講演情報
[19a-A601-4]Emission spectroscopy of hydrogen plasma produced by extreme ultraviolet light for nanolithography applications
〇(P)James Edward Hernandez1, Nozomi Tanaka1, (M1)Ryuya Yamada1, (D)Yubo Wang1, Katsunobu Nishihara1, Shinsuke Fujioka1, Atsushi Sunahara1,2, Tomoyuki Johzaki1,3, Kyung Sik Kang4, Youngduk Suh4, Jeong-Gil Kim4, Shinji Ueyama5, Ken Ozawa5 (1.ILE Osaka Univ., 2.Purdue Univ., 3.Hiroshima Univ., 4.MRSamsung El.Co.Ltd., 5.Samsung Japan Corp.)
キーワード：
EUV Lithography、Debris mitigation、Optical emission spectroscopy
Extreme ultraviolet (EUV) sources play a vital role in photolithography by enabling the semiconductor at the nanometer scale via the scanners. In typical photolithography equipment, tin droplets are used as target materials and are ablated to generate EUV light. Consequently, the ablated products disperse in the direction of plume expansion, including the reflection optics that redirect EUV light. These ablated products consist of tin ions and neutral particles, which can cause downtime in the lithography equipment due to the need for cleaning and maintenance of the multilayer scanner optics. In mitigating the contamination due to tin deposition, hydrogen gas is employed which reacts with the tin deposits to produce stannane SnH4, which can be easily evacuated from the vacuum chamber [1,2]. Therefore, hydrogen radical production is desired. The conditions for hydrogen radical production is favorable under vacuum ultraviolet (VUV) irradiation, therefore it is desired to have increased VUV production for increased radical production. In this work, the emission spectra of H-alpha and H-beta, which correspond to excited radical states, are detected and characterized using optical emission spectroscopy. A 1064 nm laser at 10 ns pulse width is incident on a Xe target, which produce EUV and wide band light. The EUV light is focued to a gas cell of 5 Pa pressure. The optical emission results indicate an increase in the VUV emission for decreased laser intensity.
[1] S.S. Harilal, O. O’Shay, Y. Yao, and M.S. Tillack, Appl. Phys. B, 86, 547-553 (2007).
[2] M. Ji, R. Nagata, and K. Uchinoo, Plas. Fus. Res. 16 1406003 (2021).
[1] S.S. Harilal, O. O’Shay, Y. Yao, and M.S. Tillack, Appl. Phys. B, 86, 547-553 (2007).
[2] M. Ji, R. Nagata, and K. Uchinoo, Plas. Fus. Res. 16 1406003 (2021).