2DEG transport characteristics by self-consistent subband calculations of Schrödinger and poisson equations in InAlN/GaN HEMT

In this paper a new HEMT structure is proposed by replacing the barrier layer of a conventional AlGaN/GaN HEMT with InAlN material. InAlN/GaN HEMTs can obtain substantially higher polarization-induced two-dimensional electron gas (2DEG) of the order of 10¹⁴ cm^-2 at the heterointerface. The spontaneous polarization in Al_0.3Ga_0.7N/GaN HEMT is 0.017C/m² while for the proposed In_0.17Al_0.83N/GaN HEMT is 0.047C/m². This large difference in spontaneous polarization results in higher 2DEG density at the heterointerface. The large band offset with respect to GaN, results in the formation of a deep quantum well which leads to better carrier confinement at the heterointerface. The confinement of electrons in the quantum well or 2DEG leads to very high speed and high power device as it doesn´t significantly suffer from large scatterings. Therefore, in this paper the 2DEG interface charge density and its transport characteristics have been carried out by self-consistent solution of Schrödinger and Poisson´s equations.