Prepration And Optical Properties Of AlN Thin Films Deposited By Magnetron Sputtering

AlN thin films were deposited by DC magnetron reactive sputtering on p-Si(111) and glass substrates. The influence of working pressure, substrate temperature, sputtering current and N2 content on the structure and optical property of AlN thin films were investigated by adopting single parameter change method, using supply beneficial reference.The main conclusions are as follows:1) AlN thin films deposited under different working pressure present hexagonal phase AlN(100) and AlN(110) orientation, as the working pressure increase, the intensity of XRD peak weaken gradually and the deposition rate of thin films first increases then decreases; when the working pressure is 0.6Pa, band gap of the as-deposited AlN thin films was 5.93eV, which is close to the intrinsic band gap(6.2eV).2) The influence of substrate temperature on the AlN thin films orientation was obvious. When the substrate temperature is below 400℃, there is a transition of the orientation from hexagonal phase AlN(002) to (100) and (110); AFM of thin films shows that higher substrate temperature is good for uniformity of the thin films; as the substrate temperature increases, average transmittance of samples decreases in the wavelength range from 200 to 1000nm; when the substrate temperature is 480℃, band gap of the thin films is 5.93eV.3) The sputtering current has strong effect on the AlN thin films orientation, h-AlN(100)and AlN(110) diffraction peak was presented in the samples when the sputtering current added up 0.4A; with the sputtering current increases, the deposition rate of thin films increases, and average transmittance of samples decreases obviously in the wavelength range from 200 to 1000nm and the band gap of the thin films gradually increases to 5.93eV.4) With the N2 concentration increase, h-AlN(100)and AlN(110) diffraction peak in thin films are strengthened gradually and the deposition rate of thin films first increases then decreases; average transmittance of samples(N2 concentration>50%) are above 80% and the maximum value is 95% in the wavelength range from 200 to 1000nm, but samples (N2 concentration<37.5%) is only 70%, so we can see that the N2 content plays an important role in average transmittance of thin films; when the N2 content is 75%, the thin films has a better band gap.