Gas Sensitivity of Tin Oxide Organic Films Prepared by Low Temperature PECVD

• Main Authors: Sheng-Hua Hsu, 徐昇華
• Other Authors: Ko-Shao Chen
• Format: Others
• Language: en_US
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/30198810429526636392

碩士 === 大同大學 === 材料工程研究所 === 88 === The development of chemical sensors is flourishing due to the environmental pollution detection and disaster-prevention. In this study, the sensor was fabricated by using PECVD process and Tetramethyltin and O2 as precusors ; further, SnOxC thin films were deposited on comb-shaped electrode. Because of Plasma contains activated species able to initiate chemical and physical reactions at solid surface, the organic gas plasma deposition leads to polymer-forming reactions. In another, graft polymerization of acrylamide (AAm) was used to modify the surface of inorganic materials, which were pre-treated with plasma polymerization. As the result of study, the plasma thickness of film increased with increasing the deposition time in a linear relationship. The plasma deposited containing SnO2 organic film can be provided in humidity sensing. By surface modification of plasma deposited films, transition from hydrophobic to hydrophilic has been achieved. After grafting AAm on plasma deposited SnOxC films, the humidity sensitivity could be improved. Due to Tin dioxide is commonly used as a gas sensor because of its conductivity depends on different gas species and concentration, the gas sensing is also discussed in the study. To stabilize the microstructure and electrical properties of gas sensors, thin film was annealed with antimony to investigate the influence of microstructure in the characteristic of films. As a result of the study, PECVD SnOxC films show the amorphous structure. After annealing treatment, the structure of thin film transferred to crystallization. gas sensitivity was found to decrease with annealing temperature in the range of 330℃ to 630℃, but At 430℃, it shows maximum gas sensitivity. In addition, increasing operating temperature and the concentration of testing gas could improve the sensitivity.