Photoluminescence and photoacoustic investigation of residual defects in semi-insulating LEC GaAs

✍ Scribed by O. Ka; O. Oda; Y. Makita; A. Yamada

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 443 KB
• Volume: 20
• Category: Article
• ISSN: 0921-5107
• DOI: 10.1016/0921-5107(93)90406-d

✦ Synopsis

Photoluminescence and photoacoustic spectroscopy were used to investigate the effect of post-growth annealing carried out to improve the uniformity of Czochralski-grown semi-insulating GaAs. Single-and multi-step, ingot-and waferannealed crystals were studied. It is shown that wafer-annealed crystals do not present the additional defect-related transitions found in ingot-annealed samples. One of these defects is concluded to originate from arsenic precipitates. A second additional band is asserted to originate from an acceptor-like defect with a binding energy of 69 meV. Besides the improvement in crystalline quality, it is shown that the residual impurities, silicon and zinc, occur in very low concentrations in wafer-annealed samples, probably owing to an out-diffusion process during the thermal treatments.