Physical Vapor Deposition

Magnetron sputtering ignites a plasma above a target material, typically in argon atmosphere. In order to achieve the most efficient sputtering rate possible, the plasma electrons are kept in spiral orbits as long as possible by the magnetic field configuration. The Ar ions are accelerated onto the target and strike atoms out of the surface. These can migrate to the substrate and condense on the surface. By accelerating the ions in the electrical field of the plasma, relatively high-energy atoms are generated, which means that the substrate is heated more strongly than during thermal evaporation. Since a relatively high gas pressure is required to ignite the plasma, the atoms are scattered more strongly on their way to the substrate. This results in a more uniform edge covering, which can be either advantageous or disadvantageous depending on the application.

Leybold Univex 300

Our sputtering system has a relatively small volume, which allows the chamber to be quickly pumped to base pressure. The system has two 2" sputter sources (Onyx-II IC, Angstrom Sciences) and can pick up wafers up to 4". Materials available are Al, Au, Cr, Cu, ITO, Mo, Ni, Ti, TiN, and W.

In pulsed laser deposition, only a small area of the target in the focus of the laser is vaporized with each laser pulse. During a deposition process the laser is rastered over the target to ensure uniform evaporation. The material is heated locally in the laser pulse extremely fast, whereby the original stoichiometry of the target is retained, while this can change over time due to different vapour pressures of the components, e. g. during thermal evaporation . In addition, the layer thickness can be very precisely defined by the number of pulses.

UHV Cluster Tool

In the case of thermal evaporation, the materials are heated until a melt is formed (or in the case of chromium directly sublimated) from which atoms can dissolve in the vacuum and condense on the substrate. The process typically takes place at a pressure of 10^-7 - 10^-6 mbar, so that the atoms hit the substrate without colliding with the residual gas. The vertical incidence of the atoms largely avoids edge covering, which is essential for lift-off processes. In addition, the impinging atoms possess only thermal energy, whereby the heat input to the substrate is reduced to the heat radiation of the source.

Pfeiffer Vacuum PLS 570

The materials can either be evaporated in up to two resistance heated boats or by means of an electron beam from up to four crucibles, one after the other. Materials available are Ag, Al, Al₂O₃, Au, Cr, Cu, Fe, Ni, Pt, Si, SiO2, Ti and TiO₂. The system can accommodate substrates up to 6".