X-Ray Phase-Shifting Mask for 0.1-μm Pattern Replication under a Large Proximity Gap Condition

概要

論文の詳細を見る
The effects of Fresnel diffraction on the patterning characteristics in synchrotron radiation lithography are greatly influenced by X-ray phase shift in the absorber, especially when a low-contrast X-ray mask is used. We show that the resolution in sub-quarter-micron region can be markedly improved without reducing the proximity gap by utilizing the phase-shifting effects in the absorber. By controlling the absober thickness within a suitable range (1.5≤mask contrast≤4.0, -30°≥phase shift ∅-120°), fine patterns as small as 0.1 μm can be replicated with a large exposure latitude at a large proximity gap of 30 μm. Based on these results, we propose a novel X-ray phase-shifting mask with shallowly etched patterns (L in width) at the absorber edge as a phase shifter. This mask can be fabricated by a simple self-alignment process and also offers the possibility of 0.1-μm pattern replication at the 30μm proximity gap by using 0.02≤L≤0.1 μm.
社団法人応用物理学会の論文
1992-12-30