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

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 (σ
_tot
), carrier concentration(n
_S
), drain current (ID), and transconductance (gm) of the device by incorporating Hafnium oxide (HfO
₂
) 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 × 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.