| 摘要 |
PURPOSE:To display performance such as high-speed switching operation, multi- valued logic operation, optical communication, etc., by forming a trench region or a projecting region to the surface of a semiconductor substrate and laminating and shaping three layers or more of superlattice layers onto the bottom and side face section of the trench region or the top face and side face section of the projecting region. CONSTITUTION:Superlattice structure is formed onto the bottom and sidewall section of a trench region 20 shaped for compensating the reduction of an element occupying area on the surface of a GaAs crystal substrate 1a, thus constituting one resonance tunneling bipolar tran sistor. An n-type AlGaAs layer 2a as an emitter region is formed onto the bottom and sidewall section of the trench region 20 first, and a p-type GaAs layer 3a, an AlAs superlattice layer (a barrier layer) 4a, a GaAs superlattice layer (a well layer) 5a, an AlAs superlattice layer (a barrier layer) 4a', a p-type GaAs layer 3a' and an n-type GaAs layer 6a re shaped onto the emitter layer 2a in succession. Accordingly, desired performance characteristics can be realized, thus acquiring a superlattice semiconductor element having high reliability. |
