Micro and Nano Engineering Center


At Michigan State University

 

PLASMA DIAGNOSTICS AND CHARACTERIZATION

Measurements are performed on plama discharges operating across a wide range of operating conditions, including pressures of 0.1 mTorr to 100's of Torr. The objectives of the plasma measurements include:

1) Understanding the physics and chemistry of microwave plasma discharges.
2) Verifying both compact control models and more complex multi-dimensional numerical models.
3) Quantifying the internal plasma variables in order to improve plasma-assisted processes.

The MNEC Center has different plasma diagnostic techniques, including:

  •  Laser spectroscopy:  LIF and CARS

  • Optical emission spectroscopy:   VUV, UV, Vis, and IR

  • Gas temperature (rotational)

  • Actinometry (plasma species concentrations)

  • Millimeter wave resonator measurements of electron density

  • Langmuir probe measurements of electron densities and energies

  • Microwave electric field  measurement and mapping

  • Partial pressure analysis of plasma composition
     

An example of a recent plasma diagnostic study is that of the gas temperature in an argon/hydrogen/methane plasma used for nanocrystalline diamond deposition. The gas temperature was measured using optical emission spectroscopy. The particular temperature measured was the C2 molecule rotational temperature.


Plasma Diagnostics and Characterization References:

1. A.K. Srivastava, M. Dahimene, T. Grotjohn, and J. Asmussen, "Experimental characterization of a compact ECR ion source," Rev. Sci. Instrum., 63, pp. 2556-2558, 1992.
2. G. King, F.C. Sze, P. Mak, T. Grotjohn, and J. Asmussen, "Ion and neutral energies in a multipolar ECR plasma source," J. of Sci. and Technol., A10, pp. 1265-1269, 1992.
3. P. Mak, G. King, T. Grotjohn, and J. Asmussen, "Investigation of the influence of electromagnetic excitation on ECR discharge properties," J. of Vac. Sci. and Technol., A10, pp. 1281-1287, 1992.
4. F.C. Sze and J. Asmussen, "Experimental scaling laws for ECR plasma sources," J. of Vac. Sci. and Technol., A11, pp. 1289-1295, 1993.
5. A.K. Srivastava and J. Asmussen, "Comparison of the operational performance of a compact ECR plasma source at excitation frequencies of 2.45 GHz and MHz" J. of Vac. Sci. and Technol., A11, pp. 1307-1312, 1993.
6. A.K. Srivastava, J. Asmussen, T. Antaya and K. Harrison, "The study of a 2.45 GHz plasma source as a plasma generator for the SCECR Electron Cyclotron Ion Source," Rev. Sci. Instrum., 65, pp. 1135-1137, 1994.
7. A.K. Srivastava, D. Sze and J. Asmussen, "Discharge characteristics of a five centimeter, multipolar ECR ion source," Rev. Sci. Instrum., 65, pp. 1749-1752, 1994.
8. A.K. Srivastava and J. Asmussen, "Measurements of the impressed electric field inside a coaxial electron cyclotron resonance plasma source," Rev. Sci. Instrum., 66, pp. 1028-1034, 1995.
9. J. Asmussen and W. Richardson, "Experimental performance of a compact microwave electrothermal thruster," J. Moscow Physical Society 1995.
10. T. A. Grotjohn, G. L. King, and W. Tan, "Microwave Plasma Processing Machine Modeling and Diagnostics for Plasma Assisted Chemical Vapor Deposition," J. Moscow Physical Society, 5, 55, 1995.
11. P. Mak, M.-H. Tsai, J. Natarajan, B. L. Wright, T. A. Grotjohn, F. M. A. Salam, M. Siegel, and J. Asmussen, "Investigation of Multipolar Electron Cyclotron Resonance Plasma Source Sensors and Models for Plasma Control," J. of Vacuum Sci. and Technol., vol. A-14, pp. 1894-1900, 1996.
12. P. Mak and J. Asmussen, "The experimental investigation of the matching and impressed electric field of a multipolar electron cyclotron resonance discharge," J. Vac. Sci. and Technol., A15, pp. 154-168, 1997.
13. J. Asmussen, T. Grotjohn, P. Mak and M. Perrin, "The design and application of electron cyclotron resonance discharges," Invited Paper, for the 25th anniversary edition of the IEEE Trans. on Plasma Science, PS-25, pp. 1196-1221, 1997.