METHOD FOR DEPOSITING GRADIENT FILMS ON A SUBSTRATE SURFACE BY ATOMIC LAYER DEPOSITION

摘要

The present invention is directed to a method for depositing gradient films on a substrate surface by atomic layer deposition (ALD), the method including (a) exposing the substrate to a vapour of a first precursor that is reactive with the surface of the substrate thereby forming a layer of first precursor molecules on the surface of the substrate, (b) removing non-reacted first precursor, (c) exposing the substrate to a vapour of a second precursor that is reactive with the first precursor, thereby forming a film of reacted first and second precursors on the surface of the substrate, (d) removing non-reacted second precursor, and (e) repeating steps (a)-(d) in a plurality of cycles, wherein (i) in a first number of cycles of the plurality of cycles, the exposure dosage of the first precursor and the exposure dosage of the second precursor is equal to or above a respective saturation exposure dosage of the respective precursor, and in subsequent cycles, the exposure dosage of the first precursor or the exposure dosage of the second precursor is reduced to below the respective saturation exposure dosage of the respective precursor, or (ii) in a first number of cycles of the plurality of cycles, the exposure dosage of the first precursor and the exposure dosage of the second precursor is below the respective saturation exposure dosage of the respective precursor, and in subsequent cycles, the exposure dosage of the first precursor or the exposure dosage of the second precursor is increased to be equal to or above the respective saturation exposure dosage of the respective precursor. The present invention also relates to the substrates thus obtained. The present invention also further relates to a substrate and an inverse photonic crystal.