Patent US5691846A successfully refreshed from Google Patents.
US6179983B1
Expired / Lapsed
US
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Method and apparatus for treating surface including virtual anode
Assignee: Novellus Systems Inc
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Filing: 1997-11-13
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Granted: 2001-01-30
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Expires: 2017-11-13
Abstract
Abstract An apparatus for depositing an electrical conductive layer on the surface of a wafer includes a virtual anode located between the actual anode and the wafer. The virtual anode modifies the electric current flux and plating solution flow between the actual anode and the wafer to thereby modify the thickness profile of the deposited electrically conductive layer on the wafer. The virtual anode can have openings through which the electrical current flux passes. By selectively varying the radius, length, or both, of the openings, any desired thickness profile of the deposited electrically conductive layer on the wafer can be readily obtained.
Inventors
- 👤 Jonathan David Reid
- 👤 Steve Taatjes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:18
CPC Classifications
C; C25; C25D; C25D7/00; C25D7/12; C25D7/123; C25D17/00; C25D17/001; C25D17/007; C25D17/10; C25D17/12; Y; Y10; Y10S; Y10S204/00; Y10S204/07
Claims Analysis
Total Claims: 40
Claim 1
Independent Claim
57 words
An apparatus for treating the surface of a substrate comprising: a clamshell for holding said substrate; a plating bath having a wall section; a virtual anode having a periphery secured to said wall section, said virtual anode having at least one opening therein; and an anode, said virtual anode being located between said clamshell and said anode.
Claim 2
Independent Claim
57 words
An apparatus for treating the surface of a substrate comprising: a clamshell for holding said substrate; a plating bath having a wall section; a virtual anode having a periphery secured to said wall section, said virtual anode having at least one opening therein; and an anode, said virtual anode being located between said clamshell and said anode.
Claim 3
Dependent Claim
15 words
The apparatus of claim 1 wherein said virtual anode has a plurality of openings therein.
Claim 4
Dependent Claim
28 words
The apparatus of claim 2 wherein at least one of said plurality of openings has a different length than at least one other of said plurality of openings.
Claim 5
Dependent Claim
28 words
The apparatus of claim 2 wherein at least one of said plurality of openings has a different radius than at least one other of said plurality of openings.
Claim 6
Dependent Claim
32 words
The apparatus of claim 2 wherein at least one of said plurality of openings has a different radius and a different length than at least one other of said plurality of openings.
Claim 7
Dependent Claim
13 words
The apparatus of claim 1 wherein said virtual anode has a contoured cross-section.
Claim 8
Dependent Claim
13 words
The apparatus of claim 1 wherein said virtual anode has a stepped cross-section.
Claim 9
Dependent Claim
31 words
The apparatus of claim 1 further comprising a plating solution, wherein said plating solution flows in said plating bath from said anode to said clamshell through said at least one opening.
Claim 10
Dependent Claim
25 words
The apparatus of claim 8 further comprising a power supply for generating an electric current flux between said surface of said substrate and said anode.
Claim 11
Dependent Claim
15 words
The apparatus of claim 9 wherein said electric current flux passes through said virtual anode.
Claim 12
Dependent Claim
53 words
The apparatus of claim 10 wherein said virtual anode has a plurality of openings therein, a first opening of said plurality of openings having a greater length than a second opening of said plurality of openings, said first opening having a greater electrical resistance to said electric current flux than said second opening.
Claim 13
Dependent Claim
24 words
The apparatus of claim 11 wherein a greater percentage of said electric current flux passes through said second opening than through said first opening.
Claim 14
Dependent Claim
53 words
The apparatus of claim 10 wherein said virtual anode has a plurality of openings therein, a first opening of said plurality of openings having a greater radius than a second opening of said plurality of openings, said second opening having a greater electrical resistance to said electric current flux than said first opening.
Claim 15
Dependent Claim
24 words
The apparatus of claim 13 wherein a greater percentage of said electric current flux passes through said first opening than through said second opening.
Claim 16
Dependent Claim
14 words
The apparatus of claim 1 wherein said virtual anode comprises an electrically insulating material.
Claim 17
Independent Claim
89 words
A method of treating a surface of a substrate comprising the steps of: providing a clamshell, an anode, a virtual anode, and a plating bath containing a plating solution; mounting said substrate in said clamshell; placing said clamshell and said substrate in said plating solution; and generating an electric current flux between said surface of said substrate and said anode, wherein said electric current flux passes through said virtual anode, said virtual anode shaping said electric current flux according to a distance between said virtual anode and said substrate.
Claim 18
Independent Claim
89 words
A method of treating a surface of a substrate comprising the steps of: providing a clamshell, an anode, a virtual anode, and a plating bath containing a plating solution; mounting said substrate in said clamshell; placing said clamshell and said substrate in said plating solution; and generating an electric current flux between said surface of said substrate and said anode, wherein said electric current flux passes through said virtual anode, said virtual anode shaping said electric current flux according to a distance between said virtual anode and said substrate.
Claim 19
Dependent Claim
32 words
The method of claim 16 wherein said virtual anode has a plurality of openings therein, wherein said electric current flux passes through said plurality of openings and thereby through said virtual anode.
Claim 20
Dependent Claim
46 words
The method of claim 17 wherein a first opening of said plurality of openings has a greater cross-sectional area than a second opening of said plurality of openings, a greater percentage of said electric current flux passing through said first opening than through said second opening.
Claim 21
Dependent Claim
44 words
The method of claim 18 wherein said first opening and said second opening are cylindrical, the electric current flux through said first opening and said second opening being directly proportional to the square of the radius of said first opening and said second opening.
Claim 22
Dependent Claim
40 words
The method of claim 19 further comprising the step of generating a flow of said plating solution through said virtual anode, wherein a greater percentage of said plating solution flow passes through said first opening than through said second opening.
Claim 23
Dependent Claim
35 words
The method of claim 20 wherein the plating solution flow through said first opening and said second opening is directly proportional to the cube of the radius of said first opening and said second opening.
Claim 24
Dependent Claim
37 words
The method of claim 21 wherein the difference in plating solution flow through said first opening and said second opening is non-linear to the difference in electric current flux through said first opening and said second opening.
Claim 25
Dependent Claim
37 words
The method of claim 22 wherein the difference in plating solution flow through said first opening and said second opening is greater than a difference in electric current flux through said first opening and said second opening.
Claim 26
Independent Claim
127 words
A method of treating a surface of a substrate comprising: providing a clamshell an anode a virtual anode having a plurality of openings therein, a first opening of said plurality of openings having a greater length than a second opening of said plurality of openings, and a plating bath containing a plating solution; mounting said substrate in said clamshell; placing said clamshell and said substrate in said plating solution; and generating an electric current flux between said surface of said substrate and said anode, wherein said electric current flux passes through said plurality of openings and thereby through said virtual anode, a greater percentage of said electric current flux passing through said second opening than through said first opening, said virtual anode shaping said electric current flux.
Claim 27
Independent Claim
127 words
A method of treating a surface of a substrate comprising: providing a clamshell an anode a virtual anode having a plurality of openings therein, a first opening of said plurality of openings having a greater length than a second opening of said plurality of openings, and a plating bath containing a plating solution; mounting said substrate in said clamshell; placing said clamshell and said substrate in said plating solution; and generating an electric current flux between said surface of said substrate and said anode, wherein said electric current flux passes through said plurality of openings and thereby through said virtual anode, a greater percentage of said electric current flux passing through said second opening than through said first opening, said virtual anode shaping said electric current flux.
Claim 28
Dependent Claim
32 words
The method of claim 24 wherein the electric current flux through said first opening and said second opening is inversely proportional to the length of said first opening and said second opening.
Claim 29
Dependent Claim
40 words
The method of claim 24 further comprising the step of generating a flow of said plating solution through said virtual anode, wherein a greater percentage of said plating solution flow passes through said second opening than through said first opening.
Claim 30
Dependent Claim
32 words
The method of claim 26 wherein the plating solution flow through said first opening and said second opening is inversely proportional to the length of said first opening and said second opening.
Claim 31
Dependent Claim
37 words
The method of claim 26 wherein the difference in plating solution flow through said first opening and said second opening is linear to the difference in electric current flux through said first opening and said second opening.
Claim 32
Independent Claim
125 words
A method of electroplating a metallic layer on a substrate comprising: immersing said substrate in an electroplating solution; immersing an anode in said solution; applying a positive voltage to said anode and a negative voltage to said substrate; interposing a virtual anode in said electroplating solution between said anode and said substrate, said virtual anode comprising at least a first opening and a second opening; and causing said first opening to have a first width and a first length and said second opening to have a second width and a second length so as to produce a particular thickness profile of said metallic layer, said thickness profile being determined at least in part by said first and second widths and said first and second lengths.
Claim 33
Independent Claim
125 words
A method of electroplating a metallic layer on a substrate comprising: immersing said substrate in an electroplating solution; immersing an anode in said solution; applying a positive voltage to said anode and a negative voltage to said substrate; interposing a virtual anode in said electroplating solution between said anode and said substrate, said virtual anode comprising at least a first opening and a second opening; and causing said first opening to have a first width and a first length and said second opening to have a second width and a second length so as to produce a particular thickness profile of said metallic layer, said thickness profile being determined at least in part by said first and second widths and said first and second lengths.
Claim 34
Dependent Claim
28 words
The method of claim 29 comprising creating a flow of said electroplating solution through said first and second openings in a direction from said anode to said substrate.
Claim 35
Dependent Claim
89 words
An electroplating system for semiconductor wafers comprising: a power supply having a negative terminal and a positive terminal; a semiconductor wafer electrically connected to the negative terminal; a plating bath holding a plating solution; an anode positioned in the plating solution and electrically connected to the positive terminal; a nonconductive virtual anode positioned in the plating solution between the anode and the wafer, the virtual anode being in the form of an annulus having a central aperture with a diameter that is less than a diameter of the anode.
Claim 36
Dependent Claim
89 words
An electroplating system for semiconductor wafers comprising: a power supply having a negative terminal and a positive terminal; a semiconductor wafer electrically connected to the negative terminal; a plating bath holding a plating solution; an anode positioned in the plating solution and electrically connected to the positive terminal; a nonconductive virtual anode positioned in the plating solution between the anode and the wafer, the virtual anode being in the form of an annulus having a central aperture with a diameter that is less than a diameter of the anode.
Claim 37
Dependent Claim
21 words
The electroplating system of claim 31 wherein the diameter of the central aperture is less than a diameter of the wafer.
Claim 38
Independent Claim
96 words
A method of electroplating a layer of metal on a semiconductor wafer comprising: immersing the wafer in a plating solution; immersing an anode in the plating solution; applying a negative voltage to the wafer and applying a positive voltage to the anode; and positioning a virtual anode between the anode and the wafer, the virtual anode being in the form of an annulus having a central aperture with a diameter less than a diameter of the wafer such that the virtual anode functions to limit a flow of current to an edge region of the wafer.
Claim 39
Independent Claim
96 words
A method of electroplating a layer of metal on a semiconductor wafer comprising: immersing the wafer in a plating solution; immersing an anode in the plating solution; applying a negative voltage to the wafer and applying a positive voltage to the anode; and positioning a virtual anode between the anode and the wafer, the virtual anode being in the form of an annulus having a central aperture with a diameter less than a diameter of the wafer such that the virtual anode functions to limit a flow of current to an edge region of the wafer.
Claim 40
Dependent Claim
24 words
The method of claim 33 wherein the diameter of the central aperture of the virtual anode is less than a diameter of the anode.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-01-30 | 2004-07-31 | 2005-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-01-30 | 2008-07-31 | 2009-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-01-30 | 2012-07-31 | 2013-01-30 | $7700.00 | Window Closed / Lapsed |