Defect study of GaInP/GaAs based heterojunction bipolar transistor emitter layer.

Defects in the emitter region of Ga[sub 0.51]In[sub 0.49]P/GaAs heterojunction bipolar transistors (HBTs) were investigated by means of deep-level transient spectroscopy. Both annealed (635 °C, 5 min) and as grown metalorganic chemical vapor deposition epitaxial wafers were investigated in this study, with an electron trap observed in the HBT emitter space-charge region from both wafers. The deep-level activation energy was determined to be 0.87 ± 0.05 eV below the conduction band, the capture cross section 3 × 10[sup -14] cm² and the defect density of the order of 10[sup 14] cm[sup -3]. This defect was also found to be localized at the emitter-base interface. [ABSTRACT FROM AUTHOR]