Abstract
A giant, anomalous piezoresponse of fully depleted silicon-on-insulator devices under mechanical stress is demonstrated by impedance spectroscopy. This piezoresponse strongly depends on the measurement frequency, , and consists of both a piezoresistance (PZR) and a piezocapacitance, whose maximum values are and , respectively. These values should be compared with the usual bulk PZR in -type silicon, . The observations are well described by models of space-charge-limited hole currents in the presence of fast electronic traps having stress-dependent capture rates () and emission rates. Under steady-state conditions (i.e., when ), where the impedance-spectroscopy measurements yield results that are directly comparable with those of previously published reports of PZR in depleted, silicon nano-objects, the overall piezoresponse is just the usual, bulk silicon PZR. Anomalous PZR is observed only under non-steady-state conditions when , with a symmetry suggesting that the electromechanically active fast traps are native interface defects. The observations suggest new functionalities for fully depleted silicon-on-insulator, and shed light on the debate over the PZR of carrier-depleted nanosilicon.
4 More- Received 17 October 2018
- Revised 28 January 2019
DOI:https://doi.org/10.1103/PhysRevApplied.11.044010
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