Patent US3873373A successfully refreshed from Google Patents.
US3873373A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fabrication of a semiconductor device
Assignee: Individual
•
Filing: 1973-12-11
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Granted: 1975-03-25
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Expires: 1993-12-11
Abstract
Abstract A semiconductor material of a first conductivity type has one of its surfaces subjected to high energy oxygen ion implantation, thereby forming an oxide layer below that surface. A gate is formed by masking at least a portion of the surface, exposing the unmasked portion to ion radiation so as to implant impurity ions in the region of the semiconductor material between its unmasked surface and the upper side of the subsurface oxide layer, and metallizing the surface above the implanted region. After removal of the masking material, source and drain areas are formed by high energy ion implantation in the semiconductor material adjacent the lower side of the subsurface oxide layer, the areas having a conductivity opposite the first conductivity type. After windows to the source and drain areas are opened in the semiconductor material and subsurface oxide layer, the exposed surfaces of these areas are metallized.
Inventors
- 👤 Bryan H Hill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:33
CPC Classifications
H; H10; H10D; H10D99/00; H10D30/00; H10D30/60; H10P; H10P95/00
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
241 words
A METHOD FOR FABRICATING AN INSULATED GATE, FIELD EFFECT TRANSISTOR WHICH COMPRISES IMPLANTING OXYGEN IONS BELOW A SURFACE OF A SEMICONTUCTOR BODY OF A FIRST CONDUCTIVITY TYPE; HEATING THE BODY AT A TEMPERATURE IN THE RANGE OF ABOUT 1,100* TO 1,300*C FOR A PERIOD OF ABOUT 3 TO 6 HOURS, THEREBY FORMING AN OXIDE LAYER OF THE SEMICONDUCTOR BELOW THE SURFACE OF THE BODY, MASKING AT LEAST A PORTION OF THE SURFACE OF THE BODY; EXPOSING THE UNMASKED PORTION OF THE BODY TO ION RADIATION SO AS TO IMPLANT IMPURITY IONS IN THE REGION OF THE SEMICONDUCTOR BODY BETWEEN ITS UNMASKED SURFACE AND THE UPPPER SURFACE OF THE SUBSURFACE OXIDE LAYER; METALLIZING THE SURFACE ABOVE THE ION IMPLANTED REGION OF THE BODY; REMOVING THE MASKING MATERIAL; BOMBARDING THE SURFACE OF THE BODY WITH HIGH IMPURITY IONS SO AS TO FORM SOURCE AND DRAIN AREAS ADJACENT THE LOWER SIDE OF THE SUBSURFACE OXIDE LAYER, THE AREAS HAVING A CONDUCTIVITY OPPOSITE THE FIRST CONDUCTIVITY TYPE; HEATING THE BODY AT A TEMPERATURE IN THE RANGE OF ABOUT 500* TO 600*C FOR A PERIOD OF ABOUT 0.5 TO 1 HOUR; REMOVING SEMICONDUCTOR MATERIAL AND SUBSURFACE OXIDE LAYER ABOVE THE SOURCE AND DRAIN AREAS, THEREBY EXPOSING AT LEAST A PORTION OF THE SURFACE OF THE SOURCE AND DRAIN AREAS; MASKING THE GATE ELECTRODE; METALLIZING AT LEAST A PROTION OF THE EXPOSED SURFACES OF THE SOURCE AND DRAIN AREAS; AND REMOVING THE MASK FROM THE GATE ELECTRODE.
Claim 2
Independent Claim
241 words
A METHOD FOR FABRICATING AN INSULATED GATE, FIELD EFFECT TRANSISTOR WHICH COMPRISES IMPLANTING OXYGEN IONS BELOW A SURFACE OF A SEMICONTUCTOR BODY OF A FIRST CONDUCTIVITY TYPE; HEATING THE BODY AT A TEMPERATURE IN THE RANGE OF ABOUT 1,100* TO 1,300*C FOR A PERIOD OF ABOUT 3 TO 6 HOURS, THEREBY FORMING AN OXIDE LAYER OF THE SEMICONDUCTOR BELOW THE SURFACE OF THE BODY, MASKING AT LEAST A PORTION OF THE SURFACE OF THE BODY; EXPOSING THE UNMASKED PORTION OF THE BODY TO ION RADIATION SO AS TO IMPLANT IMPURITY IONS IN THE REGION OF THE SEMICONDUCTOR BODY BETWEEN ITS UNMASKED SURFACE AND THE UPPPER SURFACE OF THE SUBSURFACE OXIDE LAYER; METALLIZING THE SURFACE ABOVE THE ION IMPLANTED REGION OF THE BODY; REMOVING THE MASKING MATERIAL; BOMBARDING THE SURFACE OF THE BODY WITH HIGH IMPURITY IONS SO AS TO FORM SOURCE AND DRAIN AREAS ADJACENT THE LOWER SIDE OF THE SUBSURFACE OXIDE LAYER, THE AREAS HAVING A CONDUCTIVITY OPPOSITE THE FIRST CONDUCTIVITY TYPE; HEATING THE BODY AT A TEMPERATURE IN THE RANGE OF ABOUT 500* TO 600*C FOR A PERIOD OF ABOUT 0.5 TO 1 HOUR; REMOVING SEMICONDUCTOR MATERIAL AND SUBSURFACE OXIDE LAYER ABOVE THE SOURCE AND DRAIN AREAS, THEREBY EXPOSING AT LEAST A PORTION OF THE SURFACE OF THE SOURCE AND DRAIN AREAS; MASKING THE GATE ELECTRODE; METALLIZING AT LEAST A PROTION OF THE EXPOSED SURFACES OF THE SOURCE AND DRAIN AREAS; AND REMOVING THE MASK FROM THE GATE ELECTRODE.
Claim 3
Dependent Claim
64 words
The method according to claim 1 in which the semiconductor body is a P-type monocrystalline silicon body; phosphorus ions are implanted in the unmasked portion in the region of the body between its unmasked suface and the upper surface of the oxide layer; and the surface of the body is bombarded with high energy phosphorus ions so as to form source and drain areas.
Claim 4
Dependent Claim
115 words
The method according to claim 2 in which the oxygen ions are implanted by directing onto the surface of the body a million electron volt beam of oxygen ions having an intensity of 12 X 1012 ions/cm2 for a period of about 102 to 103 seconds; the region of the semiconductor body between its unmasked surface and the upper surface of the subsurface oxide layer contains 1019 to 1020 phosphorus ions; and the surface of the body is bombarded with a 1.1 to 1.4 million electron volt beamm of phosphorus ions having an intensity of 12 X 1012 ions/cm2 for a period of 102 to 103 seconds so as to form source and drain areas.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-24 | 1978-09-23 | 1979-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-24 | 1982-09-23 | 1983-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-24 | 1986-09-23 | 1987-03-25 | $7700.00 | Window Closed / Lapsed |