US3829883A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic field detector employing plural drain igfet
Assignee: Individual
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Filing: 1973-11-09
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Granted: 1974-08-13
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Expires: 1993-11-09
Abstract
Abstract A mode of operation of a three-drain configured insulated gate field effect transistor which is extremely sensitive to magnetic fields is disclosed. The gate of the transistor is biased to a level less than transistor threshold, or alternatively, is connected to substrate ground. A first drain region opposite the source is biased to achieve avalanche breakdown of the junction. The other two drains are defined on either side of a line joining the source and first drain. These two drains are biased at a voltage below that required for avalanche of their junctions. In response to a magnetic field a voltage difference is generated across these two drains. In one embodiment of the invention, the region opposite the source is of a conductivity type the same as the substrate. In this configuration the detector does not require avalanche breakdown.
Inventors
- 👤 R Bate
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:49
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/02; G01R33/06; H; H10; H10D; H10D48/00; H10D48/40
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
158 words
A magnetic field detector comprising: a semiconductor substrate of one conductivity type; a first region of opposite conductivity type extending into said substrate from one surface thereof; a second region of said one conductivity type extending into said substrate from said one surface and of higher conductivity than said substrate, said second region being spaced from said first region and arranged in substantially bilaterally symmetrical registration therewith; third and fourth regions of said opposite conductivity type extending into said substrate from said one surface and positioned on opposite sides of a straight line extending between and bisecting said first and second regions, said third and foruth regions being spaced from each other and from said first and second regions respectively; and said third and fourth regions being effective to generate a voltage thereacross in response to a magnetic field substantially perpendicular to the plane of said substrate when said first, second, third and fourth regions are appropriately biased.
Claim 2
Dependent Claim
158 words
A magnetic field detector comprising: a semiconductor substrate of one conductivity type; a first region of opposite conductivity type extending into said substrate from one surface thereof; a second region of said one conductivity type extending into said substrate from said one surface and of higher conductivity than said substrate, said second region being spaced from said first region and arranged in substantially bilaterally symmetrical registration therewith; third and fourth regions of said opposite conductivity type extending into said substrate from said one surface and positioned on opposite sides of a straight line extending between and bisecting said first and second regions, said third and foruth regions being spaced from each other and from said first and second regions respectively; and said third and fourth regions being effective to generate a voltage thereacross in response to a magnetic field substantially perpendicular to the plane of said substrate when said first, second, third and fourth regions are appropriately biased.
Claim 3
Dependent Claim
163 words
A magnetic field detector as set forth in claim 1, further including a first insulating layer disposed over said substrate and each of said first, second, third, and fourth regions defined therein; said first insulating layer having a first aperture formed therein, said first aperture in said first insulating layer exposing a portion of said substrate located substantially centrally with respect to said four regions defined therein and including marginal portions of each of said four regions; a second insulating layer relatively thin with respect to said first insulating layer, said second insulating layer being disposed in said first aperture in said first insulating layer and covering the portion of said substrate located substantially centrally with respect to said four regions and the said marginal portions of each of said four regions; and a conductive layer disposed on said second insulating layer in overlying relationship and extending into at least partially overlying but spaced relationship with respect to each of said four regions.
Claim 4
Dependent Claim
20 words
A magnetic field detector as set forth in claim 2 including means for connecting said conductive layer to circuit ground.
Claim 5
Dependent Claim
75 words
A magnetic field detector as set forth in claim 2, wherein said means for connecting said conductive layer to circuit ground comprises a second aperture formed in said first insulating layer and exposing another portion of said substrate outwardly with respect to said portion of said substrate located substantially centrally with respect to said four regions; and said conductive layer extending into said second aperture in said first insulating layer into contact with said substrate.
Claim 6
Dependent Claim
35 words
A magnetic field detector as set forth in claim 4, wherein said substrate is n type silicon, said second region is n+ type silicon, and said first, third, and fourth regions are p type silicon.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-12 | 1978-02-11 | 1978-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-12 | 1982-02-11 | 1982-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-12 | 1986-02-11 | 1986-08-13 | $7700.00 | Window Closed / Lapsed |