Sputtering

Sputtering is the process of removal of atoms by bombardment with high speed ions. It is similar to etching, but instead of using an acid to remove material, the material (usually a thin layer) is exposed to an ionized gas. Sometimes the purpose of sputtering is to remove a material from a target to allow it to be deposited on something else. In semiconductors, sputtering can be used to move atoms from a silicon dioxide target to be deposited (along with specific contaminants) onto transistors and chips.

Sputtering is thought to be at work on planets and asteroids as well. The Solar wind provides ionised gas which can convert rocky materials into gas to form a tenuous atmosphere, or can help blow away the atmosphere that a planet has.