[14a-414-1~8] 6.6 Probe Microscopy

△ [14a-414-7] The Evaluation of Emitted Electrons on Chemical Contrast using SR-STM
-Sample Voltage dependency of Emitted Electrons-

〇Tomoyuki Saito^1,2, Akira Saito^1,2, Takeyoshi Tsuboi^1,2, Yuya Hikita^1,2, Kenji Tamasaku², Tetsuya Ishikawa², Yuji Kuwahara^1,2 (1.Osaka Univ., 2.RIKEN/SPring-8)

Keywords:STM, synchrotron radiation, semiconductor

We have long-developed the elemental analysis method in real space at an atomic scale by using SR-based STM (SR-STM). The principle of the analysis to image the chemical contrast is to extract the tiny modulation of tunneling current caused by changes of the density of state (DOS) near the Fermi level which follows the inner-shell excitation at a specific core level. But the mechanisms for changing the tip current by hard X-ray are not only changes of the DOS but also thermal expansion and emitted electron. Especially, the characteristic of emitted electron was examined only at a long tip-sample distance (~100 nm). There, we report the influence of emitted electron by X-ray on chemical contrast at a tip-sample distance of a few nanometers.