Integrated circuit structure with a gap between resistor film and substrate
AssigneeNEC Corporation
InventorYasushi Kinoshita
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Abstract
An integrated circuit structure comprises a conductor film that serves as a passive element or an interconnection, and a silicon substrate. A cavity is disposed between the substrate and the conductor film and thus underneath the conductor film. The substrate is formed by forming an island of oxide film in a surface of the substrate, and then wet etching the island from the surface of the substrate thereby forming the cavity.
Claims23
A method of forming an integrated circuit structure, comprising the steps of:
- preparing a silicon substrate;
- forming an island of oxide film in a surface of said substrate;
- depositing a silicon nitride film on said island and an exposed portion of said surface of said substrate surrounding the island;
- removing said island to leave a cavity;
- and
- forming a resistor film so that an entirety of the resistor film is separated from the silicon substrate by said cavity.
A method of forming an integrated circuit structure, comprising the steps of:
- preparing a silicon substrate;
- forming an island of oxide film in a surface of said substrate;
- forming a silicon nitride film on said island and an exposed portion of said surface of said substrate surrounding the island;
- forming through said silicon nitride film at least one aperture opening to said island;
- removing said island with wet etch via said at least one aperture to leave a cavity;
- and
- forming a resistor film so that an entirety of the resistor film is separated from the silicon substrate by said cavity.
A method of forming an integrated circuit structure, comprising the steps of:
- preparing a silicon substrate;
- forming an island of oxide film in a surface of said substrate;
- forming a silicon nitride film on said island and an exposed portion of said surface of said substrate surrounding the island;
- forming through said silicon nitride film at least one aperture opening to said island;
- removing said island with wet etch via said at least one aperture to leave a cavity;
- filling each of said at least one aperture after removing said island;
- and
- forming resistor film so that an entirety of the resistor film is separated from the silicon substrate by said cavity.
A method of forming an integrated circuit structure, comprising the steps of:
- preparing a silicon substrate;
- forming an island of oxide film in a surface of said substrate;
- forming a silicon nitride film on said island and an exposed portion of said surface of said substrate surrounding the island;
- forming through said silicon nitride film at least one aperture that is disposed in the proximity of said island and opening to said island;
- removing said island with wet etch via said at least one aperture to leave a cavity;
- forming a diffused layer in the substrate in an area disposed underneath said aperture after the process step of removing said island;
- thermally oxidizing said diffused layer to cause growth of oxide into a cap covering said aperture;
- and
- forming a resistor film so that an entirety of the resistor film is separated from the silicon substrate by said cavity.
A method of forming an integrated circuit structure, comprising the steps of:
- preparing a silicon substrate;
- forming an island of oxide film in a surface of said substrate;
- forming a silicon nitride film on said island and an exposed portion of said surface of said substrate surrounding the island;
- forming through said silicon nitride film at least one aperture that is disposed in the proximity of said island and opening to said island;
- removing said island with wet etch via said at least one aperture to leave a cavity;
- forming a diffused layer at a portion disposed underneath said aperture after the process step of removing said island;
- thermally oxidizing said diffused layer to cause growth of oxide into a cap that covers said aperture;
- and
- forming a resistor film so that an entirety of the resistor film is separated from the silicon substrate by said cavity.
Dependencies are inferred from the claim text.