Method for improving fdsoi device leakage

Abstract

The present disclosure provides a method for improving an FDSOI device leakage, including steps of: defining a bulk silicon region on the semiconductor structure, and forming an recess area by removing a silicon nitride layer, a first oxide layer, an SOI layer, and a buried oxide layer in the bulk silicon region by etch, wherein the etch is stopped at the silicon substrate; refilling the recess area in the bulk silicon region with monocrystalline silicon, until the monocrystalline silicon reaches a same height as that of the SOI layer outside of the bulk silicon region; forming an STI region, and performing ion implantation on the bulk silicon region; and forming a device structure in the bulk silicon region. In the present disclosure, a doping condition for the bulk silicon region is selected to meet the demands of the device, thereby solving the problem of the device leakage.