本研究使用溶膠凝膠法(sol-gel method)製備鋯鈦酸鉛(PZT)壓電感 測晶片。利用鋯鈦酸鉛薄膜的壓電特性，經由外加電壓使壓電薄膜產生振動，作為微重量感測元件。X-Ray 繞射實驗顯示出壓電薄膜擁有單一鈣鈦礦晶格結構，並藉由直流量測及高頻交流阻抗量測，來分析壓電感測晶片電流密度、極化特性及共振特性。本研究進而藉由微製程技術使晶片微小化，提升晶片感測的靈敏度，並將感測系統加以整合，成為高靈敏度及穩定的微重量感測系統，未來將提供在大腸桿菌之重量感測，加以應用於食品及生物醫學感測領域。 In this research, microbalance devices were developed with piezoelectric material to measure biomass based on change of resonant frequency. The sensor structure consists of a square piezoelectric PZT thin film. The Pb1.2(Zr0.52Ti0.48)O3 (PZT) thin film was prepared on Pt/Ti/SiO2/Si surface by sol-gel coating method. We designed different sizes of working area (50 × 50 μm2, 100 × 100μm2, 250 × 250μm2, 400 × 400μm2) and verified piezoelectric properties of these PZT devices. The crystallization and microstructure of the PZT thin films were characterized by X-ray diffraction and scanning electron microscopy (SEM). In this result, the PZT thin film annealed at 700℃ for 50 min showed single-phase perovskite peaks. SEM micrograph revealed that the PZT film with thickness of about 600 nm has uniform microstructure without any cracks. In the electrical properties, the leakage current density rose as the piezoelectric working areas increased. The C-V property exhibited complete butterfly patterns, whose symmetry increased with increasing piezoelectric working areas. Besides, the tunability at 250 × 250μm2 working area was maximum, hence it has excellent piezoelectric characteristic. Further, we used potassium hydroxide (KOH) wet etching technique to reduce the backside thickness.This device has great potential for biomolecular detection.
