Abstract: The subject of this paper is a review of the recent important progress in ion beam science and technology─from low dose(10¹¹~10¹⁶/cm²)ion implantation as a doping method of semicon-ductors to ion beam synthesis (IBS) by high dose(10¹⁷~10¹⁸/cm²) ion implantation as a means of forming new materials. The physical effects of high dose ion implantation, the formation process of SIMOX(Separation by Implanted Oxygen) materials, and various applications of ion beam synthesis are discussed.