Micro-fluidic channels having various critical dimensions

Abstract

Embodiments of the present invention are directed to microchannels having varied critical dimensions for efficient cooling of semiconductor integrated circuit chip packages. In a non-limiting embodiment of the invention, a patterning stack is formed over a substrate. The patterning stack includes a hard mask, an etch transfer layer on the hard mask, and a photoresist on the etch transfer layer. A manifold trench is formed in a first region of the substrate and is recessed below a surface of the etch transfer layer. A microchannel trench is formed in a second region of the substrate to expose the surface of the etch transfer layer. The manifold trench and the microchannel trench are recessed such that the manifold trench extends into the hard mask and the microchannel trench extends into the etch transfer layer. A manifold and a microchannel are formed in the substrate by pattern transfer.

Dependencies are inferred from the claim text.