US6686247B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-aligned contacts to gates
Assignee: Intel Corp
•
Filing: 2002-08-22
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Granted: 2004-02-03
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Expires: 2022-08-22
Abstract
Abstract The present invention describes methods, apparatus, and systems related to polysilicon gate contact openings over active regions formed by a separate mask to provide enough control of dielectric removal to produce a contact opening at least down to the gate layer but not down to the junction layers. Embodiments include, self-aligned polysilicon contacts done by timed contact etch, by a two layer dielectric, by adding a dielectric etch stop layer, and by partially planarizing a dielectric or etch stop layer over the gate layer. Thus, even if misaligned, the gate contact openings will be deep enough to reach active region gates, but not deep enough to reach junctions. As a result, by using a separate mask and by selecting a period of time for etching to active gates, gate contact openings can be formed during manufacture of ICs, semiconductors, MOS memory cells, SRAM, flash memory, and various other memory cells.
Inventors
- 👤 Mark Bohr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:44
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/069; Y; Y10; Y10S; Y10S257/00; Y10S257/903
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
187 words
A method comprising: forming an active region; forming a gated device within the active region; forming a conformal etch stop layer on the junction region and the gate of the gated device; then forming a first conformal dielectric layer on the gated device in the active region; planarizing the first conformal dielectric layer to expose the conformal etch stop layer on a portion of the gate; forming a second etch stop layer on the first dielectric layer and the conformal etch stop layer; forming a second dielectric layer on the second etch stop layer; forming a contact opening through the dielectric layer to a junction region of the gated device using a first mask; forming a contact opening through the dielectric layer to the gate of the gated device using a different second mask; wherein the forming a contact opening through the dielectric layer and to the gate further comprises: etching an initial gated contact opening to the second etch stop layer; and etching a subsequent gate contact opening to the gate; then forming a contact to a gate of the gated device in the active region.
Claim 2
Independent Claim
187 words
A method comprising: forming an active region; forming a gated device within the active region; forming a conformal etch stop layer on the junction region and the gate of the gated device; then forming a first conformal dielectric layer on the gated device in the active region; planarizing the first conformal dielectric layer to expose the conformal etch stop layer on a portion of the gate; forming a second etch stop layer on the first dielectric layer and the conformal etch stop layer; forming a second dielectric layer on the second etch stop layer; forming a contact opening through the dielectric layer to a junction region of the gated device using a first mask; forming a contact opening through the dielectric layer to the gate of the gated device using a different second mask; wherein the forming a contact opening through the dielectric layer and to the gate further comprises: etching an initial gated contact opening to the second etch stop layer; and etching a subsequent gate contact opening to the gate; then forming a contact to a gate of the gated device in the active region.
Claim 3
Dependent Claim
66 words
The method of claim 1 , wherein the etching a subsequent gate contact opening comprises etching for a period of time between a time necessary to etch through the conformal etch stop layer on the gate region and a time necessary to etch through the second etch stop layer, through the conformal etch stop layer, and through the first dielectric layer and to the junction region.
Claim 4
Dependent Claim
81 words
The method of claim 1 , wherein the etching a subsequent gate contact opening comprises: etching to form an opening through the second etch stop layer to the conformal etch stop layer using an etch chemistry having a good selectivity for the second etch stop layer; and etching to form an opening through said conformal etch stop layer to the gate using an etch chemistry having a greater selectivity for the conformal etch stop layer than for the first dielectric layer.
Claim 5
Independent Claim
178 words
A method comprising: forming an active region; forming a gated device within the active region; forming a first conformal dielectric layer on the gated device in the active region having a first height on a portion of the junction region which is less than the height of said gate; etching the first conformal dielectric down to form a different second height on a portion of the gate, wherein the different second height is substantially less than the first height; forming a different second dielectric layer on the gated device in the active region; forming a contact opening through the dielectric layer to a junction region of the gated device using a first mask; and forming a contact opening through the dielectric layer to the gate of the gated device using a different second mask; wherein the forming a contact opening through the dielectric layer and to the gate further comprises: forming an initial opening through the different second dielectric layer to the gate; then forming a contact to a gate of the gated device in the active region.
Claim 6
Independent Claim
178 words
A method comprising: forming an active region; forming a gated device within the active region; forming a first conformal dielectric layer on the gated device in the active region having a first height on a portion of the junction region which is less than the height of said gate; etching the first conformal dielectric down to form a different second height on a portion of the gate, wherein the different second height is substantially less than the first height; forming a different second dielectric layer on the gated device in the active region; forming a contact opening through the dielectric layer to a junction region of the gated device using a first mask; and forming a contact opening through the dielectric layer to the gate of the gated device using a different second mask; wherein the forming a contact opening through the dielectric layer and to the gate further comprises: forming an initial opening through the different second dielectric layer to the gate; then forming a contact to a gate of the gated device in the active region.
Claim 7
Dependent Claim
47 words
The method of claim 4 , wherein the forming a subsequent opening comprises etching for a period of time between a time necessary to etch through the different second height on the gate and a time necessary to etch through the first height to the junction region.
Claim 8
Dependent Claim
34 words
The method of claim 4 , wherein the etching an initial opening comprises etching using an etch chemistry having a greater selectivity for the different second dielectric layer than for the first dielectric layer.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2007-02-02 | 2007-08-04 | 2008-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2011-02-02 | 2011-08-04 | 2012-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2015-02-02 | 2015-08-04 | 2016-02-03 | $7700.00 | Window Closed / Lapsed |