Method for making diaphragm-based sensors and apparatus constructed therewith
AssigneeHoneywell Inc.
InventorsG. Benjamin Hocker, David W. Burns, Akintunde I. Akinwande, Robert D. Horning, Amir R. Mirza, Thomas G. Stratton, Deidrich J. Saathoff, James K. Carney, Scott A. McPherson
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Abstract
This patent relates to the fabrication of diaphragm-based microstructures used primarily for sensing physical phenomena by detecting a change in deflection, resonance, or curvature of the diaphragm. The methods of fabrication described and claimed herein relate primarily to diaphragm-based diaphragms made of silicon, either single crystal or polycrystalline in form, although other materials may be used.
Claims38
A method for producing diaphragm-containing microstructures comprising the steps of:
- a. creating a cavity in a 1st surface of a 1st semiconductor wafer,
- b. substantially backfilling the cavity with a solid material that is removable without damage to the wafer through an etching process,
- c. bonding a 1st surface of a 2nd semiconductor wafer to the 1st surface of the 1st wafer,
- d. creating an access passage through 1st wafer to the cavity, and
- e. removing the solid material through the access passage by the etching process.
A process for removing a projecting oxidation ridge formation caused by the upgrowth of oxide when oxidizing a surface of a semiconductor wafer, said ridge formation occurring at the periphery of a cavity in said surface, said process further comprising the step of:
- patterning to expose a portion of a surface of said wafer surface including off of at least one oxidation ridge formation
- etching said exposed portion of the surface of said wafer until said at least one oxidation ridge formation is removed.
A method for producing diaphragm-containing microstructures comprising the steps of:
- a. creating a cavity in a 1st surface of a 1st silicon wafer,
- b. bonding a 1st surface of a 2nd silicon wafer to the 1st surface of the 1st wafer,
- c. creating an access passage through said 1st wafer to said cavity,
- d. growing silicon dioxide to substantially fill the cavity,
- e. reducing the 2nd wafer in thickness to form a deformable diaphragm region over the cavity, and
- f. removing the silicon dioxide from the cavity through the access passage by etching means.
A method for producing diaphragm-containing microstructures comprising the steps of:
- a. creating a 1st cavity in a 1st surface of a 1st semiconductor wafer, then,
- b. substantially backfilling the cavity with material which is removable without damage to the wafer through an etching process, then,
- c. bonding a 1st surface of a 2nd semiconductor wafer to the 1st surface of the 1st wafer, then,
- d. reducing the 2nd wafer in thickness, thereby forming a deformable diaphragm region over the cavity and exposing a 2nd surface of the 2nd wafer, and, prior to step i,
- e. creating an access passage through the 1st wafer to the cavity,
- f. forming in the 2nd surface of the 2nd wafer at least one electrical sensor element disposed above the cavity, and forming at least one electrical conducting element electrically coupled to said electrical sensor element,
- g. creating a 2nd cavity in a 1st surface of a 3rd wafer,
- h. bonding the 1st surface of the 3rd wafer to the 2nd surface of the 2nd wafer such that the 1st and 2nd cavities are aligned substantially opposite to each other on 1st and 2nd sides of the deformable diaphragm region, respectively, and
- i. removing the material through the access passage by etching means.
A method for producing diaphragm-containing microstructures comprising the steps of:
- a. creating a cavity in a 1st surface of a 1st semiconductor wafer,
- b. substantially backfilling the cavity with material which is removable without damage to the wafer through an etching process,
- c. bonding a 2nd semiconductor wafer to the 1st surface of the 1st wafer,
- d. creating an access passage through the 2nd wafer to the cavity, and
- e. removing the material from the cavity through the access passage by etching means.
A method for producing diaphragm-containing microstructures comprising the steps of:
- a. creating a 1st cavity in a 1st surface of a 1st semiconductor wafer,
- b. substantially filling the cavity with a material which is removable without damage to the wafer through etching means,
- c. bonding a 2nd semiconductor wafer to the 1st surface of the 1st wafer,
- d. reducing the 1st wafer in thickness to form a deformable diaphragm region over the cavity and exposing a 2nd surface of the 1st wafer,
- e. creating an access passage through 2nd wafer to the cavity,
- f. forming in the 2nd surface of the 1st wafer at least one electrical sensor element disposed above the cavity, and forming at least one electrical conducting element associated with said at least one electrical sensor element,
- g. creating a 2nd cavity in a 1st surface of a 3rd wafer,
- h. bonding the 1st surface of the 3rd wafer to the 2nd surface of the 1st wafer such that the 1st and 2nd cavities are aligned substantially opposite to each other on 1st and 2nd sides of the deformable diaphragm region, respectively, and
- i. removing the material from the cavity through the access passage by etching means.
Dependencies are inferred from the claim text.