Influence of High Electric Field on Operation of AlGaN/AlN/GaN High Electron Mobility Transistor
M. Glinkowski, B. Paszkiewicz, R. Paszkiewicz
Faculty of Microsystem Electronics and Photonics, Wrocław University of Science and Technology, Janiszewskiego 11/17, 50-370 Wrocław, Poland
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In AlGaN/AlN/GaN heterostructures, as a result of spontaneous and piezoelectric polarization with the occurrence of donor surface states, a triangular potential well is formed on the interface, filled with two-dimensional electron gas with a concentration of 1013 cm-2 and a mobility of 2000 cm2/(V s). An increase of the potential in the channel of an AlGaN/AlN/GaN high electron mobility transistor, caused by the flow of the drain current, results in: a decrease of the two-dimensional electron gas concentration, an increase of electric field and an increased drift velocity of electrons. At the drainage end of the gate, the electrons reach their maximum drift velocity which is correlated with the material limitations. Consequently, a rapid nonlinear increase of the channel potential, a decay of the two-dimensional electron gas channel, and pushing of the electrons towards the buffer occurs. The vertical current component starts to increase then while the horizontal current component decreases. Moreover, between the gate and the drain electrodes the two-dimensional electron gas channel is gradually rebuilt due to the presence of a low electric field. The Advanced Physical Models of Semiconductor Devices software was used to simulate these phenomena in the structure of an AlGaN/AlN/GaN high electron mobility transistor.

DOI:10.12693/APhysPolA.140.192
topics: APSYS, AlGaN/GaN, HEMT, simulation