Extended Data Fig. 1: Fabrication process of the co-designed microfluidic-electric device.
From: Co-designing electronics with microfluidics for more sustainable cooling
a, AlGaN/GaN epilayer on a silicon substrate. b, SiO2 hard-mask deposition. c, Hard mask patterning and opening. d, Epilayer etching until the substrate is reached. e, Anisotropic deep (to depth h) etching of the silicon substrate through the epilayer opening. f, Isotropic gas etching through the epilayer opening to widen the slits under the epilayer. An in situ optical etching tracking was put in place to control the width w of the channels. g, Hard-mask removal. h, Ohmic contact deposition and annealing, and seed layer deposition for electroplating and patterning the electroplating mask. i, Manifold channel etching from the back of the substrate. j, Cr/Cu seed layer deposition for electroplating. k, Lithography step to define electroplating openings. l, Electroplating to seal the epilayer openings. m, Photoresist removal. n, Wet etch to remove Cr/Cu seed layer. o, Finish device fabrication with optional dielectric deposition. p, Finish device fabrication with optional gate metal deposition.
