Using thermal and E-Beam evaporation methods, a wide variety of materials, including refractory metals, low vapor pressure metals and alloys, can be evaporated. Since the E-Beam method concentrates large amounts of heat on a very small area, high rates of deposition are possible.
For E-Beam evaporation, tungsten filament inside the E-Beam gun is heated. The gun is located outside the evaporation zone to avoid becoming contaminated by the evaporant. When the filament becomes hot enough, it begins to emit electrons. These electrons form a beam which is deflected and accelerated toward and focused on the material to be evaporated by means of a magnetic and electric field. When the electron beam strikes the target surface, the kinetic energy of motion is transformed by the impact into thermal energy(heat). The temperature of the target material achieved in this manner can be very high. This is due to the intensity of the energy generated by the E-beam, and since the target material can be thermally isolated from the crucible liner in which it is held (the liner must be actively cooled to prevent it from melting). Deposition occurs when the target material reaches its boiling point. The advantage of this method is that deposition can occur even in ultra-high vacuum conditions. In our reserch we use a Bestec inc. deposition system (base pressure 1×10-8 Torr) with a Telemark linear e-beam evaporator.