An efficient extrinsic capacitances extraction method for small‐signal GaN HEMT devices

This article proposes a new extraction technique to determine the GaN HEMT extrinsic capacitances over a wide frequency band on two different substrates, namely, the silicon and the silicon carbide. The proposed technique, which uses a small‐signal model equivalent circuit under cold pinch‐off operating conditions, is based on the proposal of a new small‐signal equivalent circuit which allows extracting first the extrinsic resistances and inductances. Then comes the extraction of extrinsic capacitances at high frequency. The proposed approach achieved successful results through close agreement with measured data up to 60 GHz.