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Ka-Ngo Leung

Department 9174
Additional Affiliation: 

Senior Scientist
Plasma & Ion Source Technology Group
Lawrence Berkeley National Laboratory


B.S., The Chinese University of Hong Kong, Hong Kong, 1968
M.S., University of Akron, Ohio, 1970
Ph.D., University of California, Los Angeles, 1975

Teaching and Research: 

Dr. Leung is an international authority on ion sources and their application. He has been awarded over 20 patents for the inventions of the ion sources and beam technologies for numerous applications. He teaches a new graduate course, NE 290A, "Ion Source and Beam Technology.

Current Research Focus: 

Dr. Leung’s current research interest focused on Plasma and Ion Beam technology in microfabrication processes. Currently, the following projects are ongoing in his group.

Maskless ion beam lithography technology as candidates for next generation lithography (NGL) that will be used to produce feature sizes of 100 nm and below.

Focused ion beam (FIB) systems equipped with plasma ion sources.

Compact neutron tube with rf plasma ion source.

Professional Activities: 

2000 – Present Professor-in-Residence, Nuclear Engineering Dept., University of California, Berkeley.
1998 – 2000 Lecturer, Nuclear Engineering Dept., University of California, Berkeley.
Presented lectures on Plasma and Ion Beam Technology.
1988 - Present Senior Staff Physicist, Lawrence Berkeley National Laboratory.
Plasma and Ion Source Technology Group (supervising a total of 40 people including scientific staff, engineers, mechanical designers, technicians and students).
1993 – 1994 Visiting Professor at the Institute of Applied Physics, University of Frankfurt, Germany.
1978 – 1988 Staff Physicist, Lawrence Berkeley Laboratory.
1975 - 1978 James Madison University, Assistant Professor of Physics.
1975 June- Sept. University of California, Los Angeles, Postdoctoral scholar.

Served on the editorial board of the Journal, "Review of Scientific Instruments", (Jan. l982-Dec. l984). Reviewer for various technical journals.
Served in the Program Committee of the IEEE Particle Accelerator Conferences, the International Conferences on Ion Sources, and the International Symposium on the Production and Neutralization of Negative Ions and Beams.
Served as the chairman of the 9th International Conference on Ion Sources, (Berkeley, USA 2001)
Served as an IAEA Expert to the Fast Neutron Research Facility at Chiang Mai University, Thailand (1994 and 1995).

Selected Publications: 

“Combined electron and focused ion beam system for improvement of secondary ion yield in secondary ion mass spectrometry instrument” L. Ji, Q. Ji, K. N. Leung, and R. A. Gough, Appl. Phys. Lett. 89, 164103 (2006).

“Conformal metal thin-film coatings in high aspect ratio trenches using a self-sputtered rf-driven plasma source” L.Ji, J.K. Kim, Q. Ji, K.N. Leung, Y. Chen and R. Gough, J. Vac. Sci. Technol.B 25(4), Jul/Aug (2007) 1227.

“Development of C-60 plasma ion source for time-of-flight secondary ion mass spectrometry applications” Qing Ji, Ye Chen, Lili Ji, Sami Hahto, Ka-Ngo Leung, Tae Geol Lee and Dae Won Moon Rev. Sci. Instrum., 79, 02B309 (Feb 2008).

“Ion source for neutral beam injection meant for plasma and magnetic field diagnostics” Jaakko Hannes Vainionpaa, Ka-Ngo Leung, Richard A. Gough, Joe W. Kwan and Fred Levinton, Rev. Sci. Instrum., 79, 02C102 (Feb 2008).

“Negative chlorine ions from multicusp RF ion source for heavy ion fusion applications” S.K. Hahto, S.T. Hahto, J.W. Kwan, K.N. Leung, Rev. Sci. Instrum., Vol. 74, (June 2003) 2987.

“Mini RF-driven ion source for focused ion beam system” X. Jiang, Q. Ji, A. Chang, and K.N. Leung, Rev. Sci. Instrum., Vol. 74, (April 2003) 2288.

“Resolution improvement for a maskless micro-ion-beam reduction lithography system”, X. Jiang, Q. Ji, Lili Ji, Audrey Chang and Ka-Ngo Leung, J. Vac. Sci. Technol. B 21(6), Nov/Dec 2003.

“Muticusp ion source with external rf antenna for production of protons” S.K. Hahto, S.T. Hahto, Q. Ji, K.N. Leung, S. Wilde, E. L. Foley, L. R. Grisham and F. M. Levinton, Rev. Sci. Instrum., Vol. 75, (Feb 2004) 355.

“Simulation of a D-T neutron source for neutron scattering experiments” T.P. Lou, B.A. Ludewigt, J.L. Vujic and K. N. Leung, Nuclear Instruments and Methods in Physics Res. A521 (2004) 399-406.

"First PGAA and NAA experimental results from a compact high intensity D-D neutron generator” J. Reijonen, K. N. Leung, R.B. Firestone, J.A. English, D.L. Perry, A. Smith, F. Gicquel, M. Sun, H. Koivunoro, T.P. Lou, B. Bandong, G. Garabedian, Zs. Revy, L. Szentmiklosi, and G. Molnar, Nucl. Instrum. And Meth. In Phys. Res. A 522 (2004) 598-602.

“The characteristion of legacy radioactive mateials by gamma spectroscopy and prompt gamma activation analysis (PGAA)” G.A. English, R.B. Firestone, D.L. Perry, J. Reijonen, B. Ludewigt, K.N. Leung, G. Garabedian, G. Molnar and Z. Revay, Nucl. Instrum. and Meth. In Phys. Res. B 213 (2004) 410-413.

“The use of prompt gamma activation analysis (PGAA) for the analyses and characterization of materials: Photochromic materials” D.L. Perry, G.A. English, R.B. Firestone, K.N. Leung, J. Reijonen, B. Ludewigt, G. Garabedian, G.L. Molnar and Z. Revay, Nucl. Instrum. and Meth. In Phys. Res. B 213 (2004) 527-529.

“Negative ions for heavy ion fusion and semiconductor manufacturing applications” S.K. Hahto, S.T. Hahto, J. Kwan, K.N. Leung, L.R. Grisham and K. Saadatmand, Rev. Sci. Instrum. Vol.75(5) (2004).

“Combined electron- and ion-beam imprinter and its applications,” Q. Ji, L. Ji, Y. Chen, and K. N. Leung, Appl. Phys. Lett., 85, 4618 (2004).

“Fast ion beam chopping system for neutron generators,” S.K. Hahto, S. T. Hahto and K. N. Leung, Rev. Sci. Instrum. 76(2) (2005).

“Experimental evaluation of a negative ion source for a heavy ion fusion negative ion driver, L.R. Grisham, S.K. Hahto, S.T. Hahto, J. W.Kwan and K.N. Leung, Nucl. Instrum. & Meth. A544 (2005) 216-224.

“Development if a 27.12 MHz radio frequency driven ion source with 3 mTorr operation pressure for neutron genertors,” X. Jiang, Y. Chen, L. Ji, Q. Ji, and K. N. Leung, Rev. Sci. Instrum., 76, 103302 (2005).

“Development of focused ion beam systems with various ion species” Q. Ji, K. N. Leung, T-J King, X. Jiang and Bill R. Appleton, Nucl. Instrum. And Meth. In Phys. Res. B 241 (2005) 335-340.

“Application of deuteron-deuteron (D-D) fusion neutrons to Ar40/Ar39 geochronology” Paul R. Renne, Kim B. Knight, Sebastien Nomade, Ka-Ngo Leung and Tak-Pui Lou, Appl. Radiation and Isotopes, 62 (2005) 25-32.

Author of the chapter on "Negative Ion Sources" in Ion Source Technology edited by I. Brown.
Author of three chapters on the CRC Handbook for Ion Sources, Edited by B. Wolf.
Author of the chapter on "H- Ion Sources" in Handbook of Accelerator Physics and Engineering edited by Alex Chao and Maury Tigner.