Control of Thickness and Composition Variation of AlGaN/GaN on 6- and 8-in. Substrates Using Multiwafer High-Growth-Rate Metal Organic Chemical Vapor Deposition Tool

It is difficult to control the surface temperature gradient over a bowing GaN on a large-diameter silicon substrate by metal organic chemical vapor deposition (MOCVD) because the wafer bows convexly to store compressive strain during growth. In an attempt to grow uniform AlGaN/GaN on 6-in. (6'') silicon substrates using a 7×6'' reactor, we described in this paper the control of the surface temperature gradient over the wafer and the mass transport at the edge of the wafer. We attempted to grow Al 0.23 GaN/AlN/GaN/SLS/Al 0.5 GaN/AlN on six 8-in. (8'') silicon substrates using a 6×8'' reactor. The standard deviations of total thickness were less than 2.0% on wafer and 0.31% wafer to wafer. The growth rate of strained-layer superlattice (SLS) was as high as 2.8 µm/h. The typical electron mobility was 1670 cm 2 ·V -1 ·s -1 at a sheet carrier density of 1.11×10 13 cm -2 .