Electrical Conduction and Dielectric Breakdown in Aluminum Oxide Insulators on Silicon

Published

March 23, 2000

Author(s)

J Kolodzey, E A. Chowdhury, T Adam, G Qui, I Rau, J Olowolafe, John S. Suehle, Y Chen

Abstract

Leakage currents and dielectric breakdown were studied in MIS capacitors of metal - aluminum oxide - silicon. The aluminum oxide was produced by thermally oxidizing AIN at 800 0C to 1100 0C under dry O₂ conditions. The AIN films were deposited by rf magnetron sputtering on p-type Si (100) substrates. Thermal oxidation produced Al₂O₃ with a thickness and structure that depended on the process time and temperature. The MIS capacitors exhibited the charge regimes of accumulation, depletion and inversion on the Si semiconductor surface. The best electrical properties were obtained when all of the AIN was fully oxidized to Al₂O₃ with no residual AIN. The MIS flatband voltage was near 0 V, the net oxide trapped charge density, Q_OX, was less than 10¹¹ cm^-2, and the interface trap density D_it, was less than 10¹¹ cm^-2 eV^-1. At an oxide electric field of 0.3 MV/cm, the leakage current density was less than 10^-7 Amp cm^-2, with a resistivity greater than 10^12^ Ohm-cm. The critical field for dielectric breakdown ranged from 4 MV/cm to 5 MV/cm. The temperature dependence of the current versus electric field indicated that the conduction mechanism was Frenkel-Poole emission, which has the interesting property that higher temperatures reduce the current. This may be important for the reliability of circuits operating under extreme conditions. The dielectric constant ranged from 3 to 9. The excellent electronic quality of aluminum oxide may be attractive for field effect transistor applications.

Citation

IEEE Transactions on Electron Devices

Volume

47

Issue

1

Pub Type

Journals

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Keywords

aluminum oxide, dielectric breakdown, gate dielectric, metal oxide field transistor

Citation

Kolodzey, J. , Chowdhury, E. , Adam, T. , Qui, G. , Rau, I. , Olowolafe, J. , Suehle, J. and Chen, Y. (2000), Electrical Conduction and Dielectric Breakdown in Aluminum Oxide Insulators on Silicon, IEEE Transactions on Electron Devices, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=30168 (Accessed April 24, 2024)