Position and temperature monitoring of ALD platen susceptor

A deposition apparatus comprising:

• a gas distribution assembly having a front surface;
• a susceptor assembly to rotate a plurality of substrates around a central axis, the susceptor assembly having a top surface facing the front surface and a bottom surface, the region between the top surface and the front surface defining a gap, the top surface having a plurality of recesses to hold the plurality of substrates, each recess having a center, the bottom surface having an alignment reference point opposite each of the plurality of recesses and a temperature reference point comprising a groove at a fixed diameter, the alignment reference point comprising a recess center reference point and a camera reference point, the camera reference point having a shape involving at least two vertices having a known distance, the recess center reference point providing an indication of the position of the center of the recess;
• a gap control actuation device connected to the susceptor assembly and configured to adjust the gap by moving the susceptor assembly;
• a camera with a field of view directed at the bottom surface of the susceptor assembly and positioned so that when one of the plurality of recesses is positioned adjacent a loading station, the alignment reference point opposite the recess and the temperature reference point are within the field of view of the camera;
• and
• a controller connected to the camera and the gap control actuation device, the controller configured to determine a position of the recess adjacent the loading station from the alignment reference point and to determine a temperature of the susceptor assembly from the position of the temperature reference point, the controller configured to measure a distance between the at least two vertices to determine one or more of a distance of the camera from the susceptor assembly or the gap, the controller configured to control the gap control actuation device to adjust the gap.

A method of transferring a substrate to a rotatable susceptor assembly, the method comprising:

• rotating the susceptor assembly around a central axis so that one of a plurality of recesses in a top surface of the susceptor assembly is positioned adjacent a loading area of a processing chamber, each recess having a center;
• moving the susceptor assembly closer to and further from a gas distribution assembly, the top surface of the susceptor assembly facing a front surface of the gas distribution assembly, the region between the top surface of the susceptor assembly and the front surface of the gas distribution assembly defining a gap;
• finding an alignment reference point on a bottom surface of the susceptor assembly opposite the recess in the top surface using a camera with a field of view directed at the bottom surface of the susceptor assembly, the alignment reference point comprising a recess center reference point and a camera reference point, the recess center reference point providing an indication of the position of the center of the recess, the camera reference point having a shape including at least two vertices having a known distance;
• finding a temperature reference point on the bottom surface of the susceptor assembly using the camera with a field of view directed at the bottom surface of the susceptor assembly, the temperature reference point comprising a groove at a fixed diameter;
• evaluating a position of the recess on the top surface of the susceptor assembly by measuring a position of the alignment reference point on the bottom surface of the susceptor assembly to determine coordinates of the recess;
• evaluating a temperature of the susceptor assembly by measuring a position of the temperature reference point on the bottom surface of the susceptor assembly to determine the temperature of the susceptor assembly;
• evaluating one or more of a distance of the camera from the susceptor assembly or a distance between the front surface of the gas distribution assembly and the top surface of the susceptor assembly by measuring the distance between the at least two vertices;
• communicating the coordinates of the recess to one or more of a controller to rotate the susceptor assembly or a transfer robot to allow the transfer robot to place the substrate within the recess reproducibly;
• and
• communicating one or more of the distance of the camera from the susceptor assembly or the distance between the front surface of the gas distribution assembly and the top surface of the susceptor assembly to a controller to adjust the gap.