|학술대회||2013년 봄 (05/23 ~ 05/24, 여수 엠블호텔(THE MVL))|
|발표분야||F. 광기능/디스플레이 재료(Optical Functional and Display Materials)|
|제목||Investigation of effective contact resistance of ZTO-based thin film transistors|
|초록||Thin-film transistors (TFTs) based on oxide semiconductors have been regarded as promising alternatives for conventional a-Si and poly-Si TFTs. Oxide TFTs have several advantages, such as low temperature processing, transparency and high field-effect mobility. A lot of oxide semiconductors for example ZnO, SnO2, IZO, ZTO, and IGZO etc. have been researched for applications such as active-matrix liquid crystal displays(AMLCDs) and flexible displays. In particular, zinc-tin oxide (ZTO) is suitable material for channel layer of oxide TFTs. It is because ZTO has high mobility that Sn in ZTO can improve the carrier transport by overlapping large-radius s orbital. However, some issues related to the electrical performances of ZTO TFTs still remain to be resolved, such as obtaining good electrical contact between source/drain (S/D) electrodes and active channel layer.
In this study, the bottom-gate type ZTO TFTs with staggered structure were prepared. Thin films of ZTO (40 nm thick) were deposited by DC magnetron sputtering at room temperature in an Ar atmosphere with an oxygen partial pressure of 10%. For the S/D electrodes, Cu, Mo, ITO and Ti were used. Cu, Mo, ITO and Ti (200 nm thick) were also deposited by DC magnetron sputtering at room temperature. The channel layer and S/D electrodes were defined using a lift-off process which resulted in a fixed width W of 100 μm and channel length L varied from 10 to 50 μm. The S/D series resistance, intrinsic mobility (μi), and intrinsic threshold voltage (Vi) were extracted by transmission line method (TLM) using a series of TFTs with different channel lengths. And the electrical characteristics of ZTO TFTs were measured by HP 4145B semiconductor analyzer. The results showed that the Cu S/D electrodes had high intrinsic field effect mobility and a low effective contact resistance compared to other electrodes such as Mo, ITO and Ti.
|저자||강유진, 한동석, 박재형, 신소라, 박종완|
|키워드||oxdie TFTs; contact resistance; TLM|