The Deposition And Research Of H-BN/diamond Multilayer Structure Films For High-frequency SAW Device

The SAW (Surface acoustic wave) technology is a kind of burgeoning technology,developed from the end of 60's twentieth century. it is a cross knowledge of the acoustics, the optics and the electronics. h-BN(hexagonalBN) is a kind of broadband semiconductor material which has a lot of excellent properties and an extensive application foreground.It has high acoustic transmission rates and excellent optical performance. So it could be the suitable piezoelectric thin film in SAW devices. Therefore,"h-BN /Diamond"multilayer structure could be used to optimize the"Piezoelectric films/ high acoustic velocity material"films in SAW devices.In this paper, using RF magnetron sputtering technique, h-BN thin films are deposited respectively on Si and Diamond substrates with different technical parameters. The structural properties of the films are analyzed by Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscope(SEM). The experimental results show that: these films are all h-BN; the suitable experimental parameters are : substrate temperature is around 400℃, too low or too high is not conducive to h-BN deposition; sputtering power is from 200W to 240W; the substrate bias voltage is around 100V; the working pressure is 1.2Pa-1.6Pa; the inverse proportion of N2 and Ar is 9:3, and the nitrogen content in 20% to 25% are most conducive to the formation of h-BN thin films. According to the analysis of the thin films by FTIR and SEM, we find that the films are uniform and smooth,and can adhere to the surface of the diamond substrates. Therefore, it could be able to deposit h-BN thin films on Diamond substrates to form the h-BN /Diamond multilayer structure, and fabricate high quality SAW devices.