[11p-W321-1~14] 13.9 Compound solar cells

[11p-W321-10] Direct Semiconductor Wafer Bonding in Non-Cleanroom Environment

〇Ryoichi Inoue¹, Nagito Takehara¹, Katsuaki Tanabe¹ (1.Kyoto Univ.)

Keywords:semiconductor wafer bonding, multijunction solar cell, non-cleanroom environment

Semiconductor wafer bonding in a regular, non-cleanroom environment is demonstrated for low-cost fabrication of high-efficiency lattice-mismatched multijunction solar cells. The correlation among conditions of surface treatment, particle density, bonding strength, and interfacial conductivity is investigated. We have systematically examined schemes of cleaning wafers, hydrophilic / hydrophobic treatments, and conditions of bonding, and obtained strong bonds and high interfacial conductivities sufficient in device use.