Patent US3836993A successfully refreshed from Google Patents.
US3836993A
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Magnetic field dependent field effect transistor
Assignee: Telefunken Electronic GmbH
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Filing: 1973-10-18
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Granted: 1974-09-17
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Expires: 1993-10-18
Abstract
Abstract A magnetic field effect transistor comprises a semiconductor body with a region of a specific type of conductivity, a source and a drain electrode between which is provided a channel region formed by a narrowed part of the region of the specific type of conductivity at least one barrier layer defining the channel region and controlling the channel region through the space charge region issuing from the barrier layer, and at least one additional electrode positioned laterally of the direct charge carrier path between the source and drain electrodes and to which at least part of the charge carrier can be deflected in the presence of a suitable magnetic field.
Inventors
- 👤 V Joshi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 04:06
CPC Classifications
H; H10; H10D; H10D48/00; H10D48/40
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
234 words
A magnetic field dependent field effect transistor comprising a semiconductor body, a region of a specific type of conductivity in said semiconductor body, two main ohmic electrodes forming source and drain electrodes, a narrowed portion of said region of said specific type of conductivity positioned between said two main electrodes to form a channel region containing a direct path for charge carriers between said two main electrodes, at least one barrier layer defining said channel region and controlling said channel region by means of a space charge region issuing from said barrier layer and at least one additional electrode positioned laterally of said direct path for said charge carriers and located between said draIn electrode and said channel region, said space charge region extending into said channel region in a direction which lies in the plane defined by said source and drain electrodes and said additional electrode, said transistor being arranged to permit a magnetic field component perpendicular to said plane to push back said space charge region, so as to vary the width of said channel region, to an extent dependent on the strength of such magnetic field component, and to deflect such charge carriers in a direction normal to, and to an extent dependent on the strength of, such magnetic field component, and said additional electrode being positioned to receive at least part of the charge carriers which have been thus deflected.
Claim 2
Dependent Claim
234 words
A magnetic field dependent field effect transistor comprising a semiconductor body, a region of a specific type of conductivity in said semiconductor body, two main ohmic electrodes forming source and drain electrodes, a narrowed portion of said region of said specific type of conductivity positioned between said two main electrodes to form a channel region containing a direct path for charge carriers between said two main electrodes, at least one barrier layer defining said channel region and controlling said channel region by means of a space charge region issuing from said barrier layer and at least one additional electrode positioned laterally of said direct path for said charge carriers and located between said draIn electrode and said channel region, said space charge region extending into said channel region in a direction which lies in the plane defined by said source and drain electrodes and said additional electrode, said transistor being arranged to permit a magnetic field component perpendicular to said plane to push back said space charge region, so as to vary the width of said channel region, to an extent dependent on the strength of such magnetic field component, and to deflect such charge carriers in a direction normal to, and to an extent dependent on the strength of, such magnetic field component, and said additional electrode being positioned to receive at least part of the charge carriers which have been thus deflected.
Claim 3
Dependent Claim
64 words
A field effect transistor as defined in claim 1, further comprising at least one control electrode defining said barrier layer for controlling said space-charge region and means for supplying to said control electrode a voltage for causing said channel region to be just blocked by said space-charge region or regions issuing from said barrier layer or layers in the absence of said magnetic field.
Claim 4
Dependent Claim
40 words
A field effect transistor as defined in claim 1, further comprising means for providing a magnetic control field extending perpendicularly to the direction of movement of said charge carriers between said source electrode and said drain or said additional electrode.
Claim 5
Dependent Claim
37 words
A field effect transistor as defined in claim 1, wherein said semiconductor body comprises a high resistivity base and said region of said specific type of conductivity comprises a semiconductor layer arranged on said high resistivity base.
Claim 6
Dependent Claim
190 words
A magnetic field dependent field effect transistor comprising a semiconductor body composed of a high resistivity base, a region of a specific type of conductivity in said semiconductor body, said region including a semiconductor layer arranged on said high resistivity base, two main ohmic electrodes forming source and drain electrodes, a narrowed portion of said region of said specific type of conductivity positioned between said two main electrodes to form a channel region containing a direct path for charge-carriers between said two main electrodes, at least one barrier layer defining said channel region and controlling said channel region by means of a space charge region issuing from said barrier layer and at least one additional electrode positioned laterally of said direct path for said charge-carriers and located between said drain electrode and said channel region, at least a part of said charge-carriers being deflected to said additional electrode in the presence of a magnetic field of suitable direction and polarity, wherein said semiconductor layer of said specific type of conductivity defines two recesses extending to or near said semiconductor base leaving between them a narrow web forming said channel region.
Claim 7
Dependent Claim
190 words
A magnetic field dependent field effect transistor comprising a semiconductor body composed of a high resistivity base, a region of a specific type of conductivity in said semiconductor body, said region including a semiconductor layer arranged on said high resistivity base, two main ohmic electrodes forming source and drain electrodes, a narrowed portion of said region of said specific type of conductivity positioned between said two main electrodes to form a channel region containing a direct path for charge-carriers between said two main electrodes, at least one barrier layer defining said channel region and controlling said channel region by means of a space charge region issuing from said barrier layer and at least one additional electrode positioned laterally of said direct path for said charge-carriers and located between said drain electrode and said channel region, at least a part of said charge-carriers being deflected to said additional electrode in the presence of a magnetic field of suitable direction and polarity, wherein said semiconductor layer of said specific type of conductivity defines two recesses extending to or near said semiconductor base leaving between them a narrow web forming said channel region.
Claim 8
Dependent Claim
33 words
A field effect transistor as defined in claim 5, further comprising rectifying Schottky contacts contacting said semiconductor layer of said specific type of conductivity and formed by filling said recesses with a metal.
Claim 9
Dependent Claim
21 words
A field effect transistor as defined in claim 6, wherein said semiconductor layer comprises a layer of semiconductor material produced epitaxially.
Claim 10
Dependent Claim
29 words
A field effect transistor as defined in claim 6, wherein said semiconductor layer has a first type of conductivity and said semiconductor body has a second type of conductivity.
Claim 11
Dependent Claim
44 words
A field effect transistor as defined in claim 6, wherein said Schottky contacts comprise contacts of T-shaped configuration arranged symmetrically to said path of said charge-carriers with the stem of the T''s of the T-shaped configurations separated at their ends by said channel region.
Claim 12
Dependent Claim
39 words
A field effect transistor as defined in claim 9, wherein said two main electrodes comprise electrodes mounted on said semiconductor layer of said specific conductivity and spaced apart by said stems of said Schottky contacts and said channel region.
Claim 13
Dependent Claim
51 words
A field eFfect transistor as defined in claim 10, wherein said two main electrodes comprise metal filling recesses defined by said semiconductor layer of said specific type of conductivity, and extending to or near said semiconductor base and forming ohmic contacts with said semiconductor layer of said specific type of conductivity.
Claim 14
Dependent Claim
40 words
A field effect transistor as defined in claim 9, further comprising a semiconductor separating region of the opposite type of conductivity to said semiconductor layer and surrounding a part of said semiconductor layer for limiting and isolating the transistor region.
Claim 15
Dependent Claim
61 words
A field effect transistor as defined in claim 12, wherein the cross bars of the ''''T'''' of the Schottky contacts adjoins said semiconductor separating region and the association between said Schottky contacts and said semiconductor separating region is arranged to prevent current flow between said two main electrodes through a semiconductor region between said Schottky contacts and said semiconductor separating region.
Claim 16
Dependent Claim
29 words
A field effect transistor as defined in claim 11, and comprising two of said additional electrodes arranged one on either side of said direct path for said charge carriers.
Claim 17
Dependent Claim
55 words
A field effect transistor as defined in claim 14, wherein said semiconductor layer of said specific type of conductivity defines recesses for said additional electrodes extending to or near to said semiconductor base and said additional electrodes comprise metal in said recesses in ohmic contact with said semiconductor layer of said specific type of conductivity.
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) | 1977-09-16 | 1978-03-18 | 1978-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-16 | 1982-03-18 | 1982-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-16 | 1986-03-18 | 1986-09-17 | $7700.00 | Window Closed / Lapsed |