US5416038A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing semiconductor device with two different threshold voltages
Assignee: United Microelectronics Corp
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Filing: 1994-05-25
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Granted: 1995-05-16
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Expires: 2014-05-25
Abstract
Abstract A semiconductor MOSFET device manufactured by a process starting with a doped semiconductor substrate with a P-well and an N-well and field oxide structures on the surface of the P-well and the N-well separating the surfaces of the P-well and the N-well into separate regions and a silicon dioxide film on the remainder of the surface of the P-well and the N-well comprising the steps as follows: forming a mask over the N-well and an under sized mask over one of the separate regions of the P-well performing a field ion implantation of V t ' ions into the P-well, removing the mask over the portion of the P-well, performing a blanket ion implantation of V t1 ions over the entire device.
Inventors
- 👤 Chen-Chiu Hsue
- 👤 Sun-Chieh Chien
- 👤 Lee C. Yuan
- 👤 Tzong-Shien Wu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:33
CPC Classifications
H; H10; H10D; H10D84/00; H10D84/01; H10D84/0123; H10D84/0126; H10D84/0165; H10D84/0167; H10D84/02; H10D84/03; H10D84/038
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
129 words
A method of manufacture of a semiconductor MOSFET device starting with a doped semiconductor substrate with a P-well and an N-well and field oxide structures on the surface of said P-well and said N-well separating the surfaces of said P-well and said N-well into separate regions and a silicon dioxide film on the remainder of the surface of said P-well and said N-well comprising the steps as follows: forming a mask over said N-well and over a portion of one of said separate regions of said P-well using said mask, performing a field ion implantation and an implantation of V t ' ions into said P-well, removing said mask over said portion of said P-well, and performing a blanket ion implantation of V t1 ions over the resultant structure.
Claim 2
Independent Claim
129 words
A method of manufacture of a semiconductor MOSFET device starting with a doped semiconductor substrate with a P-well and an N-well and field oxide structures on the surface of said P-well and said N-well separating the surfaces of said P-well and said N-well into separate regions and a silicon dioxide film on the remainder of the surface of said P-well and said N-well comprising the steps as follows: forming a mask over said N-well and over a portion of one of said separate regions of said P-well using said mask, performing a field ion implantation and an implantation of V t ' ions into said P-well, removing said mask over said portion of said P-well, and performing a blanket ion implantation of V t1 ions over the resultant structure.
Claim 3
Dependent Claim
55 words
A method in accordance with claim 1 wherein said V t ' ion implant dopant is selected from the group consisting of B 11 and BF 2 and is applied at an energy from about 10 keV to about 80 keV with a dose from about 5×10E11 cm -2 to about 5×10E12 cm -2 .
Claim 4
Dependent Claim
46 words
A method in accordance with claim 1 wherein said V t1 ion implant dopant consists of BF 2 and is applied at an energy from about 10 keV to about 80 keV, with a dose from about 8×10E11 cm -2 to about 5×10E12 cm -2 .
Claim 5
Dependent Claim
46 words
A method in accordance with claim 2 wherein said V t1 ion implant dopant consists of BF 2 and is applied at an energy from about 10 keV to about 80 keV, with a dose from about 8×10E11 cm -2 to about 5×10E12 cm -2 .
Claim 6
Dependent Claim
50 words
A method in accordance with claim 1 wherein said V t1 ion implant dopant is selected from the group consisting of P 31 and As+ and is applied at an energy from about 30 keV to about 120 keV, with a dose from about 5×10E11 cm -2 to about 5×10E12.
Claim 7
Dependent Claim
50 words
A method in accordance with claim 2 wherein said V t1 ion implant dopant is selected from the group consisting of P 31 and As+ and is applied at an energy from about 30 keV to about 120 keV, with a dose from about 5×10E11 cm -2 to about 5×10E12.
Claim 8
Dependent Claim
50 words
A method in accordance with claim 3 wherein said V t1 ion implant dopant is selected from the group consisting of P 31 and As+ and is applied at an energy from about 30 keV to about 120 keV, with a dose from about 5×10E11 cm -2 to about 5×10E12.
Claim 9
Dependent Claim
50 words
A method in accordance with claim 4 wherein said V t1 ion implant dopant is selected from the group consisting of P 31 and As+ and is applied at an energy from about 30 keV to about 120 keV, with a dose from about 5×10E11 cm -2 to about 5×10E12.
Claim 10
Dependent Claim
27 words
A method in accordance with claim 1 wherein said field implant comprises B 11 dopant applied at an energy from about 120 keV to about 200 keV.
Claim 11
Dependent Claim
27 words
A method in accordance with claim 2 wherein said field implant comprises B 11 dopant applied at an energy from about 120 keV to about 200 keV.
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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) | 1998-05-15 | 1998-11-14 | 1999-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-05-15 | 2002-11-14 | 2003-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-05-15 | 2006-11-14 | 2007-05-16 | $7700.00 | Window Closed / Lapsed |