Two-dimensional electron gas characteristics of InP-based high electron mobility transistor terahertz detector

The samples of In_xGa_1-xAs/In_0.52Al_0.48As 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 In_xGa_1-xAs/In_0.52Al_0.48As 2DEG channel structures with mobilities as high as 10289 cm²/V·(300 K) and 42040 cm²/V·(77 K) are obtained, and the values of carrier concentration (N_c) 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.