• 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.