US5880015A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing stepped wall interconnects and gates
Assignee: STMicroelectronics lnc USA
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Filing: 1994-10-14
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Granted: 1999-03-09
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Expires: 2014-10-14
Abstract
Abstract A method is provided for making conductive structures whereby an insulating layer is formed over a substrate. A conductive layer is then formed over the insulating layer. A first photoresist layer is formed over the conductive layer, patterned and developed. The conductive layer is etched after which the first photoresist layer is removed. A second photoresist layer is formed over the integrated circuit, patterned and developed. The remaining regions of the conductive layer forming an interconnect or a gate are partially etched to form two-tiered stepped sidewalls.
Inventors
- 👤 William Y. Hata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:55
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/0223; H10D30/0227; H10P; H10P50/00; H10P50/71; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/062
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
106 words
A method of producing a conductive structure of a semiconductor integrated circuit having stepped walls, comprising the steps of: forming an insulating layer over a substrate; forming a conductive layer over the insulating layer; forming a first photoresist layer over the conductive layer; patterning the first photoresist layer; etching the conductive layer to completely remove portions not covered by the patterned first photoresist layer and to form a remaining conductive layer; forming a second photoresist layer over the remaining conductive layer and the insulating layer; patterning the second photoresist layer; partially etching the remaining conductive layer to form a step; and, removing the second photoresist layer.
Claim 2
Independent Claim
106 words
A method of producing a conductive structure of a semiconductor integrated circuit having stepped walls, comprising the steps of: forming an insulating layer over a substrate; forming a conductive layer over the insulating layer; forming a first photoresist layer over the conductive layer; patterning the first photoresist layer; etching the conductive layer to completely remove portions not covered by the patterned first photoresist layer and to form a remaining conductive layer; forming a second photoresist layer over the remaining conductive layer and the insulating layer; patterning the second photoresist layer; partially etching the remaining conductive layer to form a step; and, removing the second photoresist layer.
Claim 3
Dependent Claim
20 words
The method of claim 1, wherein the step of etching the conductive layer to completely remove portions forms an interconnect.
Claim 4
Dependent Claim
20 words
The method of claim 1, wherein the step of etching the conductive layer to completely remove portions forms a gate.
Claim 5
Dependent Claim
40 words
The method of claim 3, wherein the substrate is heavily doped after removing the first photoresist layer step to form a first source/drain region and lightly doped after removing the second photoresist layer step to form a second source/drain region.
Claim 6
Dependent Claim
11 words
The method of claim 4, wherein the dopants are N-type dopants.
Claim 7
Dependent Claim
11 words
The method of claim 4, wherein the dopants are P-type dopants.
Claim 8
Dependent Claim
35 words
The method of claim 3, further comprising the step of implanting a dopant after the second etching step to form a heavily doped first source/drain region and a lightly doped source/drain region under the step.
Claim 9
Dependent Claim
12 words
The method of claim 7, wherein the dopant is a N-type dopants.
Claim 10
Dependent Claim
12 words
The method of claim 7, wherein the dopant is a P-type dopants.
Claim 11
Dependent Claim
23 words
The method of claim 1, wherein the thickness of the first photoresist layer is thinner than the thickness of the second photoresist layer.
Claim 12
Dependent Claim
23 words
The method of claim 2, wherein the thickness of the first photoresist layer is thinner than the thickness of the second photoresist layer.
Claim 13
Dependent Claim
23 words
The method of claim 1, wherein the pattern of the second photoresist layer is smaller than the pattern of the first photoresist layer.
Claim 14
Independent Claim
66 words
A method of producing a conductive structure of a semiconductor integrated circuit having stepped sidewalls, comprising the steps of: forming an insulating layer over a substrate; forming a conductive layer over the insulating layer; completely removing portions of the conductive layer to form a remaining conductive layer; and partially etching regions on the remaining conductive layer so that the remaining conductive layer has two-tiered stepped sidewalls.
Claim 15
Independent Claim
66 words
A method of producing a conductive structure of a semiconductor integrated circuit having stepped sidewalls, comprising the steps of: forming an insulating layer over a substrate; forming a conductive layer over the insulating layer; completely removing portions of the conductive layer to form a remaining conductive layer; and partially etching regions on the remaining conductive layer so that the remaining conductive layer has two-tiered stepped sidewalls.
Claim 16
Dependent Claim
19 words
The method of claim 13, wherein the step of completely removing portions of the conductive layer forms an interconnect.
Claim 17
Dependent Claim
19 words
The method of claim 13, wherein the step of completely removing portions of the conductive layer forms a gate.
Claim 18
Dependent Claim
23 words
The method of claim 15, further comprising the step of forming a source/drain region in the substrate under the step of the gate.
Claim 19
Independent Claim
130 words
A method of producing a conductive structure of a semiconductor integrated circuit having stepped sidewalls, comprising the steps of: forming an insulating layer over a substrate; forming a conductive layer over the insulating layer; forming and patterning a first photoresist layer over the conductive layer; etching the conductive layer to completely remove portions not covered by the patterned first photoresist layer and to form a remaining conductive layer; removing the first photoresist layer; forming and patterning a second photoresist layer over the remaining conductive layer; etching partway through the remaining conductive layer; removing the second photoresist layer; forming sidewall oxide spacers in regions of the conductive layer where the conductive layer was etched partway through; and etching portions of the remaining conductive layer not covered by the sidewall oxide spacers.
Claim 20
Independent Claim
130 words
A method of producing a conductive structure of a semiconductor integrated circuit having stepped sidewalls, comprising the steps of: forming an insulating layer over a substrate; forming a conductive layer over the insulating layer; forming and patterning a first photoresist layer over the conductive layer; etching the conductive layer to completely remove portions not covered by the patterned first photoresist layer and to form a remaining conductive layer; removing the first photoresist layer; forming and patterning a second photoresist layer over the remaining conductive layer; etching partway through the remaining conductive layer; removing the second photoresist layer; forming sidewall oxide spacers in regions of the conductive layer where the conductive layer was etched partway through; and etching portions of the remaining conductive layer not covered by the sidewall oxide spacers.
Claim 21
Dependent Claim
20 words
The method of claim 17, wherein the step of etching part way through the remaining conductive layer forms an interconnect.
Claim 22
Dependent Claim
20 words
The method of claim 17, wherein the step of etching part way through the remaining conductive layer forms a gate.
Claim 23
Dependent Claim
33 words
The method of claim 19, further comprising the steps of: lightly doping the substrate after removing the photoresist layer; heavily doping the substrate after etching the exposed region of the remaining conductive layer.
Claim 24
Dependent Claim
18 words
The method of claim 20, wherein the sidewall oxide spacers are removed after the substrate is heavily doped.
Claim 25
Independent Claim
154 words
A method of producing a conductive structure having stepped walls in a semiconductor integrated circuit, comprising: forming an insulating layer over a substrate; forming a conductive layer over the insulating layer; forming a first photoresist layer over the conductive layer; patterning the first photoresist layer to leave a first photoresist region over the conductive layer; etching the conductive layer to completely remove portions of the conductive layer not covered by the first photoresist region and to form a remaining conductive layer; removing the first photoresist region; forming a second photoresist layer over the remaining conductive layer and the insulating layer; patterning the second photoresist layer to form a second photoresist region located only over the remaining conductive layer, the second photoresist region being smaller than the first photoresist region; partially etching portions of the remaining conductive layer not covered by the second photoresist region to form a step; and removing the second photoresist region.
Claim 26
Independent Claim
154 words
A method of producing a conductive structure having stepped walls in a semiconductor integrated circuit, comprising: forming an insulating layer over a substrate; forming a conductive layer over the insulating layer; forming a first photoresist layer over the conductive layer; patterning the first photoresist layer to leave a first photoresist region over the conductive layer; etching the conductive layer to completely remove portions of the conductive layer not covered by the first photoresist region and to form a remaining conductive layer; removing the first photoresist region; forming a second photoresist layer over the remaining conductive layer and the insulating layer; patterning the second photoresist layer to form a second photoresist region located only over the remaining conductive layer, the second photoresist region being smaller than the first photoresist region; partially etching portions of the remaining conductive layer not covered by the second photoresist region to form a step; and removing the second photoresist region.
Claim 27
Dependent Claim
23 words
The method of claim 22, wherein the thickness of the first photoresist layer is thinner that the thickness of the second photoresist layer.
Claim 28
Dependent Claim
20 words
The method of claim 22, wherein the step of partially etching portions of the remaining conductive layer forms an interconnect.
Claim 29
Dependent Claim
20 words
The method of claim 22, wherein the step of partially etching portions of the remaining conductive layer forms a gate.
Claim 30
Dependent Claim
40 words
The method of claim 25, wherein the substrate is heavily doped after removing the remaining first photoresist region to form a first source/drain region and lightly doped after removing the remaining second photoresist region to form a second source/drain region.
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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) | 2002-03-08 | 2002-09-07 | 2003-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-03-08 | 2006-09-07 | 2007-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-03-08 | 2010-09-07 | 2011-03-09 | $7700.00 | Window Closed / Lapsed |