Abstract: A recognition force microscope for detecting interactions between a probe and a sensed agent on a scanned surface and methods for its operation are provided. The microscope includes a scanning probe having a tip that is sensitive to a property of the scanned surface, and the probe is adapted to oscillate with a low mechanical Q factor. Operation of the microscope includes recording the displacement of the probe tip as a function of time and simultaneously recording both topographic images and the spatial location of interactions between said probe and one or more sensed agents on the surface.

Abstract: A pendulum scanner that utilizes a rocking motion to scan across a sample surface is provided. The scanner is present as a component in a scanning probe microscope that includes a microscope base, an optical stage, and a sample stage. The optical stage includes a source of a collimated beam of light, at least one beam tracking element, and a first scanning element for generating movement of the optical stage in a first plane. The microscope also includes a cantilever probe having a light-reflective surface. A second scanning element is provided for generating movement of the optical stage in a second plane that is orthogonal to the first plane. A position sensitive detector is also provided and is adapted to receive a beam of light reflected from the surface of the cantilever probe and to produce a signal that is indicative of the angular movement of the reflected beam of light.

Abstract: A combined scanning probe and optical microscope is provided. The microscope comprises a sample stage, a scanning probe microscope, an optical microscope, a microscope coupling, and a sample stage support. The microscope coupling, the sample stage, and the sample stage support are arranged to inhibit relative motion between the sample stage and the scanning probe microscope in the event of simultaneous low frequency vibrations in the optical microscope and high frequency vibrations in the scanning probe microscope. In accordance with other embodiments of the present invention scanning probe microscopes are provided comprising a slide-mounted stage assembly, a solenoid unit positioned above the cantilever unit of the probe, and a specialized solenoid driven cantilever assembly.

Abstract: A scanning probe microscope is provided for measuring at least one characteristic of a surface, the microscope including a force sensing probe which is responsive to the at least one characteristic of the surface, an oscillator which moves the position of the probe relative to the surface, a voltage source for establishing an electrical potential between the force sensing probe and the surface, and a detector which detects the oscillating component of the electrical current flow into or out of the probe as a measure of the at least one characteristic of the surface. The microscope can be operated to simultaneously acquire both electrical and topographical information from a surface of a substrate.

Abstract: A scanning probe microscope for generating a signal corresponding to the surface characteristics of a scanned sample is provided and includes a force sensing probe tip disposed on a first side of a free end of a flexible cantilever which is adapted to be brought into close proximity to a sample surface; a magnetized material disposed on a second side opposite the first side of the flexible cantilever; an XY scanner for generating relative scanning movement between the force sensing probe tip and the sample surface; a Z control for adjusting the distance between the force sensing probe tip and the sample surface; and a deflection detector for generating a deflection signal indicative of deflection of the flexible cantilever. The scanning probe microscope also includes an ac signal source and a magnetic field generator for generating a magnetic field, with the magnetic field generator being coupled to the ac signal source so as to modulate the magnetic field with the ac signal.

Abstract: Force sensing probes for use in scanning probe microscopes and a method for coating such probes with a film comprising a magnetostrictive material are provided. The probes may be magnetized by placing them in a magnetic field which can be oriented in any direction with respect to the probes. The magnetostrictive effect leads to a compression or expansion of the magnetic film, altering its length by the strength of the applied field. This in turn causes the probe, which in a preferred embodiment is in the form of a cantilever, and the applied magnetic film, to deflect or bend. The consequent motion of the probe is much greater than that obtained by direct application of a magnetic force and the effect is not sensitive to the direction of the applied field.

Abstract: A scanning probe microscope for measuring the characteristics of a surface of a sample is provided and includes a probe for scanning the surface of a sample to be measured and a sample stage which is adapted to position a sample in the microscope. In a preferred embodiment, the microscope is a conducting atomic force microscope. The microscope also includes a source of voltage in communication with the probe and the sample and a detector for measuring the electrical current to or from the probe and the sample. The probe and the sample are positioned within an enclosure which isolates the probe and the sample from the ambient environment, and the enclosure includes a gas inlet and a gas outlet for controlling the environment in the enclosure to maintain the atmosphere in the enclosure at approximately atmospheric pressure.

Abstract: A tip coating system for use with scanning tunneling microscope (STM) tips. The tip coating system includes a tip holder, a plate having a slot for receiving the tip and for holding a coating material, a heater for heating the coating material into a molten blob, a micropositioner for displacing the plate to and from the tip and for moving the tip within the slot so that selected portions of the tip contact the molten blob of coating material. The tip coating system is preferably controlled by electronic controllers, including a temperature controller for the heater. The tip coating system is used to insulate the tips with soft polymer coating material to ensure very low tip leakage current (on the order of about 1 pA typical).

Abstract: An atomic force microscope and method of operation are provided and include a force sensing probe tip adapted to be brought into close proximity with a sample surface, a scanning element for generating relative movement between the probe tip and the sample surface, a device for generating a magnetic field to cause deflection of the probe tip, a driver for the device, the driver including a source of alternating current and a source of a second current of a controlled magnitude, and a detector for detecting the position of the probe tip. In a preferred mode of operation, two signals, one of alternating current and the other of a fixed, but variable, current, are applied to cause a displacement of the time-average position of the probe tip.

Abstract: A force sensing cantilever for use in a scanning probe microscope has both a top side and a bottom side. From the bottom side extends a probe tip. The bottom side is coated with a thin film of a first material and the top side is coated with a thin film of a second material. The first and second materials may be the same or they may be different. The materials and thicknesses of the respective films are selected so as to create opposing forces to counter the tendency of such cantilevers to bend when a thin film is applied to only one side thereof.

Abstract: A heater for use in heating a sample stage of a microscope such as a scanning probe microscope is bonded to a sample stage which sits on a tube of a ceramic thermal insulator which is, in turn, mounted within or part of a tube of the same material. This re-entrant design provides an increased thermal path over straight line distances between the heater and the support structure for the sample stage and thus provides excellent thermal insulation, while also maximizing the thermal stability of the system.

Abstract: A scanning probe microscope controller includes a digital signal processor (DSP) and an analog feedback control loop. The DSP serves to process the output of the scanning probe in the digital realm after conversion of the signal to digital form. After processing, the signal is restored to analog form. The height correction signal to be applied to a transducer controlling the distance between the scanning probe and a sample surface is then generated by an analog feedback control circuit, at least one parameter of which is under computer control. At the end of each scan-line, a variance may be calculated for the data and the inverse of this quantity is used to adjust the gain with which digitization of the data is carried out. Linearization of the data to correct for non-linearities in the scanning transducers may be carried out by the DSP after the data is acquired. This permits the scanning ramps applied to the transducers to be linear but the final displayed data do not show the effects of non-linearities.

Abstract: Features for incorporation with scanning probe microscopes are provided which may be used separately or together. The features include constructing the microscope with a hinged top housing providing easy access to the heart of the microscope; a self-aligning and torque limiting magnetic clutch coupling a motor drive powering at least one vertical adjustment screw of the microscope; a removable microscope head for easy adjustment; an optical microscope, optionally mounted to an electronic camera and imaging system, installed adjacent to the head; operation on an inverted microscope stage; bowing error correction; a gas sparging system providing contaminant and noise reduction; a glove box type of loading system so that reactive materials may be safely loaded into the microscope; and a compact desk-top chamber which provides acoustic and vibration isolation.

Abstract: In accordance with a first aspect of the present invention, the sensitivity of a magnetically modulated AC-AFM is substantially improved by the use of a ferrite-core solenoid for modulating the magnetic cantilever of the ACAFM. In accordance with a second aspect of the present invention, the detection system for a magnetically modulated AC-AFM incorporates AC coupling of the signal from the position sensitive detector/beam deflection detector in order to remove the DC component of the signal, resulting in significantly improved dynamic range over systems utilizing DC coupling. High frequency modulation signals are detected through the use of fast analog multipliers which, after active filtering, give a low frequency signal which may be processed by digital electronics. In accordance with a third aspect of the present invention, operation of the microscope at small amplitudes of oscillation leaves small asperities on the tip intact and results in dramatic improvement in resolution.

Abstract: A microscope suitable for use in atomic force microscopy and scanning tunneling microscopy includes an electrochemical liquid cell. Vertically adjustable supporting mounts extend downwardly from a frame and include magnetic balls to which a sample platform may be attached. At least two adjustment pegs extend downwards from the frame and engage the platform for horizontal adjustment at apertures therethrough. The pegs may be moved out of engagement with the platform to reduce drift. An electrical sensor provides a signal to indicate whether the pegs are in contact with the platform. A bore in the frame is provided through which the chosen scanning head may be inserted so as to engage a sample on the platform. A hermetically sealed chamber may be formed around the sample by a seal between the scanner of the microscope and the frame as well as an enclosure which fits over the bottom of the microscope and engages the frame at an O-ring seal. Scanning heads may be rotated for adjustment.

Abstract: Features for incorporation with scanning probe microscopes are provided which may be used separately or together. The features include constructing the microscope with a hinged top housing providing easy access to the heart of the microscope; a self-aligning and torque limiting magnetic clutch coupling a motor drive powering at least one vertical adjustment screw of the microscope; a removable microscope head for easy adjustment; an optical microscope, optionally mounted to an electronic camera and imaging system, installed adjacent to the head; operation on an inverted microscope stage; bowing error correction; a gas sparging system providing contaminant and noise reduction; a glove box type of loading system so that reactive materials may be safely loaded into the microscope; and a compact desk-top chamber which provides acoustic and vibration isolation.

Abstract: A compact Peltier Device is used to heat or cool a small sample stage of a scanning probe (AFM or STM) microscope. The entire heating/cooling system may fit onto a small platen which may be suspended below the scanning probe where it may be held in place against magnetic balls. Alternatively, the sample stage may be supported by a Peltier Device, itself supported by a scanner such as a Piezoelectric scanner with a scanning probe tip held fixedly above the sample stage. The side of the Peltier Device in contact with the platen is cooled (or heated) by a small flow of water through a heat exchanger. The reservoir of water is held at ambient temperature, minimizing the temperature gradient generated between the sample platen and the main body of the microscope. The small mass of the sample stage results in rapid heating or cooling so that an equilibrium is attained rapidly. Heat transfer through the scanning tip is negligible.

Abstract: A tip and substrate preparation system for use with scanning probe microscopes (SPMs) includes a scanning tunneling microscope (STM) tip maker, STM tip coater, a substrate treatment method for producing clean, flat gold substrates for STM use and methods for preparing chemically activated substrates for use with an atomic force microscope (AFM). The tip maker includes a coater and an etcher which are preferably controlled by electronic controllers. The etcher provides fully automatic tip etching in a two-stage process in sodium hydroxide (NaOH) solution, permitting platinum alloys to be etched without the use of cyanide-containing chemicals. The coater is used to insulate the tips with soft polymer coatings so as to ensure very low tip leakage current (on the order of about 1 pA typical). The substrate treatment device comprises a quartz plate and a quartz torch for annealing substrates in a hydrogen flame.

Abstract: An instrument for carrying out both scanning tunneling microscopy and atomic force microscopy on the same sample under liquid. A microscope body with a magnetically-suspended sample platen permits both the force-sensing probe and the tunneling tip to be scanned from above the sample, dipping into a liquid cell. The same area of the sample may be scanned by both probes in turn by translating the sample platen that it is under the desired probe. Atomic force microscopy may be carried out on the part of the sample of interest, the sample translated so that the tunneling tip is over the same area and the sample advanced so as to bring the tunneling probe into tunneling range, and a scanning tunneling microscope image obtained.

Abstract: A thin film of a magnetic material is applied to one or both surfaces of a force sensing cantilever for use in a scanning force microscope. The cantilevers are then placed between the poles of an electromagnet and a magnetizing field applied in the direction of the soft axis of the cantilevers. The field is chosen so as to be bigger than the saturation field for the magnetic film.