Improved Electron Transport Properties of Ga_1-xIn_xSb Quantum Well Channel Using Strained-Al_0.40In_0.60Sb/Al_1-yIn_ySb Stepped Buffer

Abstract

Unstrained Ga1–xInxSb quantum well (QW) channel using strained‐Al0.40In0.60Sb/Al1–yInySb stepped buffer layer grown on GaAs (100) substrate is investigated. Ga1–xInxSb QW is lattice‐matched to the Al1–yInySb lower buffer layer. Sheet electron density (Ns) of Ga1–xInxSb QW is about twice that of InSb one. Electron mobility (μ) increases with increasing In content x of Ga1–xInxSb. Unstrained Ga0.22In0.78Sb QW channel using strained‐Al0.40In0.60Sb/Al0.25In0.75Sb stepped buffer has Ns of 2.05 × 1012 cm−2 and μ of 15 500 cm2 V−1 s−1. Compared with the InSb QW channel, Ns increases by a factor of 193% and μ decreases to 87%. Consequently, the sheet resistance decreases to 59%. These results indicate that the unstrained Ga1–xInxSb QW channel using strained‐Al0.40In0.60Sb/Al1–yInySb stepped buffer is effective to improve the electron transport properties.