I-V characteristics of MOS capacitors with polycrystalline silicon field plates

Abstract

The I‐V characteristics of MOS capacitors utilizing polycrystalline p‐type silicon field plates were investigated. It was found that sizable current flow is observable in both directions under pulsed dc conditions at voltages much below those at which current flows under applied dc. This suggests that the polycrystalline silicon film can be driven into avalanche and thus inject electrons into the oxide as well as the single‐crystal Si wafer. Charge trapping during passage of avalanche injected currents was observed to occur principally at the silicon/oxide interfaces. The rate of trapping depended strongly on the boron content of the oxide.