Thermal control of semiconductor wafer during reactive ion etching
US5609720A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 29, 1995 |
| Grant date | Mar 11, 1997 |
| Priority date | — |
| Expiry date | Sep 29, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/2001
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Apparatus and method for obtaining improved control of the temperature of a semiconductor wafer over its area during plasma processing including reactive ion etching (RIE) and similar processing. RIE reactor apparatus is provided with a novel chuck arrangement both for holding and for controlling the temperature of a wafer during processing. A top face of a chuck (either mechanical or electrostatic), against which the wafer is held, is configured into a plurality of zones into which zone coolant gas, such as helium, is admitted. The zone coolant gas passes through narrow channels between the top face of the chuck and the Underside of the wafer. Heat transfer from the wafer through the zone coolant gas and to the body of the chuck is controlled zone by zone by separately setting the pressure of zone coolant gas in each of the zones. By properly choosing pressures of zone coolant gas in the respective zones the temperature across the area from the center to the rim of both small and large diameter wafers (e.g., 8 inches) can be held substantially constant even though power dissipation per unit of area within the wafer during processing varies considerably from the center to the rim.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.