SEMI M33 : 1998

Describes the analytical procedure to determine the trace level of contaminating elements of an atomic number higher than 15 on polished or epitaxial silicon wafer surfaces in native or thermally grown or tetraethylorthosilicate (TEOS) oxide or in residues of microdroplets of process chemicals or media as analyzed with TXRF on silicon wafer surfaces as described in Sections 15.1 and 15.2. This document specifies a VPD-TXRF (Vapor Phase Decomposition Total Reflection X-Ray Fluorescence Spectroscopy) method to analyze the elemental composition and areal density of impurities, that include cations and anions with atomic numbers between 16 (S) and 92 (U) independent of their chemical state, with the exception of the X-ray source material, on polished or epitaxial silicon wafer surfaces in native or thermally grown oxide or in residues of microdroplets of process chemicals or media as analyzed with TXRF on silicon wafer surfaces.