| Autor: |
O'Connor, É., Brennan, B., Djara, V., Cherkaoui, K., Monaghan, S., Newcomb, S. B., Contreras, R., Milojevic, M., Hughes, G., Pemble, M. E., Wallace, R. M., Hurley, P. K. |
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| Zdroj: |
Journal of Applied Physics; Jan2011, Vol. 109 Issue 2, p024101, 10p, 1 Black and White Photograph, 1 Chart, 7 Graphs |
| Abstrakt: |
In this work, we present the results of an investigation into the effectiveness of varying ammonium sulphide (NH4)2S concentrations in the passivation of n-type and p-type In0.53Ga0.47As. Samples were degreased and immersed in aqueous (NH4)2S solutions of concentrations 22%, 10%, 5%, or 1% for 20 min at 295 K, immediately prior to atomic layer deposition of Al2O3. Multi-frequency capacitance-voltage (C-V) results on capacitor structures indicate that the lowest frequency dispersion over the bias range examined occurs for n-type and p-type devices treated with the 10%(NH4)2S solution. The deleterious effect on device behavior of increased ambient exposure time after removal from 10%(NH4)2S solution is also presented. Estimations of the interface state defect density (Dit) for the optimum 10%(NH4)2S passivated In0.53Ga0.47As devices extracted using an approximation to the conductance method, and also extracted using the temperature-modified high-low frequency C-V method, indicate that the same defect is present over n-type and p-type devices having an integrated Dit of ∼2.5×1012 cm-2 (±1×1012 cm-2) with the peak density positioned in the middle of the In0.53Ga0.47As band gap at approximately 0.37 eV (±0.03 eV) from the valence band edge. Both methods used for extracting Dit show very good agreement, providing evidence to support that the conductance method can be applied to devices incorporating high-k oxides on In0.53Ga0.47As. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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