Electrical Characteristics Comparison of Ni/Al Source/Drain Electrodes for P-type Channel SnOx Thin Film Transistors

Abstract

Compared with the conventional a-Si one, thinfilm transistors (TFTs) with oxide semiconductor materials drew much attention in the recent decades. Current oxide based TFTs, however, are most designed for n-channel, only a few pchannel oxide has been used for TFTs. In order to make display circuits more energy efficient, design simplicity, complementary logic circuits with both n-channel and p-channel transistors can realize the goals. In this investigation, electron beam (E-beam) evaporator plays a role in depositing tin oxide (SnO) material as device active layer, and Ni/Al as TFT devices source/drain contact. The SnO thin film is then annealed with furnace, using different temperature to treat the channel layer. With proper annealing temperature, SnO thin film is going to show p-type electrical characteristics. The result shows that below $300^{\circ} \mathrm{C}$ furnace annealing, both Ni/Al electrodes TFT devices gets better electrical characteristics as temperature gets higher. And as expected, Ni electrode based SnO TFT is actually better than that of Al electrode based one. For such low process temperature $\left(300^{\circ} \mathrm{C}\right)$, the devices have prominent potential on plastic substrates applications.