Glow Discharge Plasma Cleaning
Glow Discharge Plasma is a soup of low-pressure ionized gases which can clear nano or micro-scale contaminants from surfaces. Plasma Cleaning applies these energetic ions to the surface in a vacuum chamber before any surface process. The Plasma Cleaning Process cleans the surface and improves its adhesion using oxygen or air, as ionized gases. It would be better to use oxygen or air instead of Argon gas because O2 or oxygen mixture gas could react with organic contaminants and remove them from the surface very efficiently. More than cleaning, this plasma makes the surface activate, which leads to better adhesion and bonding.
Carbon support film in the TEM grid is hydrophobic due to hydrocarbon contamination which causes the water to beads up into droplets and does not expand uniformly. So, this surface needs to be cleaned and hydrophilized before TEM imaging of water included solutions. The Desk Sputter Coater – DSR1 hydrophilizes carbon support film using air gas in less than 10 minutes. This process is run by a DC electrical field, usually in 25 mA current.
Notably, the plasma cleaning in our Vacuum Coating Systems has a self-protection option. It means that plasma cleaner could work for a maximum of 30 minutes which is generally enough for the hydrophilization or cleaning process. However, if more time has required for cleaning, a 15-minute time interval would be needed to prevent any damage to the device. This time will show as a reverse counter on the plasma cleaner window.