ASTM International - ASTM F523-93(1997)
Standard Practice for Unaided Visual Inspection of Polished Silicon Wafer Surfaces
|Publication Date:||10 December 1997|
|ICS Code (Semiconducting materials):||29.045|
1.1 This practice covers an inspection procedure for determining the surface quality of silicon wafers that have been polished on one side.
1.2 This practice is intended as a large-volume acceptance method and as such does not require use of a microscope or other optical instruments. Because the inspection relies on the visual acuity of the operator, test results may be very operator-sensitive.
Note 1-For clarification of the identification of certain observed defects, procedures given in Practices F154 may be employed.
1.3 Defects visible to the unaided eye on polished wafer surfaces are categorized in three groups by the illumination geometry which best delineates them: front-surface high-intensity light, front-surface diffuse light, and back-surface diffuse light. These defects originate from two sources: (1) those which are caused by imperfections in the silicon crystal, and (2) those related to the manufacturing process, including handling and packaging.
1.4 The inspection described generally takes place after polishing and post-polish cleaning but before packaging. Although cleaning and packaging procedures are not a part of this practice, the inspection may be performed on a packaged product to determine the effect of such procedures on the quality of the polished wafers.
1.5 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.6 This standard does not purport to address all of the safety concerns, 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.