Methods and apparatus for controlling ion fraction in physical vapor deposition processes

A process chamber for processing a substrate, comprising:

• a body having an interior volume and a target to be sputtered, wherein the interior volume includes a central portion and a peripheral portion surrounding the central portion;
• a substrate support disposed in the interior volume opposite the target and having a support surface configured to support the substrate;
• a collimator disposed in the interior volume between the target and the substrate support;
• a first magnet disposed about the body proximate the collimator;
• a second magnet disposed about the body above the support surface of the substrate support and entirely below the collimator and spaced vertically below the first magnet;
• and
• a third magnet disposed about the body and spaced vertically between the first magnet and the second magnet,
• wherein the first magnet, the second magnet, and the third magnet are configured to generate respective magnetic fields in the interior volume to redistribute ions from the peripheral portion to the central portion and over the substrate.

A process chamber for processing a substrate, comprising:

• a body having an interior volume and a target to be sputtered, wherein the interior volume includes a central portion and a peripheral portion surrounding the central portion;
• a substrate support disposed in the interior volume opposite the target and having a support surface configured to support the substrate;
• a collimator disposed in the interior volume between the target and the substrate support;
• a first electromagnet disposed about the body disposed above a lower face of the collimator and configured to generate a magnetic field having substantially vertical magnetic field lines in the peripheral portion of the interior volume;
• a second electromagnet disposed about the body above the support surface of the substrate support and entirely below the collimator and spaced vertically below the first electromagnet, wherein the second electromagnet is configured to generate a magnetic field having magnetic field lines directed toward a center of the support surface;
• and
• a third electromagnet disposed about the body and spaced vertically between the first electromagnet and the second electromagnet and above the second electromagnet and below a substrate-facing surface of the collimator, wherein the third electromagnet is configured to generate a magnetic field having magnetic field lines directed inward and downward toward the central portion and toward the center of the support surface.