate having a semicircular cutout of a diameter greater than the platen outside diameter and less than the shield outside diameter, the shield, the platen, and the cutout being coaxial, and the plate being adapted to contact the shield overhang along the periphery of the cutout.
Claim 23
Independent Claim
19 words
An apparatus as claimed in any one of claims 16-22 comprising means for aligning the shield with the platen.
Claim 24
Dependent Claim
30 words
An apparatus as claimed in claim 23 wherein the alignment means comprises at least two pin-hole pairs associated with the shield bottom surface and the platen upper surface peripheral region.
Claim 25
Dependent Claim
28 words
An apparatus as claimed in claim 23 wherein the alignment means comprises a wedge-slot pair associated with the shield bottom surface and the platen upper surface peripheral region.
Claim 26
Dependent Claim
40 words
An apparatus as claimed in claim 23 wherein the alignment means comprises at least three flanges associated with the shield and extending beneath the bottom surface thereof, the flanges being adapted to engage progressively an outside edge of the platen.
Claim 27
Independent Claim
29 words
An apparatus as claimed in any preceding claim wherein the peripheral upper surface region of the platen is depressed relative to the interior upper surface region of the platen.
Claim 28
Independent Claim
93 words
A method of protecting the backside of a substrate disposed in a process chamber during processing, comprising the steps of: restraining the substrate; introducing a process gas comprising a mixture of a first reactant gas and a carrier gas at a preselected pressure into the process chamber; introducing a backside gas comprising a mixture of a second reactant gas and an inert gas to the periphery of the substrate backside; and maintaining a positive pressure differential between the pressure at the periphery of the substrate backside and the pressure in the process chamber.
Claim 29
Dependent Claim
36 words
A method as claimed in claim 27 wherein the substrate is disposed on a platen, and the substrate restraining step comprises the step of applying a vacuum to the backside of the substrate through the platen.
Claim 30
Dependent Claim
55 words
A method as claimed in claim 28 or 29 comprising the steps of: directing the backside gas through a cavity adapted to contain the periphery of the substrate backside, the edge of the substrate, and the periphery of the substrate frontside; and maintaining a positive pressure differential from within the cavity to the process chamber.
Claim 31
Dependent Claim
24 words
A method as claimed in claim 28, 29 or 30 wherein the carrier gas and the inert gas are the same type of gas.
Claim 32
Dependent Claim
20 words
A method as claimed in claim 28, 29, 30 or 31 wherein the inert gas is also a thermal gas.
Claim 33
Independent Claim
155 words
A method as claimed in any of claims 28-32 wherein the process gas comprises a mixture of a product reactant, the first reactant gas, and the carrier gas optimized for a desired result at the centre of the substrate, wherein the first and second reactant gases are the same type of gas, and wherein the backside gas introducing step comprises the steps of: initially setting the proportion of the second reactant gas to the inert gas in the backside gas to be substantially equal to the proportion of the first reactant gas to the carrier gas in the process gas; introducing varying proportions of the second reactant gas to the inert gas in the backside gas while monitoring deposition uniformity across a plurality of test wafers; and selecting one of the varying proportions of the second reactant gas to the inert gas in the backside gas that yields good deposition uniformity across a test wafer.
Claim 34
Independent Claim
35 words
A method as claimed in any one of claims 28-32 wherein: the process gas comprises a product reactant WF₆, and a reactant gas of hydrogen; and the backside gas comprises a reactant gas of hydrogen.
Claim 35
Independent Claim
27 words
A method as claimed in any one of claims 28-34 wherein the carrier gas and the inert gas are argon or a mixture of argon and nitrogen.
Claim 36
Independent Claim
25 words
A method as claimed in any one of claims 28-34 wherein the inert gas is argon, nitrogen, helium, freon, C₂F₆, CF₄, or any combination thereof.
References Cited (Backward Citations)
No citation records indexed.
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