Patent ID: 7382711

Claim:
An electron beam substrate processing apparatus, comprising: a substrate processing chamber defined by sidewalls, a bottom, and a top; a spindle motor assembly moveably disposed within the substrate processing chamber; a spindle shaft extending from the spindle motor assembly toward the top; a substrate support member mounted to an end of the spindle shaft distal the spindle motor assembly; an encoder wheel coupled to the spindle shaft and positioned adjacent the substrate support member; an optical detector positioned in optical communication with the encoder wheel, the optical detector being configured to generate rotation data signals in response to detected rotation of the encoder wheel; a pattern generator circuit configured to generate an electron beam control signal in response to the rotation data signals, wherein the electron beam control signal frequency varies as a function of at least one processing radius and angular velocity associated thereto; and an electron beam assembly responsive to the electron beam control signal, the electron beam assembly being disposed on the substrate processing chamber and configured to direct the electron beam onto a surface of the substrate for processing.