锗/多孔硅和锗/氧化硅薄膜光致发光的比较研究  

Comparative Study on Photoluminescence from Ge/PS and Ge/SiO_2 Thin Films

作　　者：孙小菁[1] 马书懿[1] 魏晋军[1] 徐小丽[1] 

机构地区：[1]西北师范大学物理与电子工程学院,甘肃兰州730070

出　　处：《光谱学与光谱分析》2008年第9期2033-2037,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(60276015);教育部科学技术研究项目(204139);甘肃省高分子材料重点实验室开放基金项目(KF-05-03);甘肃省自然科学基金项目(0710RJZA105)资助

摘　　要：采用磁控溅射技术,以锗为溅射靶,在多孔硅上沉积锗薄膜,沉积时间分别为4,8和12min,及以锗-二氧化硅复合靶为溅射靶,在n型硅衬底上沉积了含纳米锗颗粒的氧化硅薄膜,锗与总靶的面积比分别为5%,15%,30%。各样品在氮气氛中分别经过300,600及900℃退火30min。对锗/多孔硅和锗/氧化硅薄膜进行了光致发光谱的对比研究,用红外吸收谱分析了锗/多孔硅的薄膜结构。实验结果显示,锗/多孔硅薄膜的发光峰位于517nm附近,沉积时间对发光峰的强度有显著影响,锗层越厚峰强越弱。锗/氧化硅薄膜的发光峰位于580nm附近,锗与总靶的面积比对发光峰的强度影响较大,锗/氧化硅薄膜中的锗含量越高峰强越弱。不同的退火温度对样品的发光峰强及峰位均没有明显影响。可以认为锗/多孔硅的发光峰是由多孔硅与孔间隙中的锗纳米晶粒两者界面的锗相关缺陷引起的,而锗/氧化硅的发光峰来自于二氧化硅的发光中心。Ge thin films were deposited on porous silicon substrate using the RF magnetron sputtering technique with Ge target and sputtering for 4, 8 and 12 min respectively. Ge-containing silicon oxide thin films were deposited on n-type Si substrate using the RF magnetron sputtering technique with a Ge-SiO2 composite uarget and with Ge wafer in the target having percentage areas of 5%, 15% and 30%, respectively. These samples were annealed in a N2 atmosphere at 300 ℃, 600 ℃ and 900 ℃ for 30 min. A comparative study of photoluminescence from Ge/PS and Ge/SiO2 thin films is reported. The FTIR was used to research the structure of Ge/PS thin films. The FTIR showed that the Si—Hx（x=1-3） absorption peaks disappeared, but Si—O—Si, Si2O—SiH and H2Si—O2 absorption peaks were enhanced, and the surfaces of Ge/PS thin films have formed a goodish integrated cross-linked Si—O—Si network. It was indicated that Ge thin films deposited on porous silicon can improve the level of oxidation. At the same time, the Si—O and Si—Si bonds on the surface of PS thin films were broken, but some new bands such as Si—Ge, Ge—Ge and Ge—O formed. As the results of the experiment showed that the photoluminescence peaks of Ge/PS thin films were located at 517 nm, the sputtering time influenced the intensity of light-emission remarkably and with increasing the thickness of Ge layer coated, the intensity of light-emission dropped abruptly. When Ge sputtered for 12 min, the photoluminescence peak almost disappeared. The photoluminescence peaks of Ge/SiO2 thin films were located at 580 nm, the percentage areas of Ge wafer in the target influenced the intensity of light-emission obviously, and with increasing the percentage area of Ge wafer in the sputtering target, the photoluminescence intensity was reduced greatly. Though with increasing the annealing temperature of different thin films, all the photolu minescence spectra from Ge/PS and Ge/SiO2 thin films changed scarcely, and our explanation is that Ge-related defects at

关 键 词：锗/多孔硅 锗/氧化硅 光致发光 红外吸收 

分 类 号：O484.41[理学—固体物理]