A process for conformally doping through the vertical and horizontal
surfaces of a 3-dimensional vertical transistor in a
semiconductor-on-insulator structure employs an RF oscillating torroidal
plasma current to perform either conformal ion implantation, or conformal
deposition of a dopant-containing film which can then be heated to drive
the dopants into the transistor. Some embodiments employ both conformal
ion implantation and conformal deposition of dopant containing films, and
in those embodiments in which the dopant containing film is a pure
dopant, the ion implantation and film deposition can be performed
simultaneously.