Fabrication of three-dimensional SiC-based ceramic micropatterns using a sequential micromolding-and-pyrolysis process

A sequential micromolding and pyrolysis process is presented for fabricating three-dimensional (3D) SiC-based ceramic micropatterns with a submicron scale resolution using preceramic resins, which is a promising technique for diverse applications such as tribological micro-stamps of hot embossing. Firstly, a diffuser lithography process (DLP) and a two-photon polymerization (TPP) process have been employed to create master patterns, which are utilized in the fabrication of molds. In the DLP, various hemispheric-concave master shapes were built readily by exposing UV-light onto a thick positive photoresist film through a diffuser, which randomizes the paths of incident UV-light. Alternatively, the TPP process based on two-photon polymerization was used for the creation of real 3D master patterns with a two-photon sensitive resin mixture. Subsequently, the preceramic polymer micropatterns were fabricated via a micromolding process using polydimethylsiloxane (PDMS) molds replicated from the masters. Finally, the UV-cured preceramic micropatterns were transformed into SiC-based ceramic microstructures when pyrolyzed at 800 °C under inert atmosphere.