- SEMI MF26 - Test Method for Determining the Orientation of a Semiconductive Single Crystal
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 May 12, 2014. Available at www.semiviews.org and www.semi.org in October 2017; originally published by ASTM International as ASTM E26-63T; previously published July 2014.
E This Standard was editorially modified in November 2017. A change was made to correct a nonconforming title per the Procedure Manual, Appendix 4.
The orientation of semiconductor crystals and wafers as determined by these test methods is an important materials acceptance requirement because the orientation controls various parameters of semiconductor devices fabricated from the material.
These test methods cover techniques for determining the crystallographic orientation of a surface which is roughly parallel to a low-index atomic plane in single crystals used primarily for semiconductor devices.
Two types of test methods are covered as follows:
•Test Method A, X-ray Diffraction Orientation — This test method may be used for the orientation of all semiconductive single crystals. The X-ray test method is nondestructive and yields the more precise measurement of orientation; however, use of the equipment requires compliance with stringent safety regulations.
•Test Method B, Optical Orientation — This test method is limited in application at the present time to elemental semiconductors. The optical test method requires etching the specimen and is therefore destructive of polished wafer surfaces. This test method is less precise than the X-ray test; however, the apparatus required is less complex.
Referenced SEMI Standards
SEMI C28 — Specifications for Hydrofluoric Acid
SEMI C30 — Specifications Hydrogen Peroxide
SEMI C40 — Specification for Potassium Hydroxide, 45% Solution
SEMI C43 — Specification for Sodium Hydroxide, 50% Solution