Polymeric mold soft-patterned metal oxide field-effect transistors: critical factors determining device performance

In recent decades, the use of high performance, soluble oxide semiconductors has been of paramount interest as a channel layer in device architectures of thin-film transistors. Their excellent device performance, which is even comparable to that of vacuum deposited counterparts, has been demonstrated; but, to date, the polymeric mold soft-patterning methods, applicable to roll-to-roll high throughput processes, have not been successfully implemented in creating the device-quality, soluble oxide transistors. In this study, we clarify the heretofore unrecognized origin of limited device performance in polymeric mold soft-patterned oxide transistors, with a model experiment based on the micro molding in capillary (MIMIC) method. In order to elucidate the chemical influence of precursor solutions, three kinds of representative precursor solutions, which undergo the characteristic synthetic pathways of a conventional sol–gel reaction, combustion chemistry reaction, and chemical additive mediated reaction, are employed. Through the comparative study in terms of device performance, in conjunction with the spectroscopic, microscopic, and rheological analyses, it is suggested that the gradual solvent evaporation in structurally confined polymeric molds triggers the additional sluggish chemical reaction unlike the case of evaporation free, semi-solid involved other patterning methodologies, resulting in the significant degradation of device performance. This newly suggested finding would pave the way to generate high performance oxide transistors in a high throughput way that has not been demonstrated so far due to the lack of in-depth study on chemical/physical structural evolution in polymeric molds.