Method for heating semiconductor wafer by means of application of radiated light
Abstract
Abstract Disclosed herein is a heating method of a semiconductor wafer by means of application of radiated light. The wafer is additionally heated by subsidiary heating device which per se is heated upon exposure to the radiated light and is arranged in contact with the surface of the circumferential edge or a surface portion lying in the vicinity of the circumferential edge of the semiconductor wafer. The ratio of the characteristic value (α) of the subsidiary heating device to that (β) of the wafer is limited to 0.7 to 1.3, said α and β being expressed respectively by the following formulae: ##EQU1## where η 1 , η 2 are reflectivities, ρ 1 , ρ 2 are specific gravities (g/cm 3 ), d 1 , d 2 are thicknesses (cm) and C 1 , C 2 are specific heats (joule/g.°C.) of the subsidiary heating device and semiconductor wafer, respectively. The above heating method is effective in preventing the occurrence of "warping" and "slip line".
Inventors
- 👤 Hiroshi Shimizu
Bibliographic Details
Claims Analysis
Total Claims: 7References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-03-11 | 1988-09-10 | 1989-03-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-03-11 | 1992-09-10 | 1993-03-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-03-11 | 1996-09-10 | 1997-03-12 | $7700.00 | Window Closed / Lapsed |