MF207400 - SEMI MF2074 - Guide for Measuring Diameter of Silicon and Other Semiconductor Wafers

 The diameter of semiconductor wafers is an important parameter in microelectronic fabrication. Wafer diameters must conform to the limits specified in SEMI M1; or other agreed upon limits, or product that is otherwise suitable may not fit correctly in process equipment. Cam-follower edge rounding usually results in wafers that are circular. However, wafers ground with edge-follower edge rounding equipment may be elliptically shaped. Measurements made at the three positions specified in this Guide do not provide complete information about the roundness of the wafer. This Guide defines standardized positions for measuring diameter of circular wafers of silicon and other semiconducting materials especially those processed with edge-follower edge-rounding equipment that contain flats or notches (fiducials) on the periphery. It was developed for use with silicon wafers of 150 mm diameter or less with standard diameter and fiducial positions as given in SEMI M1. It may be applied to other t