Al 2 O 3/AlGaN metal-oxide-semiconductor capacitors show a hysteretic behavior in their capacitance vs voltage characteristics, often attributed to near-interface traps deriving from defects within the oxide layer. The origin as well as the structural/electronic properties of such defects are still strongly debated in the literature. Here, we use ab initio molecular dynamics and the climbing-image nudged elastic band method to show that aluminum Frenkel defects give rise to bistable trap states in disordered and stoichiometric Al 2 O 3. Based on these results, we propose a calibrated polaron model representing a distribution of individually interacting energy levels with an internal reconfiguration mode and coupled to continuous bands of carriers to explain the hysteresis mechanism in Al 2 O 3/AlGaN capacitors.

Aluminum Frenkel defects cause hysteresis in Al2O3/AlGaN capacitors

Deretzis I.;Fiorenza P.;Fazio T.;Schiliro' E.;Lo Nigro R.;Greco G.;Fisicaro G.;Roccaforte F.;La Magna A.
2022

Abstract

Al 2 O 3/AlGaN metal-oxide-semiconductor capacitors show a hysteretic behavior in their capacitance vs voltage characteristics, often attributed to near-interface traps deriving from defects within the oxide layer. The origin as well as the structural/electronic properties of such defects are still strongly debated in the literature. Here, we use ab initio molecular dynamics and the climbing-image nudged elastic band method to show that aluminum Frenkel defects give rise to bistable trap states in disordered and stoichiometric Al 2 O 3. Based on these results, we propose a calibrated polaron model representing a distribution of individually interacting energy levels with an internal reconfiguration mode and coupled to continuous bands of carriers to explain the hysteresis mechanism in Al 2 O 3/AlGaN capacitors.
2022
Istituto per la Microelettronica e Microsistemi - IMM
Al2O3, Frenkel defects, Density functional theory
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.14243/514872
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