Abstract: A method for forming a gate structure used in borderless contact etching is disclosed including the steps described below. Forming a conductive layer on a substrate, followed by forming a first silicon nitride layer on the conductive layer. The next step is to pattern a gate electrode by etching all the layers formed in the steps mentioned previously. The following steps is to form a second silicon nitride layer on the surface of the gate electrode and the substrate. Finally, etching the second silicon nitride layer to form a nitride spacer on the side walls of the gate electrode. The altitude of the nitride spacer is higher than the altitude of the first silicon nitride layer.