Method of fabricating microelectromechanical systems and devices having trench isolated contacts
First Claim
1. A method of sealing a chamber of a microelectromechanical device having a micromechanical structure and a contact wherein the micromechanical structure is in a chamber, the method comprising:
- depositing a sacrificial layer over at least a portion of the micromechanical structure;
depositing a first encapsulation layer over the sacrificial layer;
forming at least one vent through the first encapsulation layer to allow removal of at least a portion of the sacrificial layer;
removing at least a portion of the sacrificial layer to form the chamber;
depositing a second encapsulation layer over or in the vent to seal the chamber wherein the second encapsulation layer is a semiconductor material;
forming a trench around at least a portion of the contact which is disposed outside the chamber; and
depositing an insulating material in the trench to electrically isolate the contact.
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Accused Products
Abstract
There are many inventions described and illustrated herein. In one aspect, the present invention is directed to a MEMS device, and technique of fabricating or manufacturing a MEMS device, having mechanical structures encapsulated in a chamber prior to final packaging and a contact area disposed at least partially outside the chamber. The contact area is electrically isolated from nearby electrically conducting regions by way of dielectric isolation trench that is disposed around the contact area. The material that encapsulates the mechanical structures, when deposited, includes one or more of the following attributes: low tensile stress, good step coverage, maintains its integrity when subjected to subsequent processing, does not significantly and/or adversely impact the performance characteristics of the mechanical structures in the chamber (if coated with the material during deposition), and/or facilitates integration with high-performance integrated circuits. In one embodiment, the material that encapsulates the mechanical structures is, for example, silicon (polycrystalline, amorphous or porous, whether doped or undoped), silicon carbide, silicon-germanium, germanium, or gallium-arsenide.
351 Citations
27 Claims
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1. A method of sealing a chamber of a microelectromechanical device having a micromechanical structure and a contact wherein the micromechanical structure is in a chamber, the method comprising:
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depositing a sacrificial layer over at least a portion of the micromechanical structure;
depositing a first encapsulation layer over the sacrificial layer;
forming at least one vent through the first encapsulation layer to allow removal of at least a portion of the sacrificial layer;
removing at least a portion of the sacrificial layer to form the chamber;
depositing a second encapsulation layer over or in the vent to seal the chamber wherein the second encapsulation layer is a semiconductor material;
forming a trench around at least a portion of the contact which is disposed outside the chamber; and
depositing an insulating material in the trench to electrically isolate the contact. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 17)
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9. A method of manufacturing a microelectromechanical device having a micromechanical structure that resides in a chamber and wherein the microelectromechanical device further includes a contact, the method comprising:
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depositing a first encapsulation layer over the micromechanical structure wherein the first encapsulation layer is a semiconductor material;
forming at least one vent in the first encapsulation layer;
forming the chamber;
depositing a second encapsulation layer over or in the vent to seal the chamber wherein the second encapsulation layer is a semiconductor material;
forming a trench around at least a portion of the contact wherein the trench and at least the portion of the contact are disposed outside the chamber; and
depositing a first material in the trench to electrically isolate the contact. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 18)
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19. A method of manufacturing an microelectromechanical device having a micromechanical structure that resides in a chamber, wherein the microelectromechanical device further includes a contact, the method comprising:
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depositing a first encapsulation layer over the micromechanical structure;
depositing a second encapsulation layer on the first encapsulation layer and on the contact, wherein the second encapsulation layer is a semiconductor material;
forming a trench around at least a portion of the contact which is disposed outside the chamber;
depositing an insulating material in the trench, and on at least a first surface of the contact, and over the second encapsulation layer;
removing at least a portion of the insulating material that is disposed on the first surface of the contact to thereby expose a portion of the first surface of the contact; and
depositing a conductive material on the exposed portion of the first surface of the contact. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27)
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Specification