Preparation of AlN Thin Film Deposited on SiO₂ for Improving Temperature Frequency Coefficient of FBAR Used in CSACs

Abstract:

AlN films were deposited by RF magnetron sputtering on the SiO₂ films with different thickness. Preferred orientation, grain size, surface roughness and grain growth of the AlN films were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM) and field-emission scanning electron microscopy (FESEM). It's found that when the thickness of SiO₂ films are 100 nm and 200 nm, the AlN films have characteristics of good C-axis preferred orientation, good surface roughness and vertical grain growth, which are suitable for application in thin film bulk acoustic wave resonators (FBARs). When the thickness of SiO₂ film is 300 nm, although the AlN film has characteristics of good C-axis preferred orientation and surface roughness, the grain growth is tilted, which is not suitable for application in the FBARs.

• Periodical: Advanced Materials Research (Volumes 1004-1005)
• Pages: 791-794
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.1004-1005.791
• Online since: August 2014
• Authors: Zhong Shan Zhang, Liang Tang, Lei Ji
• Keywords: AlN Thin Film, FBAR, Preferred C-Axis Orientation, RF Magnetron Sputtering

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