Method for integrating microelectromechanical devices with electronic circuitry
US5963788A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 19, 1997 |
| Grant date | Oct 5, 1999 |
| Priority date | — |
| Expiry date | Nov 19, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S148/105
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.