US6432798B1
Expired / Lapsed
US
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Extension of shallow trench isolation by ion implantation
Assignee: Intel Corp
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Filing: 2000-08-10
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Granted: 2002-08-13
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Expires: 2020-08-10
Abstract
Abstract A shallow trench isolation (STI) structure is formed by etching trenches into the surface of a substrate in alignment with a patterned masking layer. An ion implantation of, for example, carbon, nitrogen, or oxygen, is performed so as to create an electrically insulating layer extending downwardly from a bottom surface of the trench. By implanting such extensions, STI structures with greater effective aspect ratios may be obtained which, in turn, allow greater packing density in integrated circuits. Implanted isolation structures may be formed without etching a trench by implanting into regions of the substrate. In this way, trench etch, dielectric back-fill, and planarization operations can be eliminated. Furthermore the implanted regions may be formed by multiple implants at different energies so as to obtain multiple, typically contiguous, target ranges. Ions of various masses or charges may be used so as to obtain the desired implant depth and concentration profile in the isolation structures, independent of whether these structures are trench extensions or formed directly beneath a planarized substrate surface.
Inventors
- 👤 Mark Y. Liu
- 👤 Leonard C. Pipes
- 👤 Mitchell C. Taylor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 03:24
CPC Classifications
H; H10; H10P; H10P30/00; H10P30/20; H10P30/202; H10P30/206; H10W; H10W10/00; H10W10/10; H10W10/17; H10P30/218; H10W10/01; H10W10/011; H10W10/014; H10W10/0145; H10W10/0148
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
57 words
A method of forming a shallow trench isolation structure, comprising: forming a trench in a substrate; implanting ions into at least a bottom portion of the trench, said ions of a dosage strength to produce a compound of less than stoichiometric concentration; filling the trench with dielectric material; and performing a high temperature operation on the substrate.
Claim 2
Independent Claim
57 words
A method of forming a shallow trench isolation structure, comprising: forming a trench in a substrate; implanting ions into at least a bottom portion of the trench, said ions of a dosage strength to produce a compound of less than stoichiometric concentration; filling the trench with dielectric material; and performing a high temperature operation on the substrate.
Claim 3
Dependent Claim
52 words
The method of claim 1 , wherein the substrate is a silicon wafer, and forming the trench comprises patterning a mask layer on a surface of the silicon wafer such that at least one portion of the surface is exposed, and etching the at least one exposed portion of the silicon surface.
Claim 4
Dependent Claim
12 words
The method of claim 2 , wherein implanting ions comprises implanting oxygen.
Claim 5
Dependent Claim
12 words
The method of claim 2 , wherein implanting ions comprises implanting nitrogen.
Claim 6
Dependent Claim
17 words
The method of claim 2 , further comprising removing the patterned mask layer subsequent to implanting ions.
Claim 7
Dependent Claim
11 words
The method of claim 4 , further comprising annealing the wafer.
Claim 8
Dependent Claim
11 words
The method of claim 5 , further comprising annealing the wafer.
Claim 9
Dependent Claim
35 words
The method of claim 5 , wherein implanting ions comprises implanting a first species at a first energy and a first dose, and implanting a second species at a second energy and a second dose.
Claim 10
Dependent Claim
28 words
The method of claim 8 , wherein the first species has a projected range and the second species has a projected range and the projected ranges are different.
Claim 11
Dependent Claim
18 words
The method of claim 9 , wherein at least one of the first and second species is nitrogen.
Claim 12
Independent Claim
100 words
A method of forming a shallow trench isolation structure, comprising: depositing a silicon nitride layer on a surface of a silicon wafer; photolithographically patterning the silicon nitride layer to form openings therethrough; plasma etching the surface of the silicon through the openings in the silicon nitride layer to form a plurality of recesses in the surface of the wafer, each recess having sidewalls and a bottom surface; implanting ions through the bottom surface of the recesses, said ions of a dosage strength to produce a compound of less than stoichiometric concentration; and performing a high temperature operation on the substrate.
Claim 13
Independent Claim
100 words
A method of forming a shallow trench isolation structure, comprising: depositing a silicon nitride layer on a surface of a silicon wafer; photolithographically patterning the silicon nitride layer to form openings therethrough; plasma etching the surface of the silicon through the openings in the silicon nitride layer to form a plurality of recesses in the surface of the wafer, each recess having sidewalls and a bottom surface; implanting ions through the bottom surface of the recesses, said ions of a dosage strength to produce a compound of less than stoichiometric concentration; and performing a high temperature operation on the substrate.
Claim 14
Dependent Claim
20 words
The method of claim 11 , wherein the ions are selected from the group consisting of carbon, nitrogen, and oxygen.
Claim 15
Dependent Claim
37 words
The method of claim 11 , wherein implanting comprises implanting oxygen at a dose in the range of 1.0E14 to 5.0E16 atoms/cm 2 , and at an energy in the range of 5 keV to 200 keV.
Claim 16
Dependent Claim
37 words
The method of claim 11 , wherein implanting comprises implanting nitrogen at a dose in the range of 1.0E13 to 1.5E17 atoms/cm 2 , and at an energy in the range of 5 keV to 200 keV.
Claim 17
Independent Claim
92 words
A method of forming an isolation structure in a semiconductor substrate, comprising: implanting a first plurality of ions into at least one region of the substrate, the first plurality ions being implanted with a first energy to produce a first target range, said first plurality of ions of a dosage strength to produce a compound of less than stoichiometric concentration; and implanting a second plurality of ions into the at least one region of the substrate, the second plurality ions being implanted with a second energy to produce a second target range.
Claim 18
Independent Claim
92 words
A method of forming an isolation structure in a semiconductor substrate, comprising: implanting a first plurality of ions into at least one region of the substrate, the first plurality ions being implanted with a first energy to produce a first target range, said first plurality of ions of a dosage strength to produce a compound of less than stoichiometric concentration; and implanting a second plurality of ions into the at least one region of the substrate, the second plurality ions being implanted with a second energy to produce a second target range.
Claim 19
Dependent Claim
17 words
The method of claim 15 , wherein the first ions and the second ions are the same.
Claim 20
Dependent Claim
16 words
The method of claim 15 , wherein the first ions and the second ions are different.
Claim 21
Dependent Claim
19 words
The method of claim 16 , wherein the first target range and the second target range are the same.
Claim 22
Dependent Claim
18 words
The method of claim 17 , wherein the first target range and the second target range are different.
Claim 23
Dependent Claim
21 words
The method of claim 16 , wherein the first ions are selected from the group consisting of oxygen, nitrogen, and carbon.
Claim 24
Dependent Claim
21 words
The method of claim 17 , wherein the first ions are selected from the group consisting of oxygen, nitrogen, and carbon.
Claim 25
Independent Claim
76 words
A method of forming an isolation structure in a substrate, comprising: forming a trench in the substrate; implanting a first plurality of ions at a first energy into the trench, said first plurality of ions of a dosage strength to produce a compound of less than stoichiometric concentration; and implanting a second plurality of ions at a second energy into the trench; wherein the first implanted ions and the second implanted ions have different target ranges.
Claim 26
Independent Claim
76 words
A method of forming an isolation structure in a substrate, comprising: forming a trench in the substrate; implanting a first plurality of ions at a first energy into the trench, said first plurality of ions of a dosage strength to produce a compound of less than stoichiometric concentration; and implanting a second plurality of ions at a second energy into the trench; wherein the first implanted ions and the second implanted ions have different target ranges.
Claim 27
Dependent Claim
44 words
The method of claim 22 , further comprising implanting a third plurality of ions at a third energy into the trench, wherein the third implanted ions have a target range that is different from the target ranges of the first and second implanted ions.
Claim 28
Dependent Claim
17 words
The method of claim 22 , wherein the first and second plurality of ions are different elements.
Claim 29
Dependent Claim
18 words
The method of claim 23 , wherein the first and second plurality of ions are the same elements.
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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) | 2005-08-12 | 2006-02-11 | 2006-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-08-12 | 2010-02-11 | 2010-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-08-12 | 2014-02-11 | 2014-08-13 | $7700.00 | Window Closed / Lapsed |