SBIR-STTR Award

Recent technological advancements in the growth of bulk single crystal, ternary, III-V alloys strongly indicate the potential for commercial feasibility of these alloy substrates. Commercial availability will permit realization of the concept of substrate engineering. Based on reported developments in the (In,Ga)As and (In,Ga)Sb ternary systems, we propose to develop a materials technology for the single crystal growth of InP1-xAsx' to x = 0.4, commensurate with proposed optoelectronic device applications in this materials system. The innovations are: 1) application of novel crystal growth techniques by which the alloy composition, "x" value, is increased by "bootstrapping" onto lattice matched seeds and 2) incorporation of ternary seeds with a growth technology to minimize computational variations which normally occur. In Phase I, we will determine computational and electrical characteristics, develop a wafer fabrication methodology and evaluate crystal quality. Wafers will be provided to Sensors Unlimited (Dr Gregory Olsen-Consultant) who will fabricate and test p/n junction photodetectors. In Phase II we will extend the composition to x = 0.4 and develop techniques to grow crystals in the (100) direction of highly uniform composition. Substrates for fabrication of 2.5um photodetector arrays and strained layer lasers will be provided Sensors Unlimited.

Keywords:
Lec Growth Ternary Iii-V Substrates Indium Phosphide Arsenide Photodetectors

We propose to expand the crystal growth technology for bulk ternary InP1-xAsx, achieved in our Phase I program, to address commercial substrate prerequisites and specific device requirements. In Phase I we demonstrated feasibility for single crystal production in this materials system. We established growth parameters and produced single crystals of InP1-xAsx in the <111> crystallographic direction nominally 2-3cm diameter,to 150gm size and determined accurate first-to-freeze crystal composition as a function of melt composition, for the crystal range x = 0-0.1. Coincidentally, there is a compelling interest for devices, directed toward environmental and industrial ultra-sensitive gas sensing/monitoring. Such devices are achievable with InP1-xAsx substrates, x> 0.40, would operate in the lucrative 2-3 micron spectral region and are predicted to provide enhanced sensitivity, high yield and reduced cost. Laser emission has, in fact, been demonstrated for devices fabricated on x = 0.04 substrates provided by Crystallod Inc. In Phase II we will: 1) extend crystal composition to a value of x = .40, 2) develop parameters for growth in the more desirable <100> crystallographic direction, 3) address issues related to compositional uniformity and 4) advance the growth technology for materials conformity to semiconductor process lines. Dr. Gregory Olsen of Sensors Unlimited wil consult on the program and substrates will be provided to support their Phase II program for development of 2-3 micron DFB semiconductor lasers

Keywords:
Lec Growth Ternary Iii-V Substrates Indium Phosphide Arsenide Photodetectors