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Honeywell Inc. and Mission Research Corporation (MRC) are jointly developing micro resistive heater array displays for projecting dynamic background scenes and targets in the short-wavelength infrared (SWIR) to long-wavelength infrared (LWIR) wavebands. There are two joint government contracts supporting this work: the Nuclear Optical Dynamic Display (NODDS) program under DNA contract DNA001-92-C-0041, which is developing a 512 X 512 array of 50- by 50-micrometers display pixels, and the Cryovacuum Resistor Infrared Scene Projector (CRISP) program for the USAF Wright Laboratory at Eglin AFB, which is developing a 512 X 512 array of 87.5- by 87.5-micrometers pixels. The requirements on the two programs are somewhat different due to their different missions. While the NODDS program is developing an array that can be used to create dynamic nuclear clutter scenes, the CRISP arrays are being designed for simulating multiple independently moving targets; and while the frame rate on the NODDS arrays requires an array capable of 1-kHz frame rates, the CRISP arrays will be operated at 30 Hz.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Knowledge of the diffusion coefficient and solubility of solute atoms in liquid melts is required in order to accurately predict the diffusion limited growth rate of crystals nucleated from the liquid phase. In this work, diffusion coefficients and solubilities are determined independent of the growth process by measuring the weight loss of a semiconductor wafer after being placed in contact with a melt. Data are reported for the systems Ge in Pb and GaAs in Pb, over the temperature ranges normally employed in liquid phase epitaxy. Solubility data for eutectic Pb-Sn melts are also reported. Addition of Al or Ga to a Pb-Ge melt is found to greatly lower the solubility of GaAs in the melt; this facilitates the growth of p + n Ge-GaAs heterodiodes by substantially reducing the possibility of substrate meltback. Ge layers are grown on 〈111B〉 GaAs substrates by a step-cooling technique. Excellent agreement between observed growth rates and those predicted from the diffusion coefficient and solubility data is obtained.

This report presents the results of an investigation of technological problems associated with the growth and preparation of GaAs with emphasis on problems related to microwave devices. One of the most significant accomplishments of this program is the high uniformity and reproducibility of doping profiles achieved by ion implantation into semi-insulating substrates. Such results have brought GaAs ion implantation into maturity as a technique for preparation of device quality layers. These results are not only expected to lead to increased use of ion implantation for discrete FET device fabrication, but also to pave the way for the development of a planar GaAs IC technology. Experimental measurements of the low frequency noise of IMPATT diodes have been used to extract parameters useful for device design, such as intrinsic response time and multiplication factors under operating conditions. Measurements of ionization rates as functions of the electric field showed a strong dependence on doping concentration which has been qualitatively interpreted in terms of delays in promotion of the accelerated electrons into the higher conduction bands.

Mercury cadmium telluride (Hg1-x Cdx Te) is an important material for infrared detector applications due to tde variable bandgap obtained through simply varying the mercury/cadmium ratio. Thus IR sensing systems with various wavelength requirements, typically from 2 to 12 μm, can potentially all be supplied by one materials technology. Bulk crystal growth technology was originally pursued for these applications. However, large, high quality crystals are difficult to grow because of the high melting point of HgCdTe and the resulting high Hg vapor pressure. Liquid phase epitaxial (LPE) growth techniques can lower the growth temperature through the use of a solvent, and allow the deposition of thin films on large foreign substrates that are grown without any Hg.