Process for producing surface micromechanical structures
US5683591A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 27, 1995 |
| Grant date | Nov 4, 1997 |
| Priority date | — |
| Expiry date | Nov 27, 2015 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB81C2201/0132
- WIPO fieldMicro-structural and nano-technology
- WIPO sectorChemistry
Abstract
A method for fabricating surface-micromechanical structures wherein a sacrificial layer, in particular of silicon oxide, is deposited on a silicon substrate represented by a silicon wafer, the sacrificial layer being patterned. Onto the sacrificial layer, a second layer, in particular of polysilicon, is deposited and is likewise patterned. The sacrificial layer is removed in an etching operation by means of an etching medium which attacks the sacrificial layer but not the second layer, structures being formed as a result of which are free-standing above the silicon substrate at a distance equal to the thickness of the removed sacrificial layer and are anchored at certain sites on the silicon substrate. According to the invention, for the purpose of etching and exposing, the micromechanical structures are exposed to the vapor phase of a mixture of anhydrous hydrofluoric acid and water in a vapor-phase etching process. This makes it possible to dispense with laborious rinsing operations and sublimation operations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.