Patent ID: 7465599
Filing Date: 2008-12-16
Classification: B81B,B81C,G01P

Abstract:
1. A method for manufacturing a physical quantity sensor, which includes a multi-layered substrate, a cavity, a groove portion and a movable portion, wherein the multi-layered substrate includes a support substrate, an embedded insulation film and a semiconductor layer, which are stacked in this order, wherein the cavity is disposed between the semiconductor layer and the embedded insulation film and extends in a horizontal direction of the substrate, wherein the groove portion is disposed in the semiconductor layer and reaches the cavity, wherein the movable portion is disposed in the semiconductor layer and separated from the embedded insulation film by the cavity and the groove portion, the method comprising the steps of: preparing the multi-layered substrate in such a manner that an intermediate insulation layer is disposed in the semiconductor layer at a predetermined position to be a bottom of the movable portion; forming the groove portion from a top surface of the semiconductor layer so that the groove portion extends in a vertical direction of the multi-layered substrate and reaches the embedded insulation film; and etching a part of the semiconductor layer disposed between the embedded insulation film and the intermediate insulation layer from a bottom of the groove portion by a dry-etching method with using the embedded insulation film and the intermediate insulation layer as an etching stopper so that the cavity is formed to extend in the horizontal direction of the multi-layered substrate.