Oxygen flooding and sample cooling during depth profiling of HfSiON thin films

A combination of oxygen flooding and. Cs primary ion bombardment can suppress the enhancement of the secondary ion signal at the surface and at the interface of a thin HfSiON layer on a Si substrate. The surface concentration of both Cs and O during Cs primary ion bombardment with oxygen flooding was higher than that without oxygen flooding, as confirmed by X-ray photoelectron spectroscopy. When the sample was cooled to about −150 °C, the enhancement of the secondary ion signal could be suppressed at a lower oxygen pressure.