Method and structure of monolithically integrated absolute pressure sensor
First Claim
1. A method of fabricating an integrated pressure sensing device, the method comprising:
- providing a substrate member having a surface region;
forming a CMOS IC layer overlying the surface region, the CMOS IC layer having a CMOS surface region;
forming an oxide layer overlying the CMOS surface region, the oxide layer having an oxide surface region;
removing at least a portion of the oxide layer to form at least a first cavity region;
bonding a single crystalline silicon wafer overlying the oxide surface region to seal the first cavity region;
thinning the single crystalline silicon wafer to a desired thickness;
removing at least a portion of the single crystalline silicon wafer to form at least one connection path;
depositing a metal material within the at least one connection path to form at least one via structure; and
removing at least a second portion of the single crystalline silicon wafer to expose a cavity path coupled to the first cavity region, the removed second portion of the single crystalline silicon being outside the sealed first cavity region.
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Accused Products
Abstract
An integrated pressure sensing device and method of fabrication thereof are disclosed. The method can include providing a substrate member having a surface region and forming a CMOS IC layer overlying the substrate and forming an oxide layer overlying the CMOS IC layer. A portion of the oxide layer can be removed to form a cavity region. A single crystalline silicon wafer can be bonded overlying the oxide surface region to seal the cavity region. The bonding process can include a fusion bonding or eutectic bonding process. The wafer can be thinned to a desired thickness and portions can be removed and filled with metal materials to form via structures. A pressure sensor device can be formed from the wafer, and can be co-fabricated with another sensor from the wafer. The pressure sensor and the other sensor can share a cavity pressure or have separate cavity pressures.
22 Citations
22 Claims
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1. A method of fabricating an integrated pressure sensing device, the method comprising:
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providing a substrate member having a surface region; forming a CMOS IC layer overlying the surface region, the CMOS IC layer having a CMOS surface region; forming an oxide layer overlying the CMOS surface region, the oxide layer having an oxide surface region; removing at least a portion of the oxide layer to form at least a first cavity region; bonding a single crystalline silicon wafer overlying the oxide surface region to seal the first cavity region; thinning the single crystalline silicon wafer to a desired thickness; removing at least a portion of the single crystalline silicon wafer to form at least one connection path; depositing a metal material within the at least one connection path to form at least one via structure; and removing at least a second portion of the single crystalline silicon wafer to expose a cavity path coupled to the first cavity region, the removed second portion of the single crystalline silicon being outside the sealed first cavity region. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method of fabricating an integrated pressure sensing device, the method comprising:
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providing a substrate member having a surface region; forming a CMOS IC layer overlying the surface region, the CMOS IC layer having a CMOS surface region; forming an oxide layer overlying the CMOS surface region, the oxide layer having an oxide surface region; removing at least a portion of the oxide layer to form at least a cavity region; bonding a single crystalline silicon wafer overlaying the oxide surface region to seal the cavity region; thinning the single crystalline silicon wafer to a desired thickness; removing at least a portion of the single crystalline silicon wafer to form at least one connection path; depositing a metal material within the at least one connection path to form at least one via structure; and removing at least a portion of the single crystalline silicon wafer to form a cavity path coupled to the cavity region; the method-further comprising; a first ion implantation process to form a heavily p-type doped region within a first portion of the single crystalline silicon wafer; and a second ion implantation process to form a heavily p-type doped region within a second portion of the signal crystalline silicon wafer.
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14. A method of fabricating an integrated pressure sensing device, the method comprising:
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providing a substrate member having a surface region; forming a CMOS IC layer overlying the surface region, the CMOS IC layer having a CMOS surface region, the CMOS region includes a top metal layer; forming an oxide layer overlying the CMOS surface region, the oxide layer having an oxide surface region; removing at least a portion of the oxide layer to form at least a first cavity region, the first cavity region in the oxide layer being disposed over a region of the top metal layer; bonding a single crystalline silicon wafer overlying the oxide surface region to seal the first cavity region; thinning the single crystalline silicon wafer to a desired thickness; removing at least a portion of the single crystalline silicon wafer to form at least one connection path; depositing a metal material within the at least one connection path to form at least one via structure; and removing a second portion of the oxide layer to form a second cavity region and a path connecting the first cavity region and the second cavity region, the second cavity region being outside the sealed first cavity region. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22)
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Specification