Method of fabricating an integrated CMOS-MEMS device

A method of fabricating a device, comprising:

• providing a substrate having a frontside and a backside;
• forming a movable element of a MEMS device on the frontside of the substrate;
• releasing the movable element;
• depositing a sacrificial layer on the frontside of the substrate, wherein the sacrificial layer surrounds the moveable element;
• attaching the frontside of the substrate to a handling wafer, wherein the attaching the frontside of the substrate includes providing a glue layer on the sacrificial layer;
• etching the backside of the substrate while the frontside of the substrate is attached to the handling wafer;
• and
• removing the handling wafer, glue layer, and the sacrificial layer from the substrate.

A method, comprising:

• providing a substrate including a frontside and a backside;
• forming a transistor on the frontside of the substrate;
• forming a MEMS structure on the frontside of the substrate;
• etching the frontside of the substrate to release the MEMS structure;
• forming a sacrificial layer on the frontside of the substrate, wherein the sacrificial layer is formed on the released MEMS structure and wherein the sacrificial layer includes an interface with the frontside of the substrate;
• planarizing the sacrificial layer to form a first surface;
• attaching the first surface to a handling wafer;
• etching the backside of the substrate to expose the sacrificial layer;
• and
• removing the sacrificial layer from the substrate.