Abstract: A method and apparatus for depositing self-aligned base contacts where over-etching the emitter sidewall to undercut the emitter contact is not needed. A semiconductor structure has a T-shaped emitter contact that comprises a T-top and T-foot. The T-top acts as a mask for depositing the base contacts. In forming the T-top, its dimensions may be varied, thereby allowing the spacing between the base contacts and emitter to be adjusted.

Abstract: A method of growing a p-type doped Group II-VI semiconductor film includes the steps of forming a lattice comprising a Group II material and a Group VI material wherein a cation-rich condition is established at a surface of the lattice. The method further includes the steps of generating an elemental Group V flux by evaporating an elemental Group V material and providing the elemental Group V flux to a Group VI sublattice of the lattice.

Abstract: A method of growing a p-type doped Group II-VI semiconductor film includes the steps of forming a lattice comprising a Group II material and a Group VI material and generating a first Group V flux by evaporating a solid Group V source material. The first Group V flux is then decomposed to generate a second Group V flux, which is, in turn, provided to the lattice to p-type dope the growing film. The Group V source material may by arsenic such that the second Group V flux may predominantly include dimeric arsenic decomposed from tetrameric arsenic to improve the incorporation of arsenic into the Group VI sublattice of the lattice.