Bidirectional Reflectance Distribution Function of Rough Silicon Wafers

Published

July 1, 2001

Author(s)

Y J. Shen, Z M. Zhang, Benjamin K. Tsai, D P. DeWitt

Abstract

The trend towards miniaturization of patterning features in integrated circuits (IC) has made traditional batch furnaces inadequate for many processes. Rapid thermal processing (RTP) for silicon wafers has become more popular in recent years for IC manufacturing. Light-pipe radiation thermometry is the method of choice for real-time temperature monitoring in RTP tools. However, the radiation environment can greatly affect the signal reaching the radiometer. The bidirectional reflectance distribution function (BRDF) of rough silicon wafers is needed for the prediction of the reflected radiation that reaches the radiometer and for reflective RTP furnace design. This paper presents the BRDF measurement results for several processing wafers in the wavelength region from 400 nm to 1100 nm with the Spectral Tri-function Automated Reference Reflectometer (STARR) at the National Institute of Standards and TEchnology (NIST). The rms roughness of these samples ranges from 1 nm to 2 m, as measured with an optical interferometric microscope. Correlations between the BRDF and surface parameters are obtained using different models by comparing theoretical predictions with experiments.

Citation

International Journal of Thermophysics

Volume

22

Issue

No. 4

Pub Type

Journals

Keywords

bidirectional reflectance distribution f, radiometric temperature measurement, rapid thermal processing (RTP), silicon wafers, surface roughness

Citation

Shen, Y. , Zhang, Z. , Tsai, B. and DeWitt, D. (2001), Bidirectional Reflectance Distribution Function of Rough Silicon Wafers, International Journal of Thermophysics (Accessed December 29, 2025)