1.1 The purpose of this guide is to list, illustrate, and provide reference for various characteristic features and contaminants that are seen on highly specular silicon wafers. Recommended practices for delineation and observation of these artifacts are referenced. The artifacts described in this guide are intended to parallel and support the content of the SEMI M18. These artifacts and common synonyms are arranged alphabetically in Tables 1 and 2 and illustrated in Figs. 1-68 .