Thermoelectric microsensors and microactuators (MEMS) fabricated by thin film technology and micromachining

The fabrication of thermoelectric microsensors and microactuators using thin film deposition technique and micromachining is demonstrated. Sensors with high sensitivity can be realized by anisotropic etching of silicon substrates with very thin membranes (thickness d=100 nm) or cantilever beams of silicon carbide, silicon nitride or silicon oxide. Such membranes or beams enable a good thermal insulation of the sensor films. These films (BiSbTe, polysilicon) are patterned by photolithographic technique. Most of the sensor fabrication steps are compatible with standard-IC technologies and can be performed by a batch-process. We report on the design and development of a thermopile-sensor array with integrated signal processing, the fabrication of a thermoelectric vacuum microsensor for the low vacuum range, of a heat flux sensor and of an integrated thermoelectric microcooler. The properties and parameters of these devices are represented and discussed.