PROCESS FOR DEPOSITING A LARGE-SURFACE LAYER THROUGH A MASK AND OPTIONAL CLOSURE OF SAID MASK

摘要

By deposition from various directions through a mask, a layer may be applied last on the whole surface of a substrate located below the mask. In the coating area, the mask is separated from the substrate by a cavity, and outside the coating area it is attached thereto. This process is particularly advantageous for suspended gat field effect transistors used as gas sensors. The mask also forms the gate and the sensitive layer is not exposed to any other processes after deposition. The mask may then remain open or be closed by depositing such a large amount of material that the openings in the mask are laterally stoppered, or by depositing a further layer at a flat angle. This process is also suitable for producing micromechanical membranes.