MEMS integrated pressure sensor devices and methods of forming same

摘要

A method embodiment includes providing a micro-electromechanical (MEMS) wafer including a polysilicon layer having a first and a second portion. A carrier wafer is bonded to a first surface of the MEMS wafer. Bonding the carrier wafer creates a first cavity. A first surface of the first portion of the polysilicon layer is exposed to a pressure level of the first cavity. A cap wafer is bonded to a second surface of the MEMS wafer opposite the first surface of the MEMS wafer. The bonding the cap wafer creates a second cavity comprising the second portion of the polysilicon layer and a third cavity. A second surface of the first portion of the polysilicon layer is exposed to a pressure level of the third cavity. The first cavity or the third cavity is exposed to an ambient environment.

主权项

1. A micro-electromechanical (MEMS) device comprising:
a polysilicon layer, wherein the polysilicon layer includes:
a membrane for a first MEMS device, wherein a first surface of the membrane is exposed to a sealed pressure level of a first cavity; andan electrode for a second MEMS device; a MEMS substrate over the polysilicon layer, wherein the MEMS substrate comprises:
a first MEMS structure aligned with the membrane; anda second MEMS structure aligned with the electrode; a cap over the MEMS substrate, wherein the cap comprises a second cavity exposing a second surface of the membrane to an ambient environment; and a third cavity, wherein the electrode is exposed to a sealed pressure level of the third cavity, and wherein the second MEMS structure is disposed within the third cavity.