Thermal nitridation of silicon dioxide at atmospheric pressure: Physico-chemical and electrical characterization

• Published in: Applied surface science 1989-11, Vol.40 (1), p.65-76
• Main Authors: Chartier, J.L., Plantard, M., Serrari, A., Le Bihan, R., Rigo, S., Ledys, J.L.
• Format: Article
• Language: English
• Subjects: Applied sciences; Compound structure devices; Electronics; Exact sciences and technology; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/0169-4332(89)90160-8

Thermal nitridation of silicon dioxide films was performed at atmospheric pressure in a furnace under NH 3 and at a temperature of 1100°C. Physico-chemical characterizations of the grown films were carried out by nuclear methods (NRA and ERD), electron spectroscopies (AES and ESCA) and ellipsometry. NRA measurements give quantitative results about nitrogen and oxygen concentrations and on the same samples AES and ESCA give the distribution of these elements throughout the films. The variation of the stoichiometry with the depth is determined. It is shown that the resulting nitroxide film is inhomogeneous with a nitrogen-rich surface layer and an interface pile-up of nitrogen. Nitridation is studied versus nitridation time and oxide thickness. The incorporation of nitrogen at the surface is higher when the initial oxide is thinner. As regards the bulk, the incorporation kinetics of nitrogen depends on the initial oxide thickness. Electrical characterizations of MIS structures realized with these nitroxide films show their good quality: flat-band voltage shifts are low; the difference in nature of interface charges is shown; conduction in the film is enhanced by nitridation as well as break-down electrical field.