Identification of pore size in porous SiO2 thin film by positron annihilation

• Published in: Chinese physics C Vol. 33; no. 2; pp. 156 - 160
• Main Author: 张哲 秦秀波 王丹妮 于润升 王巧占 马雁云 王宝义
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.02.2009; Graduate University of Chinese Academy of Sciences, Beijing 100049, China%Key Laboratory of Nuclear Analysis Techniques, Institute of High Energy Physics, CAS, Beijing 100049, China%China Institute of Atomic Energy, Beijing 102413, China; Key Laboratory of Nuclear Analysis Techniques, Institute of High Energy Physics, CAS, Beijing 100049, China
• Subjects: 二氧化硫多孔薄膜; 多普勒; 正电子歼灭技术; 铝-硅薄膜; porous SiO2 thin film; A1-Si thin film; positron annihilation
• ISSN: 1674-1137; 0254-3052; 2058-6132
• DOI: 10.1088/1674-1137/33/2/015

Positron annihilation lifetime and Doppler broadening of annihilation line techniques have been used to obtain information about the small pore structure and size of porous SiO2 thin film produced by sputtered Al-Si thin film and etched Al-Si thin film. The film is prepared by an Al/Si 75：25 at.-% （A175Si25） target with the radiofrequency （RF） power of 66 W at room temperature. A 5 wt.-% phosphoric acid solution is used to etch the Al cylinders. All the A1 cylinders dissolved in the solution after 15 h at room temperature, and the sample is subsequently rinsed in pure water. In this way, the porous SiO2 on the Si substrate is produced. From our results, the values of all lifetime components in the spectra of Al-Si thin film are less than 1 ns, but the value of one of the lifetime components in the spectra of porous SiO2 thin film is τ = 7.80 ns. With these values of lifetime, RTE （Rectangular Pore Extension） model has been used to analyze the pore size.