English

应用科学学报 ›› 1991, Vol. 9 ›› Issue (2): 117-122.

• 论文 • 上一篇    下一篇

氮化铝薄膜微波换能器的研制

刘付德1, 梁子南2   

  1. 1. 西安交通大学;
    2. 电子科技大学
  • 收稿日期:1989-12-04 修回日期:1990-06-21 出版日期:1991-06-30 发布日期:1991-06-30

INVESTIGATION OF ALUMINIUM NITRIDE THIN FILMTRANSDUCERS

LIUFU De1, LIANG ZINAN2   

  1. 1. Xi'an Jiaotong University;
    2. University of Electronic Science and Technology of China
  • Received:1989-12-04 Revised:1990-06-21 Online:1991-06-30 Published:1991-06-30

PDF

69

被引次数

3

摘要： 阐述用直流平面磁控溅射法在z-LiNbO3传声介质上淀积出优质氮化铝薄膜,并制成了一维纵模微波换能器,还由它制成了微波体声波延迟线.该延迟线在中心频率为2.21GHz、延迟时间为1.83μs下插损为22dB,带宽(3dB)为13%.对在微波频率下应用的这种AlN压电薄膜,由导纳法经实验曲线和理论计算结果的拟合获得这种横向受夹厚度模压电薄膜的机电耦合系数为0.13,这个结果略小于块材AlN的值,可能主要是由于所生长的AlN薄膜微晶晶粒的c轴方向有一定的分散性和c轴反向性所致.从电导测定结果表明换能器中有一等效的串联电阻,它可用于说明匹配和调谐换能器存在损耗的原因.

关键词: 氮化铝, 薄膜, 换能器

Abstract: A one-dimension longitudinal model microwave transducer made with high quality piezoele otric aluminium nitride thin films is reported in this paper. These films are deposited by d. o. planar magnetron sputtering on a z-LiNbO3 propagation medium. With these films, a microwave bulk acoustic wave delay line is fabricated which has a time delay of 1.83 μs, insertion loss of 22 dB, and bandwidth (3 dB) of 13% under the central frequency of 2.21 GHz. For such piezoelectric films used in the microwave frequency, the electromechanical coupling coefficient (kt) of 0.13 is obtained by the comparison of theoretical input admittance values of the transducer with the measured values. This kt is smaller than that of the bulk material which may be mainly caused by the derivation and inversion of c-axis orientation in crystallites. The experimental results also show that there is an equivalent series resistance in the, transducer that may illustrate why the tuned and matched transducer has losses.

Key words: transducer, aluminium nitride, thin film