A method of providing a dielectric material (18) having regions (18′, 18″) with a varying thickness in an IC manufacturing process is disclosed. The method comprises forming a plurality of patterns in respective regions (20′, 20″) of the dielectric material (18), each pattern increasing the susceptibility of the dielectric material (18) to a dielectric material removal step by a predefined amount and exposing the dielectric material (18) to the dielectric material removal step. In an embodiment, the IC comprises a plurality of pixilated elements (12) and a plurality of light interference elements (24), each comprising a first mirror element (16) and a second mirror element (22), a region of the dielectric material (18) separating the first mirror element (16) and the second element (22), and each being arranged over one of said pixilated elements (12), the method further comprising forming the respective first mirror elements (16) in a dielectric layer (14) over a substrate (10) comprising the plurality of pixilated elements; depositing the dielectric material over the dielectric layer; and forming the respective second mirror elements such that each second mirror element is separated from a respective first mirror element by a region of the exposed dielectric material. Hence, an IC having a layer of a dielectric material (18) comprising regions of different thicknesses can be obtained requiring only a few process steps.