AlGaN/GaN HFETs on 100 mm Silicon Substrates for Commercial Wireless Applications

GaN grown on Si is currently the only pathway towards high volume manufacturing of GaN based RF devices. In this paper we present the technological status of GaN grown on 100 mm Si sub-strates. Optimised growth, accounting for the lattice and thermal coefficient of expansion mismatch results in device quality GaN layers that exhibit excellent uniformity over the 100 mm Si substrate. The electrical characteristics of the fabricated devices reflect the high quality of the layers, leading to saturated power levels of 3.3 W/mm, the highest power densities reported to date for GaN on Si. Large periphery devices are shown to achieve up to 27 W of output power. Introduction The outstanding potential of group III-nitride heterostructure FETs has been repeatedly demonstrated in a wide frequency range, showing a tenfold improve-ment over “conventional ” semiconductors like Si or GaAs in terms of power density [1, 2]. This performance is mainly due to the ability of GaN based devices to operate at high drain voltages while simultaneously yielding high two-dimensional electron ga