C-Si surface passivation by aluminum oxide studied with electron energy loss spectroscopy

Author

Hoex, B. ; Bosman, M. ; Nandakumar, Naomi ; Kessels, W.M.M.

Author_Institution

Solar Energy Res. Inst. of Singapore (SERIS), Nat. Univ. of Singapore (NUS), Singapore, Singapore

fYear

2013

fDate

16-21 June 2013

Firstpage

3333

Lastpage

3336

Abstract

In this work the mechanism of c-Si surface passivation by Al₂O₃ films is studied in detail by means of spatially resolved electron energy loss spectroscopy (EELS). The bonding configuration of Al and O is studied in as-deposited and annealed Al₂O₃ films grown on c-Si substrates by plasma-assisted and thermal atomic layer deposition (ALD). The ratio of tetrahedrally and octahedrally coordinated Al is found to increase after annealing, especially for the plasmaassisted ALD sample. The increase is strongest close to the c-Si/Al₂O₃ interface and thus these results strongly support tetrahedrally coordinated Al as the origin for the negative fixed charge in Al₂O₃.

Keywords

aluminium compounds; annealing; atomic layer deposition; bonds (chemical); electron energy loss spectra; elemental semiconductors; passivation; plasma deposition; silicon; thin films; ALD; Al₂O₃; EELS; Si; aluminum oxide; annealing; bonding configuration; negative fixed charge; octahedrally coordinated Al; plasma-assisted deposition; spatially resolved electron energy loss spectroscopy; surface passivation; tetrahedrally coordinated Al; thermal atomic layer deposition; Aluminum oxide; Annealing; Energy loss; Films; Passivation; Physics; Silicon; aluminum oxide; electron energy loss spectroscopy; fixed charge; surface passivation;

fLanguage

English

Publisher

ieee

Conference_Titel

Photovoltaic Specialists Conference (PVSC), 2013 IEEE 39th

Conference_Location

Tampa, FL

Type

conf

DOI

10.1109/PVSC.2013.6745164

Filename

6745164