In one aspect, the invention includes a semiconductor fabrication process, comprising: a) providing a substrate; b) forming a layer of silicon nitride over the substrate, the layer having a thickness; and c) enriching a portion of the thickness of the silicon nitride layer with silicon, the portion comprising less than or equal to about 95% of the thickness of the layer of silicon nitride. In another aspect, the invention includes a semiconductor fabrication process, comprising: a) providing a substrate; b) forming a layer of silicon nitride over the substrate, the layer having a thickness; and c) increasing a refractive index of a first portion of the thickness of the silicon nitride layer relative to a refractive index of a second portion of the silicon nitride layer, the first portion comprising less than or equal to about 95% of the thickness of the silicon nitride layer. In yet another aspect, the invention includes semiconductor wafer assembly, comprising: a) a semiconductor wafer substrate; and b) a layer of silicon nitride over the substrate, the layer comprising a thickness and two portions elevationally displaced relative to one another, a first of the two portions having less resistance than a second of the two portions, the first portion comprising less than or equal to about 95% of the thickness of the silicon nitride layer.