Abstract: Disclosed is a majority carrier rectifying barrier semiconductor device housing a planar doped barrier. The device is fabricated in GaAs by an epitaxial growth process which results in an n.sup.+ -i-p.sup.+ -i-n.sup.+ semiconductor structure wherein an extremely narrow p.sup.+ planar doped region is positioned in adjoining regions of nominally undoped (intrinsic) semiconductive material. The narrow widths of the undoped regions and the high densities of the ionized impurities within the space charge region results in rectangular and triangular electric fields and potential barriers, respectively. Independent and continuous control of the barrier height and the asymmetry of the current vs. voltage characteristic is provided through variation of the acceptor charge density and the undoped region widths. Additionally, the capacitance of the device is substantially constant with respect to bias voltage.

Abstract: Single crystals of alpha aluminum phosphate of high crystal perfection are rown from seeded solutions of aluminum orthophosphate and orthophosphoric acid in such a manner as to provide direct visual observation of the crystal growth process and allow precise determination of nucleation and growth kinetics.The method involves sealing the seeded solution in clear quartz ampules, inserting the ampules into a precisely temperature controlled silicone oil bath, increasing the temperature of the silicone oil bath from ambient temperature to approximately 150 degrees C. over a three hour period, programming the temperature of the bath upward at the rate of 0.1 to 2.0 degrees C. per day for periods up to sixty days, and removing the quartz ampules from the silicone oil bath and quickly cooling and removing the crystals.