High Voltage Normally-Off p-GaN Gate HEMT with the Compatible High Threshold and Drain Current

Abstract

In this paper, we demonstrate a high voltage normally-off p-GaN gate high-electron-mobility-transistor (HEMT) to realize the compatible high threshold voltage (V TH) and high drain current (I D) performance. With the optimization of the epitaxial structure, the presented device shows a significantly improved V TH. Meanwhile, by using the high-quality ALD-Al2O3 passivation layer, the high I D is also realized in the device because of the access region resistance reduction. Supported by the device fabrication, the p-GaN gate HEMT delivers a V TH = 3.2 V measured by linear extrapolation, a relatively large saturation I D (I D_SAT) of 246 mA mm−1, and a high breakdown voltage (BV) of 1830 V at 1 mA mm−1. Among various p-GaN gate HEMTs with the I D_SAT over 200 mA mm−1, the fabricated p-GaN gate HEMT has a competitive V TH. The results suggest that the proposed device could be a promising candidate in high V TH and I D power electronics.