Investigation on the Thermal and Electrical Properties of Ti-Si-O Film Formed by the Composite Sputtering Deposition
- PDF / 3,746,020 Bytes
- 6 Pages / 595 x 842 pts (A4) Page_size
- 96 Downloads / 172 Views
Investigation on the Thermal and Electrical Properties of Ti-Si-O Film Formed by the Composite Sputtering Deposition Akira Nishiyama, Akio Kaneko, Masato Koyama, Yoshiki Kamata, Ikuo Fujiwara, Masahiro Koike, Masahiko Yoshiki* and Mitsuo Koike* Advanced LSI Technology Laboratory and *Environmental Engineering and Analysis Center, Toshiba Corporation 8 Shinsugita-cho, Isogo-ku, Yokohama 235-8522 Japan ABSTRACT Ti-Si-O films were sputter deposited from TiO2+SiO2 composite targets with various SiO2 content. The phase separation occurred for every SiO2 content used in this experiment (from 14% to 75%) and it has been revealed that nanocrystalline (TiO2)1-x(SiO2)x films in which anatase TiO2 forms tiny grains were obtained when x in the film is larger than 0.26. The tiny grain was effective for suppressing the thermal grooving phenomenon of the thin films by the post deposition annealing which leads to the leakage current increase. The dielectric constant of the nanocrystalline film was varied with the SiO2 content from the value of the bulk anatase to SiO2. INTRODUCTION
Many problems arise as a result of the pursuit of the miniaturization of MOSFETs. Among them, the gate leakage current increase through ultra-thin gate oxide has become a major issue in the ULSI industry. Many candidates such as Ta2O5, TiO2, ZrO2, HfO2 and La2O3 have been investigated as alternatives to SiO2; however, all of them are polycrystalline after the high temperature annealing practiced in the conventional LSI processes [1-5]. One major disadvantage respecting the use of the polycrystalline gate dielectric is the thermal grooving at the grain boundary which leads to the enhancement of the leakage current [6]. Amorphous materials such as metal silicates are preferred in order to avoid this problem; however, the dielectric constants of amorphous silicates are generally small (
Data Loading...
