Modeling the Radiative Properties of Silicon With Thin-Film Coatings and the Experimental Validation

Published

October 12, 2021

Author(s)

B J. Lee, Z M. Zhang, E A. Early, D P. DeWitt

Abstract

A critical issue for rapid thermal processing (RTP), a single wafer integrated circuit manufacturing process, is how to reduce the temperature measurement uncertainty. Achieving high-accuracy temperature measurements using radiation thermometry requires knowledge of the optical properties of silicon and related materials. However, available optical property models lack consistency and are not fully validated by experiments at the wavelength and temperature ranges critical to radiation thermometry. To remedy this problem, researchers at the Georgia Institute and Technology and the National Institute of Standards and Technology (NIST) have collaborated to develop experimentally validated software tools for the calculation of radiative properties of silicon-related materials. The present work gives a critical survey of the existing optical models, with emphasis on the need for extrapolation and validation. It also describes a computer algorithm for calculating the radiative properties of lightly doped silicon with coatings. The effect of coatings covering one or both sides of a smooth silicon wafer is theoretically studied at room temperature as well as at elevated temperatures. A spectrophotometer was used to measure the reflectance for selected samples in the wavelength region from 0.5 mm to 1 mm at room temperature. The measurement results agree well with the predicted reflectance using the optical constants extrapolated from two existing expressions. This study will facilitate a more thorough investigation of the radiative properties of silicon-based materials at elevated temperatures.

Citation

IEEE Transactions on Semiconductor Manufacturing

Pub Type

Journals

Keywords

optical constants, radiative properties, rapid thermal processing, reflectance, silicon

Citation

Lee, B. , Zhang, Z. , Early, E. and DeWitt, D. (2021), Modeling the Radiative Properties of Silicon With Thin-Film Coatings and the Experimental Validation, IEEE Transactions on Semiconductor Manufacturing (Accessed April 19, 2024)