The authors proposed a novel chemical vapor deposition system, flash boiling spray CVD (FS- CVD) to improve several kind of problem such as decomposition of precursor at supply line and evaporator. In this method, liquid precursors are supplied directly to vacuum chamber through an injector, just like fuel for an automobile engine, without any vaporizers, so as to induce an unsteady and intermittent flash boiling spray in the chamber. However, it is necessary to keep the lowest ambient pressure because the saturated vapor pressure of precursor is very low. Thus, it is very useful to modify the saturated vapor pressure of precursor. The technique to improve the vaporization of precursor is proposed by mixing a higher saturated vapor pressure organic solvent. In this paper, as a first step to ascertain FS-CVD principle, SiO2 film was formed on the Si substrate. Tetraethyl orthosilicate (TEOS) and n-pentane mixed solution was used as the mixing solution. Using this method, film thickness distribution of SiO2 film on 100 mm diameter Si wafer was ranged as +/-4%. Furthermore, this method enables us to control the film with various thicknesses by optimizing the injection period, cycle and frequency.
