The radial layout design concept for the Bi-mode insulated gate transistor

In this paper we present a new radial design concept for an optimized layout of anode shorts in the Bi-mode Insulating Gate Transistor (BiGT). The study shows that the arrangement of the n
⁺
-stripes plays a key role for the on-state characteristics of the BiGT. With the aid of 3D device simulations the visualization of the plasma distribution during the on-state conduction was obtained in a 0.25 × 4 mm
²
large BiGT model area. The influence of the dimensioning and layout of the anode shorts was simulated and compared with measured on-state curves. A clear improvement of plasma distribution in the device when the stripes are arranged orthogonally (radially) to the pilot-IGBT boundary is observed in 3D simulations. Measurements confirm lower on-state losses as a result of better utilization of the device area.