Due to the conventional cooling system limitations, miniaturization of electronic components have necessitated researchers to explore substitute working fluids and miniscale components to enhance heat transfer efficiency. Also, this immense increase in heat generation necessitated researchers to search for an alternate coolant with enhanced heat removal capabilities. In particular, supercritical CO₂ has been identified as next generation coolant owing to its realizable working condition and environment friendly characteristics. In this study, flow and thermal behavior of micro heat-sinks with micro-fins were investigated considering supercritical carbon dioxide as working fluid. In addition to plane microchannel, an extended surface namely NACA-6412 airfoil has been included in the present study. CFD analysis is performed to assess the influence of micro-fins, mass flux on flow and thermal behavior of turbulent supercritical carbon dioxide flow for P = 80 bar, q'" = 40 - 100 kW/m², G = 400 - 1000 kg/m²s, T_in = 305 - 320 K. The results showed that finned microchannels showed enhanced heat transfer coefficient due to higher surface area and disruption in flow field. Moreover, finned microchannel resulted in lower wall temperature compared to plane microchannel. For finned microchannel heat sink, higher mass flux demonstrated heat transfer enhancement.