Study on Surface acoustic wave/semiconductor functional devices

(1)提出了基于外延提升工艺的新型制备工艺。我们研究了提升和键合工艺的最佳条件，并成功地在半导体薄膜中制备了GaAs MESFET，Schttoky二极管。(2)改进了外延提升工艺，在晶圆处理、蚀刻和键合方面取得了进展。利用这些改进的工艺，我们制作了自适应滤波器等半导体协积器件的基本电路，并成功地测量了基本特性。我们还利用x射线和原子力显微镜研究了st切割石英的表面显微特征。我们正在研究这些特征对器件特性退化的影响。(3)采用衬底去除工艺制备GaAs外延膜，在GaAs衬底的AlAs薄膜上生长，并采用Au-Sn共晶键合工艺在Y-ZLINbO3衬底上键合GaAs薄膜。(4)利用石英的x轴反转现象，提出了一种AT-cut谐振器的单片集成技术。澄清了在at切割板上形成的x- x反转区非常有效地降低了板上形成的谐振腔之间的机械耦合。这表明在at切割板上存在谐振器阵列的可能性。(5)我们还研究了使用橡胶传感膜的压电式气体传感器，实验表明，使用各种薄膜的传感器具有不同的选择性，足以作为气体传感器应用。

(1)We proposed new fabrication technology based on epitaxial liftoff process. We investigated the optimal condition for liftoff and bonding processes and succeeded in fabricating GaAs MESFET,Schttoky diode without any damage in semiconductor films.(2)We improved the epitaxial lift-off process and advance in wafer handing, etching and bonding. Using these improved processes, We have fabricated basic circuit for SAW-semiconductor co-integrated devices such adaptive filter and succeeded measuring basic characteristics. We also investigated suface microspico feature of ST-cut quartz using X-ray and AFM.We are studying the effects of these features on degradation of device characteristics.(3)We also applied substrate removal process to release GaAs epitaxial film, which is grown on the AlAs thin film on GaAs substrate and adapted Au-Sn eutectic bonding process to bonding GaAs film on the Y-ZLINbO3 substrate.(4)We proposed a monolithic integration technique for AT-cut resonator using the x-axis inversion phenomenon of quartz. It was clarified that an x-aiis inversion area formed on an AT-cut plate very effectively reduces the mechanical coupling between resonators formed on the plate. This suggests the apossibility of resonator arrays on an AT-cut plate.(5)We also studied piezoeletiic gasses sensor using rubber sensing film and experiments showed that sensors using various kinds of film have different selectivity which is sufficient for application as gas sensors.