1. Sputtering is a phenomenon in which microscopic particles of a solid material are ejected from its surface, after the material is itself bombarded by energetic particles of a plasma or gas. (Wikipedia). 2. Removal of surface material (atoms, clusters and molecules) by particle bombardment. (IUPAC). 3. A process that uses ions of an inert gas to dislodge atoms from the surface of a crystalline material, the atoms then being electrically deposited to form an extremely thin coating on a glass, metal, plastic, or other surface. (dictionary.com)