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Ion-beam Sculpting
Ion-Beam sculpting is a two-step process to make solid-state nanopores. The term itself was coined by Golovchenko and co-workers at Harvard in the paper "Ion-beam sculpting at nanometer length scales." In the process, solid-state nanopores are formed by lateral mass transport about the surface of the substrate, not simply by sputtering, which is the removal of material from the surface. Basis The first step in ion sculpting is to make either a through hole or a blind hole (not penetrating completely), most commonly using a focused ion beam (FIB). The holes are commonly about 100 nm in diameter, but can be made much smaller. This step may or may not be done at room temperature, with a low temperature of -120 C. Next, three common techniques can be used to 'sculpt' the hole: broad area ion exposure, TEM exposure, and FIB exposure. Holes can be closed completely, or left open at a lower limit of 1 - 10 nm. Broad area ion exposure This technique uses a broad area argon ion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Nanopore
A nanopore is a pore of nanometer size. It may, for example, be created by a pore-forming protein or as a hole in synthetic materials such as silicon or graphene. When a nanopore is present in an electrically insulating artificial membrane, membrane, it can be used as a single-molecule detector. It can be a biological protein channel in a high electrical resistance lipid bilayer, a pore in a solid-state membrane or a hybrid of these – a protein channel set in a synthetic membrane. The detection principle is based on monitoring the ionic current passing through the nanopore as a voltage is applied across the membrane. When the nanopore is of molecular dimensions, passage of molecules (e.g., DNA) cause interruptions of the "open" current level, leading to a "translocation event" signal. The passage of RNA or single-stranded DNA molecules through the membrane-embedded alpha-hemolysin channel (1.5 nm diameter), for example, causes a ~90% blockage of the current (measured at 1 M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Wafer (electronics)
In electronics, a wafer (also called a slice or substrate) is a thin slice of semiconductor, such as a crystalline silicon (c-Si, silicium), used for Semiconductor device fabrication, the fabrication of integrated circuits and, in photovoltaics, to manufacture solar cells. The wafer serves as the substrate (materials science), substrate for microelectronic devices built in and upon the wafer. It undergoes many microfabrication processes, such as doping (semiconductor), doping, ion implantation, Etching (microfabrication), etching, thin-film deposition of various materials, and Photolithography, photolithographic patterning. Finally, the individual microcircuits are separated by wafer dicing and Integrated circuit packaging, packaged as an integrated circuit. History In the semiconductor industry, the term wafer appeared in the 1950s to describe a thin round slice of semiconductor material, typically germanium or silicon. The round shape characteristic of these wafers comes f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Ion Beam
An ion beam is a beam of ions, a type of charged particle beam. Ion beams have many uses in electronics manufacturing (principally ion implantation) and other industries. There are many ion beam sources, some derived from the mercury vapor thrusters developed by NASA in the 1960s. The most widely used ion beams are of singly-charged ions. Units Ion current density is typically measured in mA/cm2, and ion energy in electronvolts (eV). The use of eV is convenient for converting between voltage and energy, especially when dealing with singly charged ion beams. Broad-beam ion sources Most commercial applications use two popular types of ion source, gridded and gridless, which differ in current and power characteristics and the ability to control ion trajectories. In both cases electrons are needed to generate an ion beam. The most common types of electron emitter are hot filament and hollow cathode. Gridded ion source In a gridded ion source, DC or RF discharge are u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Focused Ion Beam
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 (such as in proton beam writing). These are generally quite different systems where the material is modified by other mechanisms. Ion beam source Most widespread instruments are using liquid metal ion sources (LMIS), especially gallium ion sources. Ion sources based on elemental gold an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
1 E-7 M
The following are examples of orders of magnitude for different lengths. Overview Detailed list To help compare different orders of magnitude, the following list describes various lengths between 1.6 \times 10^ metres and 10^metres. Subatomic scale Atomic to cellular scale Cellular to human scale Human to astronomical scale Astronomical scale 1 quectometre and less The ' ( SI symbol: ') is a unit of length in the metric system equal to . To help compare different orders of magnitude, this section lists lengths shorter than 10−30 m (1 qm). *1.6 × 10−5 quectometres (1.6 × 10−35 metres) – the Planck length (Measures of distance shorter than this do not make physical sense, according to current theories of physics.) *1 qm – 1 quectometre, the smallest named subdivision of the metre in the SI base unit of length, one nonillionth of a metre. 1 rontometre The ' ( SI symbol: ') is a unit of length in the metric system equal to . *1 rm †... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
