Method for forming a silicide region on a silicon body

Abstract

The invented method produces a silicide region on a silicon body that is useful for a variety of purposes, including the reduction of the electrical contact resistance to the silicon body or an integrated electronic device formed thereon. The invented method includes a step of producing an amorphous region on the silicon body using ion implantation, for example, a step of forming a metal layer such as titanium, cobalt or nickel in contact with the amorphous region, and a step of irradiating the metal with intense light from a source such as a laser, to cause metal atoms to diffuse into the amorphous region to form an alloy region with a silicide composition. In an application of the invented method to the manufacture of a MISFET device, the metal layer is preferably formed with a thickness that is at least sufficient to produce a stoichiometric proportion of metal and silicon atoms in the amorphous region of the gate of the MISFET device. Importantly, the irradiating step proceeds until the metal overlying the gate alloy region is consumed and the gate alloy region is exposed. The gate alloy region has a higher reflectivity than the metal layer, and thus reduces further thermal loading of the gate alloy region so that silicide growth can be continued in the source and drain regions without adversely impacting the gate of the MISFET device. The invention also includes an integrated MISFET device in which the gate silicide region is greater than the source/drain silicide region.