US3739236A
Expired / Lapsed
US
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Semiconductor switching device
Assignee: Microsystems International Ltd
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Filing: 1971-07-19
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Granted: 1973-06-12
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Expires: 1991-07-19
Abstract
Abstract A four layer two terminal semiconductor switch having a preferred lowest resistance current path from its base contact through the base adjacent the emitter. Means are provided to cause a particular position or region of the base periphery to break down at the switching current, or to cause base current to flow to a conductive ring at the surface of the base; whereby an emitter-biasing voltage is set up in the base. Good individual control of both the switching current (IS) and the holding current (IH) is thus afforded.
Inventors
- 👤 A Loro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:57
CPC Classifications
H; H10; H10D; H10D8/00; H10D8/80; H10D84/00; H10D84/60; H10D84/676; H10D99/00
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
187 words
A semiconductor device comprising: a. a succession of four contiguous semiconductor regions, each successive region having opposite conductivity from the previous, said regions being defined by a first emitter region, a first base region contiguous with the emitter region, a second base region diffused into a defined volume of the first base region, and a second emitter region diffused into a defined volume of the second base region; the junctions between the first base, second base and second emitter regions extending to one surface of the semiconductor device, b. contact means connecting the second emitter region to the second base region, the improvement characterized by c. a resistive path from the contact means to a predetermined portion of the outer periphery of the second base region, said portion having a significantly lower breakdown voltage than any other portion of said periphery, said path passing directly through and via the second base region adjacent a portion of the second emitter region, and having a lower resistance than any other resistive path between the contact means and any other location on said outer periphery of the second base region.
Claim 2
Dependent Claim
187 words
A semiconductor device comprising: a. a succession of four contiguous semiconductor regions, each successive region having opposite conductivity from the previous, said regions being defined by a first emitter region, a first base region contiguous with the emitter region, a second base region diffused into a defined volume of the first base region, and a second emitter region diffused into a defined volume of the second base region; the junctions between the first base, second base and second emitter regions extending to one surface of the semiconductor device, b. contact means connecting the second emitter region to the second base region, the improvement characterized by c. a resistive path from the contact means to a predetermined portion of the outer periphery of the second base region, said portion having a significantly lower breakdown voltage than any other portion of said periphery, said path passing directly through and via the second base region adjacent a portion of the second emitter region, and having a lower resistance than any other resistive path between the contact means and any other location on said outer periphery of the second base region.
Claim 3
Dependent Claim
28 words
A semiconductor device as defined in claim 1, in which the predesignated portion of said periphery has a steeper impurity concentration gradient than the remainder of said periphery.
Claim 4
Dependent Claim
28 words
A semiconductor device as defined in claim 1, in which the predesignated portion of said periphery has a shorter radius of curvature than the remainder of said periphery.
Claim 5
Dependent Claim
51 words
A semiconductor device as defined in claim 3, in which the second base region is approximately disc or ellipse shaped, comprising a border region having a reduced thickness and a shorter radius periphery in cross-section than the remainder of the second base region, the shorter radius periphery defining said predesignated portion.
Claim 6
Dependent Claim
58 words
A semiconductor device as defined in claim 3, in which the second base region is approximately disc or ellipse shaped, a C shaped portion thereof forming the major part of the outer periphery being deeper diffused than the remainder; the edge of the disc or ellipse shaped portion at the gap in the C defining said predesignated portion.
Claim 7
Dependent Claim
37 words
A semiconductor device as defined in claim 3, in which said predesignated portion is comprised of one or more sharply angled serrations lying transverse to said one surface of said device, extending into the first base region.
Claim 8
Dependent Claim
33 words
A semiconductor device as defined in claim 3, further comprising means for providing said preferred path of current flow through the second base region under and adjacent a portion of second emitter region.
Claim 9
Dependent Claim
114 words
A semiconductor device as defined in claim 7, in which the second emitter region contains a hole through which the second base region extends to said one surface of said device, the hole being disposed closer to the periphery of the second emitter region adjacent said predesignated portion of the second base region; the contact means comprising a metallization overlay within the boundary of the second emitter region contacting both the second emitter region and the second base region above the hole at said surface, the portion of the base region from the contact means through the hole to said predesignated portion of the second base region defining said preferred path of current flow.
Claim 10
Dependent Claim
40 words
A semiconductor device as defined in claim 3, further comprising means for providing said preferred path of current flow through the second base region bounded and limited by portions of the second emitter region on either side of said path.
Claim 11
Dependent Claim
124 words
A semiconductor device as defined in claim 9, in which the second emitter region contains a keyway extending transversely into the region a predetermined distance, and completely through the depth thereof, extending from the edge of the second emitter region adjacent said pre-designated portion of the second base region, the second base region extending through the keyway to said surface; the contact means comprising a metallization overlay within the boundary of the second emitter region contacting both the second emitter region, and the second base region above the keyway at the inner end thereof; the portion of the second base region from the contact means through the keyway to said predesignated portion of the second base region defining said preferred path of current flow.
Claim 12
Dependent Claim
65 words
A semiconductor device as defined in claim 7, further comprising a metallized area extending over the surface of said device to a boundary outwardly of the second base region and over the first base region, except for an area overlying the predesignated portion of the periphery of the second base region; and means insulating the metallized area from said surface outwardly of the contact means.
Claim 13
Dependent Claim
181 words
A semiconductor device as defined in claim 4 in which the second emitter region contains a keyway extending transversely into the region a predetermined distance, and completely through the depth thereof, extending from the edge of the second emitter region adjacent said predesignated portion of the second base region, the second base region extending through the keyway to said surface; the contact means comprising a metallization overlay within the boundary of the second emitter region contacting both the second emitter region, and the second base region above the keyway at the inner end thereof; the portion of the second base region from the contact means through the keyway to said predesignated portion oF the second base region defining said preferred path of current flow; further comprising a metallized area extending over the surface of said device to a boundary outwardly of the second base region and over the first base region except for an area overlying the predesignated portion of the periphery of the second base region; and means insulating the metallized area from said surface outwardly of the contact means.
Claim 14
Dependent Claim
133 words
A semiconductor device as defined in claim 12, in which the first emitter region is comprised of a P doped silicon substrate, the first base region is comprised of an N doped silicon epitaxial layer contiguous with a surface at said substrate, the second base region is comprised of P doped silicon contained within a defined region of the epitaxial layer from said surface, and the second emitter region is comprised of N doped silicon contained within a defined region of the second base region from said surface, the insulative layer being comprised of silicon dioxide contiguous with said surface of said device; further comprising a P+ doped silicon isolation region spaced from and ringing the second base region, bounded by the epitaxial region on two sides thereof, in contact with the substrate.
Claim 15
Dependent Claim
25 words
A semiconductor device as defined in claim 12, in which the insulative layer under the metallized area has a thickness less than about 2,000 angstroms.
Claim 16
Dependent Claim
40 words
A semiconductor device as defined in claim 1 further comprising an electrically conductive ring completely surrounding the second emitter region at said surface centrally above the second base region, said preferred path being between the contact means and said ring.
Claim 17
Dependent Claim
33 words
A semiconductor device as defined in claim 15 further comprising means for providing said preferred path of current flow through the second base region under and adjacent a portion of second emitter region.
Claim 18
Dependent Claim
85 words
A semiconductor device as defined in claim 16, in which the second emitter region contains a hole through which the second base region extends to said one surface of the device, the hole being disposed closer to the periphery of the second emitter region adjacent said predesignated portion of the second base region; the contact means comprising a metallization overlay within the boundary of the second emitter region contacting both the second emitter region, and the second base region above the hole, at said surface.
Claim 19
Dependent Claim
40 words
A semiconductor device as defined in claim 15 further comprising means for providing said preferred path of current flow through the second base region bounded and limited by portions of the second emitter region on either side of said path.
Claim 20
Dependent Claim
94 words
A semiconductor device as defined in claim 18, in which the second emitter region contains a keyway extending transversely into the region a predetermined distance, and completely through the depth thereof, extending from the edge of the second emitter region adjacent said predesignated portion of the second base region, the second base region extending through the keyway to said surface; the contact means comprising a metallization overlay within the boundary of the second emitter region contacting both the second emitter region, and the second base region above the keyway at the inner end thereof.
Claim 21
Dependent Claim
28 words
A semiconductor device as defined in claim 15, in which the conductive ring is comprised of a ring-shaped metallization layer adherently disposed on the surface of said device.
Claim 22
Dependent Claim
51 words
A semiconductive device as defined in claim 15, in which the conductive ring is comprised of a highly doped ring of semiconductor, doped with an element from the same group of the periodic table as the dopant of the second base region, contained within the second base region at said surface.
Claim 23
Dependent Claim
65 words
A semiconductor device as defined in claim 9, further comprising a metallized area extending over the surface of said device to a boundary outwardly of the second base region and over the first base region, except for an area overlying the predesignated portion of the pEriphery of the second base region; and means insulating the metallized area from said surface outwardly of the contact means.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-06-11 | 1976-12-11 | 1977-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-11 | 1980-12-11 | 1981-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-11 | 1984-12-11 | 1985-06-12 | $7700.00 | Window Closed / Lapsed |