Patent ID: 8991262
Filing Date: 2015-03-31
Classification: G01L

Abstract:
1. A capacitive pressure sensor, comprising: a semiconductor substrate configured to have an insulating layer and an upper semiconductor layer formed on the semiconductor substrate; a first insulating portion formed in the upper semiconductor layer to surround a sensor region disposed in an internal area of the upper semiconductor layer, the sensor region being defined by the first insulating portion together with the insulating layer; a reference pressure chamber formed in a lower portion of the sensor region to divide the lower portion of the sensor region in a direction traversing the first insulating portion, a lower surface of the reference pressure chamber being defined by the insulating layer; a second insulating portion formed in a surface portion of the sensor region above the reference pressure chamber to divide the surface portion of the sensor region in the direction; and a trench formed from a surface of the upper semiconductor layer until the insulating layer to divide the sensor region in the direction, wherein the sensor region is divided into at least three semiconductor parts disposed in sequence in the direction by the reference pressure chamber, the second insulating portion, and the trench, the three semiconductor parts being insulated from one another, and wherein the three semiconductor parts comprise: a membrane disposed between the reference pressure chamber and the trench; a first electrode facing the membrane with the reference pressure chamber being interposed therebetween; and a second electrode facing the membrane with the trench being interposed therebetween.