Scanning Electron Acoustic Microscopy

Abstract

This chapter introduces complications in the field of scanning electron acoustic microscopy (SEAM) signal interpretation. Any property of the primary electron beam itself or of any of its other interaction products that may cause a mechanical deformation of the sample can cause an SEAM signal. These properties include specimen heating due to energy dissipation of the primary electron energy in any material with non-vanishing thermal expansion coefficient, piezoelectric or electrostrictive effects in dielectric materials due to the space charge generated by the impinging electrons, magnetostrictive coupling of the magnetic field of the beam in magnetic materials, direct coupling of excess charge carriers generated by the primary beam within semiconductors, and a heat contribution of these excess carriers during their recombination process. Besides these signal generation processes, even more complex SEAM contrast mechanisms have to be considered when interpreting SEAM micrographs. The chapter explains various operation modes of SEAM in a relatively simple manner. Their usefulness for different applications and the special modifications necessary have been pointed out. Most of the typical SEAM applications have been discussed.