Microelectromechanical system pressure sensor and method for making and using
First Claim
1. A sensor apparatus, comprising:
- a wafer having a substantially flat surface defining a plane and lacking a cavity;
an insulating layer on the surface of the wafer, the insulating layer including a cavity and a reference capacitor spaced apart from said cavity, said reference capacitor being unaffected by a pressure change;
a bias area associated with the wafer and disposed apart from the conducting portion;
a conducting portion associated with the wafer and proximate to the cavity such that the conducting portion is not in direct contact with the insulating layer; and
a conducting diaphragm bonded to the insulating layer, wherein the conducting diaphragm covers the cavity and is substantially parallel to the plane.
4 Assignments
0 Petitions
Accused Products
Abstract
According to some embodiments, a conducting layer is formed on a first wafer. An insulating layer is formed on a second wafer. The insulating layer includes a cavity and a conducting area may be formed in the second wafer proximate to the cavity. The side of the conducting layer opposite the first wafer is bonded to the side of the insulating layer opposite the second wafer. At least some of the first wafer is then removed, without removing at least some of the conducting layer, to form a conducting diaphragm that is substantially parallel to the second wafer. In this way, an amount of capacitance between the diaphragm and the conducting area may be measured to determine an amount of pressure being applied to the diaphragm.
-
Citations
11 Claims
-
1. A sensor apparatus, comprising:
-
a wafer having a substantially flat surface defining a plane and lacking a cavity; an insulating layer on the surface of the wafer, the insulating layer including a cavity and a reference capacitor spaced apart from said cavity, said reference capacitor being unaffected by a pressure change; a bias area associated with the wafer and disposed apart from the conducting portion; a conducting portion associated with the wafer and proximate to the cavity such that the conducting portion is not in direct contact with the insulating layer; and a conducting diaphragm bonded to the insulating layer, wherein the conducting diaphragm covers the cavity and is substantially parallel to the plane. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A pressure sensor, comprising:
-
a lightly doped silicon wafer having a substantially flat surface defining a plane and lacking a cavity; an insulating layer formed on the surface of the silicon wafer, the insulating layer including a cavity and a reference capacitor spaced apart from said cavity, said reference capacitor being unaffected by a pressure change; a bias implant area in the silicon wafer in an area spaced apart from the conductive implant area; a highly doped conductive implant area in the silicon wafer in an area proximate to the cavity, wherein the insulating layer is not in direct contact with the highly doped conductive implant area; a conducting diaphragm bonded to the insulating layer, wherein the conducting diaphragm covers the cavity and is substantially parallel to the plane; and a device to measure capacitance between the implant area and the conducting diaphragm.
-
-
10. A system, comprising:
-
a microelectromechanical system pressure sensor, including; a wafer having a substantially flat surface defining a plane and lacking a cavity, an insulating layer on the surface of the wafer, the insulating layer including a cavity and a reference capacitor spaced apart from said cavity, said reference capacitor being unaffected by a pressure change, a bias area associated with the wafer and disposed apart from the conducting portion; a conducting portion associated with the wafer and proximate to the cavity such that the conducting portion is not in direct contact with the insulating layer, and a conducting diaphragm bonded to the insulating layer, wherein the conducting diaphragm covers the cavity and is substantially parallel to the plane; and a pressure dependent device. - View Dependent Claims (11)
-
Specification