TY - JOUR
T1 - Observation of phase defect on extreme ultraviolet mask using an extreme ultraviolet microscope
AU - Amano, Tsuyoshi
AU - Terasawa, Tsuneo
AU - Watanabe, Hidehiro
AU - Toyoda, Mitsunori
AU - Harada, Tetsuo
AU - Watanabe, Takeo
AU - Kinoshita, Hiroo
N1 - Funding Information:
The authors are grateful to Tsukasa Abe of Dai Nippon Printing Co., Ltd., for his technical advice, fabrication of the programmed phase defect mask, and measurement of the defect size using SPM. This work was supported by New Energy and Industrial Technology Development Organization (NEDO).
PY - 2014/4
Y1 - 2014/4
N2 - Influences of phase defect structures on extreme ultraviolet (EUV) microscope images were examined. Phase defects on the bottom of a multilayer (ML) do not always propagate vertically upward to the ML's top surface. For this study, two types of masks were prepared. One was an EUV blank with programmed phase defects made of lines in order to analyze the inclination angle of the phase defects. The other was an EUV mask that consists of programmed dot type phase defects 80 nm wide and 2.4 nm high with absorber patterns of halfpitch 88-nm lines-and-spaces. The positions of the phase defects relative to the absorber lines were designed to be shifted accordingly. Transmission electron microscope observations revealed that the line type phase defects starting from the bottom surface of the ML propagated toward the ML's top surface, while inclined toward the center of the EUV blank. At the distances of 0 and 66 mm from the center of the EUV blank, the inclination angles varied from 0 to 4 deg. The impacts of the inclination angles on EUV microscope images were significant even though the positions of the phase defect relative to the absorber line, as measured by a scanning probe microscope, were the same.
AB - Influences of phase defect structures on extreme ultraviolet (EUV) microscope images were examined. Phase defects on the bottom of a multilayer (ML) do not always propagate vertically upward to the ML's top surface. For this study, two types of masks were prepared. One was an EUV blank with programmed phase defects made of lines in order to analyze the inclination angle of the phase defects. The other was an EUV mask that consists of programmed dot type phase defects 80 nm wide and 2.4 nm high with absorber patterns of halfpitch 88-nm lines-and-spaces. The positions of the phase defects relative to the absorber lines were designed to be shifted accordingly. Transmission electron microscope observations revealed that the line type phase defects starting from the bottom surface of the ML propagated toward the ML's top surface, while inclined toward the center of the EUV blank. At the distances of 0 and 66 mm from the center of the EUV blank, the inclination angles varied from 0 to 4 deg. The impacts of the inclination angles on EUV microscope images were significant even though the positions of the phase defect relative to the absorber line, as measured by a scanning probe microscope, were the same.
KW - compensation repair
KW - defect mitigation
KW - extreme ultraviolet
KW - extreme ultraviolet microscope
KW - phase defect
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U2 - 10.1117/1.JMM.13.2.023012
DO - 10.1117/1.JMM.13.2.023012
M3 - Article
AN - SCOPUS:84931469067
VL - 13
JO - Journal of Micro/ Nanolithography, MEMS, and MOEMS
JF - Journal of Micro/ Nanolithography, MEMS, and MOEMS
SN - 1932-5150
IS - 2
M1 - 023012
ER -