A method for fabricating a pressure sensor using SOI wafers

摘要

A pressure sensor is manufactured by joining two wafers (1a, 14), the first wafer comprising CMOS circuitry (2) and the second being an SOI wafer. A recess is formed in the top material layer of the first wafer (1a), which is covered by the silicon layer (17) of the second wafer (14) to form a cavity (18). Part or all of the substrate (15) of the second wafer (14) is removed to forming a membrane from the silicon layer (17). Alternatively, the cavity can be formed in the second wafer (14). The second wafer (14) is electrically connected to the circuitry (2) on the first wafer (1a). This design allows to use standard CMOS processes for integrating circuitry on the first wafer (1a).