Naik R S, Lutsky J J, Reif R, Sodini C G, Becker A, Fetter L, Huggins H, Miller R, Pastalan J, Rittenhouse G, Wong Y H
IEEE Trans Ultrason Ferroelectr Freq Control. 2000;47(1):292-6. doi: 10.1109/58.818773.
Piezoelectric thin film AlN has great potential for on-chip devices such as thin-film resonator (TFR)-based bandpass filters. The AlN electromechanical coupling constant, K(2), is an important material parameter that determines the maximum possible bandwidth for bandpass filters. Using a previously published extraction technique, the bulk c-axis electromechanical coupling constant was measured as a function of the AlN X-ray diffraction rocking curve [full width at half maximum (FWHM)]. For FWHM values of less than approximately 4 degrees , K (2) saturates at approximately 6.5%, equivalent to the value for epitaxial AlN. For FWHM values >4 degrees , K(2) gradually decreases to approximately 2.5% at a FWHM of 7.5 degrees . These results indicate that the maximum possible bandwidth for TFR-based bandpass filters using polycrystalline AlN is approximately 80 MHz and that, for 60-MHz bandwidth PCS applications, an AlN film quality of >5.5 degrees FWHM is required.
压电薄膜氮化铝（AlN）在诸如基于薄膜谐振器（TFR）的带通滤波器等片上器件方面具有巨大潜力。AlN的机电耦合常数K（2）是一个重要的材料参数，它决定了带通滤波器的最大可能带宽。使用先前发表的提取技术，测量了体c轴机电耦合常数随AlN X射线衍射摇摆曲线[半高宽（FWHM）]的变化。对于小于约4度的FWHM值，K（2）在约6.5%处饱和，这与外延AlN的值相当。对于FWHM值>4度的情况，K（2）在FWHM为7.5度时逐渐降至约2.5%。这些结果表明，使用多晶AlN的基于TFR的带通滤波器的最大可能带宽约为80 MHz，并且对于60 MHz带宽的PCS应用，需要AlN薄膜质量的FWHM>5.5度。
