An EPR investigation of SiOx films with columnar structure

• Published in: Physica. B, Condensed matter Vol. 453; pp. 26 - 28
• Main Authors: Bratus', V., Indutnyi, I., Shepeliavyi, P., Torchynska, T.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Kidlington Elsevier B.V 15.11.2014; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electron paramagnetic resonance and relaxation; EPR; EX center; Exact sciences and technology; Magnetic resonances and relaxations in condensed matter, mössbauer effect; Paramagnetic defects; Physics; Porous SiOx films; Paramagnetic defects; EX center; Porous SiOx films; EPR; films; Paramagnetic center; Non radiative recombination; Oblique incidence; Porous materials; Line splitting; Line widths; Amorphous state; Columnar structure; Defects; g-factor; Dangling bonds; Nano precipitate; Silicon oxides; Porous SiO; Chemical bonds; Electron paramagnetic resonance; Thermal annealing; Vacuum deposition
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2013.11.060

The results of electron paramagnetic resonance (EPR) study of obliquely deposited porous SiOx films before and after thermal annealing in vacuum at 950°C are presented. The low intensity slightly asymmetrical and featureless EPR line with a g-value of 2.0044 and a linewidth of 0.77mT has been detected in as-sputtered films and attributed to dangling bonds of silicon atoms in amorphous SiOx domains with x=0.8. Successive annealing results in decreasing this line and the appearance of an intense EPR line with g=2.0025, linewidth of 0.11mT and a hyperfine doublet with 1.6mT splitting. According to the parameters this spectrum has been attributed to the EX center, a hole delocalized over four non-bridging oxygen atoms grouped around a Si vacancy in SiO2. The impact of chemical treatment before annealing and duration of anneals on the defect system is discussed.