Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5367483 | Applied Surface Science | 2007 | 6 Pages |
Recently electron cyclotron resonance (ECR) plasma have been explored for wafer cleaning applications, since it is known to do less damage to silicon surface than conventional plasma. Organic contaminants removal efficiency and plasma radiation damage of the ECR plasma cleaning have been investigated. In oxygen ECR plasma cleaning, the plasma exposure time needed to remove the organic contaminants on the silicon surface down to the detection limit is 40Â s, but the one to reach the lowest surface roughness is 10Â s. The leakage current level of the MOS capacitor made using the Si substrate exposed to oxygen ECR plasma for 40Â s is 8Â ÃÂ 10â9Â A. The optimum exposure time determined by considering the contaminants removal efficiency and the plasma radiation damage (or the leakage current level) is 40Â s. Organic contaminants seem to be removed through both sputter-off mechanism by oxygen ion bombardment and evaporation mechanism by chemical reactions with excited oxygen atoms.