Abstract

A narrow-linewidth KrF excimer laser is expected for a light source of microphotolithography in the production of 256 M-1 G dynamic random access memory (DRAM) generation. Typical average output power, repetition rate, and spectral linewidth of the laser working in a stepper for test production are 4 W, 800 pps and 3.0 pm (FWHM), respectively.¹ However, the higher performance of the laser for mass production have been required to achieve the same throughput as that with a conventional mercury lamp steppers. To accomplish high throughput not only high output power but also high repetition rate are needed since the excimer laser lithography has its own problems such as speckle effect, dose fluctuation, and so on.

© 1995 IEEE