Title:	XPS and XRR Study of Electronic Chemical Properties in Surface SiN Passivation on Crystalline Si
Author(s):	Y. Yamashita, N. Ikeno, H. Tokutake, T. Tachibana, Y. Ohshita, A. Ogura
Keywords:	Passivation, Silicon-Nitride, Interface(s)
Topic:	WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Subtopic:	Silicon Solar Cell Characterisation and Modelling
Event:	29th European Photovoltaic Solar Energy Conference and Exhibition
Session:	2BO.3.5
Pages:	459 - 462
ISBN:	3-936338-34-5
Paper DOI:	10.4229/EUPVSEC20142014-2BO.3.5
Price:	0,00 EUR
Document(s):	paper, presentation

Abstract/Summary:

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We investigated the electronic chemical properties of SiN passivation on crystalline Si by using X-ray photoelectron spectroscopy (XPS) and X-ray reflection (XRR). From XPS analyses, N-rich component (N-Si-N) and oxygen mixing were observed at the interface. We found that the N-rich layer varied before and after annealing process. The longest lifetime is obtained after PDA600 in which the N-rich layer shows the thinnest with small peak height. Therefore, the longer lifetime can be obtained as N concentration at the interface decreases. The film consisted of the three SiN layers and one SiO2 layer comfirmed by XRR profile fitting. The interface thickness increases with annealing high temperature. From density profiles, the density gradients were frequently observed at the surface and interface. The longer lifetime can be obtained when the density gradient was small. Additionally, N concentration became higher at the SiN (bottom)/SiO2 interface, which might produce the density gradient. Results of XPS and XRR suggested the N at the interface significantly affected lifetime. We believe it is important to understand the electronic chemical properties at the passivation interface to realize high efficiency Si solar cells.