Patent ID: 7820358

Claim:
An apparatus comprising: a substrate with a main side; a photoresist material structure arranged adjacent to the substrate so that a cavity is formed between the substrate and the photoresist material structure, the cavity having an opening; wherein the photoresist material structure comprises a frame portion disposed on the main side of the substrate and a cap portion spanning over a part of the main side of the substrate at a distance to the main side; and wherein the photoresist material structure is formed of a first photoresist layer and a second photoresist layer in direct contact with each other, wherein the cap portion is formed in the first photoresist layer and the frame portion is formed in the second photoresist layer and the first photoresist layer comprises a first photoresist material and the second photoresist layer comprises a second photoresist material, the first photoresist material being a positive resist, the second photoresist material being a negative resist and the first photoresist material having a higher absorption coefficient than the second photoresist material at a predefined wavelength.