Fabrication of High-Uniformity and High-Reliability Si3N4/AlGaN/GaN MIS-HEMTs With Self-Terminating Dielectric Etching Process in a 150-mm Si Foundry

A novel early gate dielectric AlGaN/GaN metal-insulator-semiconductor high-electron-mobility transistors (MIS-HEMTs) process is reported. With the high-quality Si 3 N 4 dielectric by low-pressure chemical vapor deposition and damage free, self-terminating passivation layer etching at the gate area, the MIS-HEMTs on 150-mm Si substrate demonstrate excellent output performance and good uniformity. The interface trap density between the gate insulator and the barrier layer is as low as 2 \times 10^{{12}}{\mathrm {cm}}^{- {2}}\,\,\cdot \,\,{\mathrm {eV}}^{- {1}} extracted by the conductance method. The MIS-HEMT fabricated on the wafer delivers an extremely small gate leakage current of 10 −9 mA/mm and a high {I}_{\mathrm{\scriptscriptstyle {ON}}}/{I}_{{\mathrm{\scriptscriptstyle {OFF}}} ratio of 10 11 . The subthreshold swing (SS) is around 80 mV/dec, and the saturated output current density is 750 mA/mm. The dynamic on-resistance increases about 42% at a quiescent drain bias of 600 V. The {V}_{ {th}} shift is −0.63 and −0.89 V at a high temperature of 200 °C and negative gate-bias stress of −25 V, respectively, indicating a comparable stability with the state-of-the-art MIS-HEMTs. An excellent threshold voltage and SS uniformity ( {1} - \sigma /\mu) with the value of 94.5% and 95.2% are achieved on the 150-mm wafer.