Semiconductor sensor with a fusion bonded flexible structure
US5578843A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 6, 1994 |
| Grant date | Nov 26, 1996 |
| Priority date | — |
| Expiry date | Oct 6, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01P2015/0828
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Fabrication of semiconductor devices with movable structures includes local oxidation of a wafer and oxide removal to form a depression in an elevated bonding surface. A second wafer is fusion bonded to the elevated bonding surface and shaped to form a flexible membrane. An alternative fabrication technique forms a spacer having a depression on a first wafer and active regions on a second wafer, and fusion bonds the wafers together with the depression over the active regions. Devices formed are integrable with standard MOS devices and include FETs, capacitors, and sensors with movable membranes. An FET sensor has gate and drain coupled together and a drain-source voltage which depends on the gate's deflection. Selected operating current, channel length, and channel width provide a drain-source voltage linearly related to gate deflection. Alternatively, two transistors subjected to the same gate deflection provide a differential voltage related to the square root of the deflection if channel currents or channel widths differ. Transistors subjected to the different gate deflections provide a differential signal that cancels effects that are independent of deflection. A capacitive sen…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.