Oxidation resistance of silicon coated by boron nitride ultra thin film

Shimoyama, Iwao   ; Miyauchi, Hideo*; Baba, Yuji  ; Sekiguchi, Tetsuhiro  ; Hirao, Norie*; Okuno, Kenji*

Boron nitride (BN) ultrathin film attracts much attention as a coating material for Si cathode due to the chemical stability, heat resistance, and negative electron affinity. In order to study the oxidation resistance of BN ultrathin film coating, thermal dry oxidation is applied to BN coated Si and non-coated Si at various temperatures. X-ray photoelectron spectroscopy is devoted to clarify the modification of chemical state of the samples. The XPS spectra change by the thermal oxidation for the non-coated Si. On the other hand, it scarcely change by the thermal oxidation for the BN coated Si. The oxidation resistance in ambient air is also investigated for BN coated Si. After the several days exposure of air, the O 1s photoelectron peak is drastically enhanced. These results mean that BN ultrathin film works as protective coating for dry thermal oxidation, however it does not work in ambient air.