Measurement of Trace Metallic Contaminants on Silicon Wafer Surfaces in Native and Dielectric Silicon Oxides by Vapor Phase Decomposition Flow Injection Inductively Coupled Plasma‐Mass Spectrometry

Abstract

A highly sensitive multielement analytical method known as vapor phase decomposition flow injection inductively coupled plasma‐mass spectrometry (ICP‐MS) was developed and used to measure the concentration of trace metals on silicon wafer surfaces. The method uses hydrogen fluoride vapor to decompose and release metal contaminants from a surface oxide. These trace metals are then collected by scanning a small drop of dilute acid solution throughout the wafer surface. Trace metals in the solution are measured by ICP‐MS using flow injection (FI) sample introduction. Potentially, 60 elements can be measured with detection limits ranging from 108 to 1011 atom/cm2. Typical surface concentrations of trace metals on silicon wafers with native oxides and dielectric oxides were measured and presented.