Physical Analysis of Carrier Lifetime Controlled IGBT [II]

For IGBTs, there are strong requirements for high current density usage from the cost reduction point of view and high speed operation from the system efficiency point of view. Strong carrier lifetime control is needed to reduce a turn-off loss (Eoff) of IGBT for high frequency usage. It seems to be insufficient for our previous report to deeply understand about correlation between electric characteristics and Cathode Luminescence (CL), which stands for free conduction carrier trap levels inside Si band structure. Clearer physical model is necessary to improve an agreement for both high current density and high speed operation. Therefore, we applied another analysis method of PL (Photo Luminescence) to ensure the physical model for carrier lifetime controlling method to combine relatively heavy dose of Electron Beam (EB) irradiation and high temperature thermal annealing.