Electrically active interface defects in the In0.53Ga0.47As MOS system

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Djara, Vladimir
O'Regan, T. P.
Cherkaoui, Karim
Schmidt, Michael
Monaghan, Scott
O'Connor, Éamon
Povey, Ian M.
O'Connell, D.
Pemble, Martyn E.
Hurley, Paul K.
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Elsevier B.V.
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In this work we present experimental results examining the energy distribution of the relatively high (>1 × 1012 cm−2 eV−1) density of electrically active defects which are commonly reported at the interface between high dielectric constant (high-k) thin films and In0.53Ga0.47As. The interface state distribution is examined for the Al2O3/In0.53Ga0.47As metal-oxide-semiconductor (MOS) system based on analysis of the full gate capacitance (Cg–Vg) of the surface n-channel In0.53Ga0.47As MOS transistors. The experimental capacitance, recorded at −50 °C and 1 MHz to approximate a high frequency response, is compared to the theoretical Cg–Vg response to evaluate the interface state distribution across the In0.53Ga0.47As energy gap and extending into the In0.53Ga0.47As conduction band. To improve the accuracy of the fitting process, the Maserjian Y-function was used in the modeling of the interface defects and fixed oxide charge densities. The analysis reveals a peak of donor-like interface traps with a density of 1.5 × 1013 cm−2 eV−1 located at ∼0.36 eV above the In0.53Ga0.47As valence band edge, a high density of donor-like states increasing towards the In0.53Ga0.47As valence band. The analysis also indicates acceptor-like interface traps located in the In0.53Ga0.47As conduction band, with a density of ∼2.5 × 1013 cm−2 eV−1 at 0.3 eV above the In0.53Ga0.47As conduction band minima. The reported interface state density is similar to reports for others oxides, suggesting that the recorded interface states originate from the In0.53Ga0.47As surface.
High-k , InGaAs , Interface state density , CV analysis , Surface n-channel InGaAs MOSFETs , Maserjian Y-function
Djara, V., O’Regan, T. P., Cherkaoui, K., Schmidt, M., Monaghan, S., O’Connor, É., Povey, I. M., O’Connell, D., Pemble, M. E., Hurley, P. K. (2013) 'Electrically active interface defects in the In0.53Ga0.47As MOS system', Microelectronic Engineering, 109, pp.182-188. doi: 10.1016/j.mee.2013.03.026
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