A Study of 64×64 Pixels Thermal Insulated Structure for (Pb,Ca)TiO3 Pyroelectric Thin Film Infrared Image Sensors

• Main Authors: Hao-Yu Lo, 羅皓佑
• Other Authors: Chung-Cheng Chang
• Format: Others
• Language: en_US
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/50691113625312903679

碩士 === 國立臺灣海洋大學 === 電機工程學系 === 96 === Abstract In this experiment, pyroelectric Pb0.7Ca0.3TiO3, (PCT) film is deposited on silicon substrate through the Radio-Frequency Magnetron Sputtering System and the integrated pyroelectric film infrared image detector is manufactured. For contrast of corresponding characteristics, two types of integrated pyroelectric film infrared image detectors with different thermal insulation structures are fabricated. Moreover, the measurement and simulated analyses of the thermal image is made with the finished pyroelectric infrared array detector. Regarding the nanoporous silica film, without surfactants aerogel, the porosity and the thermal conductivity coefficient of the porous film are 76% and 24.76(mW/m-K); compared with the addition of surfactants aerogel, the porosity and the thermal conductivity coefficient of the porous film are 81% and 19.87(mW/m-K) respectively, according to measurement and calculation. For the PCT film, the film, from the SEM, AFM and XRD experiments, shows ideal features after a 15-minute annealing process at a temperature of 650℃. For measurement of the electric characteristics of the device, the remanent polarization quantity and the coercive field are 21.5μC/cm2 and 100kV/cm respectively without the surfactants aerogel structure; 25μC/cm2 and 112.5kV/cm when compared with the addition of surfactants aerogel structure. Along with the addition of surfactants of aerogel, all of the remanent polarization quantity and the coercive field trends have obviously risen. Regarding the pyroelectric coefficient, it can be clearly seen that the pyroelectric coefficient with thermal insulation structures are substantially improved. In view of the measurement of the device characteristics, a comparison between the PCT thin film that has been added in with surfactant and the one without any added surfactant has been done, the sensor presents larger voltage response within the frequency range of 2Hz to 7Hz and shows smaller noise voltage and noise equivalent power in the frequency range of 3Hz to 11Hz; it also manifests bigger detection rate and naturalized detection rate within the frequency range of 0.2Hz to 8Hz. On the whole, it could acquire better infrared characteristics for the aerogel with added surfactant. As a result of the above mentioned, we finished the two-dimensional 64*64 pyroelectric infrared detectors. At the same time, we compared them with the addition of surfactants of aerogel thermal insulation structure detectors that formed with the heat detectors and analyzed the advantages and disadvantages. Key words: Infrared Thermal Image Detector, PCT, Residual Polarization Quantity, Coercive Field, Pyroelectric Coefficient, Voltage Response, Specific Detectivity, Surfactant, Nanoporosity