SEMICONDUCTOR DEVICE AND FORMATION THEREOF

摘要

A semiconductor device and method of formation are provided. The semiconductor device comprises a metal plug in a first opening over a substrate. The metal plug has a contact bottom surface that is substantially convex. The substantially convex contact bottom surface has an increased contact area as compared to a contact bottom surface of a metal plug that is not substantially convex. The increased contact area decreases a resistance of the metal plug. The increased contact area requires a smaller deposition amount to form a metal plug seed layer of the metal plug than a semiconductor device with a smaller contact area. A smaller deposition amount reduces an overhang of the deposited metal plug seed layer material. A reduced overhang of the deposited metal plug seed layer material reduces pitting in a metal plug formed from the deposited metal plug seed layer material.

主权项

1. A method of forming a semiconductor device, comprising:
performing a first etch on a dielectric layer overlying an epitaxial (Epi) cap to form an opening; performing a second etch on the Epi cap to establish a substantially concave Epi top surface on the Epi cap; forming a first metal layer over the substantially concave Epi top surface; forming a second metal layer over the first metal layer; and performing an anneal operation on the first metal layer, the second metal layer and Epi cap to form a silicide layer in contact with the substantially concave Epi top surface and having a silicide layer top surface that is substantially concave, wherein at least some of the first metal layer contacts an edge of the silicide layer after the anneal operation.