IR color separation in transmission through gratings on (110) silicon: FTIR experiment versus theory

Abstract

The phenomenon of filtering in zero-diffraction order is studied for transmission through 1D-periodic structures on a silicon wafer. Our study combines FTIR spectrometry in the range from 2.5 to 25 microns, and a rigorous full-vector simulation. The phenomenon exhibits itself as 'bright' and 'dark' bands in the spectra of normal transmission through grating samples, which replace each other quasi-periodically with respect to wave number, at wavelengths smaller than the grating period. The transmission modulation ratio is extremely high for two-side polished samples. Good agreement between the rigorous theory and experiment both in the range of the transmission oscillations and in the region of enhanced absorption is obtained

arXiv comment3 pages, 2 figures; Fourier Transform Spectroscopy (FTS) Santa Barbara, California, June 22, 1999; Paper FThA3 in Fourier Transform Spectroscopy: New Methods and Applications, OSA Technical Digest (Optical Society of America, 1999)