Membranes for microsensors-manufacture and measurement

The authors present results obtained, and procedures and techniques evolved for the manufacture and assessment of a micromechanical membrane light modulator. This consists of a 1 cm² silicon chip, coated with a one micron surface layer of thermal deposited oxide. An array of square holes is etched into the oxide and each hole or well contains a silicon photodiode. A polymer film is lowered onto the silicon chip and bonds to the oxide surface. It lies across the etched holes like a drumskin and is the deformable element. The membrane surface is then coated with silver using a standard evaporation technique. Each element forms an airgap capacitor between the silicon surface and membrane