Defect analysis concerning variation in characteristics of PIN diode for Hybrid Vehicles

Variation in voltage forward (Vf) characteristics was observed in test PIN diodes for Hybrid Vehicles (HV). By employing the SR, PL and DLTS methods of defect analysis, therefore, difference in carrier concentrations was produced in the I region where carbon-related defects exist (such as Ci–Cs and Ci–Oi), which is thought to be responsible for Vf variation. Using the FT-IR method of measuring minute quantities of impurities in wafers to enable measurement of carbon concentration according to ingot position (1e14 (top)–4e15 (bottom) cm−3) indicates that arranging ingot positions may be a way to lower Vf variation.