A low-cost fabrication route for silicon microchannels and microgratings with flow-enabled polymer self-assembly patterning and wet etching

Microchannels and microgratings on silicon (Si) are key components for microfluidic device, microelectromechanical system, Si photonics, micro-chemical reactor, micro-biomedical devices and other applications. In the fabrication flow of these microstructures, photolithography and dry etching are the two major steps. However, both of them incur high fabrication cost. In this paper, we introduce a novel approach for fabrication of Si microstructures. The approach uses flow-enabled polymer self-assembly (FESA) as a facile pattern formation method on Si surface; a novel wet etching method, named metal-assisted chemical etching, is employed for Si etching. These two consecutive steps show good compatibility with each other and capability of uniform microstructures fabrication on Si. The proposed approach, with combination of two low-cost yet high-performance novel technology, will serve as a promising route for microchannels and microgratings fabrication for various Si-related devices in high-volume production.