PZT壓電薄膜之懸臂樑微致動元件製程研究

Abstract

本論文研究目的是將PZT壓電薄膜沉積在Si基材的懸臂樑結構上，利用PZT良好的壓電特性趨動懸臂樑(Cantilever beam) 形成一微致動元件(Micro-actuator)。 Cantilever beam的製作過程首先須考量到Si蝕刻的情形，觀察旋轉蝕刻窗的角度對於Si (111)面的底角影響；另外研究熱處理條件對PZT薄膜的微觀結構與P-E特性表現之影響；再探討PZT溶液添加感光劑的方式，以曝光、顯影、燒結步驟製作一有選擇性的PZT薄膜圖形，觀察感光劑對於PZT薄膜的晶向、電性、微觀結構的影響，以此濕式蝕刻薄膜的方式應用在Cantilever beam的製程中，將是未來值得探討的方向。 另外研究Si和PZT之間加上含有glass的介面材料，觀察介面材料與SiO2/Si的燒結情形，作為以後Si bonding的參考。

The good quality piezoelectric characteristics of PZT materials can be used for the fabrication of piezoelectric micro-actuator. In the investigation, we first focused on the processing development of sol-gel PZT films along with Si bulk micro-machining. It was found that the heating profile of PZT films played an important role in microstructure evolution and P-E electrical properties. Also the adhesion metal in between Pt and SiO2 has a remarkable influence on the phase crystallization of PZT films. In the case of Si- bulk micro-machining, we observed the miss-alignment between pattern mask and Si wafer leads to angle shift. In this research, in order to develop the process of piezoelectric micro-actuator, semiconductor process was used in the fabrication. During the processing, the photosensitive sol-gel PZT precursor along with exposure, development and annealing were also studied to establish their effects on the surface morphology and electrical properties. In addition, the interface bonding between Si and PZT with glass as a interfacial layer was briefly discussed.