Abstract: A surface inspection system utilizes a laser light source, and a vacuum chuck to support the material whose surface is to be inspected. The vacuum chuck is rotatable. The laser beam may be translated across the work surface while the chuck is rotated, all the while maintaining mutual perpendicularity of the vacuum chuck work surface and the laser beam. An airtrack transports the material whose surface is to be inspected. Sensors are utilized to detect the position of such material along the track and to guide the system in its operation.

Abstract: An automatic four-point probe mechanism, containing various sensors, motors, and precision machine parts necessary to accurately and repeatedly lower a four-point resistivity head onto a semi-conductor slice surface is ideally suited for operator independent measurements of semi-conductor resistivity. The automatic four-point probe finds application in quality assurance incoming-outgoing inspections, materials process control, epitaxial in-process control, diffusion in-process control, thin-film process control, and similar applications. In the preferred embodiment, all torsional forces are eliminated from the probe head, thus avoiding scratch damage to the semi-conductor surface and providing for uniform depth penetration of the probe into the semi-conductor surface and great repeatability of test readings.