Effects of Processing Parameters on the MgTiO3 Dielectric Ceramic Films Prepared by Aerosol Deposition Method

• Main Authors: Li-Gia Teng, 鄧力嘉
• Other Authors: Yu-Chuan Wu
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/j737y9

碩士 === 國立臺北科技大學 === 材料科學與工程研究所 === 95 === The aerosol deposition method(ADM) is a unique technology that enables to deposit MgTiO3 thick film on the Pt/Ti/Si substrate at room temperature. The efficiency of this method is high and the 2-dimensional pattern can be established directly. Through the controls of gas kinds and flux, the influence of processing parameters on the phase components , dielectric properties and microstructures of the MgTiO3 thick film are investigated in this study. The results show that constituents and crystal structures of the thick film do not change as changing the gas kinds and flux, however, the width of peaks on XRD traces are broader than that in raw powder. The changes of densification and thickness of thick films are induced by the differences in the chamber pressure and velocity that caused by different kinds of gas. For the powder having burn out process, the densification of the films is higher under carrier gases Ar，O2，N2. The surface roughness also increases with increasing gas flux. For the TEM observation, the microstructures of as-deposited films consisted of fine grains(＜1 μm) that oriented randomly. The particle are deformed by impaction and stack alternately on the substrate to form lamellar. In the high resolution atom image, the polycrystalline MgO having short-range-ordering structure and amorphous phase are observed between the MgTiO3 grains, they play a important role in the densification of film-forming mechanism . From the C-V curve, the capacitance would not change with bias. On the other hands, the tunability is very stable and dielectric constant would not be influenced by bias. But increasing the thickness of film, the dielectric constant would increase. In the I-V curve, the leakage current of the thick film is low, the value ranges from 4×10-13 to 5.5×10-12 A/cm2 with 3L gas flux; the value ranges from 3×10-12 to 1.3×10-11 A/cm2 with 5L gas flux.