Development of a Technological Route for the Silicon Microneedles Matrix Formation

Abstract

This article shows a new technological approach for the formation of a silicon microneedles array with "smooth" side walls, a curvature radius less than 50 nm and a 3 μm of height. Usually, when sharpening the tip of the needle after forming the main profile using plasma etching, thermal silicon oxidation is being used. The results obtained in this case have a significant scatter of parameters. At this stage of the creating a microneedles array process, it is proposed to use the technology of plasma chemical oxidation (P)CO. A problem solution of the profile microroughness due to optimization of the isotropic silicon etching stage is also presented, and a technology has been developed to create a microneedles array in a single vacuum cycle. This technology made it possible to increase the reproducibility of the profile geometric characteristics more than 50% and halve the microneedles curvature radius. On semiconductor arrays created using the developed technology, various semiconductor devices can be formed, including silicon field emitters.