US6285073B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Contact structure and method of formation
Assignee: NXP USA Inc
•
Filing: 1995-05-30
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Granted: 2001-09-04
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Expires: 2015-05-30
Abstract
Abstract The horizontal surface area required to contact semiconductor devices, in integrated circuits fabricated with trench isolation, is minimized without degrading contact resistance by utilizing the vertical surface area of the trench sidewall. A trench isolation region ( 40 ) is formed within the semiconductor substrate ( 12 ). A doped region ( 74, 96 ) is then formed such that it abuts the trench sidewall ( 24 ). A portion ( 56, 110 ) of the trench sidewall ( 24 ), abutting the doped region ( 74, 96 ), is then exposed by forming a recess ( 55, 112 ) within the trench isolation region ( 40 ). A conductive member ( 66, 114, 118 ) is then formed such that it is electrically coupled to the doped region ( 74, 96 ) along the exposed trench sidewall, as well as along the major surface ( 13 ) of the semiconductor substrate ( 12 ), and results in the formation of a low resistance contact structure.
Inventors
- 👤 Kent J. Cooper
- 👤 Scott S. Roth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:41
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/011
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
173 words
A contact structure in an integrated circuit comprising: a semiconductor substrate having a major surface; a trench isolation region lying within a first portion of the semiconductor substrate, the trench isolation region comprising a trench having a trench sidewall; a first field effect transistor having a source/drain electrode lying within a second portion of the semiconductor substrate, the source/drain electrode having a first portion and a second portion, the first portion having a first depth and a first width and the second portion having a second depth and a second width, wherein the first depth is greater than the second depth and the first width is less than the second width, and the first portion of the source/drain electrode abuts the trench sidewall; and a conductive member overlying the trench isolation region, the conductive member having a first portion extending into the trench adjacent to the trench sidewall, wherein the first portion of the conductive member is electrically shorted to the first portion of the source/drain electrode of the first field effect transistor.
Claim 2
Dependent Claim
173 words
A contact structure in an integrated circuit comprising: a semiconductor substrate having a major surface; a trench isolation region lying within a first portion of the semiconductor substrate, the trench isolation region comprising a trench having a trench sidewall; a first field effect transistor having a source/drain electrode lying within a second portion of the semiconductor substrate, the source/drain electrode having a first portion and a second portion, the first portion having a first depth and a first width and the second portion having a second depth and a second width, wherein the first depth is greater than the second depth and the first width is less than the second width, and the first portion of the source/drain electrode abuts the trench sidewall; and a conductive member overlying the trench isolation region, the conductive member having a first portion extending into the trench adjacent to the trench sidewall, wherein the first portion of the conductive member is electrically shorted to the first portion of the source/drain electrode of the first field effect transistor.
Claim 3
Dependent Claim
53 words
The contact structure of claim 1 , wherein the conductive member is further characterized as having a second portion overlying the the source/drain electrode of the first field effect transistor, wherein the second portion of the conductive member is electrically shorted to a portion of the source/drain electrode that abuts the major surface.
Claim 4
Dependent Claim
24 words
The contact structure of claim 1 , wherein the conductive member is further characterized as a gate electrode for a second field effect transistor.
Claim 5
Dependent Claim
18 words
The contact structure of claim 1 , wherein the conductive member is further characterized as a contact plug.
Claim 6
Dependent Claim
27 words
The contact structure of claim 4 , wherein the contact plug comprises a material selected from the group consisting of tungsten, titanium nitride, titanium silicide, and polysilicon.
Claim 7
Dependent Claim
13 words
The contact structure of claim 1 , wherein the conductive member comprises polysilicon.
Claim 8
Dependent Claim
26 words
The contact structure of claim 1 , wherein the conductive member is further characterized as a laminate comprising a metal silicide layer overlying a polysilicon layer.
Claim 9
Dependent Claim
33 words
The contact structure of claim 1 , wherein the trench isolation region is further characterized as comprising a dielectric plug, wherein the dielectric plug lies within the trench and substantially fills the trench.
Claim 10
Dependent Claim
25 words
The contact structure of claim 8 , wherein the dielectric plug comprises a material selected from the group consisting of silicon dioxide and silicon nitride.
Claim 11
Dependent Claim
180 words
A contact structure in an integrated circuit comprising: a semiconductor substrate having a major surface; a trench isolation region lying within a first portion of the semiconductor substrate, the trench isolation region comprising a trench having a trench sidewall; a first field effect transistor, the first field effect transistor having a source/drain electrode lying within a second portion of the semiconductor substrate, the source/drain electrode having a first portion and a second portion, the first portion having a first depth and a first width and the second portion having a second depth and a second width, wherein the first depth is greater than the second depth and the first width is less than the second width, and the first portion of the source/drain electrode abuts the trench sidewall; and a second field effect transistor having a gate electrode, the gate electrode having a first portion that lies within the trench and abuts the trench sidewall, wherein the first portion of the gate electrode is electrically shorted to the first portion of the source/drain electrode of the first field effect transistor.
Claim 12
Dependent Claim
180 words
A contact structure in an integrated circuit comprising: a semiconductor substrate having a major surface; a trench isolation region lying within a first portion of the semiconductor substrate, the trench isolation region comprising a trench having a trench sidewall; a first field effect transistor, the first field effect transistor having a source/drain electrode lying within a second portion of the semiconductor substrate, the source/drain electrode having a first portion and a second portion, the first portion having a first depth and a first width and the second portion having a second depth and a second width, wherein the first depth is greater than the second depth and the first width is less than the second width, and the first portion of the source/drain electrode abuts the trench sidewall; and a second field effect transistor having a gate electrode, the gate electrode having a first portion that lies within the trench and abuts the trench sidewall, wherein the first portion of the gate electrode is electrically shorted to the first portion of the source/drain electrode of the first field effect transistor.
Claim 13
Dependent Claim
43 words
The contact structure of claim 10 , wherein the gate electrode is further characterized as having a second portion that overlies the source/drain electrode of the first field effect transistor and abuts a portion of the source/drain electrode that abuts the major surface.
Claim 14
Dependent Claim
13 words
The contact structure of claim 10 , wherein the gate electrode comprises polysilicon.
Claim 15
Dependent Claim
26 words
The contact structure of claim 10 , wherein the gate electrode is further characterized as a laminate comprising a metal silicide layer overlying a polysilicon layer.
Claim 16
Dependent Claim
33 words
The contact structure of claim 10 , wherein the trench isolation region is further characterized as comprising a dielectric plug, wherein the dielectric plug lies within the trench and substantially fills the trench.
Claim 17
Dependent Claim
25 words
The contact structure of claim 14 , wherein the dielectric plug comprises a material selected from the group consisting of silicon dioxide and silicon nitride.
Claim 18
Dependent Claim
169 words
A contact structure in an integrated circuit comprising: a semiconductor substrate having a major surface; a trench lying within a first portion of the semiconductor substrate, the trench having a trench sidewall; a first field effect transistor having a source/drain electrode lying within a second portion of the semiconductor substrate, the source/drain electrode having a first portion with a first depth and a second portion with a second depth, wherein the first depth is greater than the second depth, and the first portion of the source/drain electrode abuts the trench sidewall; a dielectric plug lying within the trench and substantially filling the trench; and a second field effect transistor having a gate electrode comprising a first polysilicon layer underlying a second polysilicon layer, the gate electrode overlying the dielectric plug and having a first portion extending into the trench and abutting the trench sidewall, wherein the first portion of the gate electrode is electrically shorted to the first portion of the source/drain electrode of the first field effect transistor.
Claim 19
Dependent Claim
169 words
A contact structure in an integrated circuit comprising: a semiconductor substrate having a major surface; a trench lying within a first portion of the semiconductor substrate, the trench having a trench sidewall; a first field effect transistor having a source/drain electrode lying within a second portion of the semiconductor substrate, the source/drain electrode having a first portion with a first depth and a second portion with a second depth, wherein the first depth is greater than the second depth, and the first portion of the source/drain electrode abuts the trench sidewall; a dielectric plug lying within the trench and substantially filling the trench; and a second field effect transistor having a gate electrode comprising a first polysilicon layer underlying a second polysilicon layer, the gate electrode overlying the dielectric plug and having a first portion extending into the trench and abutting the trench sidewall, wherein the first portion of the gate electrode is electrically shorted to the first portion of the source/drain electrode of the first field effect transistor.
Claim 20
Dependent Claim
34 words
The contact structure of claim 16 , wherein the second field effect transistor is further characterized as having a channel region wherein the channel region underlies the gate electrode and abuts the trench sidewall.
Claim 21
Dependent Claim
24 words
The contact structure of claim 16 , wherein a portion of the second polysilicon layer extends into the trench and abuts the trench sidewall.
Claim 22
Dependent Claim
25 words
The contact structure of claim 16 , wherein the dielectric plug comprises a material selected from the group consisting of silicon dioxide and silicon nitride.
Claim 23
Dependent Claim
19 words
The contact structure of claim 16 , wherein a portion of the first polysilicon layer overlies the dielectric plug.
Claim 24
Dependent Claim
152 words
A contact structure in an integrated circuit comprising: a semiconductor substrate having a major surface; a trench lying within a first portion of the semiconductor substrate, the trench having a trench sidewall; a first field effect transistor having a source/drain electrode lying within a second portion of the semiconductor substrate, the source/drain electrode having a first portion with a first depth and a second portion with a second depth, wherein the first depth is greater than the second depth, and the first portion of the source/drain electrode abuts the trench sidewall; a dielectric plug lying within the trench and substantially filling the trench; and a conductive member overlying the dielectric plug, the conductive member having a first portion lying within the trench and abutting the trench sidewall, wherein the first portion of the conductive member is electrically shorted to the first portion of the source/drain electrode of the first field effect transistor.
Claim 25
Dependent Claim
152 words
A contact structure in an integrated circuit comprising: a semiconductor substrate having a major surface; a trench lying within a first portion of the semiconductor substrate, the trench having a trench sidewall; a first field effect transistor having a source/drain electrode lying within a second portion of the semiconductor substrate, the source/drain electrode having a first portion with a first depth and a second portion with a second depth, wherein the first depth is greater than the second depth, and the first portion of the source/drain electrode abuts the trench sidewall; a dielectric plug lying within the trench and substantially filling the trench; and a conductive member overlying the dielectric plug, the conductive member having a first portion lying within the trench and abutting the trench sidewall, wherein the first portion of the conductive member is electrically shorted to the first portion of the source/drain electrode of the first field effect transistor.
Claim 26
Dependent Claim
52 words
The contact structure of claim 21 , wherein the conductive member is further characterized as having a second portion overlying the source/drain electrode of the first field effect transistor, wherein the second portion of the conductive member is electrically shorted to a portion of the source/drain electrode that abuts the major surface.
Claim 27
Dependent Claim
24 words
The contact structure of claim 21 , wherein the conductive member is further characterized as a gate electrode for a second field effect transistor.
Claim 28
Dependent Claim
18 words
The contact structure of claim 21 , wherein the conductive member is further characterized as a contact plug.
Claim 29
Dependent Claim
27 words
The contact structure of claim 24 , wherein the contact plug comprises a material selected from the group consisting of tungsten, titanium nitride, titanium silicide, and polysilicon.
Claim 30
Dependent Claim
23 words
The contact structure of claim 24 , further comprising a conductive interconnect overlying the contact plug and electrically shorted to the contact plug.
Claim 31
Dependent Claim
13 words
The contact structure of claim 21 , wherein the conductive member comprises polysilicon.
Claim 32
Dependent Claim
26 words
The contact structure of claim 21 , wherein the conductive member is further characterized as a laminate comprising a metal silicide layer overlying a polysilicon layer.
Claim 33
Dependent Claim
25 words
The contact structure of claim 21 , wherein the dielectric plug comprises a material selected from the group consisting of silicon dioxide and silicon nitride.
Claim 34
Dependent Claim
154 words
A contact structure in an integrated circuit comprising: a semiconductor substrate having a major surface; a trench isolation region lying within a first portion of the semiconductor substrate, the trench isolation region comprising a trench having a trench sidewall; a first field effect transistor having a source/drain electrode lying within a second portion of the semiconductor substrate, the source/drain electrode having a first portion with a first depth and a second portion with a second depth, wherein the first depth is greater than the second depth, and the first portion of the source/drain electrode abuts the trench sidewall; and a second field effect transistor having a gate electrode overlying the trench isolation region, the gate electrode having a first portion lying within the trench and abutting the trench sidewall, wherein the first portion of the gate electrode is electrically shorted to the first portion of the source/drain electrode of the first field effect transistor.
Claim 35
Dependent Claim
154 words
A contact structure in an integrated circuit comprising: a semiconductor substrate having a major surface; a trench isolation region lying within a first portion of the semiconductor substrate, the trench isolation region comprising a trench having a trench sidewall; a first field effect transistor having a source/drain electrode lying within a second portion of the semiconductor substrate, the source/drain electrode having a first portion with a first depth and a second portion with a second depth, wherein the first depth is greater than the second depth, and the first portion of the source/drain electrode abuts the trench sidewall; and a second field effect transistor having a gate electrode overlying the trench isolation region, the gate electrode having a first portion lying within the trench and abutting the trench sidewall, wherein the first portion of the gate electrode is electrically shorted to the first portion of the source/drain electrode of the first field effect transistor.
Claim 36
Dependent Claim
52 words
The contact structure of claim 30 , wherein the gate electrode is further characterized as having a second portion overlying the source/drain electrode of the first field effect transistor, wherein the second portion of the conductive member is electrically shorted to a portion of the source/drain electrode that abuts the major surface.
Claim 37
Dependent Claim
36 words
The contact structure of claim 30 , wherein the second field effect transistor is further characterized as having a channel region underlying the gate electrode, wherein a portion of the channel region abuts the trench sidewall.
Claim 38
Dependent Claim
21 words
The contact structure of claim 32 , wherein the gate electrode comprises a first silicon layer underlying a second silicon layer.
Claim 39
Dependent Claim
20 words
The contact structure of claim 33 , wherein a portion of the first silicon layer overlies the trench isolation region.
Claim 40
Dependent Claim
13 words
The contact structure of claim 30 , wherein the gate electrode comprises polysilicon.
Claim 41
Dependent Claim
26 words
The contact structure of claim 30 , wherein the gate electrode is further characterized as a laminate comprising a metal silicide layer overlying a polysilicon layer.
Claim 42
Dependent Claim
33 words
The contact structure of claim 30 , wherein the trench isolation region is further characterized as comprising a dielectric plug, wherein the dielectric plug lies within the trench and substantially fills the trench.
Claim 43
Dependent Claim
25 words
The contact structure of claim 37 , wherein the dielectric plug comprises a material selected from the group consisting of silicon dioxide and silicon nitride.
Claim 44
Dependent Claim
34 words
The contact structure of claim 32 , wherein the second transistor is further characterized as having a gate dielectric layer overlying the channel region, wherein the gate dielectric layer abuts the trench isolation 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) | 2004-09-03 | 2005-03-05 | 2005-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-09-03 | 2009-03-05 | 2009-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-09-03 | 2013-03-05 | 2013-09-04 | $7700.00 | Window Closed / Lapsed |