A1 Journal article (refereed)
Effective suppression of nanotextured black silicon surface recombination channels by aluminum oxide : comparison from sputtered and ALD grown films (2021)

Parashar, P. K., Kinnunen, S., Sajavaara, T., Toppari, J., & Komarala, V. K. (2021). Effective suppression of nanotextured black silicon surface recombination channels by aluminum oxide : comparison from sputtered and ALD grown films. Semiconductor Science and Technology, 36(11), Article 115013. https://doi.org/10.1088/1361-6641/ac2124

JYU authors or editors

Kinnunen, Sami
Sajavaara, Timo
Toppari, Jussi

Publication details

All authors or editors: Parashar, Piyush Kumar; Kinnunen, Sami; Sajavaara, Timo; Toppari, Jussi; Komarala, Vamsi K.

Journal or series: Semiconductor Science and Technology

ISSN: 0268-1242

eISSN: 1361-6641

Publication year: 2021

Publication date: 25/08/2021

Volume: 36

Issue number: 11

Article number: 115013

Publisher: IOP Publishing

Publication country: United Kingdom

Publication language: English

DOI: https://doi.org/10.1088/1361-6641/ac2124

Publication open access: Not open

Publication channel open access:

Abstract

Effective surface passivation of nano-textured silicon (NT-Si) using sputtered aluminum oxide (AlOx) films is demonstrated and compared with the atomic layer deposition (ALD) grown AlOx films. Silver-assisted wet chemical etching is used to obtain sub-wavelength size features of black NT-Si, and then the NT-Si surface is chemically polished to minimize the surface defect states that act as trap centres for charge carriers. The NT-Si surface passivation is characterized by the density of interface trap states (Dit) and the fixed charge density (Qf), which are also correlated with surface recombination rate (Seff). For the sputtered AlOx films, the estimated Dit and Qf are ~4 x 1011 eV-1cm-2 and ~7 x 1012 cm-2, respectively, yielding the Seff of ~34 cm/s. Whereas, for the ALD AlOx films the estimated Dit, Qf, and Seff are ~1.6 x 1011 eV-1cm-2, ~7.4 x 1012 cm-2, and ~20 cm/s, respectively. The chemical and field-effect passivation are evident for the ALD AlOx films with the reduced Seff. However, the sputtered AlOx films have shown only an indication of field-effect passivation with a small variation in the Qf, still, the observed larger Dit is due to the sputtering damage on NT-Si surface compared to ALD AlOx films.

Keywords: nanostructures; thin films; silicon; aluminum oxide; atomic layer deposition

Fields of science: