Apparatus And Methods For Wafer Rotation In Carousel Susceptor

An apparatus comprising:

• a processing chamber including a bottom, top and sidewall defining a processing region within;
• a susceptor assembly inside the processing chamber, the susceptor assembly having a top surface and a bottom surface defining a thickness, the susceptor assembly including a plurality of recesses in the top surface, each of the recesses having a recess bottom spaced a distance from the top surface of the susceptor assembly, each of the recesses having a lift pocket substantially centered within the recess, each lift pocket having a lift pocket bottom surface spaced a distance from the recess bottom defining a depth of the lift pocket;
• a lift assembly positioned within each of the plurality of recesses, the lift assemblies including a lift plate having a top surface and bottom surface defining a thickness within ±2 mm of the depth of the lift pocket, a lift shaft extending from the bottom surface of the lift plate, the lift shaft having a length sufficient to pass through the susceptor and extend the lift plate above the recess bottom by a distance greater than or equal to about 1 mm, the lift assembly including a lift friction pad with a bottom surface at an end of the lift shaft, the lift plate positioned within the lift pocket and the lift shaft positioned within an opening in the susceptor and extending a distance from the bottom of the susceptor;
• a plurality of rotation assemblies, each rotation assembly comprising a rotation friction pad with a top surface and a rotation shaft extending from the rotation friction pad, the top surface of the rotation friction pad in vertical alignment with the bottom surface of the lift friction pad,
• a flange with an opening sized to allow the rotation shaft to pass through and a bottom surface with a plurality of bolt holes therethrough, the flange positioned adjacent to and connected to the bottom of the processing chamber outside of the processing region;
• a pulley connected to the rotation shaft of each of the rotation assemblies;
• and
• a rotation motor having a belt sized to contact the pulley on each of the rotation assemblies so that all of the rotation assemblies are rotated at the same time.

A processing method comprising:

• positioning a plurality of substrates on a susceptor assembly inside a processing chamber, each of the substrates positioned within a recess in a top surface of the susceptor assembly;
• exposing at least some of the substrates to a flow of reactive gas from a gas distribution assembly positioned above and spaced from the top surface of the susceptor assembly;
• rotating the susceptor assembly while exposing at least some of the substrates to the flow of reactive gas;
• stopping rotation of the susceptor assembly;
• raising the substrates by lowering the susceptor assembly until a lift assembly within the recess contacts a rotation assembly below the susceptor assembly and causes the substrate to be lifted from the recess, the lift assembly comprising a lift plate connected to a lift shaft extending through the susceptor assembly and a lift friction pad below the susceptor assembly, the rotation assembly comprising a rotation friction pad to contact the lift friction pad, a rotation shaft connected to the rotation friction pad, the rotation shaft extending through a bottom of the processing chamber;
• rotating the substrates by turning the rotation shaft with a rotation motor connected to a pulley on the rotation shaft with a belt to rotate the rotation friction pad which contact with the lift friction pad causes rotation of the lift friction pad, the lift shaft and the lift plate which contact with the substrate causes rotation of the substrate;
• and
• lowering the substrate into the recess by raising the susceptor assembly to disengage the lift assembly from the rotation assembly.