无机氧化物沟道层/有机介质层混合型薄膜晶体管

Hybrid Thin-Film Transistors Based on an Inorganic Oxide Channel Layer/Organic Dielectric Layer Structure

基于低成本溶液法的浸渍提拉成膜工艺以无机In-Al-Zn-O(IAZO)为沟道层,以有机聚甲基丙烯酸甲酯(PMMA)为介质层,研制了无机/有机混合型薄膜晶体管(TFT),探究了PMMA厚度对IAZO TFT电学特性和电学稳定性的影响。结果表明,具备较薄PMMA介质层的TFT呈现出更优越的工作特性(饱和迁移率大于20 cm2·V^-1·s^-1,电流开关比高于104),然而随着介质层厚度的减薄,经过疲劳测试后的器件电学稳定性却明显退化。此外,有机PMMA介质层(厚度390 nm)叠加于无机IAZO沟道层有一定的增透效果:IAZO/PMMA双层薄膜在可见光区(波长400~700 nm)的平均透过率(95.0%)高于单层IAZO的平均透过率(93.0%),表明所选用的IAZO和PMMA材料在制备全透明器件方面具备一定的应用潜力。

The hybrid thin-film transistors(TFTs) with inorganic In-Al-Zn-O(IAZO) as the channel layer and organic polymethyl methacrylate(PMMA) as the dielectric layer were fabricated by a low cost solution method based dip coating process. The effects of PMMA thickness on the electrical characteristics and electrical stability of IAZO TFTs were investigated. The results show that the TFTs with thinner PMMA dielectric layers exhibit superior operating characteristics with a saturation mobility of greater than 20 cm2·V^-1·s^-1 and an on/off current ratio of over 104. However, the electrical stability of the device after the repeating test degrades obvioursly with the decrease of the dielectric layer thickness. Moreover, it has a certain anti-reflection effect when combining the organic PMMA dielectric layer(with a thickness of 390 nm) with the inorganic IAZO channel layer. The average transmittance of the IAZO/PMMA double-layer thin film in the visible region(wavelength of 400-700 nm) is 95.0%, which is higher than that of the IAZO single layer(93.0%). This result indicates that the selected IAZO and PMMA materials have certain application potential in the preparation of fully transparent devices.