Two-dimensional electron gas characteristics of InP-based high electron mobility transistor terahertz detector**Project supported by the Foundation for Scientific Instrument and Equipment Development, Chinese Academy of Sciences (Grant No. YJKYYQ20170032) and the National Natural Science Foundation of China (Grant No. 61435012).

Abstract

The samples of two-dimensional electron gas (2DEG) are grown by molecular beam epitaxy (MBE). In the sample preparation process, the In content and spacer layer thickness are changed and two kinds of methods, i.e., contrast body doping and δ-doping are used. The samples are analyzed by the Hall measurements at 300 K and 77 K. The 2DEG channel structures with mobilities as high as (300 K) and (77 K) are obtained, and the values of carrier concentration (Nc) are 3.465×1012/cm2 and 2.502×1012/cm2, respectively. The THz response rates of InP-based high electron mobility transistor (HEMT) structures with different gate lengths at 300 K and 77 K temperatures are calculated based on the shallow water wave instability theory. The results provide a reference for the research and preparation of InP-based HEMT THz detectors.