Process for manufacturing a micro-electro-mechanical device including two chambers at different pressures and related micro-electro-mechanical device

Abstract

Process for manufacturing a MEMS device, including: forming a dielectric region which coats part of a semiconductive substrate of a first semiconductive wafer; forming a region which is permeable to gases and coats the dielectric region; coupling the first semiconductive wafer to a second semiconductive wafer so as to form a first chamber, which houses a first movable mass and has a pressure equal to a first value, and a second chamber, which houses a second movable mass and has a pressure equal to the first value, the permeable region facing the second chamber; selectively removing a portion of the semiconductor substrate and an underlying portion of the dielectric region, so as to expose a part of the permeable region, so as to allow gas exchanges through the permeable region; placing the first and the second semiconductive wafers in an environment with a pressure equal to a second value, so that the pressure in the second chamber becomes equal to the second value; and subsequently forming, on the exposed part of the permeable region, a sealing region impermeable to gases.