Development of a fountain detector for spectroscopy of secondary electrons in scanning electron microscopy

作者：Agemura Toshihide^*; Kimura Takashi; Sekiguchi Takashi

来源：Japanese Journal of Applied Physics, 2018, 57(4): 046701.

DOI：10.7567/JJAP.57.046701

The low-pass secondary electron (SE) detector, the so-called "fountain detector (FD)", for scanning electron microscopy has high potential for application to the imaging of low-energy SEs. Low-energy SE imaging may be used for detecting the surface potential variations of a specimen. However, the detected SEs include a certain fraction of tertiary electrons (SE3s) because some of the high-energy backscattered electrons hit the grid to yield SE3s. We have overcome this difficulty by increasing the aperture ratio of the bias and ground grids and using the lock-in technique, in which the AC field with the DC offset was applied on the bias grid. The energy-filtered SE images of a 4H-SiC p-n junction show complex behavior according to the grid bias. These observations are clearly explained by the variations of Auger spectra across the p-n junction. The filtered SE images taken with the FD can be applied to observing the surface potential variation of specimens.

• 出版日期2018-4