PRESSURE SENSOR AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a manufacturing method for manufacturing high-quality pressure sensors with satisfactory yields at low costs. SOLUTION: An SOI substrate 20 is prepared by joining two silicon layers 21 and 23 via an insulating layer 22. One silicon layer of the SOI substrate is etched to reduce its thickness to the vicinity of the insulating layer to form a gap 24. Boron is diffused over the surface of the one silicon layer to form a P+layer 25 of a predetermined thickness. The side of the P+layer of the SOI substrate is joined onto a sensor substrate 30 in which a counter electrode and a dielectric film covering the counter electrode are formed on one side. The other silicon layer of the SOI substrate is etched with the insulating layer as an etching stop layer to expose the insulating layer and form a diaphragm 26. The method for manufacturing the pressure sensor 40 comprises the above- mentioned processes. COPYRIGHT: (C)2003,JPO