Nanotechnology refers broadly to a field of applied science and technology whose unifying theme is the control of matter on the molecular level in scales smaller than 1 micrometer, normally 1 to 100 nanometers,and the fabrication of device within that size range. It is highly multidisciplinary field, drawing from fields such as applied physics, material science, colloidal science, device physics, super molecular chemistry, and even mechanical and electrical engineering. Nanotechnology can be seen as an extension of existing sciences into the nanometer, or as a recasting of existing sciences using a newer, more modern term. Two main approaches are used in nanotechnology. The impetus for nanotechnology comes science, coupled with a new generation of analytical tools such as the atomic force microscope, and the scanning tunneling microscope. Combined with refined processes such as electron beam lithography and beam epitaxy,these instruments allow the deliberate manipulation of structures.