Growth of AlN/GaN HEMT structure Using Indium-surfactant

Abstract

We have grown AlN/GaN heterostructure which is a promising candidate for mm-wave applications. For the growth of the high quality very thin AlN barrier, indium was introduced as a surfactant at the growth temperature varied from 750 to 1070 degrees C, which results in improving electrical properties of two-dimensional electron gas (2DEG). The heterostructure with barrier thickness of 7 nm grown at of 800 degrees C exhibited best Hall measurement results; such as sheet resistance of 215 Omega/square, electron mobility of 1430 cm(2)/V.s, and two-dimensional electron gas (2DEG) density of 2.04 x 1013 /cm(2). The high electron mobility transistor (HEMT) was fabricated on the grown heterostructure. The device with gate length of 0.2 mu m exhibited excellent DC and RF performances; such as maximum drain current of 937 mA/mm, maximum transconductance of 269 mS/mm, current gain cut-off frequency of 40 GHz, and maximum oscillation frequency of 80 GHz.