US5652182A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Disposable posts for self-aligned non-enclosed contacts
Assignee: Cypress Semiconductor Corp
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Filing: 1995-12-29
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Granted: 1997-07-29
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Expires: 2015-12-29
Abstract
Abstract A disposable post process for contact openings to interconnect material of reduced geometry and no enlarged landing pads is disclosed. A layer of material is formed over interconnect regions on a semiconductor wafer and subsequently patterned into posts which define the location and shape of openings to be formed in a subsequently formed planar layer. After a layer is formed to surround the posts, the posts are removed to create openings in the layer above underlying interconnect regions. These openings may then be used to form suitable contacts to the interconnect regions.
Inventors
- 👤 James M. Cleeves
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:32
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/0698; H10W20/071; H10W20/081
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
87 words
A method for forming an opening over an interconnect on a semiconductor wafer, comprising the steps of: (a) forming an interconnect without an enlarged landing pad; (b) forming a first layer having a first material over the interconnect; (c) patterning the layer of first material to form a post over the interconnect; (d) forming a second layer having a second material over the semiconductor wafer and around the post; and (e) removing the post to form an opening in the layer of second material over the interconnect.
Claim 2
Independent Claim
87 words
A method for forming an opening over an interconnect on a semiconductor wafer, comprising the steps of: (a) forming an interconnect without an enlarged landing pad; (b) forming a first layer having a first material over the interconnect; (c) patterning the layer of first material to form a post over the interconnect; (d) forming a second layer having a second material over the semiconductor wafer and around the post; and (e) removing the post to form an opening in the layer of second material over the interconnect.
Claim 3
Dependent Claim
13 words
The method of claim 1, wherein the first material comprises a photosensitive material.
Claim 4
Dependent Claim
11 words
The method of claim 1, wherein the first material comprises polysilicon.
Claim 5
Dependent Claim
24 words
The method of claim 1, further comprising the step of: (f) forming a third material in the opening in the layer of second material.
Claim 6
Dependent Claim
22 words
The method of claim 4, wherein the second material comprises an insulative material and wherein the third material comprises a conductive material.
Claim 7
Dependent Claim
22 words
The method of claim 1, wherein the patterning step (c) comprises the step of etching the first material to form the post.
Claim 8
Dependent Claim
25 words
The method of claim 1, wherein the forming step (d) includes the step of planarizing the layer of second material to form a planarized layer.
Claim 9
Dependent Claim
33 words
The method of claim 1, wherein the post removal step (e) comprises exposing a portion of the post in the layer of second material, and etching the post material with an etchant recipe.
Claim 10
Dependent Claim
30 words
The method of claim 8, wherein the etchant recipe for etching the post material is selective toward post material compared to the interconnect layer, the wafer, and the second layer.
Claim 11
Dependent Claim
19 words
The method of claim 7, wherein the post is exposed by polishing the planarized layer using a chemical-mechanical polish.
Claim 12
Dependent Claim
14 words
The method of claim 9, wherein the post is exposed by a melt-flow process.
Claim 13
Dependent Claim
26 words
The method of claim 7, wherein the post is exposed by etching a portion of the planarized layer to a point where the post is exposed.
Claim 14
Independent Claim
130 words
A method for forming an opening over a semiconductor wafer having a region to be contacted of reduced geometry, comprising the steps of: (a) forming a region to be contacted of reduced geometry without an enlarged region; (b) forming a layer of a first material over the semiconductor wafer; (c) patterning the layer of first material to form a post over at least a portion of the region to be contacted; (d) forming a layer of insulative material over the semiconductor wafer and around the post; (e) removing the post to form an opening in the layer of insulative material over at least the portion of the region to be contacted; and (f) forming a conductive material in the opening in the layer of insulative material to contact the region.
Claim 15
Independent Claim
130 words
A method for forming an opening over a semiconductor wafer having a region to be contacted of reduced geometry, comprising the steps of: (a) forming a region to be contacted of reduced geometry without an enlarged region; (b) forming a layer of a first material over the semiconductor wafer; (c) patterning the layer of first material to form a post over at least a portion of the region to be contacted; (d) forming a layer of insulative material over the semiconductor wafer and around the post; (e) removing the post to form an opening in the layer of insulative material over at least the portion of the region to be contacted; and (f) forming a conductive material in the opening in the layer of insulative material to contact the region.
Claim 16
Dependent Claim
13 words
The method of claim 13, wherein the first material comprises a photosensitive material.
Claim 17
Dependent Claim
11 words
The method of claim 13, wherein the first material comprises polysilicon.
Claim 18
Dependent Claim
22 words
The method of claim 13, wherein the patterning step (c) comprises the step of etching the first material to form the post.
Claim 19
Dependent Claim
25 words
The method of claim 13, wherein the forming step (d) includes the step of planarizing the layer of insulative material to form a planarized layer.
Claim 20
Dependent Claim
33 words
The method of claim 13, wherein the post removal step (e) comprises exposing a portion of the post in the layer of second material, and etching the post material with an etchant recipe.
Claim 21
Dependent Claim
32 words
The method of claim 18, wherein the etchant recipe for etching the post material is selective toward post material compared to the region to be connected, the wafer, and the insulative material.
Claim 22
Dependent Claim
19 words
The method of claim 17, wherein the post is exposed by polishing the planarized layer using a chemical-mechanical polish.
Claim 23
Dependent Claim
14 words
The method of claim 19, wherein the post is exposed by a melt-flow process.
Claim 24
Dependent Claim
26 words
The method of claim 17, wherein the post is exposed by etching a portion of the planarized layer to a point where the post is exposed.
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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) | 2000-07-28 | 2001-01-27 | 2001-07-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-07-28 | 2005-01-27 | 2005-07-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-07-28 | 2009-01-27 | 2009-07-29 | $7700.00 | Window Closed / Lapsed |