US6200836B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Using oxide junction to cut off sub-threshold leakage in CMOS devices
Assignee: Taiwan Semiconductor Manufacturing Co TSMC Ltd
•
Filing: 1999-08-06
•
Granted: 2001-03-13
•
Expires: 2019-08-06
Abstract
Abstract A new method is provided for the formation of Lightly Doped Drain (LDD) regions in MOS devices. The body of the gate electrode is formed including the self-aligned LDD regions. After the LDD regions have been formed, an oxide implant is performed under an angle into the surface of the substrate on which the MOS device is being formed. This oxide implant forms an oxide layer around the interface between the source/drain regions and the surrounding silicon. The spacers for the gate electrode are formed, the source/drain region implant is completed. This implanted oxygen junction is subjected to a thermal treatment thereby forming an oxide layer around the source/drain regions. This oxide layer eliminates the leakage current across the interface between the source/drain regions and the surrounding silicon further forcing the saturation current between these regions to flow along the surface of the silicon substrate.
Inventors
- 👤 Chue-San Yoo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 12:06
CPC Classifications
H; H10; H10P; H10P30/00; H10P30/20; H10P30/208; H10P30/209; H10D; H10D62/00; H10D62/10; H10D62/113; H10D62/115; H10D62/116
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
108 words
A method of creating source and drain regions in a CMOS device in the surface of a semiconductor substrate, comprising: providing a semiconductor substrate; forming isolation regions in said semiconductor substrate, thereby creating active regions within said substrate; forming a p-well in said active regions of said substrate; creating a partial gate electrode structure on the surface of said substrate overlying said p-well; performing a tilt angle oxygen implant into the source/drain regions of said partial gate electrode structure; forming the spacers for said gate electrode structure; completing the source and the drain implant for said partial gate electrode structure; and performing a thermal treatment of said substrate.
Claim 2
Independent Claim
108 words
A method of creating source and drain regions in a CMOS device in the surface of a semiconductor substrate, comprising: providing a semiconductor substrate; forming isolation regions in said semiconductor substrate, thereby creating active regions within said substrate; forming a p-well in said active regions of said substrate; creating a partial gate electrode structure on the surface of said substrate overlying said p-well; performing a tilt angle oxygen implant into the source/drain regions of said partial gate electrode structure; forming the spacers for said gate electrode structure; completing the source and the drain implant for said partial gate electrode structure; and performing a thermal treatment of said substrate.
Claim 3
Dependent Claim
60 words
The method of claim 1 wherein said creating a partial gate electrode is: creating a layer of gate oxide on the surface of said substrate; depositing a layer of gate dielectric material over said gate oxide; patterning and etching said layer of polysilicon thereby forming said partial gate electrode structure; and performing a self-aligned LDD implant of an n-type impurity.
Claim 4
Dependent Claim
21 words
The method of claim 2 wherein said gate dielectric material is selected from the group containing oxide, nitride, polysilicon and SiGE.
Claim 5
Dependent Claim
46 words
The method of claim 2 wherein said gate dielectric material can be formed by RTO oxide or by JVD oxide or by RTP S i N or by RTP SiO x N y or by JVD T i O 2 or by JVD TaO 2 .
Claim 6
Dependent Claim
48 words
The method of claim 2 wherein said performing a self-aligned LDD implant is an arsenic or phosphorous implant performed with an implant energy within the range of between about 25 and 75 keV and a dose within the range of between about 5E11 and 5E13 atoms/cm 3 .
Claim 7
Dependent Claim
34 words
The method of claim 2 wherein said depositing a layer of gate dielectric material uses Low Pressure CVD (LPCVD) the thickness of said gate dielectric material layer is between about 1500 and 3000 Angstrom.
Claim 8
Dependent Claim
64 words
The method of claim 1 wherein said performing a tilt angle oxygen implant is implanting oxygen at a dose in the range 1×10 12 to 1×10 13 atoms/cm 3 and an energy in the range of 2 to 30 kilo electron volts said implant to be performed under an angle of about 30 to 60 degrees with respect to the plane of said substrate.
Claim 9
Dependent Claim
71 words
The method of claim 1 wherein said forming the spacers for said gate electrode structure comprises the thermally growing of a thin oxide on the sides of said gate electrode using a short dry-oxidation process whereupon a conformal CVD oxide film is deposited by decomposing TEOS at between 700 and 750 degrees C. followed by an anisotropic dry etch thereby leaving said spacers on the sidewalls of said gate electrode holes.
Claim 10
Dependent Claim
55 words
The method of claim 1 wherein said forming the spacers for said gate electrode structure is forming said spacers by a process including a substantially conformal deposition of a spacer material selected from the group consisting of nitride, oxide, BSG, PSG and any combination thereof, and a subsequent, substantially anisotropic etch of said spacer material.
Claim 11
Dependent Claim
73 words
The method of claim 1 wherein said forming the spacers for said gate electrode structure is depositing a conformal first insulating layer, preferably a low temperature SiO 2 , and anisotropically plasma etching back to the surface of said substrate whereby said insulator is deposited using a chemical vapor deposition (CVD) using tetra-ethyl-ortho-silicate (TEOS) at a temperature between about 650 and 900 degrees C. while the etchback is a reactive ion etcher (RIE).
Claim 12
Dependent Claim
67 words
The method of claim 1 wherein said completing the source and the drain implant for said partial gate electrode structure is a self aligned n + implant into the surface of said substrate provided by arsenic or phosphorous with an implant energy within the range of between about 30 and 100 keV and a dose within the range of between about 1E14 and 1E16 atoms/cm 3 .
Claim 13
Independent Claim
222 words
A method of creating source and drain regions in a CMOS device in the surface of a semiconductor substrate, comprising: providing a semiconductor substrate; forming isolation regions in said semiconductor substrate, thereby creating active regions within said substrate; forming a p-well in said active regions of said substrate; creating a partial gate electrode structure on the surface of said substrate overlaying said p-well said partial gate structure to contain a gate electrode with self-aligned Lightly Doped Drain regions; performing a tilt angle oxygen implant into the source/drain regions of said partial gate electrode structure whereby said tilt angle implant is an oxygen implant at a dose in the range 1×10 12 to 1×10 13 atoms/cm 3 and an energy in the range of 2 to 30 kilo electron volts said implant to be performed under an angle of about 30 to 60 degrees with respect to the plane of said substrate; forming the spacers for said gate electrode structure; completing the source and the drain implant for said partial gate electrode structure whereby said completion is a self aligned n + implant into the surface of said substrate provided by arsenic or phosphorous with an implant energy within the range of between about 30 and 100 keV and a dose within the range of between about 1E14 and 1E16 atoms/cm 3 .
Claim 14
Independent Claim
222 words
A method of creating source and drain regions in a CMOS device in the surface of a semiconductor substrate, comprising: providing a semiconductor substrate; forming isolation regions in said semiconductor substrate, thereby creating active regions within said substrate; forming a p-well in said active regions of said substrate; creating a partial gate electrode structure on the surface of said substrate overlaying said p-well said partial gate structure to contain a gate electrode with self-aligned Lightly Doped Drain regions; performing a tilt angle oxygen implant into the source/drain regions of said partial gate electrode structure whereby said tilt angle implant is an oxygen implant at a dose in the range 1×10 12 to 1×10 13 atoms/cm 3 and an energy in the range of 2 to 30 kilo electron volts said implant to be performed under an angle of about 30 to 60 degrees with respect to the plane of said substrate; forming the spacers for said gate electrode structure; completing the source and the drain implant for said partial gate electrode structure whereby said completion is a self aligned n + implant into the surface of said substrate provided by arsenic or phosphorous with an implant energy within the range of between about 30 and 100 keV and a dose within the range of between about 1E14 and 1E16 atoms/cm 3 .
Claim 15
Independent Claim
108 words
A method of creating source and drain regions in a PMOS device in the surface of a semiconductor substrate, comprising: providing a semiconductor substrate; forming an n-well in the surface of said substrate; forming isolation regions in said semiconductor substrate, thereby creating active regions within said substrate; creating a partial gate electrode structure in said active regions of said substrate overlying said n-well; performing a tilt angle oxygen implant into the source/drain regions of said partial gate electrode structure; forming the spacers for said gate electrode structure; completing the source and the drain implant for said partial gate electrode structure; and performing a thermal treatment of said substrate.
Claim 16
Independent Claim
108 words
A method of creating source and drain regions in a PMOS device in the surface of a semiconductor substrate, comprising: providing a semiconductor substrate; forming an n-well in the surface of said substrate; forming isolation regions in said semiconductor substrate, thereby creating active regions within said substrate; creating a partial gate electrode structure in said active regions of said substrate overlying said n-well; performing a tilt angle oxygen implant into the source/drain regions of said partial gate electrode structure; forming the spacers for said gate electrode structure; completing the source and the drain implant for said partial gate electrode structure; and performing a thermal treatment of said substrate.
Claim 17
Dependent Claim
60 words
The method of claim 12 wherein said creating a partial gate electrode is: creating a layer of gate oxide over the active regions of said substrate; depositing a layer of gate dielectric material over said gate oxide; patterning and etching said layer of polysilicon thereby forming said gate electrode structure; and performing a self-aligned LDD implant of a p-type impurity.
Claim 18
Dependent Claim
21 words
The method of claim 13 wherein said gate dielectric material is selected from the group containing oxide, nitride, polysilicon and SiGE.
Claim 19
Dependent Claim
46 words
The method of claim 13 wherein said gate dielectric material can be formed by RTO oxide or by JVD oxide or by RTP S i N or by RTP SiO x N y or by JVD T i O 2 or by JVD TaO 2 .
Claim 20
Dependent Claim
48 words
The method of claim 13 wherein said performing a self-aligned LDD implant is a boron or indium implant performed with an implant energy within the range of between about 25 and 75 keV and a dose within the range of between about 5E11 and 5E13 atoms/cm 3 .
Claim 21
Dependent Claim
34 words
The method of claim 13 wherein said depositing a layer of gate dielectric material uses Low Pressure CVD (LPCVD) the thickness of said gate dielectric material layer is between about 1500 and 3000 Angstrom.
Claim 22
Dependent Claim
64 words
The method of claim 12 wherein said performing a tilt angle oxygen implant is implanting oxygen at a dose in the range 1×10 12 to 1×10 13 atoms/cm 3 and an energy in the range of 2 to 30 kilo electron volts said implant to be performed under an angle of about 30 to 60 degrees with respect to the plane of said substrate.
Claim 23
Dependent Claim
71 words
The method of claim 12 wherein said forming the spacers for said gate electrode structure comprises the thermally growing of a thin oxide on the sides of said gate electrode using a short dry-oxidation process whereupon a conformal CVD oxide film is deposited by decomposing TEOS at between 700 and 750 degrees C. followed by an anisotropic dry etch thereby leaving said spacers on the sidewalls of said gate electrode holes.
Claim 24
Dependent Claim
55 words
The method of claim 12 wherein said forming the spacers for said gate electrode structure is forming said spacers by a process including a substantially conformal deposition of a spacer material selected from the group consisting of nitride, oxide, BSG, PSG and any combination thereof, and a subsequent, substantially anisotropic etch of said spacer material.
Claim 25
Dependent Claim
73 words
The method of claim 12 wherein said forming the spacers for said gate electrode structure is depositing a conformal first insulating layer, preferably a low temperature SiO 2 , and anisotropically plasma etching back to the surface of said substrate whereby said insulator is deposited using a chemical vapor deposition (CVD) using tetra-ethyl-ortho-silicate (TEOS) at a temperature between about 650 and 900 degrees C. while the etchback is a reactive ion etcher (RIE).
Claim 26
Dependent Claim
63 words
The method of claim 12 wherein said completing the source and the drain implant for said partial gate electrode structure is a self aligned p + implant into the surface of said substrate provided by boron or indium at a dose in the range of 1E14 to 1E16 atoms/cm 3 and an energy in the range of 30 to 100 kilo electron volts.
Claim 27
Independent Claim
238 words
A method of creating source and drain regions in a CMOS device in the surface of a semiconductor substrate, comprising: providing a semiconductor substrate; forming isolation regions in said semiconductor substrate, thereby creating active regions within said substrate; forming a n-well in the active regions of said substrate; creating a partial gate electrode structure on the surface of said substrate overlying said n-well said partial gate structure to contain a gate electrode with self-aligned Lightly Doped Drain regions in the surface of the substrate and adjacent to said gate electrode; performing a tilt angle oxygen implant into the source/drain regions of said partial gate electrode structure whereby said tilt angle implant is an oxygen implant at a dose in the range 1×10 12 to 1×10 13 atoms/cm 3 and an energy in the range of 2 to 30 kilo electron volts said implant to be performed under an angle of about 30 to 60 degrees with respect to the plane of said substrate; forming the spacers for said gate electrode structure; completing the source and the drain implant for said partial gate electrode structure whereby said completion is a self aligned p + implant into the surface of said substrate provided by boron or indium at a dose in the range of 1E14 to 1E16 atoms/cm 3 and an energy in the range of 30 to 100 kilo electron volts; and performing a thermal treatment of said substrate.
Claim 28
Independent Claim
238 words
A method of creating source and drain regions in a CMOS device in the surface of a semiconductor substrate, comprising: providing a semiconductor substrate; forming isolation regions in said semiconductor substrate, thereby creating active regions within said substrate; forming a n-well in the active regions of said substrate; creating a partial gate electrode structure on the surface of said substrate overlying said n-well said partial gate structure to contain a gate electrode with self-aligned Lightly Doped Drain regions in the surface of the substrate and adjacent to said gate electrode; performing a tilt angle oxygen implant into the source/drain regions of said partial gate electrode structure whereby said tilt angle implant is an oxygen implant at a dose in the range 1×10 12 to 1×10 13 atoms/cm 3 and an energy in the range of 2 to 30 kilo electron volts said implant to be performed under an angle of about 30 to 60 degrees with respect to the plane of said substrate; forming the spacers for said gate electrode structure; completing the source and the drain implant for said partial gate electrode structure whereby said completion is a self aligned p + implant into the surface of said substrate provided by boron or indium at a dose in the range of 1E14 to 1E16 atoms/cm 3 and an energy in the range of 30 to 100 kilo electron volts; and performing a thermal treatment of said substrate.
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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) | 2004-03-12 | 2004-09-11 | 2005-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-03-12 | 2008-09-11 | 2009-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-03-12 | 2012-09-11 | 2013-03-13 | $7700.00 | Window Closed / Lapsed |