Charge-diminution at the Si-SiO₂ system interface

6^th International Conference on Theoretical and Applied Physics

May 16-17, 2019 | Rome, Italy

D Kropman, T Laas, V Seeman, A Medvids and P Onufrievs

Tallinn University, Estonia
 University Tartu, Estonia
Riga Technical University, Riga

Posters & Accepted Abstracts: J Astrophys Aerospace Technol

Abstract :

The fact that a positive charge formation occurs in SiO2 film during the process of Si thermal oxidation is already known, with the formation being dependent upon the oxidation conditions which involve temperature, time and ambient conditions. This is connected by oxygen vacancies in the SiO2 film and unsaturated Si3Î?bonds at the interface. Until now, this process has not been studied in depth at an atomic level. The purpose of the present work is to investigate the charge formation in the Si-SiO2 system and its diminution by means of the appropriate choice of oxidation conditions via EPR spectroscopy, IR spectroscopy, CV curves, TEM, and deflection measurements. Laser irradiation and ultrasonic treatment were used for the modification of interface properties. It has been established that, at an oxidation temperature that is within the range of 1125°C-1130°C in SiO2 film with a thickness of 0.2-0.3μ at the interface, there appears a low positive or negative charge which is connected with negatively charged acceptors that are formed by Si vacancies, and the positive charge in the SiO2 is compensated. The results that were obtained coincide with the point defects generation kinetic model in the Si-SiO2 system which was proposed in and was confirmed experimentally. Integral circuit technology conditions that allow the interface charge to diminish were introduced by the semiconductor plant, ALFA (Riga, Latvia). We supposed that these results, which were obtained during long term collaboration between Estonia and Latvia, constituted a discovery that had been achieved by Si-SiO2 system investigation no less than thirty years ago: the discovery of the quantum Hall effect on the Si-SiO2structure.

Biography :

E-mail: daniel.kropman@mail.ee