Patent US4364778A successfully refreshed from Google Patents.
US4364778A
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Formation of multilayer dopant distributions in a semiconductor
Assignee: AT&T Inc
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Filing: 1980-05-30
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Granted: 1982-12-21
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Expires: 2000-05-30
Abstract
Abstract A method of making solid state devices having multilayer dopant distributions, including p-p+ and n-n+ junctions, etc. A semiconductor body is rapidly melted, typically by a laser, electron beam, or ion beam. Present in the melt is a first dopant having a low segregation coefficient and a second dopant having a high segregation coefficient. During rapid resolidification of the melt, the first dopant segregates toward the surface, while the second dopant remains substantially in place, producing a junction. The production of diodes, bipolar and field effect transistors, Schottky barriers, ohmic contacts, junction isolated surface regions, high conductivity paths, etc., is possible by this method.
Inventors
- 👤 Harry J. Leamy
- 👤 Thomas E. Seidel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:13
CPC Classifications
H; H10; H10P; H10P32/00; H10P32/10; H10P32/16
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
163 words
A method of making a semiconductor device by steps comprising melting one or more times a surface region of a semiconductor body by means of a radiation beam, wherein the duration of each melting at a given location on said body is less than 10 milliseconds, and wherein said melting extends into a single crystal region of said semiconductor body, with said single crystal region having a given dopant type immediately beneath said melted region, CHARACTERIZED IN THAT the melted region comprises a first dopant having an equilibrium segregation coefficient of less than 0.1, and a second dopant having an equilibrium segregation coefficient of greater than 0.1, with at least said second dopand being deposited on, or introduced in, said surface region prior to said melting, and with said melting extending to a depth greater than the depth of such deposited or introduced dopant or dopants prior to said melting, whereby a junction is formed within said region upon resolidification of the melt.
Claim 2
Independent Claim
163 words
A method of making a semiconductor device by steps comprising melting one or more times a surface region of a semiconductor body by means of a radiation beam, wherein the duration of each melting at a given location on said body is less than 10 milliseconds, and wherein said melting extends into a single crystal region of said semiconductor body, with said single crystal region having a given dopant type immediately beneath said melted region, CHARACTERIZED IN THAT the melted region comprises a first dopant having an equilibrium segregation coefficient of less than 0.1, and a second dopant having an equilibrium segregation coefficient of greater than 0.1, with at least said second dopand being deposited on, or introduced in, said surface region prior to said melting, and with said melting extending to a depth greater than the depth of such deposited or introduced dopant or dopants prior to said melting, whereby a junction is formed within said region upon resolidification of the melt.
Claim 3
Dependent Claim
18 words
The method of claim 1 FURTHER CHARACTERIZED in that said junction intersects said surface of said semiconductor body.
Claim 4
Dependent Claim
26 words
The method of claim 1 FURTHER CHARACTERIZED in that said radiation beam is selected from the group consisting of laser beam, electron beam, and ion beam.
Claim 5
Dependent Claim
25 words
The method of claim 1 FURTHER CHARACTERIZED in that said first dopant is deposited on, or introduced in, said surface region prior to said melting.
Claim 6
Dependent Claim
25 words
The method of claim 1 FURTHER CHARACTERIZED in that said given dopant in said single crystal region is different from said first and second dopants.
Claim 7
Dependent Claim
21 words
The method of claim 1 FURTHER CHARACTERIZED in that said given dopant in said single crystal region is said first dopant.
Claim 8
Dependent Claim
24 words
The method of claim 1 FURTHER CHARACTERIZED in that said given dopant in said single crystal region is the same as said second dopant.
Claim 9
Dependent Claim
13 words
The method of claim 1 FURTHER CHARACTERIZED in that said semiconductor is silicon.
Claim 10
Dependent Claim
23 words
The method of claim 8 FURTHER CHARACTERIZED in that said second dopant is selected from the group consisting of boron, phosphorus, and arsenic.
Claim 11
Dependent Claim
28 words
The method of claim 8 FURTHER CHARACTERIZED in that said first dopant is selected from the group consisting of lithium, aluminum, gallium, indium, thallium, antimony, bismuth, and platinum.
Claim 12
Dependent Claim
26 words
The method of claim 8 FURTHER CHARACTERIZED in that said first dopant forms a silicide with said silicon region in a portion of the resolidified region.
Claim 13
Dependent Claim
27 words
The method of claim 1 FURTHER CHARACTERIZED in that said first dopant forms an alloy or compound with said semiconductor in a portion of the resolidified region.
Claim 14
Dependent Claim
31 words
The method of claim 1 FURTHER CHARACTERIZED in that said junction forms an ohmic contact between the region dominated by said first dopant and the region dominated by said second dopant.
Claim 15
Dependent Claim
15 words
The method of claim 1 FURTHER CHARACTERIZED in that said junction is a rectifying junction.
Claim 16
Dependent Claim
27 words
The method of claim 1 FURTHER CHARACTERIZED in that said given dopant type in said single crystal region is of opposite conductivity type to said second dopant.
Claim 17
Dependent Claim
33 words
The method of claim 1 FURTHER CHARACTERIZED in that the concentration of said first dopant exceeds the equilibrium solubility limit of said dopant in said semiconductor in a portion of the resolidified region.
Claim 18
Dependent Claim
26 words
The method of claim 1 FURTHER CHARACTERIZED in that said duration of each melting at a given location on said body is less than 10 microseconds.
Claim 19
Dependent Claim
26 words
The method of claim 1 FURTHER CHARACTERIZED in that said duration of each melting at a given location on said body is greater than 10 microseconds.
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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) | 1985-12-20 | 1986-06-21 | 1986-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-12-20 | 1990-06-21 | 1990-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-12-20 | 1994-06-21 | 1994-12-21 | $7700.00 | Window Closed / Lapsed |