Membranes

Besides conductor paths, membranes are another special type of thin films. Membranes are an important mechanical basic element in microtechnique. They are the microscopic correspondence to macroscopic gaskets, bearings, and springs. They are made of silicon, oxides, nitrides, glasses, polymers, and metals. Their thickness typically is in the range of 0.5–500 μm. Membranes which are thinner than 0.5 μm are very hard to manufacture without holes and are generally not strong enough to withstand usual loads. The upper limit is given by the fact that thicker membranes are no longer a microscopic element. The lateral dimensions of membranes are typically in the range between 100 μm and 10 mm. Again the lower limit is defined by the possibilities of fabrication, while the upper limit is approximately the limit to the macroscopic world. However, all equations discussed here are valid in the macroscopic world also.