Many power devices (e.g., IGBT, thyristor) contain intrinsic parasitic bipolar transistors. Under high current or high dv/dt, the base-emitter junction of the parasitic npn or pnp can forward bias, triggering latch-up — a regenerative condition where the device loses gate control and may be destroyed.
This section categorizes devices by their structural families and defines their static and dynamic performance metrics. Many power devices (e
To withstand high reverse voltages, power devices use a lightly doped drift region (often denoted n⁻ ). When reverse biased, the depletion region extends primarily into this drift layer. The maximum electric field must stay below the critical field for impact ionization ( E_crit ≈ 2–3×10⁵ V/cm in Si). The breakdown voltage scales with the drift region thickness and doping. To withstand high reverse voltages, power devices use