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Investigation of Relation of Edge-grip Induced Defects and Near-Edge Flatness on 300 mm Silicon Wafers
  • HAO HU
HAO HU
LUT University

Corresponding Author:[email protected]

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Abstract

Surface light point defects (LPD) formation caused by edge gripper handling of silicon wafers was investigated. By relating the observed light point defects (LPD) density to flatness and edge profile measurement it is found that the variation of traditional facet parameters and near-edge geometry metric such as edge site front surface referenced least-square fit range (ESFQR) have no impact on whether surface LPD are generated or not, while the value of Z-height Double Derivative (ZDD), a metric for surface curvature, allows an efficient predication for the formation of surface LPD. Particularly, surface LPD are found to occur with frontside ZDD, taken at a radius of 149.2 mm, ranging from -500 nm/mm2 and -800 nm/mm2 , The surface is found to be LPD free when ZDD is below -1200 nm/mm2 . Surface LPD formation occurs randomly and therefore is inapplicable to predict when ZDD ranges -800 nm/mm2 and -1200 nm/mm2 .