A method for fabricating a semiconductor device with a bulb shaped recess gate pattern includes selectively etching a first portion of a substrate to form a first recess; forming a spacer on sidewalls of the first recess; performing an isotropic etching process on a second portion of the substrate beneath the first recess to form a second recess, the second recess being wider and more rounded than the first recess; removing the spacer; and forming a gate pattern having a first portion buried into the first and second recesses and a second portion projecting over the substrate.