AVS 47th International Symposium
    Dielectrics Thursday Sessions
       Session DI+EL+MS-ThM

Paper DI+EL+MS-ThM2
New Oxidation Process Using Collimated Hyperthermal Ozone Beam

Thursday, October 5, 2000, 8:40 am, Room 312

Session: Ultrathin Dielectrics and Interfaces
Presenter: T. Nishiguchi, Meidensha Corporation, Japan
Authors: T. Nishiguchi, Meidensha Corporation, Japan
Y. Morikawa, Meidensha Corporation, Japan
M. Miyamoto, Meidensha Corporation, Japan
H. Nonaka, Electrotechnical Laboratory, Japan
A. Kurokawa, Electrotechnical Laboratory, Japan
S. Ichimura, Electrotechnical Laboratory, Japan
Correspondent: Click to Email
As the electronic devices are scaled down, using more reactive process gas than molecular oxygen is required to fabricate an ultra-thin highly reliable Si dioxide film for the gate oxide in MOSFET. We used ozone as an oxidant gas and achieved the enhanced initial oxidation rate, resulting in lower temperature oxidation process. In our experiments using highly concentrated ozone gas, more than 3nm Si dioxide film was obtained within 30 minutes under the conditions of 873K of Si temperature and 10Pa of ozone pressure, where the oxidation hardly proceeds by molecular oxygen. In the present study, we carried out the laser ablation of solid ozone in order to obtain collimated ozone beam on the purpose of applying ozone beam to new oxidation processes such as local oxidation of patterned Si surface (e.g. oxidation of a bottom part of a trench). We irradiated a KrF pulsed excimer laser light to highly concentrated solidified ozone that was adsorbed on the sapphire plate cooled down to 30-60K by cryocooler in an UHV chamber. We could obtain collimated ozone beam (within 20° spread) whose supply (typically 10@super 16@ molecules per laser pulse), concentration (typically 70%) and translational energy (3eV maximum) were controlled through the laser ablation conditions such as the laser fluence. Not only the local oxidation but also even lower temperature process is expected using this high-translational-energy (hyperthermal) ozone beam. We will demonstrate the initial oxidation profile for the first 1000 laser shots by Auger Electron Spectroscopy and discuss the applicability of this ozone beam to the semiconductor process.