Method and structure of monolithically integrated absolute pressure sensor

摘要

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.

主权项

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.