ECN publication
Hydrogen kinetics in crystalline silicon - PECVD SiN studies in mc and Cz silicon
Published by: Publication date:
ECN Solar Energy 1-6-2005
ECN report number: Document type:
ECN-RX--05-018 Conference Paper
Number of pages: Full text:
4 Download PDF  

Presented at: 20th European Photovoltaic Solar Energy Conference and Exhibition, Barcelona, Spain, 6-10 juni 2005.


Trapping of hydrogen during diffusion in silicon due to impurities and/or other defects is a well known

fact. Using SIMS we can demonstrate that high amounts of oxygen can significantly slow down diffusion of

deuterium originating from PECVD SiN layers after a firing step (NH3 exchanged by ND3) in mc RGS Si. The

slowed down diffusion results in unwanted longer passivation times and lower carrier lifetimes during solar cell

processing. Experiments using Cz Si samples differing in oxygen content are presented as well. High temperature

annealing steps generate O-precipitates of defined size and concentration, and more pronounced trapping of

deuterium appears for higher oxygen concentration. Even more trapping can be detected when O-precipitates are

generated, with the highest deuterium concentrations for large precipitates. An O-depleted region near the surface is

mirrored by lower deuterium concentrations, proving the link between enhanced trapping when oxygen is present.

The overall amount of D-atoms incorporated into the Si bulk after firing can be measured to about 1A1014 cm-2.

Back to List