The ion assist solution to your vacuum coating problems!

Dr. Clive Burton President of DIGI Mount

Do you have coating adhesion problems?
Do you have poor abrasion resistance?
Do you have unacceptable absorption?
Do you deal with fussy materials like MgF₂?
Does your present ion gun fail in the middle of a run - or is it a gas hog, a pain to maintain, pitifully weak in actual ion current delivered?

DIGI Mount promotes and facilitates sales of gridless ion beam systems that can solve these problems.

DIGI Mount also provides consulting advice in designing and implementing both ion-assisted evaporative and DC reactive sputter deposition systems.

Uses of Ion Guns

Space Race Heritage: Ion guns first evolved from attempts to provide efficient propulsion for space vehicles.

Ion beam sources are used in essentially two different modes:

Preclean

• An ion gun can be used for a preclean step immediately before evaporation
• Gold films deposited by an evaporation-only method, using cold substrates, adhere very poorly.
• In contrast, gold films deposited with an ion gun preclean can have such superb adhesion that attempts to remove the gold from a glass surface will result in breakage of the glass itself rather than the bond between it and the gold film!
• Glow Discharge precleaning is ineffective because:
  • it takes place early in the pump down cycle so the substrate has time to re-contaminate before deposition
  • the energies and fluxes are relatively low

Ion Assisted Deposition IAD (or Ion Beam Assisted Deposition IBAD)

• These gridless ion sources can provide ion beam currents up to a total of 2.5 Amps which is sufficient to make significant improvements to the properties of vacuum evaporated thin films even in quite a large chamber. These improvements include:
  • much better primary adhesion as discussed above
  • much higher film density so that the films are much less sensitive to the ingress of water.
    
  • consequent upon the higher film density – significantly higher refractive indices which allow more design flexibility and better optical performance.
  • better stoichiometry and lower optical absorption
    
  • the ability to tailor the properties of each layer in a multilayer stack so that the overall stack may have the most appropriate durability parameters including those related to abrasion resistance i.e. stress, hardness and lubricity.