Evaluation Of A New Metal Analyzer For Online Process Control In The Semiconductor Industry

摘要

The control of metal ion contamination during wet-chemical cleaning processes is critical to the fabrication of next generation of high density semiconductor devices. Moreover, continuous monitoring of the different cleaning sites contributes to better understanding of both contamination sources and mechanisms. In this paper robust online analyzer for trace metal ion monitoring based on novel voltammetric detector has been presented. The analyzer is characterized by both high performance and versatility: 20 + metal and some nonmetal ions (Cu, Fe, Ni, Co, halogens etc.) can be determined at wide concentration range (μg/l to g/l). Robust and chemically inert design of the detector is compatible with electronic grade chemicals including HF, as well as with different process and waste waters. Long term overall system stability has been evaluated using continuous measuring of synthetic sample containing lead and copper ions: over 3000 consecutive measurements have been performed with high accuracy without any system maintenance. Characteristics of the detector have been demonstrated through analysis of nickel, cobalt, copper, and chromium at concentrations ranging from 0.1μg/l through 125mg/l in synthetic samples.