High voltage field effect transistor with vertical current paths and method of making the same

Abstract

A field effect transistor for a high voltage operation can include vertical current paths, which may include vertical surface regions of a pedestal semiconductor portion that protrudes above a base semiconductor portion. The pedestal semiconductor portion can be formed by etching a semiconductor material layer employing a gate structure as an etch mask. A dielectric gate spacer can be formed on sidewalls of the pedestal semiconductor portion. A source region and a drain region may be formed underneath top surfaces of the base semiconductor portion. Alternatively, epitaxial semiconductor material portions can be grown on the top surfaces of the base semiconductor portions, and a source region and a drain region can be formed therein. Alternatively, a source region and a drain region can be formed within via cavities in a planarization dielectric layer.