초록 ▼

A method is disclosed for integrating one or more microelectromechanical (MEM) devices with electronic circuitry on a common substrate. The MEM device can be fabricated within a substrate cavity and encapsulated with a sacrificial material. This allows the MEM device to be annealed and the substrate

A method is disclosed for integrating one or more microelectromechanical (MEM) devices with electronic circuitry on a common substrate. The MEM device can be fabricated within a substrate cavity and encapsulated with a sacrificial material. This allows the MEM device to be annealed and the substrate planarized prior to forming electronic circuitry on the substrate using a series of standard processing steps. After fabrication of the electronic circuitry, the electronic circuitry can be protected by a two-ply protection layer of titanium nitride (TiN) and tungsten (W) during an etch release process whereby the MEM device is released for operation by etching away a portion of a sacrificial material (e.g. silicon dioxide or a silicate glass) that encapsulates the MEM device. The etch release process is preferably performed using a mixture of hydrofluoric acid (HF) and hydrochloric acid (HCI) which reduces the time for releasing the MEM device compared to use of a buffered oxide etchant. After release of the MEM device, the TiN:W protection layer can be removed with a peroxide-based etchant without damaging the electronic circuitry.

대표청구항 ▼

[ What is claimed is:] [1.] A method for integrating a microelectromechanical (MEM) device with electronic circuitry on a substrate comprising steps for:(a) etching a cavity within a first portion of the substrate;(b) fabricating the MEM device within the cavity, and filling the cavity with a sacrif

[ What is claimed is:] [1.] A method for integrating a microelectromechanical (MEM) device with electronic circuitry on a substrate comprising steps for:(a) etching a cavity within a first portion of the substrate;(b) fabricating the MEM device within the cavity, and filling the cavity with a sacrificial material;(c) fabricating the electronic circuitry comprising a plurality of transistors within a second portion of the substrate proximate to the first portion, and interconnecting the electronic circuitry to the MEM device;(d) protecting the electronic circuitry by depositing a layer of tungsten to blanket the second portion of the substrate and cover the electronic circuitry; and(e) releasing the MEM device for operation thereof by removing at least a portion of the sacrificial material filling the cavity by etching the sacrificial material with a first wet etchant which does not substantially remove the layer of tungsten protecting the electronic circuitry.