A system for simultaneously inspecting the frontsides and backsides of semiconductor
wafers for defects is disclosed. The system rotates the semiconductor wafer while
the frontside and backside surfaces are generally simultaneously optically scanned
for defects. Rotation is induced by providing contact between the beveled edges
of the semiconductor wafer and roller bearings rotationally driven by a motor.
The wafer is supported in a tilted or semi-upright orientation such that support
is provided by gravity. This tilted supporting orientation permits both the frontside
and the backside of the wafer to be viewed simultaneously by a frontside inspection
device and a backside inspection device.