Chairman Rorze Automation Inc.
He worked for Air LIquide from 1976 to 1989 and for Agilent Technologies from 1989 to 2000 and for PerkinElmer from 2000 to 2004. He founded IAS Inc. in 2004 and developed several unique products that are integrated with ICP-MS, which cover analysis of metallic contamination in wafers, liquid chemicals and gases used in semiconductor industry.
Abstract
Direct Nanoparticle Analysis on 300 mm Silicon Wafers Using LA-GED-MSAG-ICP-MS
The detection and characterization of nanoscale particles on semiconductor wafers are becoming increasingly important as semiconductor device geometries continue to shrink. One of particle contamination sources is liquid chemicals, and a particle counter has been commonly used to monitor particles in liquid chemicals directly. However, chemical delivery components such as tubing, filters and valves are also other contamination sources. As a result, particles should be monitored on a wafer after the use of chemical solutions. A particle detection system using laser beam has been used to monitor particles on a wafer, but the composition of these particles cannot be determined. An X-ray Fluorescence technique has been used to determine elemental composition of particles on a wafer; however, the sensitivity is insufficient for detecting particles smaller than 100 nm.
A new analytical technique using LA-GED-MSAG-ICP-MS (Laser Ablation – Gas Evaluation Device – Metal Standard Aerosol Generation – Inductively Coupled Plasma Mass Spectrometry) was developed to determine the metallic particles on a wafer and was applied to the direct analysis of nanometer-sized particles on 300 mm silicon wafers. A liquid chemical sample was dispensed onto a wafer surface and dried under ambient conditions. After drying, particles remaining on the wafer surface were directly analyzed without additional transfer steps.
In order to evaluate accuracy of particle size and number of particle recovery, single Au and Fe3O4 nanoparticle standard reference materials were spiked onto a Si wafer and analyzed. The results showed that MSAG provided accurate particle size evaluation for nanoparticles, and the number of particle recovery rate of Au was greater than 80%.
The study demonstrates the capability of LA-GED-MSAG-ICP-MS for direct nanoparticle analysis on semiconductor wafers. The technique enables detailed evaluation of nanoparticles on wafers and provides a new approach for semiconductor contamination analysis.