Abstract
The invention provides a silicon pressure sensor and a method for manufacturing the same. The silicon pressure sensor includes a pressure cavity and is constituted by a P-type chip with a tapered cavity and an N-type epitaxial layer on the P-type chip. The N-type epitaxial layer has a plurality of piezo-resistance sensing unit for sensing a pressure-caused deformation. The method for manufacturing the silicon pressure sensor comprises the steps of forming in the N-type epitaxial layer a plurality of deep holes reaching an underlying P-type chip; etching the P-type chip, by an anisotropic etching-stop technique, through the plurality of deep holes to form a taperedcavity in the P-type chip; and then coating an insulating material for sealing the plurality of deep holes. The silicon pressure sensor thus formed has an ability to sense a gauge pressure between its both ends.