Impurities related micro-defects in GaSb crystal grown by LEC method

The epitaxial growth of devices based on gallium antimonide (GaSb) is negatively impacted by defects related to impurities in the crystal. Liquid encapsulated czochralski (LEC) technology was used to grow 2-inch Te-doped GaSb (1 0 0) single crystal ingots, which were then processed into polished wafers in order to investigate the origins and consequences of defects related to impurities. Polished GaSb wafers were found to have surface micro-defects. Energy dispersive x-ray spectroscopy (EDAX) and scanning electron microscopy (SEM) measurements indicate that the micro-defects are associated with carbon and oxygen impurities. Glow discharge mass spectrometry (GDMS) is used to identify the origins of carbon and oxygen impurities. Based on the findings, an optimization process was developed to enhance the crystal quality, and a micro-defect-free GaSb single crystal was produced.