Molecular Beam Epitaxial Growth and Applications of Graded Bandgap Indium Gallium Aluminum Arsenide Semiconducting Alloys

Techniques for the reliable and reproducible growth of graded-composition alloys of InGaAlAs on InP substrates by solid-source molecular beam epitaxy have been developed, implemented, tested, and demonstrated. An advanced computer control system has been developed to perform the graded -composition growths while simultaneously maintaining diagnostic supervision of the state of the crystal growth apparatus. Graded -composition alloys have been incorporated into both heterojunction bipolar transistors (HBTs) and graded-index, separate confinement heterostructure (GRINSCH) laser diodes, and performance enhancements due to the inclusion of the graded alloys have been demonstrated. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617 -253-5668; Fax 617-253-1690.).