Induction system for rapid heat treatment of semiconductor wafers
US4794217A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 15, 1987 |
| Grant date | Dec 27, 1988 |
| Priority date | — |
| Expiry date | Apr 15, 2007 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C16/46
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A semiconductor wafer is transported by a mechanical system into or out of a quartz housing filled with a protection gas. The wafer is placed between and spaced apart from two graphite plates. A RF induction coil surrounding the quartz housing is used to heat the graphite plates. Radiation from the heated graphite plates heats the wafer from room temperature to an elevated desired temperature. During the time period when a wafer absorbs radiation primarily through electron-to-electron transition, heat convection and conduction by the protection gas conveys heat from the graphite plates to the wafer to accelerate the heating of the wafer and reduces temperature nonuniformity of the wafer. A reflector means in the form of a second smaller housing is placed inside the larger quartz housing; the second housing formed by the reflector means encloses the two graphite plates and the wafer except for an opening for delivering and withdrawing the wafer and for a hole in upper part of the housing for determining temperature of the water. The reflector means reflects radiation back towards the graphite to improve heating efficiency. The second housing formed by the reflector plate confines th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.