Exposure method and system for photolithography
US4734746A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 12, 1987 |
| Grant date | Mar 29, 1988 |
| Priority date | — |
| Expiry date | May 12, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70458
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An exposure method for photolithography comprises the steps of forming a pattern on a substrate by the use of a first exposure apparatus including a first imaging optical system having a reduction magnification 1/.beta.1 and an image circle of a diameter .phi.1, and forming a second pattern on the substrate on which the first pattern has been formed, by the use of a second exposure apparatus including a second imaging optical system having a reduction magnification 1/.beta.2 different from the reduction magnification 1/.beta.1 and an image circle of a diameter .phi.2, wherein when N is an integer, the conditions that .beta.1.times..phi.1=.beta.2.times..phi.2 and .phi.1=N.times..phi.2 are satisfied.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.