HALFTONE PHASE SHIFT PHOTOMASK BLANK, MAKING METHOD, AND HALFTONE PHASE SHIFT PHOTOMASK

摘要

A halftone phase shift photomask blank is provided comprising a transparent substrate and a halftone phase shift film thereon having a phase shift of 150-200° and a transmittance of 9-40%. The halftone phase shift film consists of a transition metal, Si, O and N, has an average transition metal content of at least 3 at %, and is composed of a plurality of layers including a stress relaxation layer having an oxygen content of at least 3 at % and a phase shift adjusting layer having a higher oxygen content of at least 5 at %.

主权项

1. A halftone phase shift photomask blank comprising a transparent substrate and a halftone phase shift film thereon providing a phase shift of 150° to 200° and a transmittance of 9% to 40% with respect to light of wavelength up to 200 nm, wherein
said halftone phase shift film consists of a transition metal, silicon, oxygen and nitrogen, has an average transition metal content of at least 3 at %, and is composed of a plurality of layers including at least one stress relaxation layer consisting of the transition metal, silicon, oxygen and nitrogen and at least one phase shift adjusting layer consisting of the transition metal, silicon, oxygen and nitrogen, said stress relaxation layer has an oxygen content of at least 3 at % which is the lowest, said phase shift adjusting layer has an oxygen content of at least 5 at % which is at least 2 at % higher than the oxygen content of the stress relaxation layer.