[20a-E318-1~11] 【CS.7】 Code-sharing Session of 7.2 & 7.4 & 9.5

△ [20a-E318-8] Direct observation of electric field in GaN semiconductor hetero interface by DPC STEM

〇(M2)Satoko Toyama¹, Takehito Seki¹, Yuya Kanitani², Yoshihiro Kudo², Shigetaka Tomiya², Yuichi Ikuhara^1,3, Naoya Shibata^1,3 (1.Univ. of Tokyo, 2.Sony, 3.JFCC)

Keywords:STEM, electric field imaging, GaN semiconductor

By using differential phase contrast (DPC) imaging method in scanning transmission electron microscopy (STEM), local electromagnetic fields inside specimens can be directly observed at high spatial resolution in real-space. In DPC STEM, deflection of electron beam due to electromagnetic fields is detected by a segmented detector placed on the bright field (BF) disk region. However, the targets of DPC STEM experiment has been mostly single crystal specimens. This is because the diffraction contrast problem is critical for DPC STEM. Therefore, in this study, we chose GaN multi quantum well as a model sample and attempt to remove the diffraction contrast effect from DPC signals, and to acquire quantitative electric field and charge density image of hetero interface.