Applications of radio frequency glow discharge optical emission spectrometry on bulk and depth resolved analysis of solid materials.

摘要

Glow discharge optical emission spectrometry (rf-GD-OES), one of the direct solids analytical techniques, has proven to be reliable diagnostic and analytical devices for bulk analysis and depth profiling. Nevertheless, its capabilities are developing so rapidly that pose several challenges on the fundamental studies, instrumental developments, and its applications. This work includes applications of rf-GD-OES for elemental and depth-resolved analysis of solid materials.; The first study involves the elemental analysis of Portland cement using rf-GD-OES. The disks formed from cement powder with 1 minute of grinding time provided best plasma stabilization. Sample disks prepared from NIST SRM Portland cements, were then employed for the determination of the optimization conditions, sample-to-sample repeatability, quantitative analysis, and limits of detection. The optimal conditions were at a power of 40 W and a pressure of 3 Torr. The repeatabilities of most analytes and the calibration curves of major and minor elements were improved by use of argon emission as an internal standard. Detection Limits of chromium, zinc and manganese are presented.; The second study evaluates the discharge conditions which effect the quality rf-GD-OES depth profiles of Ni-P plated aluminum hard disks. The optimal conditions were at a power of 40 W and a pressure of 6 Torr. The depth-resolved analysis of the Ni-P plated on the AI-Mg alloy substrate reflects the microscopic non-uniformity of the interface surface. SEM, TEM, and EDX images are used to examine the physical structure of the layer interfaces. Optimized discharge conditions are employed to profile hard disk extracted from two commercial drives. Distinct composition differences are observed correlating with improvements in the base technology during 1992--1998.; Lastly, the feasibility of rf-GD-OES to monitor metallic impurities and non-metallic elements on silicon wafers is investigated. The optimal conditions were at a power of 40 W and a pressure of 5--6 Torr. The responses of the metallic impurities were compared to those in a surface-metal standard silicon wafer. To enhance the intensities of these contaminants, use of argon with added hydrogen was investigated. From this preliminary study the presence of hydrogen improves analytical responses of elements such as Cu, Mg, Ni and Zn.