Leica EM MED020 Modular High Vacuum Coating System

Leica Updated: 2009-02-06 RSS
Leica EM MED020 Modular High Vacuum Coating System

Modular High Vacuum Coating System
The MED 020, Modular High Vacuum Coating System is a very efficient turbo molecular pumped high vacuum preparation unit, which allows most coating applications in one single unit. Coating methods such as sputter coating, resistance evaporation and electron beam evaporation.

Key Features

* Self-supporting and maintenance friendly housing
* Auto- lift system facilitates for easy feeding and setting the various evaporation sources
* Quick Click system with integrated safety system for easiest and quickest change of coating systems
* Bottom flange opening in vacuum chamber bottom also permits evaporation from bottom up
* Additional flange openings in vacuum chamber bottom for diverse application purposes
* Extremely clean vacuum due to turbo-molecular pumping system.
* Universal control unit for coating technology, vacuum measurement and pumping system control
* Wide selection of different vacuum chambers
* Modular design for quick and easy operational conversions

Detailed Description

The high vacuum sputtering method
For very fine-grained sputter coated films Leica recommends high vacuum sputtering. Undesired residual gas components such as water vapour are virtually eliminated from the vacuum chamber by a high vacuum pump. The working pressure required for sputtering - approx. 10-2 mbar - is then re-established the chamber with the admission of argon gas. To start the sputtering process a high voltage is applied to the target (cathode). This produces a high voltage field between the target and the specimen table (anode). The free electrons in this field are forced into a spiral path by a magnet system where they collide with the argon atoms in the field. Each collision knocks 0ut an electron of the outer shell of the argon atom, positively charging the otherwise neutral argon. This is a cascadingprocess that causes a glow discharge (plasma) to ignite.

The positively charged argon ions are now accelerated to the cathode (target) where they impinge, knocking off metal atoms as they hit. Collisions also occur between the metal atoms thus released and the other gas molecules in the vacuum chamber.

This causes the metal atoms to scatter widely, forming a diffuse cloud. The metal atoms from this cloud impinge on the specimen from all directions and condense evenly on it. Thus even very fissured specimen surfaces are coated with an even, thin metal film that is sufficiently electrically conductive for examination in the SEM.