Semiconductor device and manufacturing method thereof

摘要

A high performance super-minituarized double gate SOIMOS being fabricated by re-distributing the impurity with high concentration at the interface of a buried gate insulative film and by aligning the double gate in a self-aligned manner and furthermore, by isolating completely the buried gate electrodes electrically from each other, in which a multi-layered SOI substrate having an amorphous or polycrystal semiconductor layer constituted by way of a buried gate insulative film to a lower portion of an SOI layer is used, ion implantation is applied to the semiconductor layer in a pattern opposite to the upper gate electrode and the buried gate is constituted in a self-alignment relation with the upper gate.