Method of fabricating semiconductor device having l-shaped spacer

Abstract

A method of fabricating a semiconductor device having an L-shaped spacer is provided. A buffer dielectric layer, a first dielectric layer, and a second dielectric layer are sequentially formed on the surface of the gate electrode and on the semiconductor substrate. Next, the second dielectric layer is etched to form a first disposable spacer on the first dielectric layer at both sidewalls of the gate electrode. Next, a deeply doped source and drain region is formed on the semiconductor substrate to be aligned to the first disposable spacer. Next, the first disposable spacer and the first dielectric layer are sequentially removed. Next, a shallowly doped source and drain region is formed on the semiconductor substrate at both sidewalls of the gate electrode adjacent to the deeply doped source and drain region. Next, a third dielectric layer, a fourth dielectric layer, and a fifth dielectric layer are sequentially formed on the buffer dielectric layer. Next, the fifth dielectric layer is etched to form a second disposable spacer on the fourth dielectric layer at both sidewalls of the gate electrode. Next, the fourth dielectric layer, the third dielectric layer, and the buffer dielectric layer are etched to form an L-shaped spacer at both sidewalls of the gate electrode. Last, a metal silicide is formed on top of the gate electrode and on the deeply doped source and drain region.