US Patent 7537978 Semiconductor device and manufacturing method thereof

A semiconductor device comprises a support layer made of semiconductor, a diffusion layer formed by implanting impurities in a surface layer of the support layer, a buried insulating layer provided on the diffusion layer, an island-like active layer provided on the buried insulating layer, a channel region formed in the active layer, source and drain regions formed in the active layer, sandwiching the channel region, a gate insulating film formed on the channel region, a gate electrode formed on the gate insulating film and on side surfaces of the island-like active layer, and insulated and isolated from the channel, source, and drain regions, and an electrode connected to the active layer.