Atomic-layer-deposition (ALD) of nanometer-thick layers of Al2O3 or other dielectrics has been established to be an effective method to create encapsulation layers of sensitive materials against their degradation by the ambient atmosphere moisture and oxygen content. Independently, the corrosive transformation of semiconductor materials into insulators induced by oxygen (respectively water), referred as dry (resp. wet) oxidation, are often used in the fabrication of microelectronic and photonic devices and integrated circuits as a way to introduce the electrical and/or photonic confinement needed to implement the on-wafer optical routing and/or electrical connections. In particular, in silicon photonics device fabrication, the latter processes typically involve high temperature or plasma exposure of a silicon layer to water/oxygen with local oxidation protection achieved by SiNx masks whose thickness is greater than 100 nm.