SOI substrate, mask blank for charged particle beam exposure, and mask for charged particle beam exposure

摘要

The invention provides an SOI substrate 10 comprising on one major surface of a silicon single crystal 13 a silicon thin-film layer 11 via a buried silicon oxide film 12 , characterized in that a substrate warp preventive layer 14 is provided on another major surface of the silicon single crystal 13 . The invention also provides a charged particle beam exposure mask blank and a charged particle beam exposure mask having high mask pattern alignment precision, each using that SOI substrate. The invention has the advantages of being easy to fabricate, and capable of preventing a warp in the substrate.