A device for measuring pressure includes a curved microbeam having opposing ends, a length extending between the pair of opposing ends, and a plurality of resonant frequencies, an actuating electrode extending along the length of the curved microbeam and spaced from the curved microbeam, an AC power source in communication with one of the opposing ends and the actuating electrode to deliver an AC signal at a first symmetric resonant frequency and a second symmetric resonant frequency selected from the plurality of resonant frequencies to the curved microbeam, a DC power source in communication with the opposing ends to pass an electrothermal voltage along a length of the curved microbeam, and a frequency monitoring device to monitor changes in the first symmetric resonant frequency and the second symmetric resonant frequency caused by an ambient pressure surrounding the curved microbeam.

A device for measuring pressure includes a curved microbeam having opposing ends, a length extending between the pair of opposing ends, and a plurality of resonant frequencies, an actuating electrode extending along the length of the curved microbeam and spaced from the curved microbeam, an AC power source in communication with one of the opposing ends and the actuating electrode to deliver an AC signal at a first symmetric resonant frequency and a second symmetric resonant frequency selected from the plurality of resonant frequencies to the curved microbeam, a DC power source in communication with the opposing ends to pass an electrothermal voltage along a length of the curved microbeam, and a frequency monitoring device to monitor changes in the first symmetric resonant frequency and the second symmetric resonant frequency caused by an ambient pressure surrounding the curved microbeam.

A lithography apparatus is disclosed, which comprises a mirror having at least two mirror segments which are joined together in such a way that an interspace is formed between the mirror segments, and a sensor for detecting the relative position of the mirror segments, wherein the sensor is arranged in the interspace between the mirror segments.

A lithography apparatus is disclosed, which comprises a mirror having at least two mirror segments which are joined together in such a way that an interspace is formed between the mirror segments, and a sensor for detecting the relative position of the mirror segments, wherein the sensor is arranged in the interspace between the mirror segments.

A device for measuring pressure includes a curved microbeam having opposing ends, a length extending between the pair of opposing ends, and a plurality of resonant frequencies, an actuating electrode extending along the length of the curved microbeam and spaced from the curved microbeam, an AC power source in communication with one of the opposing ends and the actuating electrode to deliver an AC signal at a first symmetric resonant frequency and a second symmetric resonant frequency selected from the plurality of resonant frequencies to the curved microbeam, a DC power source in communication with the opposing ends to pass an electrothermal voltage along a length of the curved microbeam, and a frequency monitoring device to monitor changes in the first symmetric resonant frequency and the second symmetric resonant frequency caused by an ambient pressure surrounding the curved microbeam.

An electromechanical pressure sensor includes an electromechanical resonator having a driving electrode, a sensing electrode, and a beam resonator arranged between the driving and sensing electrodes. The beam resonator includes a resonator beam coupled on a first end to a first fixed anchor and coupled on a second end to a fixed second fixed anchor. The electromechanical resonator also includes a first voltage source coupled to the driving electrode and configured to provide an alternating current to the driving electrode and a second voltage source coupled to the first fixed anchor. The second voltage source provides a DC bias to the resonator beam. The electromechanical resonator further includes a third voltage source coupled to the resonator beam via the first and second fixed anchors. The third voltage source is configured to supply a voltage to the resonator beam that results in a temperature differential between the resonator beam and the first and second fixed anchors. The electromechanical resonator also includes a processor coupled to the sensing electrode and configured to correlate a voltage on the sensing electrode with a pressure value.

An optomechanical pressure-measurement system measures pressure in the range of 10.sup.−6 Pa-10.sup.−2 Pa by measuring various properties of a vibrational mode of an ultra-thin membrane member. With independent measurements of the thickness and density of the membrane, in addition to the measured vibration mode properties, the system can operate as a primary pressure sensor. The membrane member is mounted on a vibration-isolated mount and is excited by a drive force. A laser beam impinges on the excited membrane, and an optical phase detector detects the amplitude of the oscillations, as well as parameters of the laser beam affected by the membrane vibration. In one embodiment, a mechanical damping is computed based on the amplitude or frequency shift (depending on the pressure range), and the pressure based on the ring-down time of the membrane vibration mode.

An electromechanical pressure sensor includes an electromechanical resonator having a driving electrode, a sensing electrode, and a beam resonator arranged between the driving and sensing electrodes. The beam resonator includes a resonator beam coupled on a first end to a first fixed anchor and coupled on a second end to a fixed second fixed anchor. The electromechanical resonator also includes a first voltage source coupled to the driving electrode and configured to provide an alternating current to the driving electrode and a second voltage source coupled to the first fixed anchor. The second voltage source provides a DC bias to the resonator beam. The electromechanical resonator further includes a third voltage source coupled to the resonator beam via the first and second fixed anchors. The third voltage source is configured to supply a voltage to the resonator beam that results in a temperature differential between the resonator beam and the first and second fixed anchors. The electromechanical resonator also includes a processor coupled to the sensing electrode and configured to correlate a voltage on the sensing electrode with a pressure value.

In order to provide a vacuum monitor that, even if a sensing mechanism is exposed to an atmosphere into which various types of material gases are introduced, enables the deposition of matter on the sensing mechanism to be prevented, and enables the lifespan of the sensing mechanism to be extended, there are provided a sensing mechanism that is in contact with an atmosphere inside a measurement space, and outputs an output signal that corresponds to a pressure inside this measurement space, and a heater that adjusts a temperature of the sensing mechanism, wherein a set temperature of the heater is adjustable.

A vacuum apparatus includes a vacuum chamber, first sensor units disposed in the vacuum chamber facing a deposition direction of particles, and second sensor units disposed in the vacuum chamber, each disposed on a corresponding first sensor of the first sensor units facing the deposition direction, wherein the first sensor units are configured to sense a pressure in the vacuum chamber and an absorption amount of the particles adsorbed to the first sensor units, and the second sensor units are configured to sense the pressure in the vacuum chamber.