The IGBT Device

3.3. Asymmetric IGBT Structure

The structure for the asymmetric, double-diffused, IGBT was shown on the left-hand side of Fig. 2.3 and an asymmetric, trench-gate, IGBT structure was shown in Fig. 2.4. The discussion in this section is applicable for both types of gate structures. The asymmetric IGBT structure was developed soon after the symmetric device structure [7]. The asymmetric structure has much superior trade-off curve between on-state voltage drop and switching loss when compared with the symmetric IGBT structure. Consequently, most of the worldwide effort in the 1980s and 1990s was focused on development of the asymmetric device structure [8–11]. The asymmetric IGBT structure has seen widespread applications in motor drives for air conditioning ...