Barbara Abraham-Shrauner 

Senior Professor

Office: 106 Cupples II
Tel. (314) 935-6134
Fax. (314) 935-7500
email:  bas@ese.wustl.edu
     

Education
Harvard University (A.M. 1957, Ph.D. 1962)
University of Colorado (B.A. 1956)

 Postdoctoral
Université Libre de Bruxelles: AAUW Illinois Fellowship
NASA-Ames Research Center : NAS-NASA Fellowship

Memberships

IEEE  
American  Geophysical Union

American Physical 
Society  
AAUP  

 
Honors  
Senior Member, IEEE
Phi Beta Kappa

Eta Kappa Nu 
Sigma Xi 
        Fellow, American  Physical Society



Professor Abraham-Shrauner joined the faculty in 1966 at Washington University where she is now a Senior Professor in the Department of Electrical and Systems Engineering.  She retired from full-time service as Professor in July, 2003.

    She continues her research activities part-time as a Senior Professor. She has done research in the past on space plasmas, on plasma theory, on charge effects in blood clotting, on high electric field transport in III-V semiconductors and on sputter depostion by plasmas  of thin films such as GaAs for applications in infrared optoelectronics.
    Currently she is concentrating on theoretical models of plasma processing and symmetry analysis of nonlinear differential equations.  The plasma processing models are of semiconductors used in the fabrication of integrated circuits. The models have included the etching of rectangular trenches and contact holes in silicon dioxide as well as in GaAs.  More recently she has modeled the etching and deposition on silicon in a fluorocarbon plasma. The three regimes of reactive sputtering, fluorocarbon suppression and fluorocarbon deposition were treated with a multilayer model.
     The symmetry analysis continues extensive investigations of Lie point symmetries of plasma problems and especially hidden symmetries of nonlinear ordinary differential equations.  Symmetries of differential equations may be used to simplify the differential equations and many analytic solutions are found as a result of symmetry analysis.   Recent research has included the systematic solution of a model diffusion equation for a fractal system by Lie symmetries with attention to initial and boundary conditions.  The analysis of hidden symmetries of linear and nonlinear partial differential partial equations has discovered a new type of hidden symmetry not seen in ordinary differential equations.
     

Selected Publications




Keshlan S. Govinder AND B. Abraham-Shrauner, An Overview of hidden Symmetries," Symbolic Symmetries and its Applications, ACA meeting, Hagenberg, Austria. July, 2008.

Keshlan S. Govinder AND B. Abraham-Shrauner, "New Origins of Hidden Symmetries, " SAMS 50, Cape Town, November, 2007.

B. Abraham-Shrauner , "Large-amplitude electron oscillations with spatially inhomogeneous ion densities?" APSDPP meeting, (November, 2007).

B. Abraham-Shrauner and Keshlan S. Govinder, "Type II hidden symmetries of nonlinear partial differential equations," ACA meeting, Oakland University July, 2007.

B. Abraham-Shrauner, K.S. Govinder and D.J. Arrigo, "Type-II hidden symmetries of the linear 2D and 3D wave equations," J. Phys A:Math. & Gen. . Vol. 39, pp. 5739-5747 , 2006.

B. Abraham-Shrauner, K.S. Govinder, "Provenance of Type II hidden symmetries from nonlinear partial differential equations," J. Nonl. Math. Phys . (to be published, 2006).

B. Abraham-Shrauner"Type II hidden symmetries of some partial differential equations," 1005th AMS Meeting, University of Delaware, Newark, Delaware, p. 37 (April, 2005).

B. Abraham-Shrauner, "Lie symmetry solutions for anomalous diffusion," J. Phys. A:Math. & Gen. Vol. 36, pp. 2547-2553, 2005

B. Abraham-Shrauner, "Simultaneous, Multilayer Plasma Etching and Deposition of Fluorocarbon Layers on Silicon," IEEE ICOPS Conference Record, p. 40, June, 2004.

T. Z. A. Zulkifi, L. H. Ouyang, D.L. Rode and B. Abraham-Shrauner,"Optical Characterization of Radio-Frequency Magnetron-Sputtered Gallium-Arsenide Films under Non-Uniform Thickness Conditions," International Conference on Compound Semiconductor Manufacturing Technology.,p.147-150 (May 3-5 , 2004) ( Miami Beach, Florida).

B. Abraham-Shrauner,"Simultaneous, multilayer plasma etching and deposition of fluorocarbon layers on silicon," Bull. Am. Phys. 48, 285 (October, 2003).

B. Abraham-Shrauner, "Simultaneous, multilayer plasma etching and deposition of   fluorocarbon layers on silicon," J. Appl. Phys. Vol. 94, pp. 4776-4780 , 2003.

C. D. Wang, B. Marlland. D. Malanaric, E. Brown, D. Galley, B. Abraham-Shrauner, R. Hoekstra, "Modeling of Etch Profiles in RF biased Inductively Coupled Plasma Etching Reactor," AVS 49th International Symposium, p. 109 (November, 2002).

L.-H.  Ouyang, D. L Rode, T. Zulkifli, B. Abraham-Shrauner, N. Lewis and M.R.Freeman, "Hydrogenated amorphous and microcrystalline GaAs Films prepared by radio-frequency magnetron sputtering," J. Appl. Phys. Vol. 91, pp. 3459-67, 2002.

C. Liu and B. Abraham-Shrauner, "Plasma Etching Model for SiO2 Contact Holes, " IEEE Trans. Plasma Sci. Vol.  30, pp, 1579-1586, 2002.

B. Abraham-Shrauner, "Hidden Symmetries, First Integrals and Reduction of Order of  Nonlinear Ordinary Differential Equations," J. Nonlinear Math. Phys. 9, Supplement  2, pp. 1-9, 2002.

C. Liu and B. Abraham-Shrauner,"Investigation of Plasma Etching of SiO2 Contact Holes using a Statistical Method and a Theoretical Profile Evolution Model," AVS 48th International Symposium, (November, 2001).

C. Liu and B. Abraham-Shrauner, " Etching, Sidewall Passivation and Microtrenching in Contact Holes and Edge Regions," PPPS-2001 (ICOPS), p. 474 (June, 2001).

B. Abraham-Shrauner, "Plasma etch profiles of passivated open-area trenches," J. Vac. Sci. & Tech. B, Vol 19, pp. 711-721, 2001.

B. Abraham-Shrauner and C. Liu, "Microtenching, Etching and Sidewall Passivation in Contact Holes and Edge Regions," AVS 47th International Symposium, (October, 2000).

P. G. L. Leach ,K. S. Govinder, and B. Abraham-Shrauner," Symmetries of First  Integrals and Their Associated Differential Equations,"  J. Math. Analysis and Applications, Vol. 253, pp. 58-93, 1999.

W. Chen and B. Abraham-Shrauner and J. R. Woodworth, "Model etch profiles for ion energy distribution functions in an inductively coupled plasma reactor ," J. Vac. Sci. & Tech.B, Vol 17, pp. 2061-2069, 1999.

B. Abraham-Shrauner, K. J. Nordheden and Y. S. Lee, "Model for etch dependence on GaAs Via Diameter, " J. Vac. Sci. Tech. B Vol 17, pp. 961-964, 1999.

B. Abraham-Shrauner and N. Jagannathan, "Modification of Plaxma Etched Profiles by Sputtering," IEEE Trans. Plasma Sci., Vol 27, pp. 665-675, 1999.

B. Abraham-Shrauner, "Contact hole model for etch depth dependence," J. Vac. Sci. Tech,B Vol 17, pp. 158-161, 1999.

B. Abraham-Shrauner, "Model for Ion-Initiated Trench Etching," IEEE Trans, Plasma Science, Vol 2, pp 433-438, 1997.

B. Abraham-Shrauner and W. Chen, "The effects of ion sheath collisions on trench etch profiles," J. Appl. Phys,, Vol 81, pp. 2547-2554, 1997.

B. Abraham-Shrauner and W. Chen, "Neutral shadowing in circular cylindrical trench holes," J. Vac. Soc. & Tech,B, Vol 14, pp. 3492-3496, 1996.

B. Abraham-Shrauner, "Hidden symmetries and nonlocal group generators of ordinary differential equations," IMA J., Vol 56, pp. 235-252, 1996.

B. Abraham-Shrauner, "Lie Symmetries, Hidden Symmetries and Time-Dependent Invariants," Dynamical Systems and Applications, (World Scientific Publishing Company, Singapore, 1995), pp.1-10.

B. Abraham-Shrauner, "Analytic Models for Plasma-Assisted Etching of Semiconductor Trenches," J. Vac. Soc. & Tech. B, Vol 12, pp. 2347-2351, 1994.

B. Abraham-Shrauner, R. Zitter, and X. Zhang, "Current generated periodic space charge in semiconductor diodes and non-ohmic injection," J. Appl. Phys., Vol 75, pp. 373-376, 1994.

B. Abraham-Shrauner and Ann Guo, "Hidden Symmetries of Differential Equations," Lie algebras, cohomology and new applications to quantum mechanics, Cont. Math. Vol 160, (AMS, 1994) pp. 1-13.

A. Guo and B. Abraham-Shrauner, "Hidden symmetries of energy conserving differential equations", IMA J. Appl. Math., 51, 147-152, 1993.