Wafer supporting apparatus
US4969168A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 31, 1989 |
| Grant date | Nov 6, 1990 |
| Priority date | — |
| Expiry date | Aug 31, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/6838
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A wafer chuck usable with a semiconductor exposure apparatus wherein a mask and a semiconductor wafer are placed in a vacuum ambience or a pressure-reduced gas ambience, and wherein the wafer is exposed through the mask to radiation energy such as X-rays contained in a synchrotron radiation beam, by which the pattern of the mask is transferred onto the wafer. The wafer is first attracted on the wafer supporting surface of the chuck by vacuum attraction, and thereafter, the wafer is attracted by the electrostatic attraction force. Thereafter, the vacuum attraction is broken by supplying a gas. When the pattern of the mask is transferred onto the wafer, the wafer is retained on the wafer supporting surface by the electrostatic attraction force only. By this, the sheet-like member (wafer) supporting apparatus can correctly contact the wafer supporting surface to the wafer without being influenced by the undulation of the wafer. In addition, the heat produced in the wafer during exposure can be removed efficiently by temperature controlled water supplied to the wafer supporting apparatus.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.