Wafer encapsulated microelectromechanical structure and method of manufacturing same

Abstract

There are many inventions described and illustrated herein. In one aspect, the present inventions relate to devices, systems and/or methods of encapsulating and fabricating electromechanical structures or elements, for example, accelerometer, gyroscope or other transducer (for example, pressure sensor, strain sensor, tactile sensor, magnetic sensor and/or temperature sensor), filter or resonator. The fabricating or manufacturing microelectromechanical systems of the present invention, and the systems manufactured thereby, employ wafer bonding encapsulation techniques.

1 - 30 . (canceled) 
   
   
       31 . A method comprising:
 forming a microelectromechanical structure in a portion of a first substrate;   securing a second substrate to the first substrate; and   providing circuitry in or on the second substrate after securing the second substrate to the first substrate.   
   
   
       32 . The method of  claim 31  wherein the first substrate comprises carbon, polycrystalline silicon, monocrystalline silicon, amorphous silicon, silicon carbide, silicon/germanium, germanium, or gallium arsenide. 
   
   
       33 . The method of  claim 31  wherein the first substrate comprises a semiconductor on insulator substrate. 
   
   
       34 . The method of  claim 33  wherein the semiconductor on insulator substrate comprises an insulation layer and a semiconductor layer disposed on the insulation layer and wherein forming a microelectromechanical structure in the portion of the first substrate comprises:
 etching the semiconductor layer of the semiconductor on insulator substrate; and   etching the insulation layer of the semiconductor on insulator substrate.   
   
   
       35 . The method of  claim 31  wherein the second substrate comprises carbon, polycrystalline silicon, monocrystalline silicon, amorphous silicon, silicon carbide, silicon/germanium, germanium, or gallium arsenide. 
   
   
       36 . The method of  claim 31  wherein securing a second substrate to the first substrate comprises bonding the second substrate to the first substrate. 
   
   
       37 . The method of  claim 36  wherein bonding the second substrate to the first substrate comprises fusion bonding, anodic-like bonding, silicon direct bonding, soldering, thermo compression bonding, thermo-sonic bonding, laser bonding and/or glass reflow bonding the second substrate to the first substrate. 
   
   
       38 . The method of  claim 31  further comprising:
 forming a first portion of a contact from a portion of the first substrate; and   forming a second portion of the contract from a portion of the second substrate.   
   
   
       39 . The method of  claim 38  wherein:
 the first portion of the contact is a semiconductor material having a first conductivity;   the second substrate is a semiconductor material having a second conductivity; and   the second portion of the contact is a semiconductor material having the first conductivity.   
   
   
       40 . The method of  claim 38  further comprising forming a trench around at least a portion of the second portion of the contact. 
   
   
       41 . The method of  claim 40  wherein the trench includes a first material disposed therein to electrically isolate the second portion of the contact from the second substrate. 
   
   
       42 . The method of  claim 40  wherein the second substrate is a semiconductor material having a first conductivity and the trench is (i) a semiconductor material having a second conductivity or (ii) an insulation material. 
   
   
       43 . The method of  claim 38  further comprising electrically connecting the contact to the circuitry. 
   
   
       44 . The method of  claim 43  wherein electrically connecting the contact to the circuitry comprises providing a low resistance electrical path to connect the second portion of the contact and the circuitry. 
   
   
       45 . The method of  claim 31  further comprising providing, in the first substrate, a cavity that forms a portion of a chamber in which the microelectromechanical structure is at least partially disposed. 
   
   
       46 . The method of  claim 31  further comprising:
 forming a first cavity in the first substrate; and   forming a second cavity in the first substrate;   wherein after the second substrate is secured to the first substrate, the first cavity and the second cavity form a chamber in which the microelectromechanical structure is at least partially disposed.   
   
   
       47 . A method comprising:
 providing a first substrate;   securing a second substrate to the first substrate;   forming a microelectromechanical structure in a portion of the second substrate;   securing a third substrate to the second substrate; and   providing circuitry in or on the third substrate after securing the third substrate to the second substrate.   
   
   
       48 . The method of  claim 47  wherein the second substrate includes polycrystalline silicon, porous polycrystalline silicon, amorphous silicon, silicon carbide, silicon/germanium, germanium, or gallium arsenide. 
   
   
       49 . The method of  claim 47  wherein the third substrate includes polycrystalline silicon, porous polycrystalline silicon, amorphous silicon, silicon carbide, silicon/germanium, germanium, or gallium arsenide. 
   
   
       50 . The method of  claim 47  wherein securing a second substrate to the first substrate comprises bonding the second substrate to the first substrate. 
   
   
       51 . The method of  claim 50  wherein bonding the second substrate to the first substrate comprises fusion bonding, anodic-like bonding, silicon direct bonding, soldering, thermo compression bonding, thermo-sonic bonding, laser bonding and/or glass reflow bonding the second substrate to the first substrate. 
   
   
       52 . The method of  claim 47  wherein forming a microelectromechanical structure in a portion of the second substrate comprises forming the microelectromechanical structure in the portion of the second substrate after securing the second substrate to the first substrate. 
   
   
       53 . The method of  claim 47  wherein securing a third substrate to the second substrate comprises bonding the third substrate to the second substrate. 
   
   
       54 . The method of  claim 53  wherein bonding the third substrate to the second substrate comprises fusion bonding, anodic-like bonding, silicon direct bonding, soldering, thermo compression bonding, thermo-sonic bonding, laser bonding and/or glass reflow bonding the third substrate to the second substrate. 
   
   
       55 . The method of  claim 47  further comprising:
 forming a first portion of a contact from a portion of the second substrate; and   forming a second portion of the contact from a portion of the third substrate.   
   
   
       56 . The method of  claim 55  wherein:
 the first portion of the contact is a semiconductor material having a first conductivity;   the third substrate is a semiconductor material having a second conductivity; and   the second portion of the contact is a semiconductor material having the first conductivity.   
   
   
       57 . The method of  claim 55  further comprising forming a trench around at least a portion of the second portion of the contact. 
   
   
       58 . The method of  claim 57  wherein the third substrate is a semiconductor material having a first conductivity and the trench is (i) a semiconductor material having a second conductivity or (ii) an insulation material. 
   
   
       59 . The method of  claim 55  further comprising electrically connecting the contact to the circuitry. 
   
   
       60 . The method of  claim 59  wherein electrically connecting the contact to the circuitry comprises providing a low resistance electrical path to connect the second portion of the contact and the circuitry. 
   
   
       61 . The method of  claim 47  further comprising providing, in the first substrate, a cavity that forms a portion of a chamber in which the microelectromechanical structure is at least partially disposed. 
   
   
       62 . The method of  claim 47  further comprising providing, in the second substrate, a cavity that forms a portion of a chamber in which the microelectromechanical structure is at least partially disposed. 
   
   
       63 . The method of  claim 47  further comprising providing, in the third substrate, a cavity that forms a portion of a chamber in which the microelectromechanical structure is at least partially disposed. 
   
   
       64 . The method of  claim 47  further comprising:
 forming a first cavity in the first substrate; and   forming a second cavity in the third substrate;   wherein after the second substrate is secured to the first substrate and the third substrate is secured to the second substrate, the first cavity and the second cavity form a chamber in which the microelectromechanical structure is at least partially disposed.   
   
   
       65 . The method of  claim 47  further comprising:
 forming a first cavity in the second substrate; and   forming a second cavity in the third substrate;   wherein after the second substrate is secured to the first substrate and the third substrate is secured to the second substrate, the first cavity and the second cavity form a chamber in which the microelectromechanical structure is at least partially disposed.   
   
   
       66 . The method of  claim 47  further comprising:
 forming a first cavity in the second substrate; and   forming a second cavity in the second substrate;   wherein after the second substrate is secured to the first substrate and the third substrate is secured to the second substrate, the first cavity and the second cavity form a chamber in which the microelectromechanical structure is at least partially disposed.   
   
   
       67 . The method of  claim 47  further comprising:
 forming a first cavity in the first substrate; and   forming a second cavity in the second substrate;   wherein after the second substrate is secured to the first substrate and the third substrate is secured to the second substrate, the first cavity and the second cavity form a chamber in which the microelectromechanical structure is at least partially disposed.