Fabrication of source and drain regions of self-aligned ZrInZnO thin-film transistors using a solution of tin and poly(propylene carbonate)

Abstract

In this paper, we report a novel doping method based on a solution process to fabricate source and drain regions of a self-aligned ZrInZnO thin-film transistor (TFT). A solution of Sn compound mixed with poly(propylene carbonate) (PPC) was used to allow Sn to be diffused into ZrInZnO source and drain regions. The resistivity of the obtained Sn-doped ZrInZnO was reduced dramatically from 4 × 103 to 1.8 × 10−2 Ω cm. The self-aligned ZrInZnO TFT exhibited a mobility of 20 cm2 V−1 s−1, a threshold voltage of 1 V, a subthreshold swing of 0.2 V/decade, and an ON/OFF ratio of 7. These results indicate that the solution-based doping could provide an alternative way to substitute the ion implantation or plasma treatment which are conducted under vacuum for fabrication of the self-aligned oxide semiconductor TFT.