“…Since the thicknesses necessary for OP-GaAs are not practically attainable using molecular beam epitaxy (MBE) or organo-metallic vapor phase epitaxy (OMVPE), we used low-pressure hydride vapor phase epitaxy (HVPE), which can have much higher growth rates [21]. To produce mm-thick layers, it is desirable to establish a rate of at least 100 mm/h and maintain that rate for approximately 10 h. Due to the tendency for parasitic deposition of GaAs on the quartz reactor walls, the total length of productive growth time may be limited as the vapor becomes depleted.…”