42 results about "Conductive atomic force microscopy" patented technology

The invention relates to a probe of a conducting atomic force microscope. The probe comprises: a substrate of a cantilever probe; a needle tip; and a conductive film, which is arranged at a surface of the needle tip. Besides, the material of the conductive film is graphene. Moreover, the invention provides a method that employs the probe to measure local conductivity of a semiconductor and a needle tip-free near-field optical detection method that employs the probe to measure a terahertz wave band. According to the invention, graphene is utilized, wherein the grapheme has the following characteristics that: the graphene is composed of carbon atoms and is thin to a monatomic layer; and the graphene is a semimetal two-dimensional thin material that has a zero gap; besides, the probe has advantages of good conductivity and high electron mobility; moreover, a Fermi surface can carry out self-adjustment with charging and discharging motions and a carrier injection potential is low. In addition, an electronic plasmon oscillating frequency of the graphene is just at a terahertz wave band; and the graphene has soft materials and strong stability on thermodynamics. The above-mentioned statements are physical bases on which the graphene is utilized to replace a traditional metal material as a plated film of a surface of an atomic force microscope probe, so that the above-mentioned limitations are broken through.

The invention discloses a preparation method of a graphene complex based humidity sensor in the technical field of nano materials. The humidity sensor is prepared through the following steps of: diluting a polyvinylpyrrolidone-graphene complex, coating on the surface of a substrate by spinning in the form of a single-layer film, electroplating a layer of metal electrodes on the single-layer film, and finally drying under vacuum. In the invention, by adopting the favorable hygroscopicity and the conductivity of the polyvinylpyrrolidone-graphene, a single-layer film of a humidity sensitive complex is formed on the surface of the substrate by using a spin coating method, and the sensitivity of the complex to the humidity is detected through an I-V curve measured by a conducting atomic force microscope at different humidities.

The invention discloses a vacuum atomic force microscope and a using method thereof, belonging to the field of micro-topography detecting equipment; the microscope comprises an electron beam launching device, a secondary electron detector, a probe with a cantilever, a piezoelectric ceramics scanner and a feedback controller. When in work, electron beams are irradiated to the cantilever of the probe; as the acting force between the probe and sample atoms causes the cantilever to become deformed; a secondary electron signal changes; the acting force between a pinpoint and the sample is controlled to be constant by the signal feedback; the pinpoint scans the surface of the sample point by point and can image surface topography of the sample. The currently common optical lever does not need to be drawn into the invention; the invention overcomes design difficulty brought about by the conventional atomic force microscope applied in vacuum environment, synthesizes two nanophase material characterization methods which are the advantages of the atomic force microscope and an electronic microscope, and can realize the continuous measuring on the material from millimeter size to the sub-nanometer size.

The method includes following steps: (1) preparation of self-assembly substrate, offering a P type Si(100) substrate that is treated by ultrasonic in organic solvent; after treated by placing into Piranha solution, and it is dried by blowing non-oxidizability gas, and then is treated by OTS solution and is cleaned up by using organic solvent; (2) nano-line etching, the nano-line is etched on self assembly substrate by using current of conduct atomic force microscope, the radius of curvature of pinpoint is less than 50 nm; (3) nanometer generating, the etched substrate is placed in the silver acetate for dipping, and then is taken out to place in ethanol in short time, and then is placed in sodium borohydride aqueous solution for dipping, washing, and then is dried by blowing non-oxidizbility gas, finally the silver enhancement solution is inputted for heighten the electrode line.

The invention discloses a periodic stripe domain structure of a ferroelectric thin film and a method for characterizing the same and belongs to the technical field of micro-nano characterization. Themethod includes the following steps: preparing a bismuth ferrite thin film by pulsed laser deposition; characterizing the lattice constant of the bismuth ferrite thin film by an X-ray diffraction instrument, determining the bismuth ferrite thin film to be a rhombus phase structure, confirming good ferroelectricity and coercive voltage of the bismuth ferrite thin film by a piezoelectric butterfly curve, and characterizing the shape of the bismuth ferrite thin film by atomic force microscopy; characterizing the periodic stripe domain in the nano-ferroelectric thin film by vector piezoresponse force microscopy, and determining the three-dimensional structure of the ferroelectric thin film by a fine vector piezoelectric microscopy analytical method; and observing the conduction of the domain wall of the stripe domain by using conductive atomic force microscopy. The method for preparing the ferroelectric thin film provided by the present invention can be used for a nonvolatile and high-density ferroelectric random access memory. Further, the provided characterization method can accurately provide the three-dimensional domain structure and the domain wall conduction of the periodic stripe domain, and provides a solution for the development of high-density ferroelectric memory devices and characterization detection.

The invention provides a method for detecting a photoelectric current signal of a photoelectric conversion material via a conductive atomic force microscope. A lock-in amplifier is used, the lock-in amplifier provides an alternating driving voltage so that a light source is driven to emit light to irradiate a material sample, the sample generates an optical current due to a photoelectric conversion effect, a conductive probe makes contact with the sample to detect the photoelectric current signal and transmits the photoelectric current signal to a current amplifier to obtain a current amplification signal, and the current amplification signal is then input to the lock-in amplifier. Thus, the frequency of a reference signal of lock-in amplification is the same with that of the driving voltage, lock-in amplification of the photoelectric current signal is realized, and the sensitivity and signal to noise ratio of photoelectric current detection are improved.

The invention discloses a method for preparing a semiconductor nanowire array with optimal photoelectric performance. The method first deposits a gold film by thermal evaporation and anneals to form random and uniformly distributed catalyst particles, and then according to the prepared III-V nanowire material system, select the optimal V/III beam current ratio, grow a series of nanowire array samples at different substrate temperatures, and then use a conductive atomic force microscope to perform statistical evaluation of the vertical photoelectric properties of a single nanowire, and finally The optimal preparation conditions were determined according to the average optoelectronic properties of single nanowires. This method is suitable for catalytic molecular beam epitaxy to grow III-V nanowire arrays such as gallium arsenide, and uses a direct, fast and simple method to evaluate and determine the optimal growth conditions of nanowire arrays through metal catalysis, and then prepares a arrays of semiconducting nanowires with optimal optoelectronic efficiency, and thus, the method is of great interest for the fabrication of high-efficiency solar cells and ultrasensitive photodetectors.

The invention discloses a processing method of binary transition metal oxide film nanometer patterns. According to the processing method, a conducting atomic force microscopy (C-AFM) probe needle point is applied with a certain direct current bias, so that ionic electrochemical reaction at the contact interface of a binary transition metal oxide film and the probe is realized, the amplitude value,applying times, needle point effect zone, and scanning times are controlled, so that processing of binary transition metal oxide film nanometer patterns of different shapes is realized. The processing method possesses following advantages: nanometer grade processing precision is achieved, processing process is simple and convenient, energy consumption is super low, no pollution is caused, and nomask is needed. The processing method is capable of reducing physical damage on probe needle point.

The invention discloses a characterization method for conductivity regulation in a ferroelectric nano dot array, and belongs to the technical field of nano ferroelectric material preparation and micro-nano characterization. A ferroelectric film is etched by an ion beam to obtain a high-density nano dot array; a domain structure of a ferroelectric topological domain is obtained by means of vector piezoelectric power microscopy characterization; a conductive atomic force microscope is used for observing conductive channels in the nanodots, that the conductive area in a single nanodot is dozens of nanometers according to a two-dimensional current image, and the conductive channels have the characteristic similar to metal conductivity; and a piezoelectric force microscope and a conductive atomic force microscope are combined to obtain regulation of polarization on conductivity. The method can be used for developing a nonvolatile and high-density ferroelectric random access memory; the central domain structure of the nanodot provides a scheme for researching the ferroelectric topological domain and a topological material; and the conductivity of the nanodots can be regulated through polarization inversion, regulation control can be visualized through the provided characterization method, and the visibility and reliability of data are improved.

The invention provides a semiconductor device failure analysis method. The method comprises the following steps of exposing a test area of a semiconductor device, wherein the test area includes a plurality of test points; selecting at least one of the plurality of test points as an input end; forming an input structure electrically connected to the input end; applying a test signal to the input structure; and using an electrical test probe to scan and test the test points except for the input end to which the test signal is applied. Through introducing the new semiconductor device failure analysis method, when a semiconductor device is tested and analyzed by using an electrical probe test method such as a conductive atomic force microscope and the like, input structures electrically connected to the test points are formed. A bias voltage is applied to the test points through the input structures and labor and time cost required for failure analysis can be effectively reduced through the multiple input structures.

The invention discloses a method for preparing nano texture through local anodic oxidation. In the method, the nano texture is prepared by adopting a local anodic oxidation method based on a conductive atomic force microscopy, and the height (0.5-12nm) of the nano texture can be controlled through selecting different pulse voltages, pulse widths and surface humidity values. With the application of the nano texture, the large-area contact with the surface of a micro-nano optical mechanical and electrical system device can be effectively blocked, and the surface adhesive force of the micro-nano optical mechanical and electrical system device can be remarkably reduced. Therefore, the surface nano texture prepared by the method has good anti-adhesion performance.

The invention discloses a single-crystal-silicon surface mechanical damage detecting method based on conductivity variation. The method includes the following steps of placing a clean and dry to-be-detected single-crystal-silicon wafer into a conductive atomic power microscope sample cavity, scanning a to-be-detected damage area to obtain a surface topography and a current distribution diagram, comparing and analyzing a scanning result, and finding the position of the single-crystal-silicon surface mechanical damage to obtain the detection result. In the method, scanning and detecting are conducted by means of a micro tip of an atomic power microscope, the contact pressure is far smaller than the clinical contact pressure of single crystal silicon during yielding, and a sample can not be damaged. The method is suitable for detecting the mechanical damage generated in the cutting, grinding, polishing and other machining processes of single-crystal-silicon surfaces.

The invention relates to a method for optimizing combination of a conduction atomic force microscope (CAFM) and a digital source meter. A conductive module (CAFM Mode) and a digital source meter of aconductive atomic force microscope are connected with a conductive atomic force microscope through a single-pole double-throw radio frequency switch, so that a probe is selectively connected with theconductive module of the conductive atomic force microscope or the digital source meter. According to the method for combining a conductive atomic force microscope and a digital source meter, a novelsystem accessory is created and applied to the conductive atomic force microscope. The conductive atomic force microscope can be freely switched to different modes (CAFM mode or source meter), the position of the needle tip is not changed in the switching process, and the same area of the test sample can be represented at the same time, so that the original defects of the AFM instrument in use aregreatly overcome, technicians in the field are simpler, more convenient and more efficient in the experimental operation process, and the time cost of the scientific research personnel can be effectively reduced.

An illustrative method disclosed herein includes measuring at least one electrical-related parameter of a doped semiconductor material by simultaneously irradiating at least a portion of an upper surface of the doped semiconductor material, urging a conductive tip of a cantilever beam probe into conductive contact with the upper surface of the irradiated portion of the doped semiconductor material, and generating an electrical current that flows through the doped semiconductor material, through a measurement device that is operatively coupled to the cantilever beam probe and through the cantilever beam probe, wherein the measurement device measures the at least one electrical-related parameter of the doped semiconductor material.

The invention discloses a nanoscale electrode processing method based on an AFM (atomic force microscopy). According to the method, a micrometer level electrode is cut and processed through the controlling on the action force of an AFM probe on a sample and the movement path and speed of the probe, thus the processing of the nanoscale electrode of which a front end has width within100 nanometers is realized, and the detection accuracy and flexibility in a nano fluidic test are increased. The nanoscale electrode processing method provided by the invention can be applied to high-flexibility detection and analysis of the fluid characteristics of fluid in a nano channel in the nano fluidic chip and biology monomolecules.