The authors report on transparent thin-film transistors using amorphous indium zinc oxides for an active channel layer and gate-source-drain electrodes fabricated by rf magnetron sputtering at room temperature. The conducting properties of the amorphous indium zinc oxides were controlled by oxygen partial pressures in the sputtering ambient. An amorphous AlOx served as the gate dielectric oxide. Devices were realized that display a threshold voltage of 1.1V and an on/off ratio of ∼106 operated as a n-type enhancement mode with saturation mobility of 0.53cm2∕Vs. The devices showed optical transmittance about 80% in the visible range.
The Si2H6/He gas mixture was used for growing fluorinated amorphous carbon thin films (a-C:F) for low-dielectric-constant intermetallic-layer dielectrics by plasma-enhanced chemical vapor deposition (PECVD) with C4F8, which has a lower fluorine/carbon ratio than CF4. Si2H6 captures excessive fluorine ions and carries C4F8 to the substrate. It is also much safer than other carrier gases such as H2 or CH4. To characterize and improve film properties, we changed conditions such as deposition temperature and ambient pressure, and we measured the growth rate, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and C–V characteristics. At a low temperature, the film properties were very poor, although the growth rate was very high. On the other hand, the growth rate was low at a high temperature. The growth rate increased with deposition pressure. The XPS result showed that the carbon peaks shifted to a higher energy level due to a carbon-fluorine combination, and the FT-IR results showed a bonding between C–F and C–F2. The dielectric constants of the samples were in the range of 1.5–5 and the sample with a constant of 2.18 showed relatively good thermal characteristics.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.