Patent US3940289A successfully refreshed from Google Patents.
US3940289A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flash melting method for producing new impurity distributions in solids
Assignee: United States Department of the Navy
•
Filing: 1975-02-03
•
Granted: 1976-02-24
•
Expires: 1995-02-03
Abstract
Abstract An impurity concentration profile is established in a solid by attaching solid to a heat sink and irradiating it with one or more fast laser pulses. The impurity may initially be located in a surface layer or it may be dispersed throughout the solid.
Inventors
- 👤 Charles L. Marquardt
- 👤 John F. Giuliani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:53
CPC Classifications
H; H10; H10W; H10W15/00; H10P; H10P34/00; H10P34/40; H10P34/42; H10W15/01; Y; Y10; Y10S; Y10S148/00; Y10S148/093
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
87 words
A method of establishing an impurity concentration profile in a solid which comprises: placing a solid with an impurity which has a segregation coefficient different from 1 by a factor greater than about 3 in an inert atmosphere; attaching said solid to a heat sink; flash melting said solid by a laser pulse with a duration from 1/10 to 1/1000 τ and an energy area density from E to 1 1/5E; and allowing said solid to resolidify, thereby causing a freezing interface to pass through said solid.
Claim 2
Independent Claim
87 words
A method of establishing an impurity concentration profile in a solid which comprises: placing a solid with an impurity which has a segregation coefficient different from 1 by a factor greater than about 3 in an inert atmosphere; attaching said solid to a heat sink; flash melting said solid by a laser pulse with a duration from 1/10 to 1/1000 τ and an energy area density from E to 1 1/5E; and allowing said solid to resolidify, thereby causing a freezing interface to pass through said solid.
Claim 3
Dependent Claim
16 words
The method of claim 1 wherein said solid is attached to a plurality of heat sinks.
Claim 4
Dependent Claim
24 words
The method of claim 1 wherein said laser pulse has a duration of 1/100 τ and an energy area density from 1.05E to 1.25E.
Claim 5
Dependent Claim
16 words
The method of claim 3 wherein said laser pulse has an energy area density of 1.1E.
Claim 6
Dependent Claim
18 words
The method of claim 3 wherein said solid is selected from the group consisting of silicon and germanium.
Claim 7
Dependent Claim
27 words
The method of claim 5 wherein said impurity is present in a concentration of 100 14 to 10 18 atoms of impurity per cubic centimeter of solid.
Claim 8
Dependent Claim
27 words
The method of claim 5 wherein said impurity is present in a concentration of 10 15 to 10 17 atoms of impurity per cubic centimeter of solid.
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) | 1979-02-23 | 1979-08-25 | 1980-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-02-23 | 1983-08-25 | 1984-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-02-23 | 1987-08-25 | 1988-02-24 | $7700.00 | Window Closed / Lapsed |