← Back to Patent Explorer
US6281082B1 Expired / Lapsed US ⏱️ 0.0 years remaining

Method to form MOS transistors with a common shallow trench isolation and interlevel dielectric gap fill

Assignee: GlobalFoundries Singapore Pte Ltd
•
Filing: 2000-03-13
•
Granted: 2001-08-28
•
Expires: 2020-03-13
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A new method of forming MOS transistors in the manufacture of an integrated circuit device has been achieved. A semiconductor substrate is provided. A pad oxide layer is deposited. A silicon nitride layer is deposited. Trenches are patterned for planned shallow trench isolations. The sidewalls of the trenches are oxidized. A photoresist layer is deposited overlying the silicon nitride layer and filling the trenches. The photoresist layer is etched down to below the top surface of the silicon nitride layer. The silicon nitride layer is patterned to form dummy gate electrodes. Sidewall spacers are formed on the dummy gate electrodes. The photoresist layer is removed. A dielectric layer is deposited overlying the dummy gate electrodes and the trenches. The dielectric layer is polished down to the top surface of the dummy gate electrodes to thereby complete the STI and the ILD. The dummy gate electrodes are etched away. A gate oxide layer is formed. A gate electrode layer is deposited overlying the dielectric layer and filling the openings for the planned transistor gates. The gate electrode layer is polished down to form the transistor gates, and the integrated circuit is completed.

Inventors

  • 👤 Feng Chen
  • 👤 Kok Hin Teo
  • 👤 Kok Hiang Tang
  • 👤 Alex See

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 06:54
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/017; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/014; H10W10/0148; H10W10/10; H10W10/17

Claims Analysis

Total Claims: 23
Claim 1
Independent Claim 224 words
A method to form transistor gates and shallow trench isolations in the manufacture of an integrated circuit device comprising: providing a semiconductor substrate; depositing a pad oxide layer overlying said semiconductor substrate; depositing a silicon nitride layer overlying said pad oxide layer; patterning said silicon nitride layer, said pad oxide layer, and said semiconductor substrate to form trenches for planned shallow trench isolations; depositing a photoresist layer overlying said silicon nitride layer and filling said trenches; etching down said photoresist layer to below the top surface of said silicon nitride layer the trench remaining filled; patterning said silicon nitride layer and said pad oxide layer to form dummy gates where said transistor gates are planned and wherein the presence of said photoresist layer protects said trenches from patterning; removing said photoresist layer; thereafter depositing a dielectric layer overlying said dummy gates and said trenches; polishing down said dielectric layer to the top surface of said dummy gates to thereby form said shallow trench isolations and to form a planarized interlevel dielectric layer; etching away said dummy gates to form openings for said planned transistor gate electrodes; depositing a gate electrode layer overlying said dielectric layer and filling said openings for said planned transistor gate electrode; and polishing down said gate electrode layer to form said transistor gates and to complete said integrated circuit device.
Claim 2
Independent Claim 224 words
A method to form transistor gates and shallow trench isolations in the manufacture of an integrated circuit device comprising: providing a semiconductor substrate; depositing a pad oxide layer overlying said semiconductor substrate; depositing a silicon nitride layer overlying said pad oxide layer; patterning said silicon nitride layer, said pad oxide layer, and said semiconductor substrate to form trenches for planned shallow trench isolations; depositing a photoresist layer overlying said silicon nitride layer and filling said trenches; etching down said photoresist layer to below the top surface of said silicon nitride layer the trench remaining filled; patterning said silicon nitride layer and said pad oxide layer to form dummy gates where said transistor gates are planned and wherein the presence of said photoresist layer protects said trenches from patterning; removing said photoresist layer; thereafter depositing a dielectric layer overlying said dummy gates and said trenches; polishing down said dielectric layer to the top surface of said dummy gates to thereby form said shallow trench isolations and to form a planarized interlevel dielectric layer; etching away said dummy gates to form openings for said planned transistor gate electrodes; depositing a gate electrode layer overlying said dielectric layer and filling said openings for said planned transistor gate electrode; and polishing down said gate electrode layer to form said transistor gates and to complete said integrated circuit device.
Claim 3
Dependent Claim 24 words
The method according to claim 1 wherein said pad oxide layer is deposited to a thickness of between about 50 Angstroms and 200 Angstroms.
Claim 4
Dependent Claim 24 words
The method according to claim 1 wherein said silicon nitride layer is deposited to a thickness of between about 1,000 Angstroms and 2,500 Angstroms.
Claim 5
Dependent Claim 23 words
The method according to claim 1 wherein said photoresist layer is deposited to a thickness of between about 4,000 Angstroms and 8,000 Angstroms.
Claim 6
Dependent Claim 21 words
The method according to claim 1 wherein said dielectric layer comprises a silicon dioxide deposited by a high density plasma process.
Claim 7
Dependent Claim 23 words
The method according to claim 1 wherein said dielectric layer is deposited to a thickness of between about 8,000 Angstroms and 15,000 Angstroms.
Claim 8
Dependent Claim 30 words
The method according to claim 1 wherein said gate electrode layer comprises a conductive material of the group containing: polysilicon, W, WSi x , WSiN, WN x , and TiN.
Claim 9
Dependent Claim 63 words
The method according to claim 1 further comprising oxidizing said trenches to form an oxide layer on the inside surfaces of said trenches wherein said oxidizing is performed after said step of patterning said silicon nitride layer, said pad oxide layer, and said semiconductor substrate to form said trenches and wherein said oxidizing is performed before said step of depositing said photoresist layer.
Claim 10
Dependent Claim 53 words
The method according to claim 1 further comprising forming sidewall spacers on said dummy gate electrodes wherein said forming is after said step of patterning said silicon nitride layer and said pad oxide layer to form said dummy gate electrodes and wherein said forming is before said step of removing said photoresist layer.
Claim 11
Independent Claim 272 words
A method to form MOS transistors with shallow trench isolations in the manufacture of an integrated circuit device comprising: providing a semiconductor substrate; depositing a pad oxide layer overlying said semiconductor substrate; depositing a silicon nitride layer overlying said pad oxide layer; patterning said silicon nitride layer, said pad oxide layer, and said semiconductor substrate to form trenches for planned shallow trench isolations; depositing a photoresist layer overlying said silicon nitride layer and filling said trenches; implanting ions into said semiconductor substrate to form transistor well junctions; etching down said photoresist layer to below the top surface of said silicon nitride layer the trench remaining filled; patterning said silicon nitride layer and said pad oxide layer to form dummy gates where said transistor gates are planned and wherein the presence of said photoresist layer protects said trenches from patterning; implanting ions into said semiconductor substrate to form lightly doped drain junctions; forming sidewall spacers on said dummy gate electrodes; implanting ions into said semiconductor substrate to form source and drain junctions; removing said photoresist layer; thereafter depositing a dielectric layer overlying said dummy gates and said trenches; polishing down said dielectric layer to the top surface of said dummy gates to thereby form said shallow trench isolations and to form a planarized interlevel dielectric layer; etching away said dummy gates to form openings for said planned transistor gate electrodes; depositing a gate electrode layer overlying said dielectric layer and filling said openings for said planned transistor gate electrode; and polishing down said gate electrode layer to form said transistor gates and to form said transistors and to complete said integrated circuit device.
Claim 12
Independent Claim 272 words
A method to form MOS transistors with shallow trench isolations in the manufacture of an integrated circuit device comprising: providing a semiconductor substrate; depositing a pad oxide layer overlying said semiconductor substrate; depositing a silicon nitride layer overlying said pad oxide layer; patterning said silicon nitride layer, said pad oxide layer, and said semiconductor substrate to form trenches for planned shallow trench isolations; depositing a photoresist layer overlying said silicon nitride layer and filling said trenches; implanting ions into said semiconductor substrate to form transistor well junctions; etching down said photoresist layer to below the top surface of said silicon nitride layer the trench remaining filled; patterning said silicon nitride layer and said pad oxide layer to form dummy gates where said transistor gates are planned and wherein the presence of said photoresist layer protects said trenches from patterning; implanting ions into said semiconductor substrate to form lightly doped drain junctions; forming sidewall spacers on said dummy gate electrodes; implanting ions into said semiconductor substrate to form source and drain junctions; removing said photoresist layer; thereafter depositing a dielectric layer overlying said dummy gates and said trenches; polishing down said dielectric layer to the top surface of said dummy gates to thereby form said shallow trench isolations and to form a planarized interlevel dielectric layer; etching away said dummy gates to form openings for said planned transistor gate electrodes; depositing a gate electrode layer overlying said dielectric layer and filling said openings for said planned transistor gate electrode; and polishing down said gate electrode layer to form said transistor gates and to form said transistors and to complete said integrated circuit device.
Claim 13
Dependent Claim 24 words
The method according to claim 10 wherein said pad oxide layer is deposited to a thickness of between about 50 Angstroms and 200 Angstroms.
Claim 14
Dependent Claim 24 words
The method according to claim 10 wherein said silicon nitride layer is deposited to a thickness of between about 1,000 Angstroms and 2,500 Angstroms.
Claim 15
Dependent Claim 23 words
The method according to claim 10 wherein said photoresist layer is deposited to a thickness of between about 4,000 Angstroms and 8,000 Angstroms.
Claim 16
Dependent Claim 21 words
The method according to claim 10 wherein said dielectric layer comprises a silicon dioxide deposited by a high density plasma process.
Claim 17
Dependent Claim 23 words
The method according to claim 10 wherein said dielectric layer is deposited to a thickness of between about 8,000 Angstroms and 15,000 Angstroms.
Claim 18
Dependent Claim 30 words
The method according to claim 10 wherein said gate electrode layer comprises a conductive material of the group containing: polysilicon, W, WSi x , WSiN, WN x , and TiN.
Claim 19
Dependent Claim 63 words
The method according to claim 10 further comprising oxidizing said trenches to form an oxide layer on the inside surfaces of said trenches wherein said oxidizing is performed after said step of patterning said silicon nitride layer, said pad oxide layer, and said semiconductor substrate to form said trenches and wherein said oxidizing is performed before said step of depositing said photoresist layer.
Claim 20
Independent Claim 302 words
A method to form MOS transistors with shallow trench isolations in the manufacture of an integrated circuit device comprising: providing a semiconductor substrate; depositing a pad oxide layer overlying said semiconductor substrate; depositing a silicon nitride layer overlying said pad oxide layer; patterning said silicon nitride layer, said pad oxide layer, and said semiconductor substrate to form trenches for planned shallow trench isolations; oxidizing said trenches to form an oxide layer on the inside surfaces of said trenches; depositing a photoresist layer overlying said silicon nitride layer and filling said trenches; implanting ions into said semiconductor substrate to form transistor well junctions; etching down said photoresist layer to below the top surface of said silicon nitride layer the trench remaining filled; patterning said silicon nitride layer and said pad oxide layer to form dummy gates where said transistor gates are planned and wherein the presence of said photoresist layer protects said trenches from patterning; implanting ions into said semiconductor substrate to form lightly doped drain junctions; forming sidewall spacers on said dummy gate electrodes; implanting ions into said semiconductor substrate to form source and drain junctions; removing said photoresist layer; thereafter depositing a dielectric layer overlying said dummy gates and said trenches wherein said dielectric layer comprises a silicon dioxide deposited by a high density plasma process; polishing down said dielectric layer to the top surface of said dummy gates to thereby form said shallow trench isolations and to form a planarized interlevel dielectric layer; etching away said dummy gates to form openings for said planned transistor gate electrodes; depositing a gate electrode layer overlying said dielectric layer and filling said openings for said planned transistor gate electrode; and polishing down said gate electrode layer to form said transistor gates and to form said transistors and to complete said integrated circuit device.
Claim 21
Independent Claim 302 words
A method to form MOS transistors with shallow trench isolations in the manufacture of an integrated circuit device comprising: providing a semiconductor substrate; depositing a pad oxide layer overlying said semiconductor substrate; depositing a silicon nitride layer overlying said pad oxide layer; patterning said silicon nitride layer, said pad oxide layer, and said semiconductor substrate to form trenches for planned shallow trench isolations; oxidizing said trenches to form an oxide layer on the inside surfaces of said trenches; depositing a photoresist layer overlying said silicon nitride layer and filling said trenches; implanting ions into said semiconductor substrate to form transistor well junctions; etching down said photoresist layer to below the top surface of said silicon nitride layer the trench remaining filled; patterning said silicon nitride layer and said pad oxide layer to form dummy gates where said transistor gates are planned and wherein the presence of said photoresist layer protects said trenches from patterning; implanting ions into said semiconductor substrate to form lightly doped drain junctions; forming sidewall spacers on said dummy gate electrodes; implanting ions into said semiconductor substrate to form source and drain junctions; removing said photoresist layer; thereafter depositing a dielectric layer overlying said dummy gates and said trenches wherein said dielectric layer comprises a silicon dioxide deposited by a high density plasma process; polishing down said dielectric layer to the top surface of said dummy gates to thereby form said shallow trench isolations and to form a planarized interlevel dielectric layer; etching away said dummy gates to form openings for said planned transistor gate electrodes; depositing a gate electrode layer overlying said dielectric layer and filling said openings for said planned transistor gate electrode; and polishing down said gate electrode layer to form said transistor gates and to form said transistors and to complete said integrated circuit device.
Claim 22
Dependent Claim 23 words
The method according to claim 18 wherein said photoresist layer is deposited to a thickness of between about 4,000 Angstroms and 8,000 Angstroms.
Claim 23
Dependent Claim 30 words
The method according to claim 18 wherein said gate electrode layer comprises a conductive material of the group containing: polysilicon, W, WSi x , WSiN, WN x , and TiN.

References Cited (Backward Citations)

JPH02177355A Cited
US4994409A Cited
KR920000708B1 Cited
US5346584A Cited
US5786255A Cited
US5856225A Cited
US6177699B1 Cited
US5915183A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2004-08-27 2005-02-26 2005-08-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2008-08-27 2009-02-26 2009-08-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2012-08-27 2013-02-26 2013-08-28 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag