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Passivation mechanism of thermal atomic layerdeposited Al2O3 films on silicon at different annealing temperatures.
- Source :
- Nanoscale Research Letters; Mar2013, Issue 3, p1-7, 7p
- Publication Year :
- 2013
-
Abstract
- Thermal atomic layer-deposited (ALD) aluminum oxide (Al<subscript>2</subscript>O<subscript>3</subscript>) acquires high negative fixed charge density (Q<subscript>f</subscript>) and sufficiently low interface trap density after annealing, which enables excellent surface passivation for crystalline silicon. Q<subscript>f</subscript> can be controlled by varying the annealing temperatures. In this study, the effect of the annealing temperature of thermal ALD Al<subscript>2</subscript>O<subscript>3</subscript> films on p-type Czochralski silicon wafers was investigated. Corona charging measurements revealed that the Q<subscript>f</subscript> obtained at 300°C did not significantly affect passivation. The interface-trapping density markedly increased at high annealing temperature (>600°C) and degraded the surface passivation even at a high Q<subscript>f</subscript>. Negatively charged or neutral vacancies were found in the samples annealed at 300°C, 500°C, and 750°C using positron annihilation techniques. The Al defect density in the bulk film and the vacancy density near the SiOx/Si interface region decreased with increased temperature. Measurement results of Q<subscript>f</subscript> proved that the Al vacancy of the bulk film may not be related to Q<subscript>f</subscript>. The defect density in the SiOx region affected the chemical passivation, but other factors may dominantly influence chemical passivation at 750°C. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 19317573
- Issue :
- 3
- Database :
- Complementary Index
- Journal :
- Nanoscale Research Letters
- Publication Type :
- Academic Journal
- Accession number :
- 102107274
- Full Text :
- https://doi.org/10.1186/1556-276X-8-114