Abstract: A substrate heating arrangement suitable for use in ultra-high vacuum MBE includes a filament responsive to a DC current for generating thermal energy, a metallic enclosure surrounding the filament and having an aperture at one end thereof, an intermediate semiconductor substrate parallel to and separated from a semiconductor growth substrate, and a substrate support mounted to the enclosure capable of holding the substrates in the prescribed relationship.The intermediate semiconductor substrate regulates the temperature on the surface of the semiconductor growth substrate to be less than or equal to a fixed temperature (approximately 1100.degree. C. for silicon) regardless of the DC current applied to the filament.

Abstract: A molecular beam epitaxial method of fabricating a semiconductor device is disclosed wherein the dopant is implanted by establishing a plasma containing ions of the dopant and the ions are coupled through a drift chamber to impinge on the growing substrate surface. The plasma formed in the ion gun has ions of boron and arsenic and therefore the dopants selected for implantation can be determined by setting a mass filter present in the ion gun. A change to the dopant of the opposite conductivity type can be accomplished in seconds by simply readjusting the mass filter in the ion gun.