Denton Vacuum - Sputtering Systems

Read the Technical Paper:
Thickness Distribution of Evaporated Films

The emission distribution characteristics of an evaporation source can be used to define the correct geometry in the vacuum chamber for the production of uniform-thickness coatings.

Producing a coating of uniform thickness over a large aperture substrate, or over a rack loaded with many small substrates, can be done by making repeated trials with the rack loaded with test pieces. From one trial run to the next, the geometry is intentionally changed - the evaporation source offset increased, for example - until the best arrangement is found.

In this paper, we first measured the thickness of coatings on test pieces positioned at known radial distances on a single rotation flat rack in the vacuum evaporation chamber and used these data to find the source emission function. The known emission function was then used to determine the source offset and calotte curvature, which produced the best thickness uniformity over the diameter. 

Lower Cost of Ownership...Higher ROI 

Ion Assisted Deposition provides high-quality, defect-free, low stress, environmentally-stable (shift-free) films that are required by the most demanding optical applications. 

You’ll benefit from:

• Independent control of ion current density and ion energy to optimize film properties
• Long-term operation with 100% O2 or N2 reactive gases for stable operation with no process drift for extended runs

A cold cathode ion source is a differentially pumped device with one end of the plasma chamber open to the vacuum environment. The operational parameters of the ion source and the quality of the films are affected by the parameters controlling the vacuum level. It’s much easier to make good films in systems with high pumping speeds. When comparing IAD film deposition parameters, differences in pressure may be due to the pumping speed.

To read about the effects of pumping speed on the cold cathode ion source, download our technical paper.