Patent US4404048A successfully refreshed from Google Patents.
US4404048A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor device manufacture
Assignee: USPHILIPS Corp A CORP OF
•
Filing: 1981-11-16
•
Granted: 1983-09-13
•
Expires: 2001-11-16
Abstract
Abstract P-type isolation regions, which surround an island of an n-type epitaxial layer, are formed by providing a p-type dopant at a part of the surface of a p-type silicon substrate. After growing the layer a p-type dopant is also provided at the surface of the layer opposite the part of the substrate surface where the dopant is provided. The dopants are diffused into the layer until the p-type regions meet. To inhibit diffusion of the p-type dopant during epitaxial growth, an n-type dopant having a lower diffusion coefficient than that of the p-type dopant is provided at the part of the substrate surface before providing the epitaxial layer. Formation of the isolation regions can be carried out simultaneously with the formation of p-type regions of a circuit element, for example a transistor, in the islands.
Inventors
- 👤 Dirk A. Vogelzang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:06
CPC Classifications
H; H10; H10P; H10P32/00; H10P32/10; H10P32/15; H10W; H10W10/00; H10W10/01; H10W10/031; H10W10/30; H10W20/00; H10W20/01; H10W20/021
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
155 words
A method of manufacturing a semiconductor device, which comprises: providing a p-type monocrystalline silicon substrate having a major surface; providing a p-type dopant at a part of said major substrate surface and diffusing said dopant into the substrate; providing an n-type dopant having a smaller diffusion coefficient than that of said p-type dopant at said part of the major substrate surface where the p-type dopant is provided in order to inhibit diffusion of said p-type dopant; diffusing said n-type dopant into the substrate; then forming an n-type epitaxial silicon layer having an upper surface on said major surface of the substrate; providing a further p-type dopant at a part of said upper surface of the epitaxial layer opposite said part of the major surface of the substrate; and then diffusing said p-type dopants into the epitaxial layer from both sides by a thermal treatment to form diffused p-type regions which meet in said epitaxial layer.
Claim 2
Independent Claim
155 words
A method of manufacturing a semiconductor device, which comprises: providing a p-type monocrystalline silicon substrate having a major surface; providing a p-type dopant at a part of said major substrate surface and diffusing said dopant into the substrate; providing an n-type dopant having a smaller diffusion coefficient than that of said p-type dopant at said part of the major substrate surface where the p-type dopant is provided in order to inhibit diffusion of said p-type dopant; diffusing said n-type dopant into the substrate; then forming an n-type epitaxial silicon layer having an upper surface on said major surface of the substrate; providing a further p-type dopant at a part of said upper surface of the epitaxial layer opposite said part of the major surface of the substrate; and then diffusing said p-type dopants into the epitaxial layer from both sides by a thermal treatment to form diffused p-type regions which meet in said epitaxial layer.
Claim 3
Dependent Claim
19 words
A method as claimed in claim 1, wherein boron is provided at the substrate surface as said p-type dopant.
Claim 4
Dependent Claim
15 words
A method as claimed in claim 2, wherein antimony is used as said n-type dopant.
Claim 5
Dependent Claim
120 words
A method as claimed in claim 1, 2 or 3, wherein when the p-type dopant is provided at one part of the substrate surface the p-type dopant is also provided at another part of the substrate surface, and when the n-type dopant is provided at said one part of the substrate surface the n-type dopant is also provided at a part of the substrate surface which is larger than and overlaps said other part, and after providing the epitaxial layer the p- and the n-type dopants are diffused from the substrate into the epitaxial layer by the thermal treatment so as to obtain a p-type region in the epitaxial layer which is separated from the substrate by an n-type region.
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) | 1986-09-12 | 1987-03-14 | 1987-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-12 | 1991-03-14 | 1991-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-12 | 1995-03-14 | 1995-09-13 | $7700.00 | Window Closed / Lapsed |