Vacuum Mechanisms of Nanoscale Precision

Abstract

The principles of design of vacuum mechanims of nanoscale precision are presented. Physical basics of the mechanisms nanoscale precision are discussed. Vacuum multicoordinate drives and manipulators are also shown.

The analysis of vacuum technological equipment and vacuum research equipment shows that the most strict requirements for the object transference are in electron beam micro lithography equipment. For example, electron beam micro lithography installations with work pressure p = 10^-5 Pa must ensure the positioning error is below 0.5–1.0 mic. The total error of instrument (and coordinate table) [1] positioning in this installation is below 100 nanometers. Even higher requirements are in X-ray lithography installations which use synchrotron source as a work beam [2]. In the process of sample transference this equipment requires that the silicon water inclination from the base X-ray sample should be below 20 nanometers. These high requirements are caused by the work beam inclination. In the X-ray installations, the work beam is not inclined by the electric field as in the electron beam lithography. In new research equipments: in the ultrahigh vacuum scanning tunneling microscopy installations, in atomic force microscopy, the error of the instrument transference must be less than 0.1 nanometer (at a work pressure p ≤ 5 · 10^-8 Pa) [3].

The other types of research equipment, for example ultralarge segmented astronomy telescopes equippedwith an adaptive optical system, requires small positioning error less than 50 nanometers. This system also has special requirements on cleaniness and absence of debris (products of wear) [4]. This equipment requires also very quick action of the drive (the time of action is less than 10^-1 micro-second). It is related with the necessity of high productivity and multi-step transference of the sample with high precision. The quick action of the drive can be achieved with the high stability of the motion of the drive: the equipment requires short time decreasing of the transference process as well as high speed of sample transfer [5]. To ensure nanometer precision in combination with millisecond quick-action of the drive, it is necessary to use the correct type of the drive and to have a system with computer control. For this task it is necessary to establish the principles of transference of ultrahigh precision of vacuum mechanisms.