A novel In_xGa_(1-x)N/InN heterostructure field-effect transistor with extremely high two-dimensional electron-gas sheet density

摘要

By self-consistently solving Schroedinger and Poisson equations, an extremely high two-dimensional electron-gas (2DEG) sheet density of 1.01 x 10~(14)cm~(-2) is calculated in a novel InN-based In_xGa_(1-x)N/InN heterostructure field-effect transistor with an In content of x = 0.1 and a doping level of N_d = 1 x 10~(19)cm~(-3) in the In_xGa_(1-x)N barrier layer. It is increased by almost one order of magnitude as compared to ～1 x 10~(13)cm~(-2) obtained in a conventional GaN-based Al_(0.2)Ga_(0.8)N/GaN heterostructure. With increasing In content of the In_xGa_(1-x)N barrier from x = 0.05 to 0.15, the 2DEG sheet density decreases from 1.14 x 10~(14)cm~(-2) to 0.91 x 10~(14)cm~(-2) due to the decreased of polarization charges and the reduced conduction band offset. And the 2DEG density increases slightly with increasing doping level of the In_xGa_(1-x)-N barrier.