Osaka University

Masahiro Nakatsuka

Hiroyuki Furukawa

Noriaki Miyanaga

Yasukazu Izawa

Yoshinori Shimada

Katsunobu Nishihara

Masakatsu Murakami

Hiroaki Nishimura

Tatsuhiko Yamanaka

Atsushi Sunahara

Takayoshi Norimatsu

Keiji Nagai

Mitsuo Nakai

Keisuke Shigemori

Shigeaki Uchida

Vasilli Zhakhovski

Ryouji Matsui

Takahiro Hibino

Tomoharu Okuno

An object of the present invention is to provide an extreme ultraviolet light source target which can emits extreme ultraviolet light with high emission efficiency. A solid target made of heavy metal or heavy-metal compound and having a density 0.5 to 80% that of the crystal density is used. When the target is irradiated with a laser beam, plasma of the heavy metal contained in the target is generated, and extreme ultraviolet light having a predetermined wavelength which corresponds to the kind of the heavy metal is emitted from the plasma. When the density of the target is made to be smaller than the crystal density as described above, space distribution of the density of the generated plasma can be controlled, and the region in which plasma absorbs energy of the laser beam overlaps the region in which the plasma emits the extreme ultraviolet light. Thus, emission efficiency can be improved, preventing energy loss. For example, in a case where the SnOtarget having a density 24% of the crystal density is used, the emission efficiency at around 13.5 nm wavelength is higher than in the case where a Sn crystal target is used.

Extreme ultraviolet light source and extreme ultraviolet light source target

Growing community of inventors

Suita, Japan

Masahiro Nakatsuka