  This paper is about a new manufacturing process aimed at developing stable
SiO2/Si3N4 patterned electrets using a Deep Reactive Ion Etching (DRIE) step
for an application in electret Vibration Energy Harvesters (VEH). Electrets
charged by a positive corona discharge show excellent stability with high
surface charge density that can reach 5mC/m^{2} on 1.1\mum-thick layers, even
with fine patterning (down to 25\mum) and harsh temperature conditions (up to
250{\deg}C), paving the way to new electret VEH designs and manufacturing
processes.
