Abstract:
A method of avoiding stiction during vapor hydrofluoride (VHF) release of a microelectromechanical system (MEMS) or nanoelectromechanical system (NEMS) composed of a mechanical device and a substrate is described. A silicon nitride layer is provided between the substrate and a sacrificial oxide layer and/or between a device layer and the sacrificial oxide layer, and/or on a side of the device layer facing away from the sacrificial oxide layer, and converted to thicker ammonium hexafluorosilicate with VHF while simultaneously removing a portion of the sacrificial oxide. The ammonium hexafluorosilicate acts as a temporary support, shim, wedge, or tether which limits device movement during fabrication and is later removed by sublimation under heat and/or reduced pressure.
Abstract:
A method of and apparatus for controlling pressure in a process chamber having a continuous gas inlet flow and a continuous gas outlet flow comprising providing a pulsed valve at a gas outlet, a pressure gauge, and a programmable controller and varying the pulse rate of the pulsed valve, wherein either the open time or closed time, or both open and closed times, is lengthened or shortened, depending on whether the gauge pressure is above or below the programmed setpoint.