Method for manufacturing a microfluidic device

A method for manufacturing a microfluidic device, the method comprising:

• a) providing a first substrate having a first layer thereon, and a second layer on the first layer, wherein the second layer has a bottom surface in contact with a top surface of the first layer, and a top surface facing away from the first layer;
• b) forming a first nanopore in the second layer in such a way that a part of the first layer coincides with a bottom of the first nanopore, wherein forming the first nanopore comprises a dry etching step;
• c) exposing said part of the first layer to a liquid etchant, thereby forming a cavity under the first nanopore, the cavity having a larger width (W) than a width (w1) of the bottom of the first nanopore after step c and before step d;
• d) filling the first nanopore and the entire cavity with a solid filling material, thereby forming a first plug;
• e) forming a bottom fluidic access for the first nanopore by removing a part of the first substrate and the part of the first layer so as to expose the first plug, and forming a top fluidic access for the first nanopore by providing a third layer over the second layer and the first plug if such a third layer is not already present, and removing part of the third layer so as to expose the first plug;
• and
• f) removing the first plug, thereby fluidly connecting the bottom fluidic access to the first nanopore.