Patent ID: 10899606

Abstract:
A method is for manufacturing a plurality of silicon microneedles which have a bevelled tip. The method includes providing a silicon substrate having a front face and a rear face, forming a first mask arrangement on the front face of the substrate, the first mask arrangement defining one or more gaps, and performing a SF6 based plasma etch of the front face through the gaps in the first mask arrangement to provide one or more etch features having a sloping face. The SF6 based plasma etch undercuts the first mask arrangement with an undercut that is at least 10% of the depth of a corresponding etch feature. The method further includes forming a second mask arrangement on the etch features to define locations of the microneedles, in which the second mask arrangement is located entirely on sloping faces of the etch features, and performing a DRIE (deep reactive ion etch) anisotropic plasma etch of the etched front face of the substrate to form a plurality of microneedles which have a bevelled tip, where the sloping faces of the etch features at least in part give rise to the bevelled tips of the microneedles.