Comparison of lateral EST and IGBT devices on SOI substrates

Lateral IGBTs (insulated-gate bipolar transistors) and ESTs (emitter-switched thyristors) on SOI (silicon-on-insulator) substrates are compared experimentally and by computer simulation. Experimental and calculated forward characteristics are presented. The influence of some device parameters on forward and blocking properties is discussed. Turn-off characteristics of both structures are presented for fabricated devices and compared to computer calculations. LESTs in SOI substrates are shown to have lower forward voltage drop or to switch faster than equivalent lateral IGBTs, depending on carrier lifetimes, which can be adjusted, for example, by electron irradiation. An advantageous LEST behavior was demonstrated by numerical simulation for comparatively small devices with small breakdown voltages (≈220 V), and this advantage is expected to increase for larger devices with larger breakdown voltages