[11p-Z04-1~14] 13.7 Compound and power electron devices and process technology

[11p-Z04-12] Structural analysis of SAB-fabricated Si/diamond heterointerfaces by X-STEM and LT-FIB

〇Yutaka Ohno¹, Jianbo Liang², Hideto Yoshida³, Yasuo Shimizu¹, Yasuyoshi Nagai¹, Naoteru Shigekawa² (1.IMR, Tohoku Univ., 2.Osaka City Univ., 3.ISIR, Osaka Univ.)

Keywords:Diamond, surface activated bonding, LT-FIB

In the SAB process, surfaces of diamond and Si wafers are activated at RT before bonding by creating dangling bonds via the irradiation of high-energy Ar atoms in a high vacuum, and the surfaces are then bonded by the contact most of the time under pressure to form strong chemical bonds even for imperfect surfaces. Atomic intermixing at the interfaces, presumably due to the transient enhanced diffusion assisted by the point defects introduced in the surface activation process, is confirmed during the bonding process. The crystallinity at the intermixing region is rather low, and it is recovered by 1000 ^oC annealing via the formation of SiC layers, that would play a pivotal role in the relaxation process of the residual stress due to the misfit of thermal expansion coefficient between diamond and Si. Therefore, the defect-assisted atomic diffusion at the interfaces would be a key concept for the formation of high thermal-stability diamond/Si heterointerfaces.