Impact of AlInN Back-Barrier Over AlGaN/GaN MOS-HEMT With HfO₂ Dielectric Using Cubic Spline Interpolation Technique

Abstract

The dc characteristics of AlGaN/gallium nitride (GaN) metal–oxide–semiconductor-high electron mobility transistor (MOS-HEMT) with an AlInN back-barrier layer has been studied here. An analytical model is proposed for evaluating the charge density ( $\sigma _{{\mathrm {tot}}}$ ), carrier concentration ( ${n}_{{\mathrm {S}}}$ ), drain current ( ${I}_{{\mathrm {D}}}$ ), and transconductance ( ${g}_{{\mathrm {m}}}$ ) of the device by incorporating Hafnium oxide (HfO2) as a high- ${k}$ dielectric layer. The charges created between the oxide and the AlGaN barrier layer influence the enhancement of carrier concentration of up to $6.2\times 10 ^{13}$ cm $^{-2}$ , at the two-dimensional electron gas (2DEG). The AlInN back-barrier increases the conduction band (CB) level of the GaN buffer and eliminates the confinement problems near the channel. By deriving the mathematical dependence of these parameters, this device demonstrated a positive threshold shift and a high current drive of 880 mA/mm. Cubic spline interpolation (CSI) technique is employed here to model the parameters in a more precise manner. The outcomes are evidence that the device could be a potential solution for high power switching as well as microwave applications.