Abstract: A novel operation regime for capacitive micromachined ultrasonic transducers (cMUTs). The collapse-snapback operation in which the center of the membrane makes intermittent contact with the substrate. This combines two distinct states of the membrane (in-collapse and out-of-collapse) to unleash unprecedented acoustic output pressures into the medium. The collapse-snapback operation utilizes a larger range of membrane defection profiles (both collapsed and released membrane profiles) and generates higher acoustic output pressures than the conventional operation. Collapse-snapback operation meets the extreme acoustic transmit pressure demands of the ultrasonic industry.

Abstract: There is described a micromachined ultrasonic transducers (MUTS) and a method of fabrication. The membranes of the transducers are fusion bonded to cavities to form cells. The membranes are formed on a wafer of sacrificial material. This permits handling for fusions bonding. The sacrificial material is then removed to leave the membrane. Membranes of silicon, silicon nitride, etc. can be formed on the sacrificial material. Also described are cMUTs, pMUTs and mMUTs.

Abstract: The present invention provides fluidic devices and systems which have micromachined ultrasonic transducers integrated into microchannels. The ultrasonic transducers generate and receive ultrasonic waves. The transducers can be disposed and operated to measure fluid characteristics such as pressure, density, viscosity, flow rate and can also be used to mix and pump fluids.

Abstract: A wafer with through wafer interconnects. The wafer includes spaced through wafer vias which extend between the back side and front side of the wafer. A conductor within each of said vias connects to front and back side pads. Functions associated with said conductor and said pads provide a depletion region in the wafer between the pads and wafer or pads and conductor and the wafer.

Abstract: There is described a method and apparatus for measuring temperature of a fluid in a microchannel of the type having spaced walls. An ultrasonic transducer transmits ultrasonic waves transmitted from one wall to the opposite wall. A processor determines the time-of-flight of the ultrasonic waves from the one wall and reflected to the opposite wall to the one wall. The processor converts the time-of-flight to velocity by dividing the distance between walls by the time-of-flight. The processor converts velocity to temperature from the relationship of velocity to temperature in the fluid.

Abstract: A wafer with through wafer interconnects. The wafer includes spaced through wafer vias which extend between the back side and front side of the wafer. A conductor within each of said vias connects to front and back side pads. Functions associated with said conductor and said pads provide a depletion region in the wafer between the pads and wafer or pads and conductor and the wafer.

Abstract: There is described a micromachined ultrasonic transducers (MUTS) and a method of fabrication. The membranes of the transducers are fusion bonded to cavities to form cells. The membranes are formed on a wafer of sacrificial material. This permits handling for fusions bonding. The sacrificial material is then removed to leave the membrane. Membranes of silicon, silicon nitride, etc. can be formed on the sacrificial material. Also described are cMUTs, pMUTs and mMUTs.

Abstract: There is described a method and apparatus for measuring temperature of a fluid in a microchannel of the type having spaced walls. An ultrasonic transducer transmits ultrasonic waves transmitted from one wall to the opposite wall. A processor determines the time-of-flight of the ultrasonic waves from the one wall and reflected to the opposite wall to the one wall. The processor converts the time-of-flight to velocity by dividing the distance between walls by the time-of-flight. The processor converts velocity to temperature from the relationship of velocity to temperature in the fluid.

Abstract: A two-dimensional sensor array for high throughput screening of fluids in micro-machined fluid arrays is provided. The sensor array includes a two-dimensional array of piezoelectric transducers which are in contact with the back-side of the micro-machined fluid array which is opposite from the fluid positions. A means is provided to generate and detect shear or longitudinal ultrasonic waves in a time-multiplexed manner whereby the waves could propagate in either a pulse or continuous mode. A means to determine fluid parameters based on the shear and longitudinal ultrasonic waves is also provided. Furthermore, a fluid dispense system could be included which is then controlled based on the determined fluid parameters and a feedback control system. The two-dimensional micro-sensor array is compatible with and based on miniaturization technologies for high-throughput biology, such as micro-fluidics, detection, sample handling, and bioassay technology amenable to high-density formats.

Abstract: A wide frequency band micromachined microphone including a plurality of micromachined cells of the type including electrodes carried by a membrane supported above a common electrode with conductive lines interconnecting the electrodes is described. A method of operating a microphone array is also described.

Abstract: A droplet ejector including a cylindrical reservoir closed at one end with an elastic membrane including at least one aperture. A bulk actuator at the other end for actuating the fluid for ejection through the aperture. Also disclosed is a micromachined two-dimensional array droplet ejector. The ejector includes a two-dimensional array of elastic membranes having orifices closing the ends of cylindrical fluid reservoirs. The fluid in the ejectors is bulk actuated to set up pressure waves in the fluid which cause fluid to form a meniscus at each orifice. Selective actuation of the membranes ejects droplets. In an alternative mode of operation, the bulk pressure wave has sufficient amplitude to eject droplets while the individual membranes are actuated to selectively prevent ejection of droplets.

Abstract: There is described a cMUT array with transducer elements which include a plurality of cells with membranes formed on one surface of a wafer. Voltages applied between said spaced electrodes drive said membranes. The voltages applied to said electrodes are applied from the opposite surface of the wafer through the wafer and through vias formed in the wafer.

Abstract: An r.f. probed strain gauge is described. The strain gauge is in the form of an r.f. transmission line where electrical characteristics (r.f. impedance and propagation contrast) vary with strain in the element or structure whose strain is being measured.

Abstract: The present invention provides fluidic devices and systems which have micromachined ultrasonic transducers integrated into microchannels. The ultrasonic transducers generate and receive ultrasonic waves. The transducers can be disposed and operated to measure fluid characteristics such as pressure, density, viscosity, flow rate and can also be used to mix and pump fluids.

Abstract: A wide frequency band micromachined microphone including a plurality of micromachined cells of the type including electrodes carried by a membrane supported above a common electrode with conductive lines interconnecting the electrodes is described. A method of operating a microphone array is also described.

Abstract: A droplet ejector including a cylindrical reservoir closed at one end with an elastic membrane including at least one aperture. A bulk actuator at the other end for actuating the fluid for ejection through the aperture.

Abstract: There is described a capacitive micromachined ultrasonic transducer array which is configured to minimize the excitation and propagation of plate waves traveling in the substrate and ultrasonic waves propagating at the interface between the array surface and the immersion fluid.

Abstract: There is provided a monitor and method for monitoring the condition of a photoresist film on a wafer in which the phase of high frequency ultrasonic pulses reflected from the wafer/photoresist interface provides an indication of the condition of the photoresist film.

Abstract: An apparatus and method are disclosed for characterizing semiconductor wafers or other test objects that can support acoustic waves. Source and receiving transducers are configured in various arrangements to respectively excite and detect acoustic waves (e.g., Lamb waves) in a wafer to be characterized. Signals representing the detected waves are digitally processed and used to compute a measurement set correlated with the waves' velocity in the wafer. A characterization sensitivity is provided that describes how different wafer characteristics of interest vary with changes in the propagation of the acoustic waves. Using the characterization sensitivity and measurement sets computed at a setup time when all wafer characteristics are known and one or more process times when at least one of the characteristics is not known the perturbation in wafer characteristics between the setup and the process times can be determined.

Abstract: A system is disclosed that employs ultrasonic waves to perform in-situ measurements to determine the properties of films deposited on substrates in the course of various semiconductor or processing steps. In one embodiment a single transducer excites incident acoustic waves at multiple frequencies that reflect from the films. The reflected waves are received by the same transducer. An analysis system determines the phase shift of the received reflected waves and, based on the phase shift, determines the film properties. Other embodiments employ distinct source and receiving transducers. Embodiments are also disclosed that compensate the measured phase shift for temperature variations in the substrate. In one such system, temperature compensation is performed based on the processing of phase measurements made at multiple frequencies or incidence angles or with multiple ultrasonic modes. The disclosed techniques are equally applicable to determining the degree of erosion of chamber members.