Low temperature Fourier transform infrared measurements at 20 K on some wafers containing substitutional atomic carbon and oxygen are presented. Spectral subtraction techniques at 20 K indicate an increase of approximately 5 times in sensitivity compared to the room temperature evaluation of the carbon and oxygen concentrations.
D. G. Mead, "Low Temperature Evaluation of Carbon and Oxygen Contaminants in Silicon," Appl. Spectrosc. 34, 171-173 (1980)