Mechanism of beta-FeSi2 precipitates growth-and-dissolution and pyramidal defects' formation during oxidation of Fe-contaminated silicon wafers

作者：De Luca Anthony; Texier Michael^*; Portavoce Alain; Burle Nelly; Grosjean Catherine; Morata Stephane; Michel Fabrice

来源：Journal of Applied Physics, 2015, 117(11): 115302.

DOI：10.1063/1.4915086

Fe-implanted Si-wafers have been oxidized at 900 degrees C and 1100 degrees C in order to investigate the behaviour of Fe atoms at the growing SiO2/Si interface and the impact on the integrity of microelectronic devices of an involuntary Fe contamination before or during the oxidation process. As-implanted and oxidized wafers have been characterized using secondary ion mass spectroscopy, atom probe tomography, and high-resolution transmission electron microscopy. Experimental results were compared to calculated implantation profiles and simulated images. Successive steps of iron disilicide precipitation and oxidation were evidenced during the silicon oxidation process. The formation of characteristic pyramidal-shaped defects, at the SiO2/Si interface, was notably found to correlate with the presence of beta-FeSi2 precipitates. Taking into account the competitive oxidation of these precipitates and of the surrounding silicon matrix, dynamic mechanisms are proposed to model the observed microstructural evolution of the SiO2/Si interface, during the growth of the silicon oxide layer.

• 出版日期2015-3-21