| AVS 62nd International Symposium & Exhibition | |
| In-Situ Spectroscopy and Microscopy Focus Topic | Monday Sessions |
| Session IS+AS+SA+SS-MoA |
| Session: | Ambient Pressure X-ray Photoelectron Spectroscopy Studies for Catalytic and Energy Materials in Gas Phase |
| Presenter: | Yaser Helal, The Ohio State University |
| Authors: | Y.H. Helal, The Ohio State University C.F. Neese, The Ohio State University F.C. De Lucia, The Ohio State University A. Agarwal, Applied Materials, Inc. B. Craver, Applied Materials, Inc. P.R. Ewing, Applied Materials, Inc. P.J. Stout, Applied Materials, Inc. M.D. Armacost, Applied Materials, Inc. |
| Correspondent: | Click to Email |
Plasmas used by the semiconductor manufacturing industry are similar in pressure, temperature, and electron density to those used for the laboratory study of astrophysical neutrals, ions, and radicals. Thus, methods developed over several decades in the submillimeter/terahertz spectral region are directly applicable. Important attributes of terahertz absorption spectroscopy are that it can provide from first principles, without need for calibration, absolute concentrations and temperatures. Furthermore, since there are no intrusive probes, terahertz observations do not impact or change the plasma under study. Such measurements provide details and insight into the interactions and reactions occurring within the plasma and their implications for semiconductor manufacturing processes. In this work, a continuous wave, 0.5 – 0.75 THz absorption spectrometer was developed and used to study the processes in a commercial inductively coupled plasma (ICP) etch chamber. Because of the relatively long wavelength of the terahertz radiation, diffraction is more serious than in the optical regime. As a result, an important part of this work was the development of optical strategies to couple this spectrometer to the plasma reactor using its existing viewports. Comparisons of the experimental results with predictions from equipment models for ICPs will also be presented for Ar/CF4/CHF3 with varying pressures, powers, and gas mixture ratios. Comparisons such as this provide a basis for validating and improving models, whose development is a complex and difficult science in itself. The results presented in this talk show that terahertz rotational spectroscopy can provide unique and easy to interpret information about manufacturing plasmas and is a useful development tool for process, theoretical and physical models, and the improvement of etch methods.