Preparation Of Silicon Nanowires By Chemical Etching

Nano science and technology was born in the late 1980 s,and now nano science and technology in rapid development stage. Nano science and technology refers to the material on the atomic and molecular scale, semiconductor nanometer science and technology is the most important and the most active part of nano science. Silicon semiconductor is a kind of three-dimensional material, while silicon nanowires is nanometer level in two dimension,silicon nanowires is one-dimensional semiconductor materials.C haracteristic of silicon nanowires, in physical, chemical, electrical and optical is different,compared with nature of crystal silicon. Silicon nanowires have been lots research and application,for examples in solar cell, optoelectronic devices and nano electronic devices.Undoubtedly, the fabrication of silicon nanowires, which is the foundation of its performance research and application, is the focus of semiconductor nano- materials research. In this research we uses silver assisted chemical etching solution method, and research power up the current impact on the preparation of silico n nanowires, the preparation technology, compared with other preparation technology is inexpensive, simple operation and suitable for mass production, and many other advantages.This research we uses the electrolytic solution preparation of silicon nanowires, and on the basis of a large number of experiments, using optical microscope, scanning electron microscope(SEM) to observe the sample surface and cross-section morphology, study samples along with the changing rule of the etching conditions.This study found that, samples in silver nitrate and HF solution with 1h corrosion, the corrosion sample best temperature is around 50℃. The corrosion of the sample at 50℃ and the sample without corrosion,then the samples under the same etching conditions, after 50℃ corrosion experiments of samples etching with silicon nanowires, however direct etching silicon without silicon nanowires. This study we found that the corrosion process of sample plays a vital role in preparation of nanometer silicon etching process.Under the condition of low current etching, with the increase of etching time, samples of etching is more and more deeply, Samples preparation etching time 4h have the best silicon nanowires form, when etching time greater than 4hours after samples appeared over etching phenomenon. At the same time, this study found that the sample etching rate proportional to the size of the etching current. When etching current is 3mA, samples form of silicon nanowires appear statified phenomenon..The sample after 50℃ corrosion,samples under the condition of large current,the etching rate is increased with the increase of current, In this study we found in 30 mA electrical flow produce silicon nano layered, etching current 50 mA tiered disappear.Corrosion under large current(change the direction of current) produced silicon nanometer when the samples be etching,the fabrication of silicon nanowires with length increases and diameter decreases.