Novellus Systems Incorporated

Ronald L Kinder

Anshu A Pradhan

Alexander Dulkin

Douglas Brenton Hayden

Roey Shaviv

Daniel R Juliano

Local plasma density, e.g., the plasma density in the vicinity of the substrate, is increased by providing an ion extractor configured to transfer ions and electrons from a first region of magnetically confined plasma (typically a region of higher density plasma) to a second region of plasma (typically a region of lower density plasma). The second region of plasma is preferably also magnetically shaped or confined and resides between the first region of plasma and the substrate. A positively biased conductive member positioned proximate the second region of plasma serves as an ion extractor. A positive bias of about 50-300 V is applied to the ion extractor causing electrons and subsequently ions to be transferred from the first region of plasma to the vicinity of the substrate, thereby forming higher density plasma. Provided methods and apparatus are used for deposition and resputtering.

Method and apparatus for increasing local plasma density in magnetically confined plasma

Recessed features on a Damascene substrate are filled with metal using plasma PVD. Recessed features having widths of less than about 300 nm, e.g., between about 30-300 nm can be filled with metals (e.g., copper and aluminum), without forming voids. In one approach, the deposition is performed by exposing the substrate to a high-density plasma characterized by high fractional ionization of metal. Under these conditions, the metal is deposited within the recess, without forming large overhang at the opening of the recess. In some embodiments, the metal is deposited within the recess, while diffusion barrier material is simultaneously etched from the field region. In a second approach, recessed features are filled by performing a plurality of profiling cycles, wherein each cycle includes a net etching and a net depositing operation. Etching and depositing parameters are adjusted such that the recessed features are filled without forming overhangs and voids.

PVD-based metallization methods for fabrication of interconnections in semiconductor devices

Methods for resputtering and plasma etching include an operation of generating an ultra-high density plasma using an ultra-high magnetic field. For example, a plasma density of at least about 10electrons/cmis achieved by confining a plasma using a magnetic field of at least about 1 Tesla. The ultra-high density plasma is used to create a high flux of low energy ions at the wafer surface. The formed high density low energy plasma can be used to sputter etch a diffusion barrier or a seed layer material in the presence of an exposed low-k dielectric layer. For example, a diffusion barrier material can be etched with a high etch rate to deposition rate (E/D) ratio (e.g., with E/D&#x3e;2) without substantially damaging an exposed dielectric layer. Resputtering and plasma etching can be performed, for example, in iPVD and in plasma pre-clean tools, equipped with magnets configured for confining a plasma.

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Oakland, CA, United States of America

Ronald L Kinder