Susceptors with film deposition control features

A semiconductor processing system, comprising:

• a reactor having a hollow interior;
• a divider seated within the hollow interior of the reactor with a divider aperture, the divider dividing the hollow interior of the reactor into an upper chamber and a lower chamber;
• a susceptor arranged within the hollow interior of the reactor and supported for rotation about a rotation axis, the rotation axis extending through the divider aperture, wherein the susceptor comprises:
• a circular pocket portion arranged along the rotation axis and having a perforated surface;
• an annular ledge portion extending circumferentially about the circular pocket portion and having a ledge surface, the ledge surface sloping upward along the rotation axis from the perforated surface and having a support circumference at which the ledge surface is arranged to support a substrate along a periphery of the substrate;
• and
• an annular rim portion extending circumferentially about the annular ledge portion, connected to the circular pocket portion by the annular ledge portion of the susceptor, and having a planar rim surface axially offset from the ledge surface of the susceptor;
• wherein the planar rim surface and the support circumference define therebetween a tuned pocket to tune an edge thickness, relative to a radially inner region of the substrate, of a film deposited onto the substrate supported on the ledge surface of the susceptor;
• a purge source connected to the reactor and configured to flow a purge gas through the lower chamber of the reactor;
• and
• a precursor source connected to the reactor and configured to flow a precursor gas through the upper chamber of the reactor.

A film deposition method, comprising:

• at a susceptor including a circular pocket portion arranged along a rotation axis and having a perforated surface;
• an annular ledge portion extending circumferentially about the circular pocket portion and having a ledge surface, the ledge surface sloping upward along the rotation axis from the perforated surface and having a support circumference at which the ledge surface is arranged to support a substrate along a periphery of the substrate;
• and an annular rim portion extending circumferentially about the annular ledge portion, connected to the circular pocket portion by the annular ledge portion of the susceptor, and having a planar rim surface axially offset from the annular ledge surface of the susceptor;
• the planar rim surface and the support circumference defining therebetween a tuned pocket configured and adapted to tune an edge thickness, relative to a radially inner region of the substrate, of a film deposited onto the substrate supported on the ledge surface of the susceptor,
• supporting the substrate on the ledge surface of the susceptor, the substrate having a topside and an underside axially separated from one another by the periphery of the substrate;
• flowing a purge gas through the perforated surface and into a purged volume defined between the underside of the substrate and the perforated surface of the susceptor;
• flowing a precursor gas across the topside of the substrate;
• depositing the film onto the topside of the substrate using the precursor gas;
• and
• tuning edge thickness of the film deposited onto the topside of the substrate using the tuned pocket defined by the susceptor.

A susceptor, comprising:

• a circular pocket portion arranged along a rotation axis and having a perforated surface;
• an annular ledge portion extending circumferentially about the circular pocket portion and having a ledge surface, wherein the ledge surface slopes upward along the rotation axis from the perforated surface;
• and
• an annular rim portion extending circumferentially about the annular ledge portion, connected to the circular pocket portion by the annular ledge portion of the susceptor, and having a planar rim surface axially offset from the ledge surface of the susceptor,
• wherein the ledge surface has a support circumference at which the ledge surface is configured to support a periphery of a substrate such that a topside of the substrate is substantially coplanar with the planar rim surface or is axially between the planar rim surface and the perforated surface of the circular pocket portion.