Photoluminescence Based Semiconductor Defect Detection.
Rockmore, Robert S.
- Abstract: In this thesis, a characterization system for semiconductor materials was designed, fabricated, and tested. The capabilities of this setup include measuring photoluminescence emission at a single location of a sample, as well as performing spatially resolved “micro-photoluminescence” measurements throughout a region on the surface of the sample. A number of Gallium Arsenide semiconductor ... read moresamples were examined in order to validate this testing setup. A Gallium Arsenide sample with known features was fabricated and tested using the spatially resolved imaging capability in order to determine the minimum defect and feature sizes that could be detected. After performing a number of different spatially resolved photoluminescence tests on this sample, photoluminescence blocking features of as small as 10 microns were detected (the smallest of the fabricated features), and the effective focused laser spot size was determined to be on the order of 100 microns. Optimal testing parameters and settings for both standard and spatially resolved PL were determined experimentally. This setup can be used to characterize the relevant performance characteristics, such as material uniformity, defect location, and variations in doping concentration in semiconductor materials for use in photovoltaics and other devices.read less