Study on the Low-Temperature PZT Thick Film Microfabrication Process Using Aerosol Deposition Method
Date Issued
2008
Date
2008
Author(s)
Wang, Xuan-Yu
Abstract
This dissertation presents a low-temperature lead-zirconate-titanate (PZT) thick film microfabrication process using aerosol deposition method. The equipment of aerosol deposition has been constructed to deposit the PZT thick film for this research. The PZT film is deposited at room temperature and already has perovskite crystal phase. An ultra high deposition rate 2-10 μm/h can be achieved in a 50 x 70 mm2 deposition area. While the PZT film was annealed by 650 oC for 3 hours, the material quality of the PZT film was about 1/3 compared to its bulk sample. The relative dielectric constant ε33 and piezoelectric constant d31 were 420 and -45 pm/V, respectively. To set up a silicon-based fabrication process of PZT thick film resonators, a special lift-off pattern method has been developed for aerosol deposition method. The negative photoresist THB-151N was selected as the suitable sacrificial layer for lift-off method. In our process, the smallest line width of the PZT microstructure was limited to 30 μm when the thickness PZT film was 10 μm. Based on the developed techniques, PZT double-layer structures have also been fabricated by conducting twice lift-off processes. Besides, the hemisphere PZT shell structures can also be fabricated by paraffin wax. To realize the PZT transducer devices, the 4 x 400 x 1000 μm3 PZT micro-cantilever and the flexion piezoelectric transformer with 1500 μm in diameter have been fabricated. The cantilever was annealed by 4 different temperatures: 390 oC, 450 oC, 550 oC, and 650 oC. The cantilever still has piezoelectricity with the lowest annealing temperature 390 oC. This low temperature process is possible to combine with CMOS process. To improve the flexion transformer from a circumference fixed end bondary, a reduced constraint design with 4 legs was frabricated. The step up ratio is improved from 0.1 to 0.58.
Subjects
PZT
piezoelectric thick film
piezoelectric transducer
aerosol deposition method
low temperature process
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-97-F91543031-1.pdf
Size
23.53 KB
Format
Adobe PDF
Checksum
(MD5):05408bc4f8cfa6c4ee35517b8407a82c