Injection and trapping of electrons in Y2O3 layers on Si
Abstract
We have investigated yttrium oxide (Y2O3) as a charge trapping layer for nonvolatile memory cells. The Y2O3 films of 7 to 55 nm thick were deposited by atomic vapour deposition on (100)Si with a 2 or 5-nm thick pregrown thermal SiO2 serving as a tunnel dielectric. Analyses of these structures using spectroscopic ellipsometry, photoconductivity and internal photoemission reveal that Y2O3 has a 5.6-eV wide optical bandgap and a conduction band offset of 2.0 eV with respect to silicon. Upon electron tunneling, an efficient oxide charging was observed. Photo-(dis)charging experiments reveal that the optical energy depth of most of the electron traps exceeds 2 eV with respect to the Y2O3 conduction band.
- Publication:
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Materials Science and Engineering Conference Series
- Pub Date:
- February 2010
- DOI:
- 10.1088/1757-899X/8/1/012028
- Bibcode:
- 2010MS&E....8a2028W