Electron-beam lithography system for high-precision reticle making

Abstract

A high precision electron beam lithography system which can be used to make reticles for 0.3 p.m devices has been developed. This system is an enhanced model of the Hitachi electron beam lithography system, HL-700M. Key technologies used in this system are (1) the minimum address unit (0.0125 tm) and the stage-positioning measurement unit (0.005 p.m) to correspond with higher precision specifications, (2) the refined beam correction functions and (3) the efficient environmental controls. The items of improvement on environmental controls are to design an anti-vibration column and to adopt a reticle temperature control system.The main specifications of this system are 1) the positioning accuracy : 0.06p.m, 2) stitching accuracy : 0.05p.m, 3) pattern width accuracy : 0.05j.tm and 4) throughput : 0.5 reticle/hr. The system enables to write phase shift masks using the direct writing mode in HL-700D.