Characteristic Study Of DLC Thin Film Prepared By Ion Beam Assisted UBMS

Diamond-like carbon (DLC) thin film was discovered in the 1970s. It is an amorphous carbon which processes the similar properties with diamond and contains sp3 and sp2 buttons. DLC thin film is widely applied to various fields of mechanical, electronic, optical and medical researches for its properties of high wear resistance, low coefficient of friction, excellent thermal stability, high light transmittance, high resistivity, low dielectric constant and biocompatibility. Especially in optical field, DLC thin film is a hot topic because it can applied as antireflection coating and protection film in infrared region.In this paper, the ion beam assisted deposition (IBAD) technology is employed into depositing DLC thin films by unbalanced magnetron sputtering (UBMS) technology, aiming to figure out the effects of ionic bombardment on DLC thin films (hydrogenous and non-hydrogenous), such as the deposition rate, weave construction, hardness, roughness, refractive index and infrared penetrability of DLC thin films.The research is composed of two parts:a processing of DLC thin films with ion beam after the DLC thin films being deposited; And a simultaneous procession of depositing the DLC thin films by UBMS and bombarding the DLC thin films by ion beam. The effect of ion beam current (20-40mA), bombardment energy (0.8-1.2KeV) and time (6-12min) on DLC thin films (hydrogenous and non-hydrogenous) are discussed in present thesis. For research need, Raman tester is used to measure the content of sp3 and sp2 in DLC thin films, Taylor Hobson profile detector is adopted to test the step height, and the M2000-UI ellipsometer is used to measure the optical constant and thickness of DLC thin films. Moreover, SPECTRUM GX Fourier transform infrared spectrometer is adopted in measuring the infrared transmittance of DLC thin films.The study finds out that,(1) ion bombardment can cause the change of corresponding physical structures and the properties of the DLC thin films, which mainly depend on the ion energy, sp3 constant of DLC thin film will be highest and DLC thin film will process more diamond-like properties when ion bombardment energy is 1.2 KeV. There are dispersed diamond microcrystalline region of carbon thin film amorphous matrix which bombarded by ion beam at the energy of 400-1 OOOeV;(2) Refractive index decreases from 2.2 to 2.09 (1000nm) when the bombardment energy is 1.2 KeV and beam current is 40 mA; Meanwhile, transmittivity increases from 60.65% to 65.98% when optimum bombardment time is 8 min. Roughness of DLC thin film is decreased and the surface is more smooth and dense which bombarded by small bombardment energy (under 800eV) and small beam current (about 20mA);(3) It is found in the study of reaction gas ratio of hydrogenous DLC thin film that the transmittivity can reach 68.66%, and the deposition ration is 4 times higher than that of non-hydrogenous, but the optical properties improvement of hydrogenous DLC thin films is less obvious than that of non-hydrogenous in ion beam assisted experiments.(4) In alternate experiment, the improvement is not very satisfactory. The transmittivity is increased a bit only when bombardment energy is 1200eV, ion beam current is 30mA and bombardment time is 8 min. Compared to the DLC thin films in the alternate experiment, DLC thin films processed by ion beam after being deposited by UBMS have obvious improvements in properties;...