Projection exposure apparatus wherein focusing of the apparatus is changed by controlling the temperature of a lens element of the projection optical system
USRE38320E1 · kind E1 · reissue
Assignee
Inventors
Key dates
| Filing date | Mar 16, 2001 |
| Grant date | Nov 18, 2003 |
| Priority date | — |
| Expiry date | Mar 16, 2021 |
Classification
- Technology area (CPC —)General
Abstract
A projection optical system of a projection exposure apparatus according to the present invention has a plurality of optical members made of glass materials at least one of which has a temperature characteristic of index of refraction different from that of the other glass material. Further, a temperature control device for controlling a temperature of at least one of the optical members is provided. An imaging characteristic of the projection optical system is controlled. The imaging characteristic to be controlled is a non-linear magnification or curvature of field. The temperature control device sets the temperature to be controlled to a variable target temperature determined in accordance with the imaging characteristic of the projection optical system. An exposing operation for transferring a mask pattern to a photosensitive substrate is started after the temperature of the optical member to be controlled reaches a predetermined allowable range of the target temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.