Microfluidics Manufacturing: DRIE Process (Deep reactive ion etching)
The DRIE – Deep reactive ion etching: In this attack , a highly anisotropic(focus on one direction) etching, we can define the desired structures on silicon with the heights defined before. It is a used to create also through holes and estructures in wafers / substrates, with typically high aspect ratio.
The definition obtained with this attack over the Silicon is very good. We use the Bosch process to do it.
First we passivate with metals the wafer parts you want to keep and then do the attach with the ion plasma which removes the silicon from the non passivated parts.
To do the DRIE process , we use a special machine you can see in the photo below.