Microelectromechanical system pressure sensor and method for making and using
View Patent ↗According to some embodiments, an apparatus includes a substrate that defines a plane. The apparatus also includes a first conducting plate that is substantially normal to the substrate and a second conducting plate that is (i) substantially normal to the substrate and (ii) deformable in response to a pressure.
1. A method, comprising:
on a wafer that includes a first non-conducting layer bonded onto a conducting layer, etching substantially parallel trenches through the layers to form a plurality of conducting plates substantially normal to a plane defined by the wafer, wherein at least one conducting plate is to be deformable in response to pressure; and
bonding a second non-conducting layer onto the first non-conducting layer.
2. The method of claim 1 , wherein pairs of conducting plates form fingers.
3. The method of claim 2 , wherein a first set of fingers is formed on a first comb and a second set of fingers is formed on a second comb, the fingers of the first and second combs being interleaved.
4. The method of claim 3 , further comprising:
etching away a portion of the second non-conducting layer and the first non-conducting layer to expose a portion of the conducting layer.
5. The method of claim 4 , further comprising:
creating a vacuum within a finger.
6. The method of claim 4 , further comprising:
bonding a cap wafer onto the second non-conducting layer.
7. The method of claim 6 , wherein the cap wafer includes at least one of: (i) a ground via, (ii) a voltage via, (iii) a first pressure via, and (iv) a second pressure via.
8. The method of claim 1 , wherein at least one pressure input cavity is formed while etching the trenches.