Targeted heat control systems

A semiconductor processing chamber pedestal radiation shield, comprising:

• a ceramic material;
• and
• a block, wherein:
• the shield defines a central aperture coaxial with a central axis of the shield,
• the shield is characterized by a first surface and a second surface that is opposite the first surface, the first surface and the second surface being orthogonal relative to the central axis of the shield;
• the shield defines a plurality of apertures uniformly spaced about the central aperture, each aperture of the plurality of apertures extending through both the first surface and the second surface,
• the block extends across and covers at least one aperture of the plurality of apertures, and
• the plurality of apertures are defined within an area confined by a radial distance of 90% or less of a radius of the shield.

A method of semiconductor processing comprising:

• flowing a carbon-containing precursor into a processing chamber, wherein the processing chamber comprises a faceplate and a substrate support on which a substrate is disposed, wherein the substrate support extends through a base of the processing chamber, wherein the substrate support comprises:
• a support platen on which the substrate is disposed,
• a shaft coupled with the support platen,
• a shield coupled with the shaft of the substrate support, wherein:
• the shield is characterized by a first surface that faces the support platen and a second surface that is opposite the first surface;
• and
• the shield comprises a plurality of apertures defined through the shield, each aperture of the plurality of apertures extending through both the first surface and the second surface, and
• a block covering and closing off at least one aperture of the plurality of apertures;
• generating a plasma of the carbon-containing precursor within the processing chamber;
• and
• depositing a carbon-containing material on the substrate.