| Positive and Negative Pulse Etching Method of Porous Silicon Fabrication |
| |
| 作者姓名： | 葛进 殷文静 龙永福 丁训民 侯晓远 |
| |
| 作者单位： | State Key Laboratory for Surface Physics, Fudan University, Shanghai 200433 |
| |
| 基金项目： | Supported by the National Key Basic Research Programme of China, and the National Natural Science Foundation of China under Grant No 10321003. |
| |
| 摘 要： | We present a new method in which both positive and negative pulses are used to etch silicon for fabrication of porous silicon （PS） monolayer. The optical thickness and morphology of PS monolayer fabricated with different negative pulse voltages are investigated by means of reflectance spectra, scanning electron microscopy and photoluminescence spectra. It is found that with this method the PS monolayer is thicker and more uniform. The micropores also appear to be more regular than those made by common positive pulse etching. This phenomenon is attributed to the vertical etching effect of the PS monolayer being strengthened while lateral etching process is restrained. The explanation we propose is that negative pulse can help the hydrogen cations （H^＋） in the electrolyte move into the micropores of PS monolayer. These H^＋ ions combine with the Si atoms on the wall of new-formed micropores, leading to formation of Si-H bonds. The formation of Silt bonds results in a hole depletion layer near the micropore wall surface, which decreases hole density on the surface, preventing the micropore wall from being eroded laterally by F^- anions. Therefore during the positive pulse period the etching reaction occurs exclusively only at the bottom of the micropores where lots of holes are provided by the anode.
|
| 关 键 词： | 脉冲 硅 多孔渗水 光学 |
| 收稿时间： | 2006-12-18 |
| 修稿时间： | 2006-12-18 |
Positive and Negative Pulse Etching Method of Porous Silicon Fabrication |
| |
| GE Jin,YIN Wen-Jing,LONG Yong-Fu,DING Xun-Min,HOU Xiao-Yuan.Positive and Negative Pulse Etching Method of Porous Silicon Fabrication[J].Chinese Physics Letters,2007,24(5):1361-1364. |
| |
| Authors: | GE Jin YIN Wen-Jing LONG Yong-Fu DING Xun-Min HOU Xiao-Yuan |
| |
| Affiliation: | State Key Laboratory for Surface Physics, Fudan University, Shanghai 200433 |
| |
| Abstract: | We present a new method in which both positive and negative pulses areused to etch silicon for fabrication of porous silicon (PS) monolayer. The optical thickness and morphology of PS monolayer fabricated with different negative pulse voltages are investigated by means of reflectance spectra, scanning electron microscopy and photoluminescence spectra. It is found that with this method the PS monolayer is thicker and more uniform. The micropores also appear to be more regular than those made by common positive pulse etching. This phenomenon is attributed to the vertical etching effect of the PS monolayer being strengthened while lateral etching process is restrained. Theexplanation we propose is that negative pulse can help the hydrogen cations (H+) in the electrolyte move into the micropores of PS monolayer. These H+ ions combine with the Si atoms on the wall of new-formed micropores, leading to formation of Si--H bonds. The formation of Si--H bonds results in a hole depletion layer near the micropore wall surface, which decreases hole density on the surface, preventing the micropore wall from being eroded laterally by F- anions. Therefore during the positive pulse period the etching reactionoccurs exclusively only at the bottom of the micropores where lots of holes are provided by the anode. |
| |
| Keywords: | 78 20 -e 61 43 Gt 74 25 Gz 78 55 Mb |
| 本文献已被 维普 等数据库收录！ |
| 点击此处可从《中国物理快报》浏览原始摘要信息 |
|
点击此处可从《中国物理快报》下载免费的PDF全文 |
