Transparent p-type SnO_x thin film transistors produced by reactive rf magnetron sputtering followed by low temperature annealing

摘要

P-type thin-film transistors (TFTs) using room temperature sputtered SnO_x (x < 2) as a transparent oxide semiconductor have been produced. The SnO_x films show p-type conduction presenting a polycrystalline structure composed with a mixture of tetragonal β-Sn and α-SnO_x phases, after annealing at 200 ℃. These films exhibit a hole carrier concentration in the range of ≈10~(16)-10~(18) cm~(-3); electrical resistivity between 10~1-10~2 Ω cm; Hall mobility around 4.8 cm~2/ V s; optical band gap of 2.8 eV; and average transmittance ≈85% (400 to 2000 nm). The bottom gate p-type SnO_x TFTs present a field-effect mobility above 1 cm~2/V s and an ON/OFF modulation ratio of 10~3.