Patent US4584594A successfully refreshed from Google Patents.
US4584594A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Logic structure utilizing polycrystalline silicon Schottky diodes
Assignee: National Semiconductor Corp
•
Filing: 1983-09-16
•
Granted: 1986-04-22
•
Expires: 2003-09-16
Abstract
Abstract An integrated circuit structure and process for fabricating it are described which allow fabrication of a very compact high-speed logic gate. The structure utilizes a bipolar transistor formed in an epitaxial silicon pocket surrounded by silicon dioxide. A pair of Schottky diodes and a resistor are formed outside the epitaxial pocket on the silicon dioxide and connected to the pocket by doped polycrystalline silicon.
Inventors
- 👤 Madhukar B. Vora
- 👤 Hemraj K. Hingarh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:58
CPC Classifications
H; H10; H10D; H10D1/00; H10D1/40; H10D1/47; H03; H03K; H03K19/00; H03K19/02; H03K19/08; H03K19/082; H03K19/084; H03K19/0846; H10D62/00; H10D62/40; H10D8/00; H10D8/60; H10D88/00; Y; Y10; Y10S; Y10S257/00; Y10S257/926
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
155 words
An integrated circuit structure comprising: a semiconductor body having an upper surface; a transistor fabricated in the body, the transistor including a first electrode and a second electrode each adjacent the upper surface; a surrounding region of insulating material inset into the body around the transistor; an electrically conductive layer of a metal silicide disposed on the surrounding region but not in contact with either the first or the second electrodes; a first region of polycrystalline silicon disposed on the electrically conductive layer; a second region of polycrystalline silicon disposed across the body and the surrounding region, a first part of the second region being disposed on the first region and a second part of the second region being disposed on the first electrode, the second part being doped to electrically connect the first electrode to the electrically conductive layer; and at least one metal electrode disposed on the first part of the second region.
Claim 2
Dependent Claim
155 words
An integrated circuit structure comprising: a semiconductor body having an upper surface; a transistor fabricated in the body, the transistor including a first electrode and a second electrode each adjacent the upper surface; a surrounding region of insulating material inset into the body around the transistor; an electrically conductive layer of a metal silicide disposed on the surrounding region but not in contact with either the first or the second electrodes; a first region of polycrystalline silicon disposed on the electrically conductive layer; a second region of polycrystalline silicon disposed across the body and the surrounding region, a first part of the second region being disposed on the first region and a second part of the second region being disposed on the first electrode, the second part being doped to electrically connect the first electrode to the electrically conductive layer; and at least one metal electrode disposed on the first part of the second region.
Claim 3
Dependent Claim
89 words
A structure as in claim 1 further comprising: a third region of polycrystalline silicon disposed across the body and the surrounding region, a first portion of the third region being disposed on the second electrode in electrical contact therewith, a second portion of the third region being disposed on the surrounding region and separated from the first portion by a third portion of the third region; and wherein the third portion is doped to provide a resistance to electrical signals flowing between the first portion and the second portion.
Claim 4
Dependent Claim
50 words
A structure as in claim 2 wherein: the first electrode is connected to a collector of the transistor; the second electrode comprises an emitter of the transistor; and at least one metal electrode and the first part of the second region form a Schottky diode connected to the first electrode.
Claim 5
Dependent Claim
54 words
A structure as in claim 3 further comprising: a third electrode coupled to a base of the transistor and adjacent the upper surface; and a fourth region of polycrystalline silicon disposed on the body in contact with the third electrode and electrically isolated from each of the first and second regions of polycrystalline silicon.
Claim 6
Dependent Claim
37 words
A structure as in claim 4 further comprising a metal shorting region disposed on the fourth region of polycrystalline silicon and on the first portion of the third region to electrically connect the base to the emitter.
Claim 7
Dependent Claim
34 words
A structure as in claim 5 wherein a fourth electrode comprising a second emitter of the transistor is disposed adjacent to the third electrode and separated from the second electrode by the third electrode.
Claim 8
Dependent Claim
41 words
An integrated structure as in claim 6 wherein the third portion of the third region of polycrystalline silicon is more lightly doped with an impurity than the first portion of the third region and the second portion of the third region.
Claim 9
Dependent Claim
17 words
A structure as in claim 7 wherein the insulating material comprises an oxide of the semiconductor body.
Claim 10
Dependent Claim
20 words
A structure as in claim 8 wherein the second region of polycrystalline silicon is doped with n conductivity type impurity.
Claim 11
Dependent Claim
29 words
A structure as in claim 9 wherein the semiconductor body comprises silicon, the surrounding region of insulating material comprises silicon dioxide, and the electrically conductive layer comprises tungsten silicide.
References Cited (Backward Citations)
US3978515A
Cited
JPS54101288A
Cited
US4450470A
Cited
US4297721A
Cited
US4329706A
Cited
US4292730A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-04-21 | 1989-10-21 | 1990-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-21 | 1993-10-21 | 1994-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-21 | 1997-10-21 | 1998-04-22 | $7700.00 | Window Closed / Lapsed |