1.1 This test method covers measurement of the diameter of silicon wafers up to 205 mm in diameter. Other semiconductor materials with a circular shape can also be measured.

1.2 This test method is independent of surface finish and may be performed on edge-contoured specimens.

1.3 This test method is to be carried out at a temperature of 23 + 5°C.

1.4 This test method was developed for use with silicon wafers with standard diameters as given in SEMI Specifications M1, and may be used for wafers of other diameter or materials within the specified limit, provided suitable gage blocks are available and standard flat configurations are used.

1.5 This test method is intended for use as a referee method.

1.6 Roundness is not measured by this method.

1.7 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

1.8 For wafers of diameter 3 in. or smaller, the values stated in inch-pound units are to be regarded as standard; the values stated in acceptable metric units in parentheses are for information only. For wafers of diameter larger than 3 in., the values stated in acceptable metric units are to be regarded as standard whether or not they appear with parentheses; inch-pound units are for information only.