A new spectroscopic technique for imaging the spatial distribution of nonradiative defects in a scanning transmission electron microscope

A new spectroscopic technique for imaging the spatial distribution of nonradiative defects in semiconductor materials is presented. The technique combines the versatility and sensitivity of deep-level transient spectroscopy (DLTS) with the capability for defect analysis at high resolution of the scanning transmission electron microscope. This scanning DLTS method (SDLTS) is illustrated by observing Cu-related defect centers in Ga1−xAlxAs epitaxial layers. A high sensitivity (3×1015 Cu defects cm−3 have been detected) and a spatial resolution of 2 μ or better illustrate the potential of the technique for the study of the electrical behavior of defects in semiconductor devices.