We investigated the electrical characteristics of amorphous silicon-zinc-tin-oxide (a-SZTO) thin films deposited by RF-magnetron sputtering at room temperature depending on the deposition time. We fabricated a thin film transistor (TFT) with a bottom gate structure and various channel thicknesses. With increasing channel thickness, the threshold voltage shifted negatively from -0.44 V to -2.18 V, the on current (I_on) and field effect mobility (μFE) increased because of increasing carrier concentration. The a-SZTO film was fabricated and analyzed in terms of the contact resistance and channel resistance. In this study, the transmission line method (TLM) was adopted and investigated. With increasing channel thickness, the contact resistance and sheet resistance both decreased.

The dependency of annealing temperature on the electrical performances in amorphous silicon-zinc-tin-oxide thin film transistors (SZTO TFT) has been investigated. The SZTO channel layers were prepared by using radio frequency (RF) magnetron sputtering method with different annealing treatment. The field effect mobility (UFE) increased and threshold voltage (Vth) shifted to negative direction with increasing annealing temperature. As a result, oxygen vacancies generated in SZTO channel layer with increasing annealing temperature resulted in negative shift in V1h and increase in on-current.

The dependency of processing pressure on the electrical performances in amorphous silicon -zinc-tin-oxide thin film transistors (SZTO-TFT) has been investigated. The SZTO channel layers were deposited by using radio frequency (RF) magnetron sputtering method with different partial pressure. The field effect mobility (μFE) increased and threshold voltage (Vth) shifted to negative direction with increasing pressure during deposition processing. As a result, oxygen vacancies generated in SZTO channel layer with increasing partial pressure resulted in negative shift in Vth and increase in on-current.