Research on Surface Roughness of Acid Etched Silicon Wafers

With the development of power electronic devices, the market demand for acid etched wafers of monocrystalline silicon, which has good surface properties and minimum surface roughness, increases rapidly. But there has been rarely report about the impact of acid etching process on the wafer surface roughness. This paper studied the surface roughness of the wafer, which was etched by mixture of HNO3, HF and HAC. The results showed that the surface roughness became smaller with the increase of wafer remove amount, while the roughness became worse with the service life extension of the acid; however, fluid infusion discharge method could be adopted in the etching process so that the etching acid system could achieve a relatively balanced state and wafer roughness became stabilized. The process mechanism was studied and analyzed in this investigation.