US Patent 7892944 Method of forming transistor in semiconductor device

A method of forming a transistor in a semiconductor device includes forming device isolation structures in a substrate to define an active region. An oxide-based layer and a nitride-based layer are then formed between the active region and the device isolation structures. A predetermined gate region is etched in the active region to form a recess region. The damage layers are formed by a tilted ion implantation process using neutral elements on portions of the oxide-based layer exposed at the sidewalls of the recess region and other portions of the oxide-based layer below the recess region. The damage layers are then removed, thus causing a portion of the active region exposed at the bottom of the recess region to protrude.