Evidence of charging effect in silicon nano-crystals using a feedback chargemethod with metal oxide–semiconductor capacitors

Abstract

In some new types of non-volatile memory, where silicon nano-crystals(nc-Si) are implemented as a floating gate at a tunnel distance from thechannel, the evidence of charging effect in these nc-Si is observed andstudied experimentally. We present quasi-static capacitance–voltage (C–V) and current–voltage(I–V)measurements of MOS capacitors containing nc-Si based on a feedback chargemethod. Doing so we can measure simultaneously and separate the capacitancefrom leakage and excess currents. Depending on the presence or not of nc-Si in acapacitor, we observe the presence of a maximum of four peaks in the current, ofwhich only one depends on the voltage scan rate. This behaviour is explained interms of nc-Si dynamic charge and discharge and offset charge influence as well.