Emi Kawamura

Contact:

Biographical:

Finished Ph.D. dissertation in Physics at the University of California at Berkeley on December 17, 2003.
Undergraduate degree was a B.A. in Physics from Harvard University. Currently working as a staff researcher with a joint appointment to the Electrical Engineering and Chemical and Biomolecular Engineering Departments at the University of California at Berkeley.

Research:

Developing and optimizing models using the COMSOL (finite elements method) tool and Matlab to study capacitive and inductive coupling, uniformity, and electron heating in single and multi-frequency TCP and CCP plasma reactors.

Analytic and numerical studies of double layers in inductive plasma discharges, series resonance heating, dc bias, secondary electron emission and electromagnetic effects in capacitive discharges using Matlab, Mathematica, and particle-in-cell (PIC) codes. Developing and optimizing 1D and 2D PIC codes written in C/C++.

Analysis and numerical simulation of capacitive discharges driven by combined DC/RF sources, and study of effect of DC bias on secondary electron emission. Developing and testing analytical and numerical models to study electron heating mechanisms and ion energy distributions at the electrodes of single and multi-frequency capacitive plasma discharges used in semiconductor processing.

Journal Articles:

1. E. Kawamura, M.A. Lieberman, A.J. Lichtenberg, and D.B. Graves, "Two-Dimensional Simulation of Inductive-Capacitive Transition Instability in an Electronegative Plasma". To be submitted.

2. E. Kawamura, D.B. Graves and M.A. Lieberman, "Fast 2D hybrid fluid-analytical simulation of inductive/capacitive discharges", Plasma Sources Science and Technology, vol. 20, 035009 (2011).

3. E. Kawamura, A.J. Lichtenberg and M.A. Lieberman, "Two-dimensional particle-in-cell simulations of transport in a magnetized electronegative plasma", Journal of Applied Physics, vol. 108, 103305 (2010).

4. E. Kawamura, A.J. Lichtenberg and M.A. Lieberman, "Waves in expanding electronegative plasmas containing double layers", Journal of Applied Physics, vol. 107, 123301 (2010).

5. E. Kawamura, A.J. Lichtenberg, M.A. Lieberman and J.P. Verboncoeur, "Double layer formation in a two-region electronegative plasma", Physics of Plasmas vol. 16, 122114 (2009).

6. T. Mussenbrock, R.P. Brinkmann, M.A. Lieberman, A.J. Lichtenberg and E. Kawamura, "Enhancement of Ohmic and stochastic heating by resonance effects in in capacitive radio frequency discharges: A theoretical approach", Physical Review Letters, vol. 101, 085004 (2008).

7. M.A. Lieberman, A.J. Lichtenberg, E. Kawamura, T. Mussenbrock and R.P. Brinkmann, "The effects of nonlinear series resonance on Ohmic and stochastic heating in capacitive discharges", Physics of Plasmas, vol. 15, 063505 (2008).

8. E. Kawamura, M.A. Lieberman and A.J. Lichtenberg, "Secondary electrons in rf and dc/rf capacitive discharges", Plasma Sources Sci. Technol., vol. 17, 045002 (2008).

9. E. Kawamura, M.A. Lieberman and A.J. Lichtenberg and E.A. Hudson, "Capacitive discharges driven by combined dc/rf sources", Journal of Vacuum Sci. and Technol. A, vol. 25, 1456 (2007).

10. E. Kawamura, M.A. Lieberman and A.J. Lichtenberg, "Stochastic heating in single and dual frequency capacitive discharges", Physics of Plasmas, vol. 13, 053506 (2006).

11. E. Kawamura and C.K. Birdsall, "The effect of Coulomb scattering on low pressure high density electronegative discharges". Physical Review E, vol.71, 026403 (2005).

12. E. Kawamura and J.H. Ingold, "Particle in cell simulations of low pressure small radius positive column discharges", Journal of Physics D: Applied Physics, vol.34, 3150 (2001).

13. E. Kawamura, C.K. Birdsall, and V. Vahedi, "Physical and numerical methods of speeding up particle codes and paralleling as applied to RF discharges", Plasma Sources, Science and Technology, vol.9, 413 (2000).

14. E. Kawamura, V. Vahedi, M. A. Lieberman, C.K. Birdsall,"Ion energy distributions in rf sheaths, review, analysis and simulation", Plasma Sources, Science and Technology, vol.8, R45 (1999).

Conference Presentations:

Invited Talk:
E. Kawamura, D.B. Graves and M.A. Lieberman, "2D hybrid fluid-analytical model of inductive/capacitive plasma discharges." Invited talk at the 63rd Gaseous Electronics Conference, Paris, France, 4-8 October 2010.

Other Presentations:
E. Kawamura, M.A. Lieberman, A.J. Lichtenberg, and D.B. Graves "Hybrid fluid-analytical simulations of E to H instability in electronegative discharges", Gaseous Electronics Conference, Salt Lake City, Utah, November 2011.

E. Kawamura, M.A. Lieberman, and D.B. Graves "2D Axisymmetric Simulation of an Inductive/ Capacitive Discharge", Gaseous Electronics Conference, Saratoga, NY, October 2009.

E. Kawamura, M.A. Lieberman, A.J. Lichtenberg, and J.P. Verboncoeur "Double Layer Formation in an Expanding Electro-negative Discharge", IEEE International Conference on Plasma Science, San Diego, CA, May 2009.

E. Kawamura, M.A. Lieberman, A.J. Lichtenberg "Stochastic Heating in RF Capacitive Discharges", Gaseous Electronics Conference, San Jose, CA, October 2005.

Skills:

Developing and optimizing electromagnetic (EM), bulk fluid and analytical sheath models for COMSOL and Matlab in order to simulate TCP and CCP plasma reactors. Includes developing a new EM model with both inductive and capacitive coupling of TCP coils to plasma, and a new sheath model which incorporates the effects of sheath Ohmic heating, stochastic heating, and ion wall losses.

Developing and optimizing C/C++ particle-in-cell (PIC) codes used to numerically simulate bounded plasma discharges. Writing parallel versions of planar (XPDP1) and radial (XPDC1) PIC codes using MPI (message passing interface) library. Incorporating Coulomb collisions into XPDP1 to study their effect on low pressure high density inductive discharges. Developing and testing analytical and numerical models of bounded plasmas using Matlab, Mathematica and numerical differential equation solvers. Writing a wrapper program to interface a graphics package written in C and Tcl/Tk (Xgrafix) with a Fortran fluid code (INDUCT95) simulating inductive plasma discharges.

Proficient in COMSOL, C/C++, Fortran, Mathematica, Matlab/Octave, Latex/Tex and Linux/Unix environment. Familiar with ODE/PDE, MPI, Tcl/Tk, Java, Lisp and MS Windows environment. Proficiency in Japanese and French.

Past Research:

Developing and testing analytical and numerical models of bounded plasma discharges used in the semiconductor manufacturing and fluorescent lighting industries. Developing and optimizing computer codes used to numerically simulate bounded plasma devices.

Outline of Thesis,"Particle-in-Cell Simulations of Bounded Plasma Discharges Applied to Low Pressure High Density Sources and Positive Columns":

1. Discussion of methods to accelerate Particle-in-cell (PIC) simulations and make PIC more competitive with other types of codes such as fluid codes. Speedup methods include parallelling, implicit methods, better initial conditions, subcycling, variable weighting of particles, etc.

2. Analysis, review and simulation of ion energy and angular distributions hitting wafer target of low pressure high density rf plasma sources.

3. Application of PIC simulations to study low pressure, small radius positive column discharges used in the fluorescent lighting industry and comparison of results to fluid codes, Monte-Carlo codes and experiment.

4. Incorporate Coulomb collision model into our 1d3v PIC code XPDP1 to study the effect of Coulomb scattering between positive and negative ions in low pressure high density electronegative plasma sources.

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