Method of fabricating a microfabricated high aspect ratio device with electrical isolation
First Claim
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1. A method of fabricating a microelectromechanical system, comprising:
- providing a substrate having a device layer including single-crystal silicon, a handle layer and a sacrificial layer between the device layer and the handle layer;
etching a first trench in the single-crystal silicon;
depositing a dielectric isolation layer in the first trench to form an isolation trench;
after depositing the dielectric isolation layer, etching a second trench in the single-crystal silicon, the second trench defining a microstructure including a plurality of elements laterally anchored to the isolation trench such that the isolation trench provides electrical isolation for the anchored elements of the microstructure from each other; and
removing a portion of the sacrificial layer, wherein the removed portion entirely undercuts the plurality of laterally anchored elements.
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Abstract
A microfabricated device having a high vertical aspect ratio and electrical isolation between a structure region and a circuit region. The device may be fabricated on a single substrate and may include electrical interconnections between the structure region and the circuit region. The device includes a substrate and an isolation trench surrounding a structure region in the substrate. The isolation trench includes a lining of a dielectric insulative material. A plurality of microstructure elements are located in the structure region and are laterally anchored to the isolation trench.
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Citations
19 Claims
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1. A method of fabricating a microelectromechanical system, comprising:
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providing a substrate having a device layer including single-crystal silicon, a handle layer and a sacrificial layer between the device layer and the handle layer;
etching a first trench in the single-crystal silicon;
depositing a dielectric isolation layer in the first trench to form an isolation trench;
after depositing the dielectric isolation layer, etching a second trench in the single-crystal silicon, the second trench defining a microstructure including a plurality of elements laterally anchored to the isolation trench such that the isolation trench provides electrical isolation for the anchored elements of the microstructure from each other; and
removing a portion of the sacrificial layer, wherein the removed portion entirely undercuts the plurality of laterally anchored elements. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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Specification