Gas source molecular beam epitaxy of Ga/sub x/In/sub 1//sub -x/P/sub y/As/sub 1//sub -y/

The use of P/sub 2/ and As/sub 2/ beams generated by several different beam sources for the growth of InP, GaAs, and Ga/sub x/In/sub 1-x/P/sub y/As/sub 1-y/ has been investigated. Accommodation coefficients for As/sub 2/ and P/sub 2/ were determined for heated GaAs and InP surfaces. It is demonstrated that a source utilizing decomposition of the hydrides over the range 200--2000 Torr and providing a leak of the resulting P/sub 2/, As/sub 2/, and H/sub 2/ molecules into a molecular beam epitaxy (MBE) system can be used for the growth of Ga/sub x/In/sub 1-x/P/sub y/As/sub 1-y/ layers lattice matched to InP. Heterostructure lasers emitting at 1.5 ..mu..m with room temperature threshold current densities of 2000 A/cm/sup 2/ and differential quantum efficiencies of 17%--19% were fabricated to demonstrate the quality of the epitaxy by this method. Initial studies of the cracking of AsH/sub 3/ and PH/sub 3/ at low pressures in contact with heated Ta suggest that Ta acts as a catalyst for the decomposition and that low pressure beam sources may also be useful for gas source MBE.