Sputter deposition for semiconductor manufacturing

Abstract

Sputter deposition, also known as physical vapor deposition, or PVD, is a widely used technique for depositing thin metal layers on semiconductor wafers. These layers are used as diffusion barriers, adhesion or seed layers, primary conductors, antireflection coatings, and etch stops. With the progression toward finer topographical dimensions on wafers and increasing aspect ratios, the broad angular distribution of depositing, sputtered atoms leads to poor or nonexistent coverage in deep features. This has been partially addressed using directional sputtering techniques such as collimated sputtering or long-throw sputtering. More recently, work originating in IBM has moved toward the deposition of films from metal-rich plasmas fed by sputtering, a technique known as I-PVD (for ionized PVD). This technique, based on fairly minor modifications of existing PVD systems, solves many of the intrinsic problems of PVD and appears headed for widespread manufacturing applications.