Method for making a finger capacitor with tuneable dielectric constant

A method of making finger capacitors in an integrated circuit comprises forming a plurality of conductive strips in a substrate having a first dielectric constant, removing a portion of the substrate material between the conductive strips to define a space and then filling the space with a material having a second dielectric constant which is greater than the first dielectric constant. By selecting the proportion of the high and low dielectric constant materials, the capacitance of the finger capacitors can be selected to have any value from a minimum, in which very little of the original, first dielectric constant material is removed and replaced by the second dielectric constant material, to a maximum, in which all of the first dielectric constant material between the conductive strips is removed and replaced with the second dielectric constant material.