Formation And Evolution Of Self-organized Hexagonal Patterns On Silicon Surface By Laser Irradiation In Water

摘要

It was found that laser irradiation of silicon immersed in water can lead to regular hexagonal patterns on the silicon surface with period of ～ 10 μm within several tens of minutes. The formation and the evolution of the surface patterns can be interpreted as Rayleigh-Taylor instability of the melted silicon layer under the interfacial pressure formed by fast boiling of the interfacial water at the laser-heated silicon surface. Based on the mechanism, a liquid film equation was proposed. The time evolution of the patterns was then compared with that of the well-defined classical Rayleigh-Taylor instability system. It showed that the two systems were qualitatively consistent in several aspects, supporting the Rayleigh-Taylor instability mechanism proposed.