Atomic layer profiling of diffusion barrier and metal seed layers

摘要

Material is removed from a substrate surface (e.g., from a bottom portion of a recessed feature on a partially fabricated semiconductor substrate) by subjecting the surface to a plurality of profiling cycles, wherein each profiling cycle includes a net etching operation and a net depositing operation. An etching operation removes a greater amount of material than is being deposited by a depositing operation, thereby resulting in a net material etch-back per profiling cycle. About 2-10 profiling cycles are performed. The profiling cycles are used for removing metal-containing materials, such as diffusion barrier materials, copper line materials, and metal seed materials by PVD deposition and resputter. Profiling with a plurality of cycles removes metal-containing materials without causing microtrenching in an exposed dielectric. Further, overhang is reduced at the openings of the recessed features and sidewall material coverage is improved. Integrated circuit devices having higher reliability are fabricated.

主权项

1. A method of processing a layer of material on a semiconductor substrate having a recessed feature, the method comprising:
(a) depositing a layer of diffusion barrier material on the semiconductor substrate, to coat at least a bottom portion of the recessed feature; and (b) performing a plurality of profiling cycles, after depositing the layer of diffusion barrier material in (a), wherein each profiling cycle comprises a net etching operation removing a first portion of a material residing at the bottom of the recessed feature by resputter and a net deposition operation depositing a second portion of a material at the bottom of the recessed feature, the removed portion of the material being greater than the deposited portion of the material for each of the profiling cycles, and wherein performing the plurality of profiling cycles achieves net material etching at the bottom portion of the recessed feature.