Wafer holder
US6844921B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 30, 2002 |
| Grant date | Jan 18, 2005 |
| Priority date | — |
| Expiry date | Nov 21, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/707
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A wafer holder (20) is capable of preventing foreign matter such as dust from becoming adhered to the wafer. The holder (20) is constituted by providing a wafer supporting portion (13) at one disk surface of a disk-shaped substrate portion (12), with the wafer supporting portion (13) having a ring shape with the smallest possible width over which the peripheral portion of the wafer (10) can be supported. Even if there is foreign matter present on the wafer holder or there is dust/deposit film adhering to the rear surface of the wafer, it is possible to prevent the occurrence of a local resist pattern defect by ensuring that the height of the wafer surface including the resist layer remains unchanged.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.