An analysis on synthesizing large-area silicon nanowire arrays by electroless metal deposition

One-dimensioned semiconductor nanostructures have demonstrated to be good materials for novel nanoscale optoelectronics and high-sensitivity molecule sensors. Recent years have seen increased attention given to silicon nanowires (SiNWs), owing to their unusual quantum-confinement effects for developing various applied device, such as optoelectronics, biosensor, and other devices. The key application is the geometric control of fabricated SiNWs including their lengths, sizes, and orientations. Therefore, in this paper, simple and convenient approach to generate SiNWs of single-crystalline, well-aligned, and large area has been directly synthesized on p-type (100) silicon wafer via an electroless metal deposition (EMD) method The experimental results show that microstructures of SiNWs have been observed at the concentration ratio of 0.02M: 4.6M for AgNO₃/HF at 50°C with different chemical etching time. Growing structures and physical properties of the SiNWs arrays were analyzed and investigated by the scanning electron microscopy (SEM), Raman Spectrum, and X-ray diffraction spectrum (XRD), respectively. The following experimental results were obtained: (1) the length of SiNWs arrays which are grown on the (100) wafer shows a linear relationship with the reaction etching time; (2) the Raman peak of the SiNWs shows a downshift and asymmetric broadening due to the phonon quantum confinement effects and intensity enhancement, compared with that of bulk crystal silicon; (3) the XRD analysis indicate that highly dominant peak at 69° is belong to (004) silicon plane. It has been observed that the best quality of SiNW arrays can be obtained by electroless metal deposition (EMD) which is simple and low cost These large-area SiNW arrays could be expected to have favorable applications in bio-technology, optoelectronic devices or so on.