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 .