Determination of Temperature-Dependent Stress State in Thin AlGaN Layer of AlGaN/GaN HEMT Heterostructures by Near-Resonant Raman Scattering

Table 1

Model parameters for AlGaN, GaN, and substrate [16].

Material	(K)	(K)	(K)	(K)	(10^−7/K)	(10^−7/K)	(10^−7/K)	(10^−7/K)
GaN
	75	581.25	1684.375		0.487	52.152	4.21
	75	590.625	1675		0.621	47.312	1.125
AlN
	125	600	1852.5		−4.348	44.074	35.056
	100	528.75	1723.75		−5.174	29.857	39.565
Al0.27Ga0.73N
	88.5	586.313	1729.77		−0.0818	4.997	1.254
	81.75	573.919	1688.16		−0.0943	4.26	1.1504
Sapphire
	135	565.625	1231.25	5468.75	1.2176	53.401	35.613	23.661
	135	598.438	1468.75	5198.438	2.856	72.079	23.202	29.087