There are several means of coating a base material with high purity thin layer films. The most recent and most promising of which is a radio frequency induction plasma chemical vapor deposition. This has been highly sought after by several industries, mainly the computer industry where they can take various base materials and grow microprocessors on them by depositing layers of different doped chemicals to grow semiconductor gates and traces. Until now the technology has been based on silicon however the shift is coming where this method once perfected should allow the growth of diamond cores for processor base materials seeing as they have extraordinary thermal properties and should be able to handle far more power.
The Rf induction plasma works by using an electromagnet with an RF frequency to pull on ions back and forth to induce a plasma due to the magnetic energy being translated into kinetic energy from induced high energy collisions forcing the electrons from the atoms creating more ions. This needs to be done at a very low pressure, usually 1 mtorr at most. The design of the magnets and the sophistication of the electronics powering it can greatly improve results in that the velocity and deflection of different atoms can be calculated based on the efficiency of the magnet, the Green and Maxwell functions of how the magnetic field will be created and changes. The frequency can be altered to change the amount of energy transferred into various atoms and secondary fields can be used to deflect particles.
The Plasma will also not start without any ions in the atmosphere as the magnets have nothing to pull on, so it is generally initiated with a sacrificial set of electrodes of a relatively inert material or with a microwave emitter to initiate some atoms into a plasma state. The plasma is then initiated with a larger field from the magnet as it takes less energy to sustain the plasma once it has started. These generators are currently working in many Chemical vapor deposition labs in sizes from the sub watt scale to tens of kilowatts.
