2DEG Transport Properties in AlGaN/GaN Double Heterostructure HEMT with High In Composition InGaN Channel

Abstract

AlGaN/InGaN/GaN double heterostructure high electron mobility transistor (HEMT) with In composition from 0.08 to 0.26 were grown by MOCVD. 2DEG density and mobility of different channel In composition were investigated. When In composition below 0.19, 2DEG density increased nearly linearly with In composition, and the mobility decreased a bit. While In composition over 0.19, phase separation became more serious, 2DEG density nearly not changed, and the mobility dropped sharply. A high 2DEG mobility of 1163 cm2/V·s with low sheet resistance of 342Ω/ was obtained with In composition 0.19.

Modeling charge density in AlGaN/AlN/InGaN/GaN-based double heterostructures including InGaN layer strain relaxation

“…table 2) has been used here. As all the experimental data reported by Peng et al [21] fit well with the model predictions, one infers that the effect of strain relaxation in the Table 2. Comparison of the 2DEG density between the model prediction (cf equation (7)) and the experimentally reported data [8,11,19] InGaN layer has been properly included.…”

“…The 2DEG density in a thin-InGaN conducting layer AlGaN/AlN/InGaN/GaN DH significantly increases with increasing In content as may be observed from the experimental Hall data [15][16][17][18][19][20][21] (the formal definition of 'thin' will be provided in the following sections). One intuitively expects that this increment in the 2DEG density is due to a modulation of the polarization charge at the AlGaN/InGaN interface caused by the In content of the InGaN layer.…”

“…Comparison of the 2DEG density between the model prediction and the experimentally reported data[21,30,35] is shown (d AlN =1 nm). The parameter r is extracted for d InGaN =12 nm.…”