AlGaN/GaN/AlGaN Double Heterostructures Grown on 200 mm Silicon (111) Substrates with High Electron Mobility

In this work, we demonstrate, for the first time, Al0.35GaN/GaN/Al0.25GaN double heterostructure field effect transistors on 200 mm Si(111) substrates. Thick crack-free Al0.25GaN buffer layers are achieved by optimizing Al0.75GaN/Al0.5GaN intermediate layers and AlN nucleation layers. The highest buffer breakdown voltage reaches 1380 V on a sample with a total buffer thickness of 4.6 mu m. According to Van der Pauw Hall measurements, the electron mobility is 1766 cm(2) V-1 s(-1) and the electron density is 1.16 x 10(13) cm(-2), which results in a very low sheet resistance of 306 +/- 8 Omega/square. (C) 2012 The Japan Society of Applied Physics