- SEMI MF671 - Test Method for Measuring Flat Length on Wafers of Silicon and Other Electronic Materials
This Standard was technically approved by the Silicon Wafer Global Technical Committee. This edition was approved for publication by the global Audits and Reviews Subcommittee on February 1, 2018. Available at www.semiviews.org and www.semi.org in July 2018; originally published by ASTM International as ASTM F671-80; previously published March 2012.
The length of fiducial flats is an important materials characteristic for determining the suitability of material for use in semiconductor processing.
Automatic wafer handling equipment widely used in semiconductor device manufacturing processes relies on identification and orientation of the primary flat to obtain correct alignment.
This Test Method is suitable for use in research, development, process control, quality assurance, and materials acceptance applications.
This Test Method covers techniques for determination of the length of the flatted portion of a wafer periphery.
This Test Method is intended primarily for use on electronic materials in the form of nominally circular edge-contoured wafers with flat lengths up to 65 mm. The precision of this Test Method has been established directly only for silicon wafers, but it is not expected to be material dependent.
This Test Method is suitable for referee measurement purposes and may be used for routine acceptance measurements when specified limits require test precision greater than can be obtained with hand held scale and unaided eye.
This Test Method is independent of surface finish.
For application to wafers of diameter 3 inch or smaller, the values stated in inch-pound units are to be regarded as the standard whether or not they appear in parentheses; the values stated in acceptable metric units are for information only. For application to wafers of diameter larger than 3 inch, the values stated in acceptable metric units are to be regarded as the standard; the values stated in inch-pound units are for information only.
Referenced SEMI Standards
SEMI M1 — Specification for Polished Single Crystal Silicon Wafers
SEMI M59 — Terminology for Silicon Technology