A Strategy for Patterning Conducting Polymers Using Nanoimprint Lithography and Isotropic Plasma Etching

Conducting polymer (CP) patterns with feature sizes of submicrometer to nanometer dimensions have attracted considerable attention due to their applications in light-emitting diodes (OLEDs), organic field effect transistors (OFETs), polymeric electrochromic devices, sensors, and biotechnology. In the last decade, the integration of two or more functional materials together is of increasing interest because materials with multiple components may exhibit integrative properties that single component materials do not possess. For example, CPs have been integrated with doping agent molecules or nanoparticles in order to improve properties or achieve multiplex character. Efforts to prepare conducting polymer patterns have mainly focused on photochemical patterning, microcontact printing (mCP), scanning probe lithography (SPL), electron-beam lithography (EBL), and dip-pen nanolithography. However, most of the techniques are incapable of integrating high resolution with high throughput. Nanoimprint lithography (NIL), which has gained significant attention due to its low cost and high throughput, is based on the mechanical deformation of the resist polymer by heating above the glass transition temperature (Tg) or by UVcrosslinking. By taking the CP or its mixture as resist layers and a subsequent reactive ion etching process, CPs have been patterned using NIL. However, NIL can only be applied on polymers that have a Tg or are UV-crosslinkable.