Migration Enhanced Metalorganic Chemical Vapor Deposition of AlN/GaN/InN based heterostructures

We applied a new Migration Enhanced Metalorganic Chemical Vapor Deposition (MEMOCVD) epitaxial technique for growing AlN/GaN/InN epitaxial films and heterostructure layers on 2”, 3” and 4” substrates. The growth of the AlN/GaN/InN layers was carried out using controlled precursor pulsed flows to achieve accurate thickness control over large area substrates. This technique bridges the gap between molecular beam epitaxy (MBE) and metalorganic chemical vapor deposition (MOCVD). The Al composition in AlGaN barrier layer of AlGaN/GaN high electron mobility transistor (HEMT) structures varied less than 3% over 3” and 4” wafers. For AlGaN/GaN HEMTs, the sheet resistance of 463 ohm/sq has been achieved over a 4” diameter wafer grown on sapphire. The MEMOCVD technique ensures an improved material quality resulting in a better device performance. This technology should also find applications for nitride photonic devices, such as deep ultraviolet light emitting diodes, ultraviolet lasers, and solar blind ultraviolet photodetectors.