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

Abstract

We investigated the effect of strain in channel on the electron transport properties of Ga1-xInxSb channel HEMT structures (x = 0.60, 0.78, 0.85, 0.90 and 0.94) with the strained-Al0.40In0.60Sb/Al0.25In0.75Sb stepped buffer. The strain in Ga1-xInxSb channel is determined by the Al0.25In0.75Sb lower buffer. The electron mobility (μ) showed the maximum value at x = 0.78 (unstrained). The sheet electron density (Ns) showed the maximum value at x = 0.60 (tensile strained) due to the deepest quantum well. We obtained the minimum sheet resistance (Rs) of 202 Ω/□ for the Ga0.22In0.78Sb channel. The μ may reach nearly 30,000 cm²/Vs by reducing threading dislocation density.