Chrome blanks: evaporated vs. sputtered films

Thin Films were originally produced by the evaporation of material in vacuum. The heating and evaporation of material was and still is achieved e.g. by putting the material into a boat of high melting point material. By passage of electric current the boat is then heated to a temperature high enough to evaporate the material in the boat. A more modern method is electron beam evaporation. The material to be deposited is heated by an intense electron beam. In sputtering the ejection of material from a surface (e.g. chrome target) is achieved by momentum transfer. This can e.g. be done by accelerating argon ions towards said surface. There are many methods to produce energetic argon ions. Hence many different types of sputtering systems were developed e.g. diode sputtering, triode sputtering, post magnetron sputtering. The planar magnetron as sputtering source brought the break-through for sputter deposition as production method for thin films.