Abstract: Humidity sensors may exhibit a relatively small amount of hysteresis and/or a faster response time. In some cases, a humidity sensor may include a polymeric humidity sensing layer disposed over an electrode layer. The polymeric humidity sensing layer may include a halogenated layer disposed over the polymeric humidity sensing layer. The polymeric humidity sensing layer may, for example, include a polyimide and the halogenated layer may include a monolayer or less than a monolayer of a halogenated material such as a fluorinated material.

Abstract: Humidity sensors may exhibit a relatively small amount of hysteresis and/or a faster response time. In some cases, a humidity sensor may include a polymeric humidity sensing layer disposed over an electrode layer. The polymeric humidity sensing layer may include a halogenated layer disposed over the polymeric humidity sensing layer. The polymeric humidity sensing layer may, for example, include a polyimide and the halogenated layer may include a monolayer or less than a monolayer of a halogenated material such as a fluorinated material.

Abstract: A humidity sensor may include a first substrate having a recess formed in a first side, a second substrate and an insulating layer supported by the second substrate. The second substrate and the insulating layer may be supported by the first side of the first substrate and extend over the recess to form a diaphragm with the insulating layer facing the recess. The diaphragm may be at least partially thermally isolated from a remainder of the second substrate. A resistive heater element may be supported by the diaphragm. A pair of sensing electrodes are electrically separated from each other and supported by the diaphragm. A sensing material is disposed over the pair of sensing electrodes, wherein an electrical property of the sensing material changes in response to a change in moisture content of the sensing material.

Abstract: A humidity sensor may include a first substrate having a recess formed in a first side, a second substrate and an insulating layer supported by the second substrate. The second substrate and the insulating layer may be supported by the first side of the first substrate and extend over the recess to form a diaphragm with the insulating layer facing the recess. The diaphragm may be at least partially thermally isolated from a remainder of the second substrate. A resistive heater element may be supported by the diaphragm. A pair of sensing electrodes are electrically separated from each other and supported by the diaphragm. A sensing material is disposed over the pair of sensing electrodes, wherein an electrical property of the sensing material changes in response to a change in moisture content of the sensing material.

Abstract: A sensor assembly includes a first wafer having a cavity formed therein and a second wafer bonded relative to the first wafer to form a diaphragm over the cavity. A trench is formed in the second wafer in or around the diaphragm and the trench may be filled with an isolating material to help thermally and/or electrically isolate the diaphragm. The diaphragm may support one or more sense elements. The sensor assembly may be used a flow sensor, a pressure sensor, a temperature sensor, and/or any other suitable sensor, as desired.

Abstract: A sensor assembly includes a first wafer having a cavity formed therein and a second wafer bonded relative to the first wafer to form a diaphragm over the cavity. A trench is formed in the second wafer in or around the diaphragm and the trench may be filled with an isolating material to help thermally and/or electrically isolate the diaphragm. The diaphragm may support one or more sense elements. The sensor assembly may be used a flow sensor, a pressure sensor, a temperature sensor, and/or any other suitable sensor, as desired.

Abstract: A corrosion resistant flow sensor apparatus includes a flow sensor including a micromachinable substrate mounted on a package substrate that includes electrically conductive traces and substrate bond pads. The flow sensor includes a MEMS sensing structure for sensing a mass flow parameter and sensor bond pads coupled to the sensing structure. The sensor bond pads include a top metal layer on a metal diffusion barrier layer including a metal diffusion barrier layer sidewall. Bond wires couple the sensor bond pads to the substrate bond pads. A housing including sides and a top portion is around the flow sensor and includes a flow channel having an inlet and an outlet. A multi-layer corrosion protection coating includes a nm scale adhesion layer and a self assembled monolayer (SAM) is on the adhesion layer. The protection coating covers the sensor bond pads including the metal diffusion barrier layer sidewall.

Abstract: A corrosion resistant flow sensor apparatus includes a flow sensor including a micromachinable substrate mounted on a package substrate that includes electrically conductive traces and substrate bond pads. The flow sensor includes a MEMS sensing structure for sensing a mass flow parameter and sensor bond pads coupled to the sensing structure. The sensor bond pads include a top metal layer on a metal diffusion barrier layer including a metal diffusion barrier layer sidewall. Bond wires couple the sensor bond pads to the substrate bond pads. A housing including sides and a top portion is around the flow sensor and includes a flow channel having an inlet and an outlet. A multi-layer corrosion protection coating includes a nm scale adhesion layer and a self assembled monolayer (SAM) is on the adhesion layer. The protection coating covers the sensor bond pads including the metal diffusion barrier layer sidewall.

Abstract: A corrosion resistant flow sensor apparatus includes a flow sensor including a micromachinable substrate mounted on a package substrate that includes electrically conductive traces and substrate bond pads. The flow sensor includes a MEMS sensing structure for sensing a mass flow parameter and sensor bond pads coupled to the sensing structure. The sensor bond pads include a top metal layer on a metal diffusion barrier layer including a metal diffusion barrier layer sidewall. Bond wires couple the sensor bond pads to the substrate bond pads. A housing including sides and a top portion is around the flow sensor and includes a flow channel having an inlet and an outlet. A multi-layer corrosion protection coating includes a nm scale adhesion layer and a self assembled monolayer (SAM) is on the adhesion layer. The protection coating covers the sensor bond pads including the metal diffusion barrier layer sidewall.

Abstract: A corrosion resistant flow sensor apparatus includes a flow sensor including a micromachinable substrate mounted on a package substrate that includes electrically conductive traces and substrate bond pads. The flow sensor includes a MEMS sensing structure for sensing a mass flow parameter and sensor bond pads coupled to the sensing structure. The sensor bond pads include a top metal layer on a metal diffusion barrier layer including a metal diffusion barrier layer sidewall. Bond wires couple the sensor bond pads to the substrate bond pads. A housing including sides and a top portion is around the flow sensor and includes a flow channel having an inlet and an outlet. A multi-layer corrosion protection coating includes a nm scale adhesion layer and a self assembled monolayer (SAM) is on the adhesion layer. The protection coating covers the sensor bond pads including the metal diffusion barrier layer sidewall.

Abstract: A thermal liquid flow sensor and method of forming same. The sensor has a substrate and one or more sensing elements, disposed on the substrate, for sensing a property of a liquid. The liquid flow sensor, which can be for example a microsensor having a microbrick® structure, has a hydrophilic layer which is disposed on the substrate and covers the sensing element(s). The hydrophilic layer is preferably formed from a spin on glass material, such as for example a silicate or phosphosilicate. A silicon nitride layer can be disposed on the sensing element(s) and interpose the substrate and the hydrophilic layer. The silicon nitride layer can be oxidized, for example, by means of plasma oxidation or oxygen ion implantation so to form the hydrophilic layer thereon. A variety of other hydrophilic compounds can be utilized to form the hydrophilic layer such as, gold, palladium and diamond like carbon.

Abstract: A flip-chip flow sensor has electrical components, such as temperature sensors and a heater, on the top of a substrate and has a channel formed in the bottom of the substrate. The channel is separated from the substrate's top by a membrane of substrate material. A fluid flowing through the channel is separated from a heater, upstream temperature sensor, downstream temperature sensor, bond pads, and wire bonds by the membrane. Heat flows through the membrane easily because the membrane is thin. As such, the electrical elements of the flow sensor, the bond pads and the wires are physically separated from a fluid flowing through the channel but can function properly because they are not thermally isolated.

Abstract: A method has been developed for the removal of silicon nitride and silicon dioxide, or other semiconductor materials from a surface of a wafer or CVD reactor. The method uses NF.sub.3, mixed with an electropositive diluent, preferably argon, at a given range of concentration, pressure, flowrate, and power to obtain the fastest possible etch rates. The etch rates of the film being processed can be caused to increase even as the concentration of NF.sub.3 in the diluent is decreased by choosing the proper diluent and operating conditions. Not only does this method increase the etch rate, thereby increasing the throughput of the reactor using this process, it also accomplishes this task at low concentrations of NF3 resulting in a lower cost.