Electron Beam Source Molecular Beam Epitaxy of AlxGal−xAs Graded Band Gap Device Structures

Autor: R.W. Ryan, D.V. Lang, A. F. J. Levi, B.F. Levine, L. C. Hopkins, R.J. Malik, R.C. Miller
Rok vydání: 1989
Předmět:
Zdroj: Band Structure Engineering in Semiconductor Microstructures ISBN: 9781475707724
DOI: 10.1007/978-1-4757-0770-0_18
Popis: A new method has been developed for the growth of graded band-gap Al x Ga 1-x As alloys by molecular beam epitaxy which is based upon electron beam evaporation of the Group III elements. The metal evaporation rates are measured real-time and feedback controlled using beam flux sensors. The system is computer controlled which allows precise programming of the Ga and AJ evaporation rates. The large dynamic response of the metal sources enables for the first time the synthesis of variable band-gap Al x Ga 1-x As with arbitrary composition profiles. This new technique has been demonstrated in the growth of unipolar hot electron transistors, graded base bipolar transistors, and M-shaped barrier superlattices.
Databáze: OpenAIRE