Development of Reactive-Ion Etching for ZnO-Based Nanodevices

We report on the systematic studies of reactive-ion etching (RIE) conditions for zinc oxide (ZnO) films with methane and hydrogen gases. The etching conditions were optimized to ensure high selectivity of ZnO to poly(methyl methacrylate) (PMMA), which is commonly used as an etching mask in nanolithography. We also show the feasibility of fabricating nanofeatures patterned onto a thin layer (<;200 nm) of PMMA by nanoimprint technique and electron -beam lithography with the optimized RIE process parameters. Finally, planar nanodevices including self-switching diodes and side-gate transistors were successfully fabricated.