An electron microscope is a microscope that uses a beam of accelerated electrons as a source of illumination. As the wavelength of an electron can be up to 100,000 times shorter than that of visible light photons,electron microscopes have a higher resolving power than light microscopes and can reveal the structure of smaller objects. A scanning transmission electron microscope has achieved better than 50 pm resolution in annular dark-field imaging mode and magnifications of up to about 10,000,000×whereas most light microscopes are limited by diffraction to about 200 nm resolution and useful magnifications below 2000×.
MEMS is the technology of microscopic devices incorporating both electronic and moving parts. MEMS are made up of components between 1 and 100 micrometers in size,and MEMS devices generally range in size from 20 micrometres to a millimetre,although components arranged in arrays can be more than 1000 mm2. They usually consist of a central unit that processes data and several components that interact with the surroundings.
In integrated circuit manufacturing,photolithography or optical lithography is a general term used for techniques that use light to produce minutely patterned thin films of suitable materials over a substrate,such as a silicon wafer,to protect selected areas of it during subsequent etching,deposition,or implantation operations. Typically,ultraviolet light is used to transfer a geometric design from an optical mask to a light-sensitive chemical (photoresist) coated on the substrate. The photoresist either breaks down or hardens where it is exposed to light. The patterned film is then created by removing the softer parts of the coating with appropriate solvents.
A scanning electron microscope (SEM) is a type of electron microscope that produces images of a sample by scanning the surface with a focused beam of electrons. The electrons interact with atoms in the sample,producing various signals that contain information about the surface topography and composition of the sample. The electron beam is scanned in a raster scan pattern,and the position of the beam is combined with the intensity of the detected signal to produce an image. In the most common SEM mode,secondary electrons emitted by atoms excited by the electron beam are detected using a secondary electron detector. The number of secondary electrons that can be detected,and thus the signal intensity,depends,among other things,on specimen topography. Some SEMs can achieve resolutions better than 1 nanometer.
An excimer laser,sometimes more correctly called an exciplex laser,is a form of ultraviolet laser which is commonly used in the production of microelectronic devices,semiconductor based integrated circuits or "chips",eye surgery,and micromachining. Since 1960s excimer lasers are widely used in high-resolution photolithography machines,one of the critical technologies required for microelectronic chip manufacturing.
Thomas Eugene Everhart FREng is an American educator and physicist. His area of expertise is the physics of electron beams. Together with Richard F. M. Thornley he designed the Everhart–Thornley detector. These detectors are still in use in scanning electron microscopes,even though the first such detector was made available as early as 1956.
A cathodoluminescence (CL) microscope combines methods from electron and regular microscopes. It is designed to study the luminescence characteristics of polished thin sections of solids irradiated by an electron beam.
Electron-beam lithography is the practice of scanning a focused beam of electrons to draw custom shapes on a surface covered with an electron-sensitive film called a resist (exposing). The electron beam changes the solubility of the resist,enabling selective removal of either the exposed or non-exposed regions of the resist by immersing it in a solvent (developing). The purpose,as with photolithography,is to create very small structures in the resist that can subsequently be transferred to the substrate material,often by etching.
Nanolithography (NL) is a growing field of techniques within nanotechnology dealing with the engineering of nanometer-scale structures on various materials.
Dip pen nanolithography (DPN) is a scanning probe lithography technique where an atomic force microscope (AFM) tip is used to create patterns directly on a range of substances with a variety of inks. A common example of this technique is exemplified by the use of alkane thiolates to imprint onto a gold surface. This technique allows surface patterning on scales of under 100 nanometers. DPN is the nanotechnology analog of the dip pen,where the tip of an atomic force microscope cantilever acts as a "pen," which is coated with a chemical compound or mixture acting as an "ink," and put in contact with a substrate,the "paper."
Focused ion beam,also known as FIB,is a technique used particularly in the semiconductor industry,materials science and increasingly in the biological field for site-specific analysis,deposition,and ablation of materials. A FIB setup is a scientific instrument that resembles a scanning electron microscope (SEM). However,while the SEM uses a focused beam of electrons to image the sample in the chamber,a FIB setup uses a focused beam of ions instead. FIB can also be incorporated in a system with both electron and ion beam columns,allowing the same feature to be investigated using either of the beams. FIB should not be confused with using a beam of focused ions for direct write lithography. These are generally quite different systems where the material is modified by other mechanisms.
Secondary electrons are electrons generated as ionization products. They are called 'secondary' because they are generated by other radiation. This radiation can be in the form of ions,electrons,or photons with sufficiently high energy,i.e. exceeding the ionization potential. Photoelectrons can be considered an example of secondary electrons where the primary radiation are photons;in some discussions photoelectrons with higher energy (>50 eV) are still considered "primary" while the electrons freed by the photoelectrons are "secondary".
Interference lithography is a technique for patterning regular arrays of fine features,without the use of complex optical systems or photomasks.
Haroon Ahmed FREng,is a British Pakistani scientist in specialising the fields of microelectronics and electrical engineering. He is Emeritus Professor of Microelectronics at the Cavendish Laboratory,the Physics Department of the University of Cambridge,Honorary Fellow of Corpus Christi College,Cambridge,and Fellow of the Royal Academy of Engineering.
Electron-beam-induced deposition (EBID) is a process of decomposing gaseous molecules by an electron beam leading to deposition of non-volatile fragments onto a nearby substrate. The electron beam is usually provided by a scanning electron microscope,which results in high spatial accuracy and the possibility to produce free-standing,three-dimensional structures.
Scanning confocal electron microscopy (SCEM) is an electron microscopy technique analogous to scanning confocal optical microscopy (SCOM). In this technique,the studied sample is illuminated by a focussed electron beam,as in other scanning microscopy techniques,such as scanning transmission electron microscopy or scanning electron microscopy. However,in SCEM,the collection optics is arranged symmetrically to the illumination optics to gather only the electrons that pass the beam focus. This results in superior depth resolution of the imaging. The technique is relatively new and is being actively developed.
Jonathan Harris Orloff is an American physicist,author and professor. Born in New York City,he is the eldest son of Monford Orloff and brother of pianist Carole Orloff and historian Chester Orloff. Orloff is known for his major fields of research in charged particle optics,applications of field emission processes,high-brightness electron and ion sources,focused ion and electron beams and their applications for micromachining,surface analysis and microscopy and instrumentation development for semiconductor device manufacturing.
X-ray lithography is a process used in semiconductor device fabrication industry to selectively remove parts of a thin film of photoresist. It uses X-rays to transfer a geometric pattern from a mask to a light-sensitive chemical photoresist,or simply "resist," on the substrate to reach extremely small topological size of a feature. A series of chemical treatments then engraves the produced pattern into the material underneath the photoresist.
Thermal scanning probe lithography (t-SPL) is a form of scanning probe lithography (SPL) whereby material is structured on the nanoscale using scanning probes,primarily through the application of thermal energy.
A probe tip is an instrument used in scanning probe microscopes (SPMs) to scan the surface of a sample and make nano-scale images of surfaces and structures. The probe tip is mounted on the end of a cantilever and can be as sharp as a single atom. In microscopy,probe tip geometry and the composition of both the tip and the surface being probed directly affect resolution and imaging quality. Tip size and shape are extremely important in monitoring and detecting interactions between surfaces. SPMs can precisely measure electrostatic forces,magnetic forces,chemical bonding,Van der Waals forces,and capillary forces. SPMs can also reveal the morphology and topography of a surface.
