Wafer Spin-Up Algorithm for Detection Scanning
Original Publication Date: 1987-Aug-01
Included in the Prior Art Database: 2005-Feb-01
The data detection rate of any wafer-scanning microscope can be kept constant by varying the rate of rotation in relation to a scanning detector. In a wafer-scanning inspection tool, the detector arrays are oriented such that the wafer can be translated under the detection optics in one direction at a uniform velocity. This allows for fast wafer scanning since every detector element is able to observe a strip of wafer that is different from that seen by other detectors. For example, the detectors could form a line, and the wafer is then moved perpendicular to that line. However, in order to produce data at the fullest rate of speed, the wafer must also be scanned at a uniform velocity over its entire surface.