Microelectronic mechanical system and methods
US6991953B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 2002 |
| Grant date | Jan 31, 2006 |
| Priority date | — |
| Expiry date | Oct 5, 2022 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB81C2203/0735
- WIPO fieldMicro-structural and nano-technology
- WIPO sectorChemistry
Abstract
The current invention provides for encapsulated release structures, intermediates thereof and methods for their fabrication. A multi-layer structure has a capping layer, that preferably comprises silicon oxide and/or silicon nitride, and which is formed over an etch resistant substrate. A patterned device layer, preferably comprising silicon nitride, is embedded in a sacrificial material, preferably comprising poly-silicon, and is disposed between the etch resistant substrate and the capping layer. Access trenches or holes are formed in to capping layer and the sacrificial material is selectively etched through the access trenches, such that portions of the device layer are release from sacrificial material. The etchant preferably comprises a noble gas fluoride NGF2x, (wherein NG=Xe, Kr or Ar: and where x=1, 2 or 3). After etching that sacrificial material, the access trenches are sealed to encapsulate released portions the device layer between the etch resistant substrate and the capping layer. The current invention is particularly useful for fabricating MEMS devices, multiple cavity devices and devices with multiple release features.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.