Micro-patterning of silicon by frictional interaction and chemical reaction

In this paper a novel and economical method of generating three-dimensional micropatterns on single crystal silicon without the need for a mask is presented. The technique is based on the fundamental understanding of frictional interaction at light loads. Micro-patterning is done through a two-step process that comprises mechanical scribing and chemical etching. The basic idea is to induce micro-plastic deformation along a prescribed track through frictional interaction between the tool and the workpiece. Then, by exposing the surface to a chemical under controlled conditions, preferential chemical reaction is induced along the track to form hillocks about 5 pm wide and 1 pm high. This method of micro-machining may be used for making patterns in micro-electro-mechanical systems (MEMS) at low cost. Furthermore, this process demonstrates how microtribological processes can be utilized in the fabrication of micro-structures.