Dielectric relaxation spectroscopy of single- and double-layer polyimide/SiO<inf>2</inf> thin films

Abstract

High temperature dielectric relaxation spectroscopy (DRS) experiments have been performed on MIS (metalinsulator-semiconductor), MOS (metal-oxide-semiconductor) single-layer and MIOS (metal-insulator-oxide-semiconductor) double-layer structures, where I is polyimide (PI) film (10µm), and O is PECVD SiO 2 thin film (1.5 µm-thick), from 200 to 350 °C, in the 10 -1 Hz to 10 6 Hz frequency range. In such a high temperature range and/or at low frequencies, the dielectric spectra are often influenced by interfacial dielectric relaxations such as Maxwell-Wagner-Sillars (MWS) and electrode polarization (EP). The empirical Havriliak-Negami (H-N) model is used to determine the values from the effective ac dielectric response. For single-(PI) and double-layer structures (PI/SiO 2 ), thevaries from 1.1x10 -10 to 5.5x10 -9 Ω -1 cm -1 and from 7x10 -14 to 2.3x10 -12 Ω -1 cm -1 between 250 and 350°C, with an activation energy of the conduction phenomenon of 1.1 and 0.95 eV, respectively. The PI/SiO 2 structure is suited for semiconductor device passivation applications at high temperature up to 300°C.