Effect of Strain in Channel on Electron Transport Properties of Ga1-xInxSb HEMT Structures with Strained-Al0.40In0.60Sb/Al0.25In0.75Sb Stepped Buffer

We investigated the effect of strain in channel on the electron transport properties of Ga
1-
x
In
x
Sb channel HEMT structures (x = 0.60, 0.78, 0.85, 0.90 and 0.94) with the strained-Al
0.40
In
0.60
Sb/Al
0.25
In
0.75
Sb stepped buffer. The strain in Ga
1-
x
In
x
Sb channel is determined by the Al
0.25
In
0.75
Sb lower buffer. The electron mobility (μ) showed the maximum value at x = 0.78 (unstrained). The sheet electron density (N
s
) showed the maximum value at x = 0.60 (tensile strained) due to the deepest quantum well. We obtained the minimum sheet resistance (R
s
) of 202 Ω/□ for the Ga
0.22
In
0.78
Sb channel. The μ may reach nearly 30,000 cm
²
/Vs by reducing threading dislocation density.