Patent US4396933A successfully refreshed from Google Patents.
US4396933A
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US
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Dielectrically isolated semiconductor devices
Assignee: International Business Machines Corp
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Filing: 1973-10-01
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Granted: 1983-08-02
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Expires: 1993-10-01
Abstract
Abstract A dielectrically isolated semiconductor device can be manufactured. The structure is useable for integrated circuits, including field effect and/or bipolar transistors, wherein a significant savings in surface area and reduction in capacitances can be obtained over prior techniques. The method involves forming a layer of dielectric material upon a semiconductor body, having a diffused region where a bipolar device is to be formed, and then forming an opening in the layer to expose a part of the surface of the diffused region of the semiconductor body. An epitaxial layer of silicon is deposited on top. Single crystal silicon will grow over the exposed silicon area and if a diffused region is present in the substrate a pedestal will outdiffuse through the same area from the buried diffused region. Polycrystalline silicon will grow on top of the dielectric material. The pedestal is formed in a single crystal epitaxial layer of another impurity type. Two other active elements of a bipolar transistor, such as the emitter and intrinsic base regions, are then formed in the same single crystal epitaxial layer while the inactive area, such as the extrinsic base, is formed in polycrystalline silicon. A reach through is made through the dielectric layer to the third element of the transistor, that is collector region.
Inventors
- 👤 Ingrid E. Magdo
- 👤 Steven Magdo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:52
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/20; H10D; H10D10/00; H10D10/01; H10D10/051; H10D10/054; H10D99/00; H10W10/00; H10W10/01; H10W10/011; H10W10/018; H10W10/10; H10W20/01; H10W20/021
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
148 words
A semiconductor device comprising a body, said body comprising: a monocrystalline substrate; at least a first layer consisting of silicon semiconductor material on a surface of said substrate; a second layer of insulating material located at only part of the said substrate surface and buried within the body; and means forming an isolation zone for isolating part of the first semiconductor layer from another part of the semiconductor layer; said isolation zone comprising at least partly a third layer of insulating material inset in the first semiconductor layer from its surface and extending down to and at least partly adjoining the second insulating layer; said third layer consisting of silicon oxide formed by in situ conversion of the semiconductor material of the first semiconductor layer; the lateral extent of the second layer being different from the lateral extent of the third layer where it adjoins the second layer.
Claim 2
Dependent Claim
148 words
A semiconductor device comprising a body, said body comprising: a monocrystalline substrate; at least a first layer consisting of silicon semiconductor material on a surface of said substrate; a second layer of insulating material located at only part of the said substrate surface and buried within the body; and means forming an isolation zone for isolating part of the first semiconductor layer from another part of the semiconductor layer; said isolation zone comprising at least partly a third layer of insulating material inset in the first semiconductor layer from its surface and extending down to and at least partly adjoining the second insulating layer; said third layer consisting of silicon oxide formed by in situ conversion of the semiconductor material of the first semiconductor layer; the lateral extent of the second layer being different from the lateral extent of the third layer where it adjoins the second layer.
Claim 3
Dependent Claim
24 words
A semiconductor device as claimed in claim 1, wherein the second layer is inset in the substrate to a depth of more than 0.5u.
Claim 4
Dependent Claim
42 words
A semiconductor device as claimed in claim 1, wherein in the substrate adjacent the buried second layer is a highly doped semiconductor zone, and a semiconductor circuit element is built into the part of the first layer over the said semiconductor zone.
Claim 5
Dependent Claim
22 words
A semiconductor device as claimed in claim 1, wherein the inset third layer entirely overlaps the buried second layer at least locally.
Claim 6
Dependent Claim
85 words
A semiconductor device as claimed in claim 1, wherein the body comprises at least a transistor in which the collector zone is at the surface and the emitter zone is buried in the body, the isolation zone comprises insulating material which laterally bounds the base zone, and the buried emitter zone is connected to a contact provided on the semiconductor surface along a path underneath said isolation zone and via an upwardly conducting path through the semiconductor on the other side of the isolation zone.
Claim 7
Dependent Claim
24 words
A semiconductor device as claimed in claim 5, wherein the emitter-base junction is substantially flat and is bounded along its circumference by insulating material.
Claim 8
Dependent Claim
29 words
A semiconductor device as in claim 1 further comprising: a silicon region extending from said substrate at least to said first layer through an opening in said second layer.
Claim 9
Dependent Claim
51 words
A semiconductor device as in claim 1 wherein at least a portion of said first layer is doped with impurities of a first conductivity type and further comprising: a doped region of opposite conductivity type formed into the portion of said first layer doped with impurities of said first conductivity type.
Claim 10
Dependent Claim
108 words
A semiconductor device as in claim 1 wherein at least a portion of said first layer is doped with impurities of a first conductivity type, said substrate being doped with impurities of the first conductivity type, and at least a portion of said substrate under said second layer being doped with impurities of opposite conductivity type, further comprising: a plurality of silicon regions extending from said substrate to at least said first layer through openings in said second layer; and the portion of said substrate under said second layer doped with impurities of opposite type forming an electrical connecting path between two of said plurality of monocrystalline regions.
Claim 11
Dependent Claim
84 words
A semiconductor device as in claim 1, wherein the body comprises at least a transistor in which the emitter zone is at the surface and the collector zone is buried in the body, the isolation zone comprises insulating material which laterally bounds the base zone, and the buried collector zone is connected to a contact provided on the semiconductor surface along a path underneath said isolation zone and via an upwardly conducting path through the semiconductor on the other side of the isolation zone.
Claim 12
Dependent Claim
41 words
A semiconductor device as in claim 1, wherein the second layer of insulating material located at only part of the said substrate is in adjacent contact with said substrate and also in adjacent contact with a portion of said first layer.
Claim 13
Dependent Claim
146 words
A semiconductor device comprising a body, said body comprising: a monocrystalline substrate; at least a first layer consisting of silicon semiconductor material on a surface of said substrate; a second layer of insulating material located at only part of the said substrate surface and buried within the body; and an isolation zone for isolating part of the first semiconductor layer from another part of the semiconductor layer; said isolation zone comprising at least partly a third layer of insulating material inset in the first semiconductor layer from its surface and extending down to and at least partly adjoining the second insulating layer; said third layer consisting of silicon oxide formed by in situ conversion of the semiconductor material of the first semiconductor layer; the lateral extent of the second layer being different from the lateral extent of the third layer where it adjoins the second layer.
Claim 14
Dependent Claim
146 words
A semiconductor device comprising a body, said body comprising: a monocrystalline substrate; at least a first layer consisting of silicon semiconductor material on a surface of said substrate; a second layer of insulating material located at only part of the said substrate surface and buried within the body; and an isolation zone for isolating part of the first semiconductor layer from another part of the semiconductor layer; said isolation zone comprising at least partly a third layer of insulating material inset in the first semiconductor layer from its surface and extending down to and at least partly adjoining the second insulating layer; said third layer consisting of silicon oxide formed by in situ conversion of the semiconductor material of the first semiconductor layer; the lateral extent of the second layer being different from the lateral extent of the third layer where it adjoins the second layer.
Claim 15
Dependent Claim
147 words
A semiconductor device comprising a body, said body comprising: a monocrystalline substrate; at least a first layer consisting of silicon semiconductor material on a surface of said substrate; a second layer of insulating material located at only part of the said substrate surface and buried within the body; and means forming an isolation zone for isolating part of the first semiconductor layer from another part of the semiconductor layer; said means comprising at least partly a third layer of insulating material inset in the first semiconductor layer from its surface and extending down to and at least partly adjoining the second insulating layer; said third layer consisting of silicon oxide formed by in situ conversion of the semiconductor material of the first semiconductor layer; the lateral extent of the second layer being different from the lateral extent of the third layer where it adjoins the second layer.
Claim 16
Dependent Claim
147 words
A semiconductor device comprising a body, said body comprising: a monocrystalline substrate; at least a first layer consisting of silicon semiconductor material on a surface of said substrate; a second layer of insulating material located at only part of the said substrate surface and buried within the body; and means forming an isolation zone for isolating part of the first semiconductor layer from another part of the semiconductor layer; said means comprising at least partly a third layer of insulating material inset in the first semiconductor layer from its surface and extending down to and at least partly adjoining the second insulating layer; said third layer consisting of silicon oxide formed by in situ conversion of the semiconductor material of the first semiconductor layer; the lateral extent of the second layer being different from the lateral extent of the third layer where it adjoins the second layer.
Claim 17
Dependent Claim
34 words
A semiconductor device as in claim 1 wherein the lateral extent of the second layer is different from the lateral extent of the third layer in the plane where it adjoins the second layer.
Claim 18
Dependent Claim
147 words
A semiconductor device comprising a body, said body comprising: a monocrystalline substrate; at least a first layer consisting of silicon semiconductor material on a surface of said substrate; a second layer of insulating material located at only selected portions of the said substrate and buried within the body; and means forming an isolation zone for isolating part of the first semiconductor layer from another part of the semiconductor layer; said means comprising at least partly a third layer of insulating material inset in the first semiconductor layer from its surface and extending down to and at least partly adjoining the second insulating layer; said third layer consisting of silicon oxide formed by in situ conversion of the semiconductor material of the first semiconductor layer; the lateral extent of the second layer being different from the lateral extent of the third layer where it adjoins the second layer.
Claim 19
Dependent Claim
147 words
A semiconductor device comprising a body, said body comprising: a monocrystalline substrate; at least a first layer consisting of silicon semiconductor material on a surface of said substrate; a second layer of insulating material located at only selected portions of the said substrate and buried within the body; and means forming an isolation zone for isolating part of the first semiconductor layer from another part of the semiconductor layer; said means comprising at least partly a third layer of insulating material inset in the first semiconductor layer from its surface and extending down to and at least partly adjoining the second insulating layer; said third layer consisting of silicon oxide formed by in situ conversion of the semiconductor material of the first semiconductor layer; the lateral extent of the second layer being different from the lateral extent of the third layer where it adjoins the second layer.
Claim 20
Dependent Claim
37 words
A semiconductor device as in claim 15, wherein the second layer of insulating material located at only selected portions of the said substrate is silicon dioxide material in adjacent contact with a portin of said first layer.
Claim 21
Dependent Claim
54 words
A semiconductor device as in claim 16, where the second layer of insulating material is also in adjacent contact with said third layer and further comprising: silicon material extending from the substrate to the surface of the body; said silicon material being surrounded partly by said second layer and partly by said third layer.
Claim 22
Dependent Claim
24 words
A semiconductor device as in claim 17 wherein said silicon material comprises: an electrical contact from the surface of the body to the substrate.
Claim 23
Dependent Claim
15 words
A semiconductor device as in claim 17 wherein said silicon material is doped with impurities.
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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) | 1986-08-01 | 1987-01-31 | 1987-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-01 | 1991-01-31 | 1991-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-01 | 1995-01-31 | 1995-08-02 | $7700.00 | Window Closed / Lapsed |