Preparation And Characterization Of SiAlON/SiC Films Deposited By Magnetron Sputtering

SiAlON/SiC composite film can be used as the protective film for the printer head.Compared with the traditional printer head,film printing has advantages of high strength,good heat resistance and tear resistance.It is often used in high-quality photo printing,advertising consumables,medical printing film and making high-end business card.Therefore,it is required that the film has good uniformity and flatness,and ensure the smooth flow of the media.Good temperature resistance avoids high temperature distortion of printing process;Good adhesion and hardness ensures its service period.Silicon carbide film(SiC)is a very ideal semiconductor material with good electrical and mechanical properties.It has many merits:wide band gap,high thermal conductivity,high temperature resistance,anti-corrosion,high chemical stability characteristics and so on.It has broad market and application prospects as device.structure protective film.For example,SiC film can be used in many high-tech fields such as space technology,nuclear physical and other basic industries such as petrochemicals,machinery,vehicles,shipbuilding.Silicon aluminum oxynitride film(SiAlON)has excellent mechanical properties,physicochemical properties and outstanding performance in the thermal shock test.SiAlON combines the properties of oxide and nitride,with excellent hardness,wear resistance and fracture toughness.These characters allow SiAlON to be used in cutting tools and high temperature structural components to prolong the service time of devices.However,there are few studies on the magnetron sputtering of SiAlON thin films.Bodart et al injected oxygen and nitrogen into the sputtered SixAly thin films by ion implantation to fabricate SiAlON layers.It is also reported that scholars obtain SiAlON films by using unbalanced direct current and radio frequency sputtering deposition.However,the properties of these SiAlON films are not satisfactory.In view of its high adhesion and practical application of the film,SiAlON film is used as buffer layer to prepare the SiAlON/SiC composite film in this experiment.Up to now,the researches on the preparation of SiC thin films by RF magnetron sputtering are relatively complete.However,the research on the preparation of SiC by pulsed DC magnetron sputtering and SiAlON/SiC composite films is still inadequate at home and abroad.Based on above reasons,SiC,SiAlON and SiAlON/SiC composite films were prepared on glass,silicon and ceramic substrates by magnetron sputtering.The influence of bias amplitude,pluse frequency,O2 flow flux and buffer thickness on the properties of films was studied.The result shows that the mechanical properties of the films are excellent.(1)A series of SiC films with different bias amplitudes were prepared by RF magnetron sputtering at room temperature.The morphological and mechanical properties of the films were characterized respectively.The results are as follows:The bias voltage has no obvious effect on the surface morphology and structure of the film.The surfaces of all films are dense and flat,all films are amorphous.With the increase of the bias amplitude,the hardness and adhesion of the film both increase first and then decrease,and reach the maximum value both at 120V:16.05GPa,36N respectively.(2)Using pulsed DC magnetron sputtering technology,SiC hard films were prepared under different pulse frequencies.The effects of pulse frequency on the surface morphology,structure and mechanical properties of the films were also studied.The change of pulse frequency had little effect on the crystallization of the films.The films are all amorphous when the pulse frequency varied from 0kHz to 300kHz.With the increase of the sputtering frequency,the size of film particles gradually decreased smaller,the film surface more dense and smooth.Due to dislocation migration and diffusion in the smaller particles in the film was inhibited,so the higher pulse frequency,the higher hardness values.The adhesion of films sample in this group are between 31N and 39N,which needs to be improved.When the pulse frequency is 250kHz,the film hardness can reach 26.75GPa,and the experiment is repeatable.(3)Using RF magnetron sputtering,SiAlON films were deposited at room temperature to study influence of the changes of oxygen flow rate on the film properties.The Ar flow was set at 50 sccm,nitrogen flow was set at 40 sccm and the oxygen flow was set at 3 sccm,5 sccm,8 sccm and 10 sccm,respectively.Through the test and analysis of the four groups of thin film samples,the following conclusions can be drawn:Four samples of SiAlON films are all amorphous,the change of oxygen flow flux is not enough to change the structure of SiAlON film.The surface morphology of SiAlON film sample changes with oxygen flow rate.The hardness of the film increased and then decreased slightly with the increase of the oxygen flow,reaching 11.21GPa at 5sccm and close to the maximum of 11.57GPa at 8sccm.The adhesion performance is extremely prominent.With the increase of oxygen,the adhesion has a rising tendency,the overall change amplification is not large,all above 72N.Uphold the resource conservation and oxygen excessive influx may affect the performance of the composite film,so 5sccm oxygen was chosen as the best process parameters.(4)We studied the influences of buffer layer thickness on the film performances.Using the experimental methods and the optimized experimental parameters of(2)and(3),SiC composite films with SiAlON buffer layers were deposited at room temperature.SiAlON buffer layer was deposited in RF magnetron sputtering.The thickness of the SiAlON buffer layer is the only variables:500nm,1000nm,1500nm,2000nm and 2500nm.SiC layer was deposited in DC Pulsed magnetron sputtering.The thickness of SiC layer of all the sample-films is 1000nm.The surface of the films is smooth and dense,and the particles have an increasing tendency.After adding SiAlON buffer layer,the composite film not only maintaining the advantages of high hardness SiC film,but also the adhesion was greatly improved.Hardness value is up to 24.41GPa,adhesion is up to 83N.Film particles arranged in short-range order,film structure is amorphous.Magnetron sputtering was used to obtain a new type of composite membrane with outstanding mechanical properties by using two kinds of power sources.Up to now,no report has been published on the mechanical properties of this composite membrane.