Basic studies of ultratrace chemical analysis for metallic elements in several semiconductor materials

The reduction of the blank levels of analytical procedures: has long been an important consideration in analytical chemistry. Continuous improvements in the sensitivity of analytical techniques have necessitated the mitigation of the contamination levels in many ultratrace procedures. Chapter 1 reviews the history of ultratrace analysis for the introduction. Chapter 2 outlines the reduction of analytical blanks from containers. A mirror-polishing technique was developed for treating fluorocarbon polymers surfaces using high-precision diamond cutting tools. A degree of surface smoothness of 0.1 mu m PTV (peak to valley) was obtained. Ultratrace analysis contamination levels for contamination fabricated from such polymers were reduced by more than 1 order of magnitude relative to those prevalent in a commercially available container. Chapter 3 discusses the determination of an ultratrace analysis of inorganic semiconductor materials, such as silicon wafers, copper layers, barrier metals, and so forth. Silicon wafers 0.01 to 10 mu m thick could be dissolved by controlling the acidities of HF and HNO3 in the etching solution. When a few hydrogen annealed wafers were analyzed by this method, different annealing treatments of silicon wafer were found to have clearly different depth-profiles of elements. Chapter 4 considers the determination of an ultratrace analysis of organic semiconductor materials. A digestion method was successfully used to determine ultratrace concentrations of Na, K, Mg, Ca, and Cl in organic materials. The method is very effective in measuring the ions of organic materials whilst preventing their contamination from the surrounding environment and from the procedure.