Characteristics of planar doped FET structures

The recent demonstration of single atomic planes of doping using molecular beam epitaxy gives rise to the possibility of single plane FET's with the channel confined to the dopant plane. In this paper an analysis of the Structure is presented which takes account of the spread of the free-carrier density normal to the plane. This rigorous analysis is compared with the simple case of a plane of free carriers. Under certain conditions the simple model gives good agreement with the exact analysis but for shallow, low-density planes, substantial departures from the simple model occur.