In evaporation a material is heated in vacuum until it boils, the resulting vapour then condenses on the substrate to form a thin film. This film can be from a few atoms thick (less than 1nm) to hundreds or thousands of nm thick. Thermal evaporation is carried out at high vacuum, typically better than 1x10-6 mbar.For materials with higher melting points which cannot be easily evaporated by resistive heating the e-beam evaporation processes are used. Resistance evaporation systems pass a high electrical current through a filament or a ‘boat’ source in which the material is placed, the heating effect of which is sufficient to evaporate many materials. Electron beam sources use a dedicated power supply to provide a high-power electron beam to heat the source material, and are capable of evaporating higher melting point or reactive materials.
Electron beam (e-beam) sources are used for the evaporation of materials which have melting points above 1800C or which react with evaporation boats or filaments. Sources typically have a turret which can accommodate 4 to 8 crucibles which can be selected for multi-layer films. E-beam can be used in small systems like the Auto306 and is commonly used in large deposition tools for optics and ophthalmics where simultaneous ion-beam process is often applied. Electron beam sources range from 3kW to over 20kW
Ion Beam Technology
Ion beam sources convert a process gas into a stream of gas ions using an external high voltage power supply and an internal cathode. The output ion beam is typically parallel or divergent, with parallel beams being used to sputter a material target with high-energy ions, and divergent beams being used to bombard a large-area work holder with lower energy ions to compact or modify the growing film during a deposition process. Ion sources are available in a wide range of sizes and with a range of options for cathode design, neutraliser construction and RF or DC operation.Ion sources require the use of high-throughput vacuum systems.
Magnetron sputtering employs plasma to generate ions which bombard the surface of a ‘target’ which then sputters the thin film material on to a substrate. HHV offers a range of circular and linear magnetron sputter sources, engineered to meet R&D and production requirements. HHV offers a full range of circular and linear magnetron sputter sources which are engineered to meet specific and stringent R&D and production requirements. It uses well proven designs providing ease of use, with excellent target utilization, deposited film uniformity and reliability.
Film Thickness Monitor and Process Control
A film thickness monitor uses a quartz crystal microbalance to measure the deposition rate and total thickness of the film during deposition. Film thickness monitors can also operate source shutters for end-point termination.
Film thickness controllers also display the deposition rate and total thickness but are capable of controlling the deposition sources to provide a user-defined rate and thickness. These controllers are ideal for multi-layer films and for production applications. We offer film thickness monitors and controllers to suit different customer applications and budgets. We also supply spare monitor crystals.