Transistor fabrication employing formation of silicide across source and drain regions prior to formation of the gate conductor

Abstract

The present invention advantageously provides a method for forming a transistor in which silicide contact areas are formed to the junctions during fabrication of the transistor. The silicide contact areas may be formed using a single high temperature anneal since silicide forming near sidewalls of the gate oxide is prevented. In one embodiment, dopants are first forwarded into a lateral region of a silicon-based substrate to form an implant region. Then a silicide layer is formed across the implant region using a high temperature anneal. A sacrificial material is deposited across the silicide layer and the substrate. A contiguous opening is formed vertically through the sacrificial material and the silicide layer, exposing a portion of the substrate. Dopants of the type opposite to the dopants implanted previously are then implanted into the exposed substrate region to form a channel. Thus, the implant region is separated into source and drain regions having a channel interposed between them. Spacers may be formed on opposed sidewall surfaces of the sacrificial material within the opening. A gate oxide is then formed across the exposed region, followed by the formation of a polysilicon gate conductor across the gate oxide. A polycide is formed across the gate conductor before the sacrificial material is removed.

Dependencies are inferred from the claim text.