Methods and apparatus for substrate edge uniformity

An apparatus for controlling substrate edge uniformity in a semiconductor process chamber, comprising:

• a substrate support with a top surface for holding a substrate when present;
• the substrate support being movable;
• a cover ring that engages with an electrically insulating spacer that engages with a grounded shield such that the cover ring is held stationary;
• and
• a controller that adjusts the substrate support in response to a deposition of material on a surface of the cover ring.

An apparatus for controlling substrate edge uniformity in a semiconductor process chamber, comprising:

• a substrate support with a top surface for holding a substrate when present;
• the substrate support being movable;
• a cover ring that engages with an electrically insulating spacer that engages with a grounded shield such that the cover ring is held stationary;
• and
• a controller that maintains a shadow effect of the cover ring on the substrate by adjusting the substrate support in response to deposition of material on a top surface of the cover ring.

An apparatus for controlling substrate edge uniformity in a semiconductor process chamber, comprising:

• a substrate support with a top surface for holding a substrate when present;
• the substrate support being movable;
• a cover ring that engages with an electrically insulating spacer that engages with a grounded shield such that the cover ring is held stationary;
• and
• a controller that maintains a shadow effect of the cover ring on the substrate by adjusting the substrate support in response to an increase in weight of the cover ring.

A system for controlling substrate edge uniformity in a semiconductor process chamber, comprising:

• a process volume in the semiconductor process chamber;
• a shield surrounding the process volume and electrically grounded;
• a substrate support with a top surface for holding a substrate when present;
• the substrate support being movable;
• a deposition ring surrounding the substrate support;
• a cover ring that engages with an electrically insulating spacer that engages with the shield such that the cover ring is held stationary, the cover ring is isolated from the deposition ring and electrically isolated from the shield;
• and
• a controller that adjusts the substrate support in response to a deposition of material on a surface of the cover ring.