Surface engineering of standing hollow circular cylinder ordered arrays (HCCA) and used as platform for excellent SERS substrate

Herein, we reported a facile and efficient method to mass fabricate special structure of standing hollow circular cylinder ordered arrays (HCCA). The strategy of fabrication of the HCCA is reactive ion etching of silicon covered with monolayer colloidal spheres as mask under the mixture of SF6 and O2 plasma. Based on study of the whole formation process and different factor (such as sample stage, the flow of SF6 and O2, power), we put forward the formation mechanism of HCCA. Research shows that Al sample stage play a crucial effect in formation of such structure. And the presence of O2 and the flow of SF6 are also important factor. Based on HCCA as platform, we can obtain Au@ HCCA structure through sputtering deposition method. The formed Au@HCCA can be used as SERS substrate, and exhibit excellent SERS property using Handheld Raman Spectrometer excited with wavelength of 785 nm. The finite difference time domain (FDTD) simulation results have revealed that SERS "hot spots" are almost distributed at edge site of Au@HCCA. Obviously, such HCCA structure as platform, it can also be applied to a more wide range of fields.