Disposable spacer process for field effect transistor fabrication

Abstract

According to one exemplary embodiment, a method for forming a field effect transistor on a substrate comprises a step of forming disposable spacers adjacent to a gate stack situated on the substrate, where the disposable spacers comprise amorphous carbon. The disposable spacers can be formed by depositing a layer of amorphous carbon on the gate stack and anisotropically etching the layer of amorphous carbon. The method further comprises forming source and drain regions in the substrate, where the source and drain regions are situated adjacent to the disposable spacers. According to this exemplary embodiment, the method further comprises removing the disposable spacers, where the removal of the disposable spacers causes substantially no gouging in the substrate. The disposable spacers can be removed by using a dry etch process. The method can further comprise forming extension regions in the substrate adjacent to the gate stack prior to forming the disposable spacers.