Method of making a semiconductor transducer having multiple level diaphragm structure
First Claim
1. A method of fabricating a semiconductor transducer having a multiple level diaphragm structure comprising the steps ofproviding a semiconductor substrate,forming a first layer of selectively etchable material on a surface of said substrate,forming a second layer of a second material over said layer of selectively etchable material,forming openings through said second layer and exposing said selectively etchable material,forming additional selectively etchable material over limited positions of said first layer and in said openings as plugs having laterally extending portions,forming a third layer of a third material over said second layer and and said additional selectively etchable material,forming openings through said third layer and exposing said additional selectively etchable material, andapplying an etchant to remove said selectively etchable material thereby forming a multiple level diaphragm including said second and third layers of materials.
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Accused Products
Abstract
A semiconductor pressure transducer includes a silicon substrate, a recessed portion in a major surface of the substrate, and a multiple level diaphragm overlying the recessed portion. A selectively etchable spacer material is employed when fabricating the diaphragm by forming successive layers of diaphragm material over the spacer material. Holes through the diaphragm are filled with the selectively etchable material thereby allowing the etching of the spacer material. Support posts can be provided in the recessed portion to help support the diaphragm.
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Citations
22 Claims
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1. A method of fabricating a semiconductor transducer having a multiple level diaphragm structure comprising the steps of
providing a semiconductor substrate, forming a first layer of selectively etchable material on a surface of said substrate, forming a second layer of a second material over said layer of selectively etchable material, forming openings through said second layer and exposing said selectively etchable material, forming additional selectively etchable material over limited positions of said first layer and in said openings as plugs having laterally extending portions, forming a third layer of a third material over said second layer and and said additional selectively etchable material, forming openings through said third layer and exposing said additional selectively etchable material, and applying an etchant to remove said selectively etchable material thereby forming a multiple level diaphragm including said second and third layers of materials.
Specification