O− emission from 12CaO·7Al2O3 and MSZ composite and its application for silicon oxidation

The solid electrolyte 12CaO·7Al2O3 (C12A7) is an interesting material where an atomic oxygen radical anion (O−) can be emitted from the C12A7 to vacuum when it is heated to 1000 K under an applied electric field (100 V/cm). However, the mechanical strength of the C12A7 is not enough for an application study. In order to enhance the mechanical strength of the C12A7, a magnesia-stabilized zirconia (MSZ) support C12A7 film composite was developed, and ion emission from the MSZ/C12A7 composite was investigated. The MSZ/C12A7 composite showed O− emission and also electron emission. The generated O− was applied to a silicon sample to confirm its oxidation ability. Even though the surface temperature is less than 383 K, SiO2 film formation was achieved.This O− oxidation method is applicable for low-temperature and low-damage silicon oxidation processes.