Fabrication of diaphragms and “floating” regions of single crystal semiconductor for MEMS devices
AssigneeJBCR Innovations, LLP
InventorRichard A. Blanchard
Life of this patent
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Abstract
A single crystal semiconductor region is fabricated in a semiconductor wafer. The region is either cantilevered, supported at one or both ends, or midpoint, or supported at multiple locations. After a pattern and etch step, a dielectric fill step is performed to define the boundaries of the region in the semiconductor wafer. Oxygen or nitrogen is implanted in the semiconductor wafer on a surface area of the semiconductor wafer that corresponds to a top surface of the region. The annealing of the oxygen or nitrogen ions convert the silicon to an oxide or a nitride beneath the surface area. The silicon dioxide or silicon nitride is etched away to produce a semiconducting region of a single crystal material.
Claims27
A method for fabricating a semiconductor single crystal structure, comprising the steps of:
- masking a first surface of a semiconductor wafer according to a predetermined shape to create an implant area on the first surface;
- implanting oxygen or nitrogen ions into the implant area;
- annealing the semiconductor wafer to create a temporary region of dielectric in the semiconductor area beneath the first surface;
- applying a masking layer and performing a trench etch above selected areas of the temporary region to at least the depth of the temporary region;
- and
- removing the temporary region to achieve the predetermined shape of the single crystal structure.
A method of fabricating a single crystal air bridge comprising the steps of:
- masking a first surface of a semiconductor wafer according to a predetermined shape to create an implant area on the first surface;
- implanting oxygen or nitrogen ions into the implant area;
- annealing the semiconductor wafer to create a temporary region of dielectric in an epitaxial region beneath the first surface;
- applying a masking layer and performing a trench etch above selected areas of the temporary region to at least the depth of the temporary region;
- and
- removing the temporary region to achieve the predetermined shape.
A method for fabricating a semiconductor region having a single crystal structure, comprising the steps of:
- depositing an epitaxial layer on a first surface of a semiconductor wafer;
- masking the first surface according to a predetermined shape to create an implant area;
- implanting oxygen or nitrogen ions into a the implant area;
- annealing the semiconductor wafer to create a temporary region in an epitaxial area beneath the first surface;
- applying a masking layer and performing a trench etch above selected areas of the temporary region to at least the depth of the temporary region;
- and removing the temporary region to create the predetermined shape having single crystal structure.
A method of fabricating an air bridge having a single crystal structure, comprising the steps of:
- applying a blocking layer to the first surface of a semiconductor wafer;
- masking the first surface according to a predetermined shape to create an implant area on the first surface;
- implanting oxygen or nitrogen ions into the implant area;
- annealing the semiconductor wafer to create a temporary region beneath the first surface;
- applying a masking layer and performing a trench etch above selected areas of the temporary region to at least the depth of the temporary region;
- and
- removing the temporary region to achieve the predetermined shape.
Dependencies are inferred from the claim text.