Abstract:
An atomic force microscope (2) is comprised of a microactuator (14) for preventing the transfer of any net forces from the microactuator (14) to a support structure (22). The net force transfer prevention can be achieved using either a multi-actuator assembly (230) including a primary microactuator (234) and a counteracting actuator (236) operating substantially out-of-phase with respect to the primary microactuator (234), or a single microactuator (332) mounted on the microactuator's support structure (314) to prevent momentum transfer to the support structure (22) during microactuator (14) operation.
Abstract:
An AFM (10) that combines an AFM Z position actuator (16) and a self-actuated Z-position cantilever (20) (both operable in cyclical mode and contact mode), with appropriate nested feedback control circuitry to achieve high-speed imaging and accurate Z-position measurements. The self-actuated cantilever (20) includes a Z-positioning element (36) integrated therewith and an oscillator that oscillates the cantilever (20) at a resonant frequency and at an oscillation amplitude equal to a setpoint value. The AFM includes a first feedback circuit (12) nested within a second feedback circuit (14), wherein the first feedback circuit generates a cantilever control signal in response to vertical displacement of the self-actuated cantilever (20) during a scanning operation, and the second feedback circuit (14) is responsive to the cantilever control signal to generate a position control signal.
Abstract:
A method of and apparatus for producing improved real-time continual nanometer scale positioning data of the location of sensing probe used with one of a scanning tunneling microscope, an atomic force microscope, or a capacitive or magnetic field-sensing system, for measuring the probe distance and the position relative to an atomic surface or other periodically undulating surface such as a grating or the like moving relatively with respect to the probe, and between which and the surface there exists a sensing field, through rapid oscillating of the probe under the control of sinusoidal voltages, and comparison of the phase and/or amplitude of the output sinusoidal voltages produce by current in the sensing field to provide positional signals indicative of the direction and distance off the apex of the nearest atom or undulation of the surface; and, where desired, feeding back such positional signals to control the relative movement of the probe and surface; and wherein improved operation is achieved through one or all of eliminating errors caused by phase delays between the sinusoidal voltage driving the probe and its actual oscillation position, particularly when near the probe natural frequency, thereby providing for increased speed, frequency response and reliability; preventing the possible crashing of the probe into the surface and other probe-to-surface gap control problems; providing for absolute positioning; and providing for improved single and multi-probe micromachined probe design particularly of monolithic crystal wafer construction.
Abstract:
An electromechanical transducer is described with a moveable, flexible element (1-10) and an amplifier stage (3-7), wherein the amplifier stage is integrated into said element. The transducer further comprises piezoelectric materials (8) to generate a deflection depending signal as input signal of the amplifier stage (3-7). In a preferred embodiment, the flexible element comprises layers (1, 9) of material with different thermal expansion coefficient to enhance the sensitivity of the device as temperature sensor. The new device is applicable in local probe microscopy, such as atomic force microscopy, or as an actuator, as a (chemical) sensor, or as an oscillator.
Abstract:
An AFM (10) that combines an AFM Z position actuator (16) and a self-actuated Z-position cantilever (20) (both operable in cyclical mode and contact mode), with appropriate nested feedback control circuitry to achieve high-speed imaging and accurate Z-position measurements. The self-actuated cantilever (20) includes a Z-positioning element (36) integrated therewith and an oscillator that oscillates the cantilever (20) at a resonant frequency and at an oscillation amplitude equal to a setpoint value. The AFM includes a first feedback circuit (12) nested within a second feedback circuit (14), wherein the first feedback circuit generates a cantilever control signal in response to vertical displacement of the self-actuated cantilever (20) during a scanning operation, and the second feedback circuit (14) is responsive to the cantilever control signal to generate a position control signal.
Abstract:
An improvement to a phase controlled mechanical oscillator (111) consists of a balancing network (150) which generates a feedback signal from two different input signals with adjustable weights. One of these input signals is directly derived from the oscillator signal, the other is derived from a phase tracking loop (140). Using the balancing network, adjustments can be made to adapt the feedback to the mechanical properties, in particular to the Q factor, of the oscillator. In a preferred embodiment, all major components are working at an intermediate frequency level, generated by mixing the oscillator frequency with a reference frequency. As a major advantage of this (heterodyne) mixing, the bandwidth of any applied frequency detector can be narrowed, thus increasing the achievable signal-to-noise ratio.
Abstract:
A scanning probe microscope (100) has a probe (101) removably mounted in the head (108), using kinematic mounting techniques. A motorized, non-stacked x, y coarse movement stage (116) is kinematically positioned with respect to the base (114). A motorized z coarse movement stage (112) positions the head kinematically with respect to the base (114) and allows the height, tilt and pitch of the probe (101) to be adjusted. The scanner (118) includes x, y and z sample position detectors which provide an accurate measurement of the position of the sample with respect to the probe. The outputs of the x, y and z position detectors may also be connected in feedback loops with the controller (110) to improve the performance of the scanning probe microscope (100). An optical viewing assembly (124) provides combined coaxial and oblique views of the cantilever (102) and sample (104). A graphical user interface has simultaneous on-screen optical and scanning probe microscope views.
Abstract:
The present invention describes an apparatus for nanolithography and a process for thermally controlling the deposition of a solid organic "ink" from the tip of an atomic force microscope to a substrate. The invention may be used to turn deposition of the ink to the substrate on or off by either raising its temperature above or lowing its temperature below the ink's melting temperature. This process may be useful as it allows ink deposition to be turned on and off and the deposition rate to change without the tip breaking contact with the substrate. The same tip can then be used for imaging purposes without fear of contamination. This invention can allow ink to be deposited in a vacuum enclosure, and can also allow for greater spatial resolution as the inks used have lower surface mobilities once cooled than those used in other nanolithography methods.