Laser Beam Lithography for Direct Patterning of Interconnections on Prediffused ASIC's

Abstract

A lithography machine designed for laser direct writing of metallisation in ASIC'S and MCM, and the associated practical process are described.To demonstrate the feasibility of the laser direct writing, the last level of metallisation on a bipolar ASIC has been drawn.The design rules have been calculated using a theoretical modelling of the interaction between laser beam and photoresists.Calculation and experiment are in good agreement for two kinds of photoresists.1.