Magnetoresistance Recovery in the Amorphous Dielectric Material SiCOH
Philip A. Williams *
College of Nanoscale Science and Engineering, State University of New York at Albany, 1400 Washington Avenue, Albany, 12222, New York, US.
James R. Lloyd
College of Nanoscale Science and Engineering, State University of New York Polytechnic Institute 257 Fuller Road, Albany, 12203-New York, US.
*Author to whom correspondence should be addressed.
Abstract
The use of a magnetoresistance in the characterization of transport properties in the amorphous low-k dielectric material SiCOH is demonstrated. The double occupancy of charge carriers in trap states within the dielectric material can only exist in spin singlet formation due to Pauli Exclusion. The trap-assisted negative magnetoresistance (MR) in amorphous SiCOH, driven by an applied electric field that results in an observed increase in magnitude of the current in the conduction band is due to singly occupied trap spin-mixing suppression of carriers with the application of an external magnetic field. The material MR decays with time under electrical bias and temperature stress as traps are filled by charge carriers and from space charge accumulation. The MR can be reinstated by the ionization of these traps via the conduction mechanisms of nonthermally activated tunneling and thermal ionization with the assistance of an applied coulombic potential barrier lowering electric field. In this work a direct correlation is shown between a material MR and the trapping, de-trapping, and trap avoidance of singly occupied traps in the transport of charge carriers in the amorphous low-k dielectric material SiCOH (a-SiCOH).
Keywords: Dielectric breakdown, dielectric materials, magnetic materials, magnetoresistance, hyperfine