Silicide process utilizing pre-amorphization implant and second spacer

Abstract

A gate electrode is formed on a substrate with a gate insulating layer therebetween. A liner is then deposited on sidewalls of the gate electrode. Source / drain extensions are implanted into the substrate. A first spacer is then formed on the liner. Deep source / drain are implanted into the substrate. A second spacer is formed at the foot of the first spacer. A tilt-angle pre-amorphization implant (PAI) is conducted to form an amorphized layer next to the second spacer. A metal layer is then sputtered on the amorphized layer. The metal layer reacts with the amorphized layer to form a metal silicide layer thereto.

Description

BACKGROUND OF INVENTION [0001] 1. Field of the Invention [0002] The present relates generally to semiconductor device fabrication. More particularly, the present invention relates to a silicide process utilizing pre-amorphization implant (PAI) and a second spacer. [0003] 2. Description of the Prior Art [0004] As known in the art, silicide such as titanium silicide (TiSi2) is a typical contact material used to reduce contact resistance. It is also known that TiSi2 exists as a C49 phase or as a C54 phase. When using the general processing conditions for forming TiSi2, the less desirable, higher-resistivity C49 phase is formed first. In order to obtain the lower-resistivity C54 phase, a second high-temperature annealing step is required. Besides, the titanium silicide process is flawed because each titanium atom consumes two silicon atoms to form the titanium silicide. [0005] To cope with the difficulties arose due to the use of titanium silicide, nickel (Ni) has been used to replace t...

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Problems solved by technology

Besides, the titanium silicide process is flawed because each titanium atom consumes two silicon atoms to form the titanium silicide.

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