Improvement of single event transients effect for a novel AlGaN/GaN HEMT with enhanced breakdown voltage

Abstract

A novel AlGaN/GaN HEMT is proposed to improve its single event transient (SET) effect and breakdown characteristics. The device features an AlGaN back barrier layer and a buried P-GaN island in the back barrier layer (BP-HEMT). First, the P-GaN island not only modulates the electric field distribution and reduces impact ionization at both the blocking state and after ion strike but also increases the hole-electron recombination rate. Therefore, it not only effectively increases the breakdown voltage (BV), but also improves the anti-SET performance owing to decreasing the current peak after ion strike. Second, the AlGaN back barrier confines electrons in the channel, and thus, on one hand, it is beneficial to the high saturation drain current (I_d,sat) and low on-state resistance (R_on); on the other hand, it effectively prevents the electrons in the buffer layer introduced by ion strike from reaching the drain electrode both at the blocking state and after ion strike. The TCAD simulation results show that the SET peak drain current of the BP-HEMT is significantly dropped to 0.49 A/mm from 4.17 A/mm of the conventional HEMT with a linear energy transfer (LET) of 0.6 pC/μm, and the BV is significantly increased to 1318.3 V from 175.2 V, as well as the R_on decreases by 11.1%.