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, Al 0.35 GaN/GaN/Al 0.25 GaN double heterostructure field effect transistors on 200 mm Si(111) substrates. Thick crack-free Al 0.25 GaN buffer layers are achieved by optimizing Al 0.75 GaN/Al 0.5 GaN 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 µm. 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 × 10 13 cm -2 , which results in a very low sheet resistance of 306±8 Ω/square.