铜-钼源漏电极对非晶氧化铟镓锌薄膜晶体管性能的改善

Improved performance of the amorphous indium-gallium-zinc oxide thin film transistor with Cu-Mo source/drain electrode

在铜(Cu)和非晶铟镓锌氧化物(a-IGZO)之间插入30 nm厚的钼(Mo)接触层,制备了具有Cu-Mo源漏电极的a-IGZO薄膜晶体管(TFT).Mo接触层不仅能够抑制Cu与a-IGZO有源层之间的扩散,而且提高了Cu电极与玻璃基底以及栅极绝缘层的结合强度.制备的Cu-Mo结构TFT与纯Cu结构TFT相比,具有较高的迁移率(～9.26 cm2·V-1·s-1)、更短的电流传输长度(～0.2μm)、更低的接触电阻(～1072Ω)和有效接触电阻率(～1×10-4Ω·cm2),能够满足TFT阵列高导互联的要求.

Copper is an alternative material for aluminum electrode to meet the stringent requirement for high mobility and low resistance-capacitance （RC） delay of amorphous indium-gallium-zinc oxide （a-IGZO） thin film transistor （TFT） for next generation of display technology due to its intrinsic high conductivity. However, low bonding strength between copper layer and insulator/glass and easy diffusion into active layer restrict its application in the field of TFT. In this work, a 30 nm thin film of molybdenum is introduced into copper electrode to form a copper-molybdenum source/drain electrode of a-IGZO TFT, which not only inhibits the diffusion of copper, but also enhances the interracial adhesion between electrode and substrate. The obtained Cu-Mo TFT possesses a high mobility of ~9.26 cm^2·V^-1·s^-1 and a low subthreshold swing of 0.11 V/Decade. Moreover, it has shorter current transfer length （-0.2μm）, lower contact resistance （-1072Ω）, and effective contact resistance （~1×10^-4Ω·cm^2） than the pure copper electrode. Cu-Mo electrode with low contact resistance and high adhesion to substrates paves the way to the application of copper in high conductivity interconnection of a-IGZO TFT.