Environment-proof writing chamber for next generation electron beam mask writing system

We have developed an environment-proof writing chamber for an electron beam mask writing system. The chamber is made of low thermal expansion metal. The measured size dependence on the chamber temperature is more than one order less than in the case of iron or stainless steel. The results of a numerical study indicate that this chamber can suppress the influence of environmental temperature change on the positioning error to nanometer level or below. This chamber is suitable for a 70-nm generation mask writing system and beyond.