Nano Technology

Molecular-Beam Epitaxy Molecular-beam epitaxy (MBE) is an epitaxy method for thin-film deposition of single crystals. MBE is widely used in the manufacture of semiconductor devices, including transistors, and it is considered one of the fundamental tools for developing nanotechnologies. MBE is used to fabricate diodes and MOSFETs (MOS field-effect transistors) at microwave frequencies and to manufacture the lasers used to read optical discs (such as CDs and DVDs). History Original ideas of the MBE process were first established by K. G. Günther. Films he deposited were not epitaxial, but were deposited on glass substrates. With the development of vacuum technology, the MBE process was demonstrated by John Davey and Titus Pankey who succeeded in growing GaAs epitaxial films on single crystal GaAs substrates using Günther's method. Major subsequent development of MBE films was enabled by J.R. Arthur's investigations of the kinetic behavior of growth mechanisms and Alfred Y. Cho&#

 Atom lithography  Atom lithography designates a physical method where the forces exerted by interfering laser beams on the atoms of an atomic beam are used to steer the atoms into nanostructures fabricated on a plane surface. While atom lithography is the most frequently used term, the method is also known as light-force lithography and atomic nanofabrication (ANF). Atom lithography is an application of a field called atom optics. In this field, atomic motion is controlled by means of forces exerted by laser beams or a combination of laser and magnetic forces. All concepts of geometric and wave optics—refraction, diffraction, and interference—are straightforwardly transferred to atomic beams. Wave properties of atomic beams are governed by the de Broglie wavelength, λdB = h/mv, where h is Planck’s constant, and m and v are the mass and the speed of the atom. Structure formation by atom lithography relies on the deposition of atoms on a surface. Typical experimental atomic beams have a

Lithography  Lithography comes from the Greek words lithos means stone and grapho means write. Low dimensional structures are defined with writing patterns at micro/nano-meter scale designed by printing text or graphics on the surface of materials. Lithography is currently one of the most feasible techniques used for patterning micro/nanoscale features of desired designs with definite shapes, sizes and material compositions, selectively on the material of choice for device fabrication. Several lithographic methods are developed with different resolutions, reproducibility, speed, simplicity for processing, acquisition costs, etc., by using different sources of energy. The process of utilizing a light source for patterning is termed as photolithography and the utilization of energetic beams as a source is nomenclatured according to the type of energy source.  During semiconductor processing, the fabrication of micro/nano-structures rearranges the additives by deposition, subtractives by