Method of making dense vertical FET's

摘要

A dielectrically isolated region of a monocrystalline substrate, which has a <100> orientation, has a drain region of a field effect transistor (FET) in a surface having a (100) crystal orientation with the drain region being of opposite conductivity to the conductivity of the substrate. A gate channel extends into the substrate from the drain region and is surrounded at its upper end by the drain region. An enlarged recess extends into the substrate beneath the gate channel and has its walls of opposite conductivity to the conductivity of the substrate to form a source region and a plate of a capacitor when the FET is part of a storage cell. The source region has its upper end surrounded by the gate channel.