- Conventional cleaning methods often fail to completely remove surface films, leaving a thin
contamination layer; additionally, solvent cleaning typically leaves a surface residue
- Plasma cleaner use exposes the surface to a gas plasma discharge, gently and thoroughly
scrubbing the surface
- Plasma cleaning will remove non-visible oil films, microscopic rust or other contaminants that
typically form on surfaces as a result of handling, exposure or previous manufacturing or cleaning
processes; additionally, plasma cleaning does not leave a surface residue
- A plasma cleaner can treat both a wide variety of materials - including plastics, metals and
ceramics — as well as complex surface geometries
- A plasma cleaner is most commonly used prior to adhesive bonding both to clean away loosely
held contaminant residues and to activate the surface for increased bonding strength
Figures 1 and 2 below show the ATR spectra, respectively, of Ge and Si substrates prior to and
following surface contaminant removal via plasma cleaning.

Figure 1. ATR spectra (qave=45°, N=20) of a Ge surface before and after plasma cleaning
with a Harrick plasma cleaner. The lower trace shows Ge coated with a thick (about I micron) film
of photoresist (AZ111). The upper trace shows same surface after fifteen minutes of plasma cleaning
with 02, indicating Ge is restored to its original organic free condition with the photoresist
stripped off the surface.

Figure 2. Harrick plasma cleaner hydrocarbon removal from the surface of a silicon ATR plate
(60 reflections, q = 45°). The C-H band (bottom trace), representing 10% absorption, is completely
eliminated (top trace) after one minute exposure to an air plasma.