I. Introduction
In recent years, the emergence of GaN HEMT has widely used in the high-density and high-efficiency applications like fast charger and data center, due to the low on-resistance and high switching speed compared with Si MOSFET [1]. However, the yield and reliability of large die size GaN is still limited considering the relative immature GaN-on-Si process. Therefore, paralleling GaN HEMTs are needed for high power applications. The extremely fast switching speed (dv/dt may reach 100 V/ns) makes GaN HEMTs very sensitive to parasitic parameter and thus difficult in paralleling.