AVS 45th International Symposium
    Electronic Materials and Processing Division Thursday Sessions
       Session EM1-ThA

Paper EM1-ThA8
Ultra Thin Silicon Oxide Film on Si(100) Fabricated by High Purity Ozone at Atmospheric Pressure

Thursday, November 5, 1998, 4:20 pm, Room 314/315

Session: Dielectrics
Presenter: K. Nakamura, Electrotechnical Laboratory, Japan
Authors: K. Nakamura, Electrotechnical Laboratory, Japan
S. Ichimura, Electrotechnical Laboratory, Japan
A. Kurokawa, Electrotechnical Laboratory, Japan
K. Koike, Iwatani International Corporation, Japan
G. Inoue, Iwatani International Corporation, Japan
T. Fukuda, Iwatani International Corporation, Japan
Correspondent: Click to Email
Microstructure of electronic devices requires much thinner silicon oxide film so that alternative oxidants must be developed to lower substrate temperature during oxidation. High purity ozone is expected as one of such oxidants because of its higher reactivity not only for adsorption on surfaces@footnote 1,2@ but also for thin film growth@footnote 3@ in comparison with that of molecular oxygen. However, lowering oxidation temperature also needs high dose of ozone to compensate decreasing oxidation rate. We investigated growth kinetics of oxide film under different ozone pressure conditions and succeeded in formation of oxide with the thickness >2nm at room temperature. First we fabricated oxide by exposing Si(100) with the substrate temperatures between 300°C and 700°C to 8x10@super -4@Pa ozone for 90 min. in an UHV chamber. Etching rates by 0.1wt% hydrofluoric acid solution of these SiO@sub 2@ films are equivalent to that of device-grade thermally grown oxide. Etching rate is so sensitive to film density that oxide films made by use of high purity ozone at lower substrate temperatures are expected to be as dense as thermally grown oxide. However, the oxidation rate, especially at oxide thickness >5Å, decreased as oxidation temperature decreased. So we utilized another ozone generator system giving an atmospheric pressure for much higher ozone dose. In this processing, oxide film >2nm was successfully grown on Si(100) even at room temperature. Etching rate of SiO@sub 2@ fabricated on Si(100), for example, at 350°C by this method is almost the same as that of thermally grown oxide or as those with lower ozone dose mentioned above. Effects of such treatment as preoxidation or hydrogen termination on oxidation kinetics and film quality will also be discussed. @FootnoteText@ @footnote 1@ K. Nakamura, A. Kurokawa and S. Ichimura, J. Vac. Sci. Technol. A 15, 2441 (1997). @footnote 2@ K. Nakamura, A. Kurokawa and S. Ichimura, Surf. Interface Anal. 25, 88 (1997). @footnote 3@ A. Kurokawa, S. Ichimura and D. W. Moon, Mat. Res. Soc. Symp. Proc. 477, 359 (1997).