PROCESS FOR PREPARING MICROMECHANICAL COMPONENTS HAVING FREE-STANDING MICROSTRUCTURES OR MEMBRANES

摘要

The invention concerns a process for preparing micromechanical components having free-standing microstructures or membranes which are under a predetermined mechanical stress. According to the process a sacrificial layer is first applied to a substrate, a polysilicon layer is applied to the sacrificial layer by vapour phase deposition, and finally at least part of the sacrificial layer is removed again. The process is distinguished in that the type of layer stress on the polysilicon layer depends on the processing pressure selected during deposition, the amount of layer stress being adjusted by the process temperature selected. The process pressure in each case is above the pressure range set for low pressure chemical vapour deposition reactors. In this way free-standing structures can in particular be produced such that they can be reproduced with specific tensile stress.