Regrowth of InAs on the sides of in-situ etched InAs/AlSb superlattices

We propose to bias uniformly a superlattice by etching mesas of an InAs/AlSb superlattice in-situ and subsequently regrowing InAs on the sidewalls. A uniformly biased semiconductor superlattice produces a Stark ladder which can support gain for frequencies just below the Stark splitting. Since the Stark ladder can be easily tuned with the applied bias, the superlattice can be the basis for a terahertz frequency solid state oscillator. Unfortunately, charge accumulation, electric field instabilities, and electric field domain formation occur in superlattices. "Circuit models" of the domain formation suggest that a thin (4-40 nm) layer of InAs on the sidewall of a /spl sim/1 /spl mu/m wide InAs/AlSb mesa could suppress domain formation without compromising the gain at terahertz frequencies.