Scanning voltage microscopy

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Scanning voltage microscopy (SVM), sometimes also called nanopotentiometry, is a scientific experimental technique based on atomic force microscopy. A conductive probe, usually only a few nanometers wide at the tip, is placed in full contact with an operational electronic or optoelectronic sample. By connecting the probe to a high-impedance voltmeter and rastering over the sample's surface, a map of the electric potential can be acquired. SVM is generally nondestructive to the sample although some damage may occur to the sample or the probe if the pressure required to maintain good electrical contact is too high. If the input impedance of the voltmeter is sufficiently large, the SVM probe should not perturb the operation of the operational sample. [1] [2]

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Applications

SVM is particularly well suited to analyzing microelectronic devices (such as transistors or diodes) or quantum electronic devices (such as quantum well diode lasers) directly because nanometer spatial resolution is possible. [1] SVM can also be used to verify theoretical simulation of complex electronic devices. [3]

For example, the potential profile across the quantum well structure of a diode laser can be mapped and analyzed; such a profile could indicate the electron and hole distributions where light is generated and could lead to improved laser designs.

Scanning gate microscopy

In a similar technique, scanning gate microscopy (SGM), the probe is oscillated at some natural frequency some fixed distance above the sample with an applied voltage relative to the sample. The image is constructed from the X,Y position of the probe and the conductance of the sample, with no significant current passing through the probe, which acts as a local gate. The image is interpreted as a map of the sample's sensitivity to gate voltage. A lock-in amplifier aids noise reduction by filtering through only the amplitude oscillations that match the probe's vibration frequency. Applications include imaging defect sites in carbon nanotubes and doping profiles in nanowires.

Related Research Articles

Opto-electronics is the study and application of electronic devices and systems that source, detect and control light, usually considered a sub-field of photonics. In this context, light often includes invisible forms of radiation such as gamma rays, X-rays, ultraviolet and infrared, in addition to visible light. Optoelectronic devices are electrical-to-optical or optical-to-electrical transducers, or instruments that use such devices in their operation.

Atomic force microscopy

Atomic force microscopy (AFM) or scanning force microscopy (SFM) is a very-high-resolution type of scanning probe microscopy (SPM), with demonstrated resolution on the order of fractions of a nanometer, more than 1000 times better than the optical diffraction-limit.

Scanning probe microscopy (SPM) is a branch of microscopy that forms images of surfaces using a physical probe that scans the specimen. SPM was founded in 1981, with the invention of the scanning tunneling microscope, an instrument for imaging surfaces at the atomic level. The first successful scanning tunneling microscope experiment was done by Gerd Binnig and Heinrich Rohrer. The key to their success was using a feedback loop to regulate gap distance between the sample and the probe.

Electronic component Discrete device in an electronic system

An electronic component is any basic discrete device or physical entity in an electronic system used to affect electrons or their associated fields. Electronic components are mostly industrial products, available in a singular form and are not to be confused with electrical elements, which are conceptual abstractions representing idealized electronic components and elements.

Kelvin probe force microscope Noncontact variant of atomic force microscopy

Kelvin probe force microscopy (KPFM), also known as surface potential microscopy, is a noncontact variant of atomic force microscopy (AFM). By raster scanning in the x,y plane the work function of the sample can be locally mapped for correlation with sample features. When there is little or no magnification, this approach can be described as using a scanning Kelvin probe (SKP). These techniques are predominantly used to measure corrosion and coatings.

Scanning gate microscopy (SGM) is a scanning probe microscopy technique with an electrically conductive tip used as a movable gate that couples capacitively to the sample and probes electrical transport on the nanometer scale. Typical samples are mesoscopic devices, often based on semiconductor heterostructures, such as quantum point contacts or quantum dots. Carbon nanotubes too have been investigated.

Nanophotonics or nano-optics is the study of the behavior of light on the nanometer scale, and of the interaction of nanometer-scale objects with light. It is a branch of optics, optical engineering, electrical engineering, and nanotechnology. It often involves dielectric structures such as nanoantennas, or metallic components, which can transport and focus light via surface plasmon polaritons.

Test probe

A test probe is a physical device used to connect electronic test equipment to a device under test (DUT). Test probes range from very simple, robust devices to complex probes that are sophisticated, expensive, and fragile. Specific types include test prods, oscilloscope probes and current probes. A test probe is often supplied as a test lead, which includes the probe, cable and terminating connector.

Nanometrology Metrology of nanomaterials

Nanometrology is a subfield of metrology, concerned with the science of measurement at the nanoscale level. Nanometrology has a crucial role in order to produce nanomaterials and devices with a high degree of accuracy and reliability in nanomanufacturing.

The following outline is provided as an overview of and topical guide to nanotechnology:

Molecular scale electronics, also called single-molecule electronics, is a branch of nanotechnology that uses single molecules, or nanoscale collections of single molecules, as electronic components. Because single molecules constitute the smallest stable structures imaginable, this miniaturization is the ultimate goal for shrinking electrical circuits.

Local oxidation nanolithography

Local oxidation nanolithography (LON) is a tip-based nanofabrication method. It is based on the spatial confinement on an oxidation reaction under the sharp tip of an atomic force microscope.

Conductive atomic force microscopy

Conductive atomic force microscopy (C-AFM) or current sensing atomic force microscopy (CS-AFM) is a mode in atomic force microscopy (AFM) that simultaneously measures the topography of a material and the electric current flow at the contact point of the tip with the surface of the sample. The topography is measured by detecting the deflection of the cantilever using an optical system, while the current is detected using a current-to-voltage preamplifier. The fact that the CAFM uses two different detection systems is a strong advantage compared to scanning tunneling microscopy (STM). Basically, in STM the topography picture is constructed based on the current flowing between the tip and the sample. Therefore, when a portion of a sample is scanned with an STM, it is not possible to discern if the current fluctuations are related to a change in the topography or to a change in the sample conductivity.

Piezoresponse force microscopy

Piezoresponse force microscopy (PFM) is a variant of atomic force microscopy (AFM) that allows imaging and manipulation of piezoelectric/ferroelectric materials domains. This is achieved by bringing a sharp conductive probe into contact with a ferroelectric surface and applying an alternating current (AC) bias to the probe tip in order to excite deformation of the sample through the converse piezoelectric effect (CPE). The resulting deflection of the probe cantilever is detected through standard split photodiode detector methods and then demodulated by use of a lock-in amplifier (LiA). In this way topography and ferroelectric domains can be imaged simultaneously with high resolution.

In microscopy, scanning joule expansion microscopy (SJEM) is a form of scanning probe microscopy heavily based on atomic force microscopy (AFM) that maps the temperature distribution along a surface. Resolutions down to 10 nm have been achieved and 1 nm resolution is theoretically possible. Thermal measurements at the nanometer scale are of both academic and industrial interest, particularly in regards to nanomaterials and modern integrated circuits.

Photoconductive atomic force microscopy

Photoconductive atomic force microscopy (PC-AFM) is a variant of atomic force microscopy that measures photoconductivity in addition to surface forces.

The following outline is provided as an overview of and topical guide to electronics:

Nanoprobing is method of extracting device electrical parameters through the use of nanoscale tungsten wires, used primarily in the semiconductor industry. The characterization of individual devices is instrumental to engineers and integrated circuit designers during initial product development and debug. It is commonly utilized in device failure analysis laboratories to aid with yield enhancement, quality and reliability issues and customer returns. Commercially available nanoprobing systems are integrated into either a vacuum-based scanning electron microscope (SEM) or atomic force microscope (AFM). Nanoprobing systems that are based on AFM technology are referred to as Atomic Force nanoProbers (AFP).

Sergei V. Kalinin

Sergei V. Kalinin is a corporate fellow at the Center for Nanophase Materials Sciences (CNMS) at Oak Ridge National Laboratory. He is also a Joint Associate Professor at the Department of Materials Science and Engineering at the University of Tennessee-Knoxville.

Multi-tip scanning tunneling microscopy

Multi-tip scanning tunneling microscopy extends scanning tunneling microscopy (STM) from imaging to dedicated electrical measurements at the nanoscale like a ″multimeter at the nanoscale″. In materials science, nanoscience, and nanotechnology, it is desirable to measure electrical properties at a particular position of the sample. For this purpose, multi-tip STMs in which several tips are operated independently have been developed. Apart from imaging the sample, the tips of a multi-tip STM are used to form contacts to the sample at desired locations and to perform local electrical measurements.

References

  1. 1 2 Kalinin, Sergei V.; Gruverman, Alexei (2007-04-03). Scanning Probe Microscopy: Electrical and Electromechanical Phenomena at the Nanoscale. Springer Science & Business Media. pp. 562–564. ISBN   978-0-387-28668-6.
  2. Kuntze, Scott B.; Ban, Dayan; Sargent, Edward H.; Dixon-Warren, St. John; White, J. Kenton; Hinzer, Karin (2007), Kalinin, Sergei; Gruverman, Alexei (eds.), "Scanning Voltage Microscopy", Scanning Probe Microscopy: Electrical and Electromechanical Phenomena at the Nanoscale, New York, NY: Springer, pp. 561–600, doi:10.1007/978-0-387-28668-6_21, ISBN   978-0-387-28668-6 , retrieved 2021-04-22
  3. Kuntze, S. B.; Ban, D.; Sargent, E. H.; Dixon-Warren, St J.; White, J. K.; Hinzer, K. (2005-04-01). "Electrical Scanning Probe Microscopy: Investigating the Inner Workings of Electronic and Optoelectronic Devices". Critical Reviews in Solid State and Materials Sciences. 30 (2): 71–124. doi:10.1080/10408430590952523. ISSN   1040-8436.