A technique to create scaled three-dimensional nanochannel networks is developed using sequentially stacked thermal nanoimprint lithography on planarized self-supporting dielectric sealing material over polymer sacrificial layers. Void-free plasma enhanced chemical vapor deposited SiO2 encloses and seals nanochannels that are formed upon the removal of the sacrificial polymer. Planarization of the SiO2 surface allows the utilization of the vertical dimension to sequentially apply nanoimprint lithography for the formation of multiple-level nanochannel networks. Removal of the sacrificial polymer is performed with a high-power and high-pressure O-2 plasma. Wet chemical processes using common solvents are found to be ineffective in removing the sacrificial polymer. Two level nanochannels with cross-sectional dimensions of 300 nm X 200 nm and lengths of 65 mu m that are aligned offset from one another and aligned on top of one another are demonstrated. (c) 2005 American Vacuum Society.