Electron traps at interfaces between Si(100) and noncrystalline Al2O3, Ta2O5, and (Ta2O5)x(Al2O3)1-x alloys

The physical and electrical properties of noncrystalline Al2O3, Ta2O5, and their alloys, (Ta2O5)(x)(Al2O3)(1-x) are investigated. Characterization by Auger electron spectroscopy and Fourier transformation infrared spectroscopy confirm these alloys are homogeneous with pseudobinary in character, and display increased thermal stability. Capacitance - voltage and current density-voltage data as a function of temperature demonstrate that the Ta d states of the alloys act as localized electron traps, and are at an energy approximately equal to the conduction band offset of Ta2O5 with respect to Si. (C) 2001 American Vacuum Society.