| 摘要 |
Semiconductor devices such as a MOGFET 300 with a movable gate membrane 306 are made by local oxidation of a substrate and oxide removal to form a depression in a mesa in the substrate surface. A second substrate is fusion bonded to the mesa and shaped to form a flexible membrane. 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 gates 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 sensor is also described. <IMAGE> |
