Department of

Chemistry and Physics

Professor - William Paterson University (1977-Present). Teaching: Physical Chemistry, General Physics, Electronics.

Visiting Research Scientist- IBM T. J. Watson Research Laboratory- Summer 2001. EPR study of high-K dielectrics.

Research Physicist-US Army Research Laboratory, Ft.Monmouth, NJ (1981-1985). Electron paramagnetic resonance studies of point electrical defects in semiconductors.

Research Associate - Rutgers University, New Brunswick, N.J. (1976 -1980). Study of weak intermolecular interactions in liquidsusing dynamic nuclear polarization (DNP).

Assistant Professor- College of New Jersey (1972-1977). Teaching: Spectroscopy, General Chemistry, Physical Chemistry.

Instructor- York College- City University of NY (1968-1972). Teaching: Physical Chemistry, Physics, Mathematics, Advanced Inorganic Chemistry.

Postdoctoral Research- Louisiana State University (1969-1970). Quantum Chemistry: Electron correlation energy of the 1s-hole state of neon.

Ph.D. Chemical Physics- St. John's University (1969)

M.S. Physical Chemistry- St. John's University (1965)

B.S. Chemistry - Manhattan College (1963)

Research

The spectroscopic identification and physico-chemical characterization of atomic-scale defects and impurity elements in semiconductor materials is important for the development of electronic devices such as diodes and transistors. Electrically active defects in these materials can trap electric charge carriers leading to poor device performance or failure.

Electron paramagnetic resonance (EPR) spectroscopy detects the presence of unpaired electrons in materials. It is is one of the principal spectroscopic techniques used to detect and characterize electrically active defects in semiconductor materials. In many cases a definitive structural identification is possible from an EPR study. This is more likely when the unpaired electron of the defect center interacts with nearby nuclei that have a magnetic moment giving rise to hyperfine structure in the EPR spectrum.

At the important Si/SiO2 interface, for example, Si dangling bond defects are readily formed and must be passivated with hydrogen to achieve the electrical characteristics required for metal-oxide-semiconductor transistors. The work I've done with associates at the US Army Research Laboratory involved the study of the nature of silicon dangling bond defects at the Si/SiO2 interface (referred to as Pb centers). Specifically, we were able to determine the energy levels of Pb centers in the silicon bandgap on the (100) surface. We also identified the critical role of water in the oxidation ambient as the most liklely cause of the negative-bias-temperature instability of metal-oxide-semiconductor transistors. We also studied the effects of Pb centers in the luminescence of porous silicon. Other work involved spin-dependent recombination in silicon diodes, gallium arsenide surface passivation, and impurity-band conduction in aluminum-doped silicon carbide.

Present work concerns the study of aluminum-ion implantation of silicon carbide and dopant activation by thermal annealing.

Publications
Presentations