| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To decrease defects in a film by reducing the film thickness of a two-layer phase shift mask and to improve pattern resolution as a photomask. <P>SOLUTION: The "two-layer" phase shift mask is designed in such a manner that a phase shift amount of light propagating in a transmittance adjusting film and a phase shift amount of light propagating in a phase adjusting film are in "the same sign". The former phase shift amount is defined by a phase differenceδϕ<SB>t</SB>=ϕ<SB>t</SB>-ϕ<SB>0</SB>between a phase change amountδ=ϕ<SB>t</SB>of light propagating in the transmittance adjusting film and a phase change amountδ<SB>0</SB>=ϕ<SB>0</SB>of light propagating in a medium in contact with the pattern surface of the mask during exposure, propagating in the same "thickness" (distance) as that of the transmittance adjusting film; and the latter phase shift amount is defined by a phase differenceδϕ<SB>p</SB>=ϕ<SB>p</SB>-ϕ<SB>0</SB>between a phase change amountδ=ϕ<SB>p</SB>of light propagating in the phase adjusting film and a phase change amountδ<SB>0</SB>=ϕ<SB>0</SB>of light propagating in the medium in contact with the pattern surface of the mask during exposure, propagating in the same "thickness" (distance) as that of the phase adjusting film. Thereby, the phase shift film can be made thinner, which suppresses defects in the film and improves pattern resolution. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
