High-performance AlGaN∕GaN lateral field-effect rectifiers compatible with high electron mobility transistors

Abstract

A high electron mobility transistor (HEMT)-compatible power lateral field-effect rectifier (L-FER) with low turn-on voltage is demonstrated using the same fabrication process as that for normally off $\mathrm{Al}\mathrm{Ga}\mathrm{N}∕\mathrm{Ga}\mathrm{N}$ HEMT, providing a low-cost solution for GaN power integrated circuits. The power rectifier features a Schottky-gate-controlled two-dimensional electron gas channel between the cathode and anode. By tying up the Schottky gate and anode together, the forward turn-on voltage of the rectifier is determined by the threshold voltage of the channel instead of the Schottky barrier. The L-FER with a drift length of $10\mu \mathrm{m}$ features a forward turn-on voltage of $0.63\mathrm{V}$ at a current density of $100\mathrm{A}∕{\mathrm{cm}}^2$ . This device also exhibits a reverse breakdown voltage (BV) of $390\mathrm{V}$ at a current level of $1\mathrm{mA}∕\mathrm{mm}$ and a specific on resistance $\left(R_{\text{ON},\mathrm{sp}}\right)$ of $1.4\mathrm{m}\Omega {\mathrm{cm}}^2$ , yielding a figure of merit $({\mathrm{BV}}^2∕R_{\text{ON},\mathrm{sp}})$ of $108\mathrm{MW}∕{\mathrm{cm}}^2$ . The excellent device performance, coupled with the lateral device structure and process compatibility with $\mathrm{Al}\mathrm{Ga}\mathrm{N}∕\mathrm{Ga}\mathrm{N}$ HEMT, make the proposed L-FER a promising candidate for GaN power integrated circuits.