Low-Temperature Oxidation of Silicon in Dry O₂ Ambient by UV-Irradiation

Abstract

The mechanism of thermal oxidation of silicon in dry O2 ambient with UV-irradiation has been discussed. The dependence of SiO2 thickness on oxidation time follows the model proposed by Cabrera and Mott for relatively short oxidation time. Such dependence follows the model by Deal and Grove for longer time. The main oxidizing species is ozone (O3) or some other reactive species generated from O3 at lower temperatures and this gradually changes to O2 with an increase in temperature. The SiO2 film formed at 500°C for 1 h by the present technique has a similar quality to that of SiO2 formed at high temperatures in dry O2 ambient, as evaluated from Fourier Transform-Infrared (FT-IR), Auger Electron Spectroscopy (AES) and Capacitance-Voltage (C-V) characteristics.

Diffusion and reactions of interstitial oxygen species in amorphous SiO2: A review

“…O 0 becomes mobile above $200°C and is mostly converted back to interstitial O 2 after heating above 400°C. This temperature range coincides with that of the silicon oxidation by O 0 [93,95,97].…”

“…The activation energy evaluated from the dimerization rate ($1.0-1.5 eV [74,75]) is in accord with a theoretical calculation predicting the diffusion of O 0 as POL [86]. However, the activation energy of the parabolic rate constant of the O 0 oxidation is much small ($0.1-0.4 eV) [94][95][96][97].…”

“…Oxidation of silicon by O 0 below $500-600°C is a promising technique to fabricate thin gate dielectric oxide films while avoiding undesirable phenomena occurring at high temperatures [92][93][94][95][96][97]. Mobility of O 0 in a-SiO 2 can be studied via the rate of the dimerization of O 0 s (reverse reaction of Eq.…”

Rapid thermal oxidation of silicon in ozone

“…A systematic IR study of the ultrathin oxide growth in ozone ambient is needed. 5,10 The MER-FTIR we have developed to study process-property relationships of ultrathin films allows us to study in situ oxide IR spectral features at different processing environments, for oxides as thin as 3 Å. Using in situ data from MER-FTIR spectroscopy coupled with complementary information obtained from x-ray photoelectron spectroscopy ͑XPS͒, spectral ellipsometry, and surface charge analyzer ͑SCA͒, the ozone oxidation kinetics and properties of the oxides are obtained, presented, and discussed.…”

The effect of ultrathin oxides on luminescent silicon nanocrystallites

“…It has been shown by FTIR, Auger, and capacitance-voltage measurements that the quality of the oxide formed by this method at elevated temperatures is comparable to that formed by dry oxygen, and thus, well passivated. 20 It appears that the oxidation methods are affecting the luminescence mechanism, which might be due to the different methods resulting in different crystallite termination.…”