The use of negative ion beams for self-sputtering deposition method has been applied as a new and very practical way to obtain highly pure thin films. With this method the sputtering ion beam is composed of the same element that composes the target sputtered by this ion beam. The ions for sputtering are not anymore impurities of the film as is the case of conventional sputtering deposition methods where for example argon ions are used as sputtering material. Furthermore since the negative ion source does not use any gases for plasma discharge deposition circumstances can be kept very clean which means a reduction of the inclusion of impurities such as hydrogen or oxygen in the film.