[20p-B12-1~11] 13.9 Compound solar cells

[20p-B12-9] Cross-sectional TEM analysis of SAB-fabricated Si/GaAs interfaces using LT-FIB

〇Yutaka Ohno¹, Yasuo Shimizu¹, Yasuyoshi Nagai¹, Ryotaro Aso², Masato Kamiuchi², Hideto Yoshida², Jianbo Liang³, Naoteru Shigekawa³ (1.IMR, Tohoku Univ., 2.ISIR, Osaka Univ., 3.Osaka City Univ.)

Keywords:surface activated bonding at room temperature, low-temperature focused ion beam

Surface-activated bonding (SAB) at room temperature (RT) is applied to form Si/GaAs hetero-interfaces with a low interface electrical resistance, and high-efficiency InGaP/GaAs/Si triple-junction cells are demonstrated. We have recently clarified that the structural and compositional properties of semiconductor homo-interfaces fabricated by SAB are modified during FIB processes operated at RT, and such a modification can be suppressed by FIB processes operated at -150 ^oC. In the present work, we have therefore examined the atomic arrangement and composition at Si/GaAs hetero-interfaces fabricated by SAB using X-TEM specimens fabricated by FIB milling operated at -150 ^oC.