Abstract Ions bombardment is very important in thin films and surface processing. The ionenergy and ion flux are two important parameters in ion bombardment. The ion current densitymainly dependent on the plasma density gives the number of energetic ions bombarding thesubstrate. The self-bias voltage in plasma sheath accelerates plasma ions towards the substrate.RF discharge can increase plasma density and RF bias can also provide the insulator substrate witha plasma sheath. In order to choose and control ion energy,ion density,the angle of incidence,and ion species, ion beam sources are used. New types of electrodeless ion sources (RF, MW,ECR-MW) have been introduced in detail. In the last, the effects of ion bombardment on thinfilms and surface processing are presented. Abstract Ions bombardment is very important in thin films and surface processing. The ionenergy and ion flux are two important parameters in ion bombardment. The ion current density mainly dependent on the plasma density gives the number of energetic ions bombarding thesubstrate. The self-bias voltage in plasma sheath accelerates plasma ions towards the substrate. RF discharge can increase plasma density and RF bias can also provide the insulator substrate witha plasma sheath. New types of electrodeless ion sources (RF, MW, ECR-MW) have been introduced in detail. In the last, the effects of ion bombardment on thinfilms and surface processing are presented.