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作者对溅镀的压电膜能否应用于甚高频至微波频率的声波器件进行了研究。本文介绍了切变波谐振器用的C轴倾斜的氧化锌(ZnO)和氮化铝(AlN)膜的生长及特性。文中计算了某些膜的切变波激动的定向关系。这些膜在C轴取向与表面法线成大约45°时,可能激励出接近于纯的切变波。在其他角度,则只能激励准切变波和准纵向波。 C轴对膜法线倾斜方向合适的ZnO或AlN膜,是在配有辅助阳极的反应式直流面磁控管溅镀系统中生长的。这类膜可用扫描式电子显微镜(SEM)和体声波器件测量法进行鉴定。自Si基片法线倾斜的C轴晶粒柱形结构可在扫描式电子显微镜中清楚地看到。C轴倾斜角达45°,厚度达10微米的薄膜已经制做成功。在P~+Si基片上溅镀上ZnO和AlN可以制成复合谐振器。这类谐振器的Q值在200兆赫到500兆赫基频谐振范围内大约为5000。特别令人感兴趣的是可以对谐振频率进行温度补偿。在ZnO/Si和AlN/Si的复合结构上已制造出室温下串联谐振频率的绝对温度系数小于1×10~6/℃的谐振器。ZnO和AlN晶片谐振器的温度系数已测出为-36.2×10~-6/℃和-25×10~-6/℃。这表明P~+Si基片在切变膜时的温度系数大约是+9×10~6/℃、
The authors have investigated whether sputtered piezoelectric films can be used in sonic devices from very high frequencies to microwave frequencies. This article describes the growth and properties of C-axis tilted ZnO and AlN films for use in a shear wave resonator. In this paper, the directional relationship of shear wave activation of some films has been calculated. These films, when oriented in the C-axis at approximately 45 ° to the surface normal, may excite a nearly pure shear wave. In other perspectives, quasi-shear waves and quasi-longitudinal waves can only be excited. The C-axis ZnO or AlN films suitable for film normal tilt are grown in a reactive-dc magnetron sputtering system equipped with an auxiliary anode. Such films can be identified by scanning electron microscopy (SEM) and bulk acoustic wave device measurements. The C-axis crystal grain columnar structure inclined from the normal to the Si substrate can be clearly seen in a scanning electron microscope. C-axis tilt angle of 45 °, the thickness of 10 microns film has been made successfully. Sputtering ZnO and AlN on the P ~ + Si substrate can be used as a composite resonator. The Q of this type of resonator is about 5000 in the fundamental frequency range of 200 MHz to 500 MHz. Of particular interest is the temperature compensation of the resonant frequency. In the composite structure of ZnO / Si and AlN / Si, a resonator with an absolute temperature coefficient of the series resonance frequency of less than 1 × 10 -6 / ° C at room temperature has been fabricated. The temperature coefficients of the ZnO and AlN wafer resonators have been measured as -36.2 x 10 -6 / C and -25 x 10 -6 / C. This shows that the temperature coefficient of P ~ + Si substrate is about 9 × 10 ~ 6 / ℃,