| 摘要 |
Multi-layer silicon structures particularly micromechanical sensors, can be made by cleaning and polishing respective surfaces of two silicon wafers, assembling the wafers together under clean room conditions and adhering them together by temperature treatment. This method is improved by the pretreatment of the wafer surfaces using fuming nitric acid (e.g., 100% HNO3), rinsing with de-ionized water, drying, and temperature treatment at a lower temperature than was previously thought necessary, namely between 100 DEG and 400 DEG C. This has the advantage that such gentler treatment preserves previously-applied integrated circuit structures, which can therefore be applied before the wafer assembly steps. The method is particularly suitable for producing pressure sensors having a pressure-responsive silicon membrane, and an evaluation circuit integrated on the silicon wafer. Such sensors are suitable for use in motor vehicles for measuring engine pressures and for measuring brake fluid pressures in anti-lock braking systems (ABS).
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