Improvement in Bioactivity of Single Crystalline Silicon Wafer

Silicon wafers as ideal choice of substrate materials for fabrication of microchips, including biochips and the package materials of biosensors. The surface bioactivity and biocompatibility of silicon are usually poor and the interaction between silicon-based biosensors or microelectromechanical systems (MEMS) and the human body may not be desirable. According as our previous work and literatures, the special hlction groups (Si-H, Si-OH and Si-0) on the silicon wafer may be beneficial to improve its bioactivity and biocompatibility. Therefore, to obtain the special function groups on the silicon wafer, in this work, the surface of the single crystal silicon wafer are modified using wet chemical etching methods and plasma immersion ion implantation technology for improving its bioactivity and biocompatibility. The structure and compositions of the treated silicon wafer were examined using various surface characterization technologies, such as AFM, SEM, TEM, Raman, RBS, SIMS and etc. The bioactivity of the silicon wafer treated using various methods were also investigated by simulated body fluid soaking test. After treatment using wet chemical etching methods and plasma immersion ion implantation technology, the silicon wafer possessed a surface consisting of Si-OH and/or Si-H groups. Bone-like apatite could be precipitated on the surface of the treated silicon wafer after soaking in simulated body fluids for two weeks. The results indicate that the bioactivity of the silicon wafer can be improved by wet chemical methods and plasma immersion ion implantation technology.