RELAXATIONAL POLARIZATION AND CHARGE INJECTION IN THIN-FILMS OF SILICON-NITRIDE

Relaxational polarization phenomena and charge injection in silicon nitride deposited on an n-type silicon substrate are studied. After application of low electric fields (<1 MV cm(-1)), currents with a time dependence j similar to t(-alpha), alpha approximate to 1 in a time range 500 ns less than or equal to-t less than or equal to 10,000 s flow to the dielectric. After shore circuiting, currents with the same time behaviour but opposite sign flow back in the outer circuit. These currents are due to reversible proton fluctuations within the silicon nitride. At higher field strengths, a charge injection process sets in. About 0.05 s after application of a field E=3.5 MV cm(-1), the currents deviate from the t(-1) law and become constant. This charge injection process depends upon the density of protons within the silicon nitride.