Preparation Of Zirconium(α-Zr) Thin Films On Silicon Substrate By Magnetron Sputtering

Zirconium thin film has good thermal and chemical stability and good electrical conductivity,and its stable hexagonalα-Zr phase is an excellent ohmic contact metal electrode material in silicon-based microelectronic device technology and power electronic device technology.In addition,the smaller lattice mismatch and thermal expansion coefficient difference betweenα-Zr and Si and Ga N materials will also play an important role as a buffer layer in preparing high-quality Ga N thin films and improving the performance of Ga N power electronic devices.In this paper,for the practical value of preparing Zr thin films on Si substrate in the semiconductor field,the most commonly used magnetron sputtering process is adopted.By improving the sputtering process and optimizing the sputtering parameters,the single preferred orientation growth ofα-Zr thin films on Si substrate is realized.X-ray diffractometer（XRD）was used to characterize the phase and crystal structure of the film,and the relationship between growth parameters,film structure and growth quality was analyzed.X-ray rocking curve（XRC）was used to further measure the growth quality of the films.The effects of growth conditions on the resistivity,carrier concentration and conductivity type of thin films were studied by Hall measurement.Scanning electron microscope（SEM）and atomic force microscope（AFM）were used to test the films with the best growth quality,and the surface morphology characteristics of the films were observed.The α-Zr films prepared by RF magnetron sputtering all achieve the preferred orientation growth in the c axis.Theα-Zr films prepared at 650℃have high crystal quality of quasi-single crystal level,the surface of the films is more flat,and the XRC half height and width are as low as 1.6952°.The film prepared at 550℃has a lower resistivity(5.70×10^-5Ω×cm).On Si（111）substrate,a thicker zirconium nitride barrier layer was first prepared at a higher growth temperature of 650℃and a lower RF sputtering power of 100W,and then zirconium metal thin film was prepared.However,higher crystal quality growth of zirconium metal thin film was not achieved,but due to the pure phase and high single preferred orientation of zirconium nitride thin film.The miscible growth or polycrystalline growth of zirconium films with poor crystal quality can be caused.The growth process of α-Zr thin films prepared by magnetron sputtering was optimized.It is found that the crystal quality of zirconium films prepared by DC magnetron sputtering is better,and the grain size（68.60nm）is about twice that of the films prepared by RF.The zirconium nitride barrier layer prepared on Si substrate can achieve pureα-Zr phase growth,but theα-Zr（002）highly preferred orientation high crystal quality growth is not achieved.Theα-Zr films prepared after 30min deposition of Zr N are obviously better than those prepared after 10min deposition.The grain size can reach 66.86nm,and the resistivity of the films can still reach the level of 10^-6Ω×cm,which is not affected by the increase of film thickness.The films prepared at 0.25Pa have better crystal quality than those prepared at 0.5Pa.The XRC half-width and height are only 4.3315°,and have a higher deposition rate of 561nm per hour and a smooth morphology with a roughness of 2.99nm.The crystal quality and conductivity of the films do not change linearly with the sputtering power.Higher sputtering power is more conducive to improving the growth rate and quality of the film and enhancing the conductivity of the film.At 25W,the crystal quality of the film is better,and the grain size can reach 79.63nm.And at 100W the film has a lower resistivity,resistivity can reach 6.8×10^-6Ω×cm.In this paper,a growth process for preparing high-qualityα-Zr thin films on Si substrate is obtained,which shows that the performance ofα-Zr thin films can be effectively improved by improving the growth process ofα-Zr thin films and further exploring the growth mechanism ofα-Zr to meet the application in Ga N power electronic devices.Therefore,this paper can provide some data and technical reference for the application ofα-Zr thin films in the field of ohmic contact electrode materials in power electronic devices and the preparation of Ga N thin films.