AlGaN/GaN Heterostructure Field-Effect Transistors (HFETs) on Si Substrates for Large-Current Operation

We demonstrated AlGaN/GaN heterostructure field-effect transistors (HFETs) grown on 2 inch Si (111) substrates by metalorganic chemical vapor phase epitaxy (MOVPE). Using GaN/AlN multilayers, we successfully fabricated nonpitted and crack-free GaN films thicker than 1 µm on Si substrates. An electron mobility of 1200 cm 2 /V·s, a sheet carrier density of 4.5 ×10 12 /cm 2 , and a sheet resistance of 1100 Ω/sq were obtained. Fabricated 60-mm-gate-width HFETs exhibited a maximum drain current of more than 10 A, an on-state resistance of 0.5 Ω, and a breakdown voltage of more than 350 V.