Test structures for analyzing the mechanisms of wafer chemical contaminant removal

The design of an electrochemical sensor to measure wafer contaminant concentrations during ultrapure water rinses is discussed in the article. The techniques discussed in this paper also demonstrate the need to have additional monitor devices on-chip that enable the characterization of unwanted parasitic devices. The results obtained from the experiments conducted will provide, for the first time, data on the removal rates of contaminants from deep trenches, thereby enabling the identification of mechanisms and the development of models for wafer contaminant removal in advance semiconductor processes.