AlGaN/GaN hybrid MOS-HEMT analytical mobility model

Analytical Modeling of Depletion-Mode MOSHEMT Device for High- Temperature Applications

“…Then, with 𝑛 𝑠 = 𝜀 𝑞𝑑 𝐴𝑙𝐺𝑎𝑁 (𝑉 𝑔𝑠 − 𝑉 𝑡ℎ ) and 𝜇 = 𝐶 𝑛 𝑠 𝛿 ⁄ 𝑇 𝛾 , equation ( 30) [38], where 𝐶 ,δ, and 𝛾 are the empirical constant for describing the dependence on the 2DEG density n s and temperature. The mobility constants of 𝛾 = 2.7 and δ=0.3 have been fitted to the theoretical computed 𝜇 2𝐷 (2DEG) of [39,40] with ( ℏ𝜔 0 = 91.2 MeV, 𝑚 * 𝑚 0 ⁄ = 0.2, 𝜀 𝑠 = 8.9 and 𝜀 𝑠,∞ = 5.35) for 𝑛 𝑠 = 1 × 10 13 cm −2 and T = 300 K, respectively. However, it was reported [41] that GaN optical phonon energy ( ℏ𝜔 0 ̴ 90 MeV) is high compared to the energy separation of sub-bands.…”

Modeling the effect of thin gate insulators (SiO2, SiN, Al2O3 and HfO2) on AlGaN/GaN HEMT forward characteristics grown on Si, sapphire and SiC

“…As stressed before, the introduction of the gate insulator affects the Schottky gate capacitance of the HEMT. The MIS-HEMT gate capacitance (C o ) is now the parallel sum of the contribution of C H and the gate oxide (C ins ) [11]. This simple gate capacitance approximation can be naturally improved to take into account the different discontinuities present in the structure.…”

Temperature impact and analytical modeling of the AlGaN/GaN-on-Si saturation drain current and transconductance

“…At elevated T the impurity scattering is minimized due to the spatial separation of electrons and ionized impurities, being especially true for temperatures above 300 K. Equations in [6,13] describe this mobility for a 2DEG, using the conventional relaxation-time approximation, for the case when the optical-phonon energy is greater than the thermal energy. Simple empirical relationships for the polar-optical mobility have been proposed in previous works [14,15]:…”

“…This expression for the low field mobility is very useful since it relates μ n to n s (and hence, V gs ) and the temperature. Mobility constants of γ = 1.8-2.7 (figure 3(a)) and δ = 0.28 (figure 3(b)) have been fitted to the theoretical computed μ po,2D (2DEG) of [15,16] with ( ω 0 = 91.2 MeV, m * /m 0 = 0.2, ε s = 8.9 and ε s,∞ = 5.35) for n s = 1 × 10 13 cm −2 and T = 300 K, respectively. Nevertheless, it is also well known [13] that GaN opticalphonon energy ( ω 0 ∼90 MeV) is high compared to the energy separation of the sub-bands.…”