Metody měření povrchové a objemové kontaminace křemíkových desek

Abstract

In this work a trace analysis of iron, nickel and copper on the silicon wafer surface and in the bulk silicon is studied. It attempts to explain metal diffusion characteristics, their solubility, precipitation behavior and electrical properties in a single crystal silicon. A uniform distribution of contaminant through the silicon surface layer was achieved by metal adsorption from intentionally contaminated solution. Surface analysis such as total reflection X – ray fluorescence (TXRF) and vapor phase decomposition pairing with inductively coupled plasma mass spectrometry (VPD – ICP MS) were performed. The bulk contamination measurement is strongly dependent on the metal characteristics and the ability to form electrically active complexes, which can be detected by lifetime measurement techniques. Both surface and bulk techniques of trace analysis are commonly used for monitoring metal contamination in a wafer processing. The goal is to determine suitable diffusion conditions for a thermal annealing process, that will be used to quantify the electrically active impurities in the bulk silicon. The results related to bulk and surface contamination and metal detection capability in the bulk silicon are discussed. Correlations between surface and lifetime techniques are tested here.