Alignment Microscope for e-beam lithography using JEOL JBX9300FS
The PAMS-1101 tool is used to pre-align chips and wafers before insertion into the e-beam lithography systems. The workpiece cassette is mounted on a 300mm stage with digital encoders in X and Y. A USB camera with 1x-4x digital zoom is attached to a PC. Since the cassette is mounted upside-down, the workpiece position and rotation may be adjusted before the backside fixture is attached. Special software analyzes the mark positions and calculates workpiece rotation and mounting offset, to be save into a log file. Also, arbitrary points on the workpiece may be mapped and logged for later use when the cassette is introduced into the e-beam chamber. Expected accuracy of the mark location measurement in reference to the ebeam coordinate system is in the order of 30um or less.