Silicon oxide synthesized using an atmospheric pressure microplasma jet from a tetraethoxysilane and oxygen mixture

Local deposition of SiOx was studied using an atmospheric pressure very-high-frequency (VHF) inductive coupling microplasma jet (AP-MPJ) from a tetraethoxysilane ((Si(OC2H5)4), TEOS) and oxygen mixture. The SiOx obtained showed the dielectric constant of 3.8 with a low leakage current of the order of ∼ 10− 6 A ·cm− 2 up to 8 MV ·cm− 1. Bottom-gated sputtered-ZnO thin-film transistors with a AP-MPJ SiOx as a gated dielectric layer exhibited a relatively high field-effect mobility of 24 cm2 V− 1 s− 1, a threshold voltage of 14 V and an on/off current ratio of ∼ 104, a performance comparable to that of thermal silicon dioxide. The TFT performance was also obtained for the top-gated ZnO-TFTs with a field-effect mobility of 1.4 cm2 ·V− 1 s− 1, a threshold voltage of − 1.9 V, and an on/off current ratio of ∼ 103.