Structure having reduced lateral spacer erosion

A process for minimizing lateral spacer erosion of an insulating layer adjacent to a contact region and an apparatus whereby there is provided a contact opening with a small alignment tolerance relative to a gate electrode or other structure are disclosed. The process includes the steps of forming a conductive layer on a semiconductor body, then depositing an insulating layer adjacent to the conductive layer. Next, substantially rectangular insulating spacers are formed adjacent to the gate electrode. An etch stop layer is deposited adjacent the insulating layer, followed by an etch to remove the etch stop layer material from the contact region. This etch is conducted under conditions wherein the etch removes the etch stop layer, but retains the substantially rectangular lateral spacer profile of the first insulating layer. The apparatus is capable of maintaining high quality contacts between the conductive material in the contact region and an underlying device region such as a source or drain, or some other layer or structure, and is an effective structure for small feature size structures, particularly self-aligned contact structures.