Depth Directional Study by Electron-Acoustic Microscopy

Observation depth of electron-acoustic microscopy (EAM) was studied by in situ observation of a same area of a Darlington npn Si Tr-chip under several accelerating voltages (HV) of a scanning electron beam which was used as an experimental parameter. Comparison of several SEM mode images and electron acoustic images (EAIs) of EAM revealed that the application of higher HV increased the observation depth of EAM. EAI contrast changed in proportion to the variation of HV, increasing and decreasing in intensity.