Convex corner induced capacitance–voltage response from depletion to deep depletion in non-planar substrate metal-oxide-semiconductor capacitors with ultra thin oxide

Abstract

The convex corner induced capacitance responses from depletion to deep depletion regions in non-planar substrate metal-oxide-semiconductor (MOS) capacitors with ultra thin oxides are comprehensively studied. The non-planar sample shows that the corner effect may induce minority carrier crowding and contribute to the abnormal deep depletion capacitance–voltage (C–V) behavior. The convex corner exhibits broader depletion width due to the sharing effect of depletion widths from the overlap of top plane and sidewall regions near convex corner which is responsible for the observed lower depletion capacitance as compared with the planar MOS capacitors. Moreover, the negative constant voltage stress induced C–V behaviors between non-planar and planar samples are different and are discussed in detail in this work.