Lateral confinement in a resonant tunneling transistor with a buried metallic gate

We have fabricated a resonant tunneling transistor by epitaxial overgrowth over a tungsten grating placed 30 nm above a GaAs/GaInP semiconductor, double barrier, resonant tunneling heterostructure. The Schottky depletion around the buried metal contacts controls the current to a vertical transistor channel. The lateral extension of this channel is defined by a square opening in the grating with a side length of 1.4 mu m, which corresponds to a sub-mu m electrical width. The transport properties at 20 K show a fine structure in the resonant tunneling characteristics, and it is affected by the gate bias. These effects are discussed in terms of lateral quantum confinement in the transistor channel defined. (C) 1999 American Institute of Physics. [S0003-6951(99)00102-3].