Growth of large-area, single-crystalline AlN substrates (Subtopic A: Electronic Materials)

"The objective of this proposal is to demonstrate the feasibility of large-area aluminum nitride (AlN) wafers for III-nitride substrate applications. The growth strategy consists of growing single crystalline AlN on adequately prepared SiC templates using asublimation process. We propose to employ a multi-step deposition process to (1) avoid SiC decomposition, (2) prepare the SiC seed surface for AlN growth, and (3) to greatly reduce stress in the overgrown, single crystalline AlN. The use of SiC templatesis appealing due to the ability of instantly producing large area growth. In this project, the feasibility of the proposed growth process will be explored on 1" 6H-SiC wafers. The proposed growth strategy will demonstrate the growth of large-area, singlecrystalline AlN crystals using specially prepared SiC wafers as seeds. The availability of large-size 6H-SiC wafers will enable and expedite future upscaling efforts. AlN wafers that will be fabricated eventually from the grown crystals will find animmediate application as lattice-matched substrates for high-quality epitaxy of III-nitrides and will enable the fabrication of superior quality AlGaN electronic and optoelectronic devices, including blue and ultraviolet solid state laser diodes,high-power and high-frequency transistors, solar-blind UV detectors and surface acoustic wave (SAW) devices. Since the epitaxial processes and a variety of III-nitride device structures have been developed during the past ten years on less favorablesubstrates with large lattice mismatch, the penetration of these new AlN wafers into the market place can occur without delay and to the immediate benefit of device performance."