An array of thermal sensitive elements (16) may be formed from a pyroelectric substrate (46) having an infrared absorber and common electrode assembly (18) attached thereto. A first layer of electrically conductive contacts (60) is formed to define in part masked (61) and unmasked (68) regions of the substrate (46). A second layer of electrically conductive contacts (62) may be formed on the first layer of contacts (60). A mask layer (66) is formed to encapsulate the exposed portions of the second layer of contacts (62). The unmasked regions (68) are exposed to an etchant (70) and irradiated to substantially increase the reactivity between the unmasked regions (68) and the etchant (70) such that during irradiation, the etchant (70) removes the unmasked regions (68) substantially faster than the first layer of contacts (60) and the mask layer (66).