The lattice-matched AlInN/GaN high electron mobility transistor with BGaN buffer

Abstract

This work studies the lattice-matched AlInN/GaN high-electron mobility transistor (HEMT) with BGaN buffer in drain-current (DC) and radio-frequency (RF) characteristics in theory. The results demonstrate that the BGaN buffer can effectively confine two-dimensional electron gas (2DEG) in the channel area and significantly improve the pinch-off velocity of devices. Compared with the standard GaN buffer HEMT as a reference, the BGaN buffer HEMT with only 1.5% B-component significantly suppressed the short-channel effects (SCEs). And the subthreshold swing (SS) and drain-induced barrier lower (DIBL) are reduced to 124 mV/dec and 77 mV/V, respectively. The threshold voltage of the proposed HEMT is about −3.61 eV, which positive shifts about 2.45 eV compared with the reference HEMT, and this mainly due to the reduction of 2DEG density. In addition, the peak current gain cutoff frequency (fT) and maximum oscillation frequency (fmax) of the proposed HEMT are 155 GHz and 174 GHz, respectively. And this is slightly lower than that of the reference device, which mainly results from the lower transconductance and 2DEG density.