US4829361A
Expired / Lapsed
US
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Semiconductor device
Assignee: Hitachi Ltd
•
Filing: 1987-11-16
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Granted: 1989-05-09
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Expires: 2007-11-16
Abstract
Abstract A semiconductor device wherein a layer doped with impurities is provided between a buried layer and an epitaxial layer, said layer doped with impurities having a conductivity of the type opposite to that of said buried layer and said epitaxial layer, a reversely biasing voltage is applied across the buried layer and the layer doped with impurities, and side surfaces of the epitaxial layer are surrounded by an insulator. This helps effectively prevent the element formed in the epitaxial layer from being affected by α-particles and greatly improve reliability of the semiconductor device.
Inventors
- 👤 Kazuhiko Sagara
- 👤 Tohru Nakamura
- 👤 Kazuo Nakazato
- 👤 Tokuo Kure
- 👤 Kiyoji Ikeda
- 👤 Noriyuki Homma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:55
CPC Classifications
H; H10; H10B; H10B10/00; H10B10/10; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/10; H10W15/00; H10W15/01; Y; Y10; Y10S; Y10S257/00; Y10S257/906
Claims Analysis
Total Claims: 40
Claim 1
Independent Claim
347 words
A semiconductor device, including at least one semiconductor element formed in an active region constituted by a semiconductor epitaxial layer, comprising: a semiconductor substrate of a first type of conductivity; a buried layer which is formed in a surface region of said semiconductor substrate of a first type of conductivity, said buried layer having a second type of conductivity opposite to the first type of conductivity; an epitaxial layer of the second type of conductivity stacked on said buried layer, said epitaxial layer having sides extending from a bottom surface closest to the buried layer to an upper surface of the epitaxial layer, the active region, in which at least one semiconductor element is formed, being constituted by said epitaxial layer; a doped layer, of the first type of conductivity, interposed between the buried layer and the epitaxial layer, the doped layer of the first type of conductivity having a bottom surface adjacent the buried layer and an upper surface opposite the bottom surface, and having sides extending from the upper surface thereof to the bottom surface, the doped layer including first and second portions, the first portion being covered by the epitaxial layer, and the second portion not being covered by the epitaxial layer; an insulator region which extends the length of the sides of said epitaxial layer of the second type of conductivity, surrounding said epitaxial layer, the insulator region having a bottom surface closest to the substrate and an upper surface opposite the bottom surface, and sides extending between the bottom and upper surfaces, with the insulator region, together with the buried layer and doped layer, being positioned so as to shield said active region from the semiconductor substrate such that any electrons produced in the semiconductor substrate by α-particles are prevented from infiltrating into the active region; a further semiconductor layer, of the second type of conductivity, provided on the substrate and contacting the buried layer, so that electrical contact to the buried layer can be provided; and at least one semiconductor element formed in said active region constituted by the epitaxial layer.
Claim 2
Dependent Claim
347 words
A semiconductor device, including at least one semiconductor element formed in an active region constituted by a semiconductor epitaxial layer, comprising: a semiconductor substrate of a first type of conductivity; a buried layer which is formed in a surface region of said semiconductor substrate of a first type of conductivity, said buried layer having a second type of conductivity opposite to the first type of conductivity; an epitaxial layer of the second type of conductivity stacked on said buried layer, said epitaxial layer having sides extending from a bottom surface closest to the buried layer to an upper surface of the epitaxial layer, the active region, in which at least one semiconductor element is formed, being constituted by said epitaxial layer; a doped layer, of the first type of conductivity, interposed between the buried layer and the epitaxial layer, the doped layer of the first type of conductivity having a bottom surface adjacent the buried layer and an upper surface opposite the bottom surface, and having sides extending from the upper surface thereof to the bottom surface, the doped layer including first and second portions, the first portion being covered by the epitaxial layer, and the second portion not being covered by the epitaxial layer; an insulator region which extends the length of the sides of said epitaxial layer of the second type of conductivity, surrounding said epitaxial layer, the insulator region having a bottom surface closest to the substrate and an upper surface opposite the bottom surface, and sides extending between the bottom and upper surfaces, with the insulator region, together with the buried layer and doped layer, being positioned so as to shield said active region from the semiconductor substrate such that any electrons produced in the semiconductor substrate by α-particles are prevented from infiltrating into the active region; a further semiconductor layer, of the second type of conductivity, provided on the substrate and contacting the buried layer, so that electrical contact to the buried layer can be provided; and at least one semiconductor element formed in said active region constituted by the epitaxial layer.
Claim 3
Dependent Claim
25 words
A semiconductor device according to claim 1, wherein said first type of conductivity is the p-type and said second type of conductivity is the n-type.
Claim 4
Dependent Claim
33 words
A semiconductor device according to claim 1, wherein said element is at least one selected from the group consisting of a bipolar transistor, a diode a MOS transistor, a resistor and a capacitor.
Claim 5
Dependent Claim
24 words
A semiconductor device according to claim 3, wherein the semiconductor element is the bipolar transistor, and said bipolar transistor has a lateral pnp structure.
Claim 6
Dependent Claim
22 words
A semiconductor device according to claim 3, wherein the semiconductor element is the diode, and said diode is a Schottky barrier diode.
Claim 7
Dependent Claim
24 words
A semiconductor device according to claim 1, wherein a memory device is formed in said active region layer of the second type of conductivity.
Claim 8
Dependent Claim
39 words
A semiconductor device according to claim 1, wherein said first portion of the doped layer of the first type of conductivity has a thickness greater than 0.4 μm and an impurity concentration greater than 1×10 17 cm -3 .
Claim 9
Dependent Claim
19 words
A semiconductor device according to claim 1, further comprising electrical connection means for contacting said at least one element.
Claim 10
Dependent Claim
19 words
A semiconductor device according to claim 3, further comprising electrical connection means for contacting said at least one element.
Claim 11
Dependent Claim
44 words
A semiconductor device according to claim 1, wherein said insulator region extends the length of the sides of the doped layer of the first type of conductivity, surrounding said doped layer, in addition to extending the length of the sides of said epitaxial layer.
Claim 12
Dependent Claim
50 words
A semiconductor device according to claim 1, further comprising means for applying a voltage to said buried layer, via said further semiconductor layer, so as to form a depletion layer at a surface of the buried layer and prevent infiltration of electrons through said buried layer into said active region.
Claim 13
Dependent Claim
113 words
A semiconductor device according to claim 11, wherein said means for applying a voltage to said buried layer is a means for applying a reversely biasing voltage across said buried layer and said doped layer of the first type of conductivity, said means for applying a reversely biasing voltage including means for contacting said doped layer of the first type of conductivity, the means for contacting said doped layer being electrically connected to the second portion of the doped layer, and means for contacting the further semiconductor layer, of the second type of conductivity, said further semiconductor layer being electrically insulated from said active region and said second portion of the doped layer.
Claim 14
Dependent Claim
160 words
A semiconductor device according to claim 12, wherein said second portion of the doped layer is a doped region of the first type of conductivity provided adjacent one of the sides of said epitaxial layer, said doped region of the first type of conductivity extending to be in electrical contact with a side of said first portion of said doped layer of the first type of conductivity, the means for contacting said doped layer including a polycrystalline silicon layer having a low resistivity in contact with said doped region of the first type of conductivity, said polycrystalline silicon layer extending between said doped region of the first type of conductivity and the insulator region surrounding the sides of said epitaxial layer, and wherein the voltage is applied to said first portion of the doped layer of the first type of conductivity via said doped region of the first type of conductivity and said polycrystalline silicon layer having a low resistivity.
Claim 15
Dependent Claim
25 words
A semiconductor device according to claim 13, wherein said first type of conductivity is the p-type and said second type of conductivity is the n-type.
Claim 16
Dependent Claim
33 words
A semiconductor device according to claim 13, wherein said element is at least one selected from the group consisting of a bipolar transistor, a diode a MOS transistor, a resistor and a capacitor.
Claim 17
Dependent Claim
23 words
A semiconductor device according to claim 15, wherein said element is the bipolar transistor, and said bipolar transistor has a lateral pnp structure.
Claim 18
Dependent Claim
21 words
A semiconductor device according to claim 15, wherein said element is the diode, and said diode is a Schottky barrier diode.
Claim 19
Dependent Claim
17 words
A semiconductor device according to claim 13, wherein a memory device is formed in said active region.
Claim 20
Dependent Claim
34 words
A semiconductor device according to claim 13, wherein the insulator region, the epitaxial layer, the doped region of the first conductivity type and the polycrystalline silicon layer all extend to a common planar surface.
Claim 21
Dependent Claim
28 words
A semiconductor device according to claim 11, wherein the at least one semiconductor element is provided such that all semiconductor regions thereof are provided in said active region.
Claim 22
Dependent Claim
28 words
A semiconductor device according to claim 1, wherein the at least one semiconductor element is provided such that all semiconductor regions thereof are provided in said active region.
Claim 23
Dependent Claim
37 words
A semiconductor device according to claim 11, wherein said insulator region is positioned relative to said buried layer and said doped layer such that there is no direct contact between the semiconductor substrate and the active region.
Claim 24
Dependent Claim
37 words
A semiconductor device according to claim 1, wherein said insulator region is positioned relative to said buried layer and said doped layer such that there is no direct contact between the semiconductor substrate and the active region.
Claim 25
Dependent Claim
44 words
A semiconductor device according to claim 11, wherein said insulator region extends the length of the sides of the doped layer of the first type of conductivity, surrounding said doped layer, in addition to extending the length of the sides of said epitaxial layer.
Claim 26
Dependent Claim
16 words
A semiconductor device according to claim 1, wherein said insulator region is formed of silicon oxide.
Claim 27
Dependent Claim
63 words
A semiconductor device according to claim 1, wherein peripheral portions of the buried layer do not have the doped layer thereon; and wherein the insulator region extends the length of the sides of both said epitaxial layer and said doped layer, surrounding both said epitaxial layer and said doped layer, and contacts an upper surface of the peripheral portions of the buried layer.
Claim 28
Dependent Claim
52 words
A semiconductor device according to claim 1, wherein the insulator region, in combination with the buried layer and doped layer, are positioned so as to shield all semiconductor regions of said at least one semiconductor element formed in said active region from infiltration of electrons formed in the semiconductor substrate by α-particles.
Claim 29
Dependent Claim
26 words
A semiconductor device according to claim 1, wherein said insulator region is interposed between the second portion of the doped layer and the further semiconductor layer.
Claim 30
Dependent Claim
32 words
A semiconductor device according to claim 28, wherein said second portion of the doped layer extends adjacent a side of the epitaxial layer, interposed between the epitaxial layer and the insulator region.
Claim 31
Dependent Claim
30 words
A semiconductor device according to claim 29, wherein the insulator region is adjacent the second portion of the doped layer, and the further semiconductor layer is adjacent the insulator region.
Claim 32
Dependent Claim
66 words
A semiconductor device according to claim 30, wherein the doped layer is bounded by the insulator region, the buried layer extends beyond a periphery of the insulator region, and the further semiconductor layer extends along a side of the insulator region beyond the periphery of the insulator region, so that electrical contact to the buried layer can be made outside the periphery of the insulator region.
Claim 33
Dependent Claim
33 words
A semiconductor device according to claim 30, wherein each of said buried layer and said doped layer extend so as to be underneath all of the epitaxial layer surrounded by the insulator region.
Claim 34
Dependent Claim
33 words
A semiconductor device according to claim 1, wherein each of said buried layer and said doped layer extend so as to be underneath all of the epitaxial layer surrounded by the insulator region.
Claim 35
Dependent Claim
66 words
A semiconductor device according to claim 1, wherein the doped layer is bounded by the insulator region, the buried layer extends beyond a periphery of the insulator region, and the further semiconductor layer extends along a side of the insulator region beyond the periphery of the insulator region, so that electrical contact to the buried layer can be made outside the periphery of the insulator region.
Claim 36
Dependent Claim
68 words
A semiconductor device according to claim 1, wherein the insulator region is positioned to prevent electrons produced in the semiconductor substrate by α-particles from infiltrating into the active region through the sides of the epitaxial layer, and the doped and buried layers are positioned to prevent electrons produced in the semiconductor substrate by α-particles from infiltrating into the active region through the bottom surface of the epitaxial layer.
Claim 37
Dependent Claim
58 words
A semiconductor device according to claim 1, wherein said doped layer and said buried layer form a pn-junction therebetween, said pn-junction, together with said insulator region, being positioned so as to shield said active region from the semiconductor substrate such that any electrons produced in the semiconductor substrate by α-particles are prevented from infiltrating into the active region.
Claim 38
Dependent Claim
26 words
A semiconductor device according to claim 36, wherein said pn-junction extends so as to be beneath all of the epitaxial layer surrounded by the insulator region.
Claim 39
Dependent Claim
65 words
A semiconductor device according to claim 36, wherein the insulator region is positioned to prevent electrons produced in the semiconductor substrate by α-particles from infiltrating into the active region through the sides of the epitaxial layer, and the pn-junction is positioned to prevent electrons produced in the semiconductor substrate by α-particles from infiltrating into the active region through the bottom surface of the epitaxial layer.
Claim 40
Dependent Claim
29 words
A semiconductor device according to claim 10, wherein said pn-junction extends so as to be beneath all of the epitaxial layer and doped layer surrounded by the insulator region.
References Cited (Backward Citations)
US4476480A
Cited
US4573064A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-05-08 | 1992-11-07 | 1993-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-08 | 1996-11-07 | 1997-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-08 | 2000-11-07 | 2001-05-09 | $7700.00 | Window Closed / Lapsed |