Patent US3173265A successfully refreshed from Google Patents.
US5644166A
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US
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Sacrificial CVD germanium layer for formation of high aspect ratio submicron VLSI contacts
Assignee: Micron Technology Inc
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Filing: 1995-07-17
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Granted: 1997-07-01
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Expires: 2015-07-17
Abstract
Abstract A high aspect ratio submicron VLSI contact and corresponding method of manufacture is disclosed. The contact is formed through an insulative layer, such as silicon dioxide, to an underlying active region on a substrate of silicon wafer. The contact comprises a layer of titanium germanosilicide at the bottom of the contact opening, and a layer of titanium germanide at the sides of the contact opening, with an overlying layer of titanium nitride. The contact is metallized, preferably using tungsten or aluminum. The disclosed method of manufacturing the contact comprises first etching the contact opening, then exposing the bottom of the contact opening to germane gas to clean native silicon dioxide from the bottom of the contact opening. A 50 Angstrom layer of germanium is then deposited over the contact opening. A layer of titanium is then deposited over the germanium layer in the contact opening. The deposition of titanium is preferably accomplished using a collimator having an aspect ratio lower than about 2.5:1. After annealing in a nitrogen atmosphere, the contact is metallized with tungsten or aluminum. The anneal step can be conducted at a temperature of around 600° C. Less titanium may be used than with conventional processes, allowing a higher aspect ratio of the contact opening as well as the use of the collimator having a lower than conventional aspect ratio.
Inventors
- 👤 Jeffrey Honeycutt
- 👤 Sujit Sharan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:43
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/032; H10W20/047; H10W20/049; H10D; H10D64/00; H10D64/01; H10D64/011; H10D64/0111; H10D64/0112; H10D64/01125; H10W20/033; H10W20/048; H10W20/40; H10W20/41; H10W20/425
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
106 words
A high aspect ratio submicron VLSI contact on a substrate of a silicon wafer, the contact having an opening, a bottom, and a plurality of sides and comprising: a doped active region in said silicon substrate; an insulating layer on said silicon substrate adjacent to and above said active region; a region of titanium germanosilicide located above the active region at the bottom of the contact opening; and a metallization material substantially filling the contact opening: a layer of titanium germanide on the sides of the contact, and an layer of titanium nitride on the layer of titanium germanosilicide and on the layer of titanium germanide.
Claim 2
Dependent Claim
106 words
A high aspect ratio submicron VLSI contact on a substrate of a silicon wafer, the contact having an opening, a bottom, and a plurality of sides and comprising: a doped active region in said silicon substrate; an insulating layer on said silicon substrate adjacent to and above said active region; a region of titanium germanosilicide located above the active region at the bottom of the contact opening; and a metallization material substantially filling the contact opening: a layer of titanium germanide on the sides of the contact, and an layer of titanium nitride on the layer of titanium germanosilicide and on the layer of titanium germanide.
Claim 3
Dependent Claim
20 words
A contact as recited in claim 1, wherein the contact opening has an aspect ratio of greater than about 2:1.
Claim 4
Dependent Claim
19 words
A contact as recited in claim 1, wherein the titanium nitride layer has a thickness of approximately 25 Angstroms.
Claim 5
Dependent Claim
18 words
A contact as recited in claim 1, wherein the titanium germanosilicide region has thickness of approximately 100 Angstroms.
Claim 6
Dependent Claim
19 words
A contact as recited in claim 1, wherein the titanium germanide layer has a thickness of approximately 50 Angstroms.
Claim 7
Dependent Claim
35 words
A contact as recited in claim 1, wherein the layer of germanium is doped with a material compatible with the active region thereon, whereby the concentration of doping in the active region is substantially consistent.
Claim 8
Dependent Claim
13 words
A contact as recited in claim 1, wherein the metallization material is tungsten.
Claim 9
Dependent Claim
13 words
A contact as recited in claim 1, wherein the metallization material is aluminum.
Claim 10
Dependent Claim
14 words
A contact as recited in claim 1, wherein the insulating layer comprises silicon dioxide.
Claim 11
Dependent Claim
13 words
A contact as recited in claim 1, wherein the insulating layer comprises BPSG.
Claim 12
Dependent Claim
193 words
A high aspect ratio submicron VLSI contact on a substrate of a silicon wafer, the contact having an opening, a bottom, and a plurality of sides and comprising: (a) an doped active region in the silicon substrate; (b) a layer of BPSG adjacent to and above the active region on the silicon substrate; (c) a region of titanium germanosilicide above the active region on the bottom of the contact, the titanium germosilicide having a thickness of about 75 Angstroms; (d) a layer of titanium germanide on the sides of the contact, the titanium germanide having a thickness of about 100 Angstroms; (e) a layer of titanium nitride on the layer of titanium germanosilicide and on the layer of titanium germanide, the layer of titanium nitride having a thickness of about 20 Angstroms; and (f) a metal material substantially filling the center of the contact opening, wherein the contact opening has an aspect ratio greater than about 2:1, and wherein the layer of germanium has a doping level compatible with the underlying active region whereby the concentration level of the dopant in the active region is maintained at a substantially consistent level of concentration.
Claim 13
Dependent Claim
193 words
A high aspect ratio submicron VLSI contact on a substrate of a silicon wafer, the contact having an opening, a bottom, and a plurality of sides and comprising: (a) an doped active region in the silicon substrate; (b) a layer of BPSG adjacent to and above the active region on the silicon substrate; (c) a region of titanium germanosilicide above the active region on the bottom of the contact, the titanium germosilicide having a thickness of about 75 Angstroms; (d) a layer of titanium germanide on the sides of the contact, the titanium germanide having a thickness of about 100 Angstroms; (e) a layer of titanium nitride on the layer of titanium germanosilicide and on the layer of titanium germanide, the layer of titanium nitride having a thickness of about 20 Angstroms; and (f) a metal material substantially filling the center of the contact opening, wherein the contact opening has an aspect ratio greater than about 2:1, and wherein the layer of germanium has a doping level compatible with the underlying active region whereby the concentration level of the dopant in the active region is maintained at a substantially consistent level of concentration.
Claim 14
Dependent Claim
89 words
A high aspect ratio submicron VLSI contact on a substrate of a silicon wafer, the contact having an opening, a bottom, and a plurality of sides and comprising: a doped active region in said silicon substrate; an insulating layer on said silicon substrate adjacent to and above said active region; a region of titanium germanosilicide located above the active region at the bottom of the contact opening; and a metallization material substantially filling the contact opening, wherein the contact opening has an aspect ratio of greater than about 2:1.
Claim 15
Dependent Claim
89 words
A high aspect ratio submicron VLSI contact on a substrate of a silicon wafer, the contact having an opening, a bottom, and a plurality of sides and comprising: a doped active region in said silicon substrate; an insulating layer on said silicon substrate adjacent to and above said active region; a region of titanium germanosilicide located above the active region at the bottom of the contact opening; and a metallization material substantially filling the contact opening, wherein the contact opening has an aspect ratio of greater than about 2:1.
Claim 16
Dependent Claim
82 words
A high aspect ratio submicron VLSI contact on a substrate of a silicon wafer, the contact having an opening, a bottom, and a plurality of sides and comprising: a doped active region in said silicon substrate; an insulating layer on said silicon substrate adjacent to and above said active region; a region of titanium germanosilicide located above the active region at the bottom of the contact opening; and a metallization material substantially filling the contact opening, wherein the metallization material is tungsten.
Claim 17
Dependent Claim
82 words
A high aspect ratio submicron VLSI contact on a substrate of a silicon wafer, the contact having an opening, a bottom, and a plurality of sides and comprising: a doped active region in said silicon substrate; an insulating layer on said silicon substrate adjacent to and above said active region; a region of titanium germanosilicide located above the active region at the bottom of the contact opening; and a metallization material substantially filling the contact opening, wherein the metallization material is tungsten.
Claim 18
Dependent Claim
87 words
A high aspect ratio submicron VLSI contact on a substrate of a silicon wafer, the contact having an opening, a bottom, and a plurality of sides and comprising: a doped active region in said silicon substrate; an insulating layer on said silicon substrate adjacent to and above said active region; a region of titanium germanosilicide located above the active region at the bottom of the contact opening; a metallization material substantially filling the contact opening; and a layer of titanium germanide on the sides of the contact.
Claim 19
Dependent Claim
87 words
A high aspect ratio submicron VLSI contact on a substrate of a silicon wafer, the contact having an opening, a bottom, and a plurality of sides and comprising: a doped active region in said silicon substrate; an insulating layer on said silicon substrate adjacent to and above said active region; a region of titanium germanosilicide located above the active region at the bottom of the contact opening; a metallization material substantially filling the contact opening; and a layer of titanium germanide on the sides of the contact.
Claim 20
Dependent Claim
20 words
A contact as recited in claim 14, wherein the contact opening has an aspect ratio of greater than about 2:1.
Claim 21
Dependent Claim
19 words
A contact as recited in claim 14, wherein the titanium nitride layer has a thickness of approximately 25 Angstroms.
Claim 22
Dependent Claim
18 words
A contact as recited in claim 14, wherein the titanium germanosilicide region has thickness of approximately 100 Angstroms.
Claim 23
Dependent Claim
19 words
A contact as recited in claim 14, wherein the titanium germanide layer has a thickness of approximately 50 Angstroms.
Claim 24
Dependent Claim
35 words
A contact as recited in claim 14, wherein the layer of germanium is doped with a material compatible with the active region thereon, whereby the concentration of doping in the active region is substantially consistent.
Claim 25
Dependent Claim
13 words
A contact as recited in claim 14, wherein the metallization material is tungsten.
Claim 26
Dependent Claim
13 words
A contact as recited in claim 14, wherein the metallization material is aluminum.
Claim 27
Dependent Claim
14 words
A contact as recited in claim 14, wherein the insulating layer comprises silicon dioxide.
Claim 28
Dependent Claim
13 words
A contact as recited in claim 14, wherein the insulating layer comprises BPSG.
References Cited (Backward Citations)
JPH056995A
Cited
US5401674A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-06-30 | 2000-12-30 | 2001-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-06-30 | 2004-12-30 | 2005-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-06-30 | 2008-12-30 | 2009-07-01 | $7700.00 | Window Closed / Lapsed |