为了实现氧化物薄膜晶体管(TFT)的低电阻布线,采用Cu作为氧化物TFT的源漏电极。通过优化成膜工艺制备了电阻率低至2.0 μΩ·cm的Cu膜,分析了Cu膜的晶体结构、粘附性及其与a-IZO薄膜的界面,制备了以a-IZO为有源层和Cu膜的粘附层的TFT器件。结果表明: 所制备的Cu膜呈多晶结构; 引入a-IZO粘附层增强了Cu膜与衬底的粘附性; 同时,Cu在a-IZO中的扩散得到了抑制。所制备的TFT的迁移率、亚阈值摆幅和阈值电压分别为12.9 cm2/(V·s)、0.28 V/dec和-0.6 V。

Cu was used as the source/drain (S/D) electrodes of amorphous indium-zinc-oxide (a-IZO) thin-film transistors (TFTs) in order to realize low-resistance metallization in oxide thin film transistors. Cu film with a resistivity as low as 2.0 μΩ·cm was deposited by optimizing the sputtering process. The crystal structure, adhesive property of Cu film as well as the interfaces of Cu/a-IZO were investigated. In addition, a-IZO TFTs with Cu S/D electrodes were fabricated. The Cu films were polycrystalline. The adhesion of Cu to glass substrate was enhanced by introducing an a-IZO film. Meanwhile, the diffusion of Cu atoms was suppressed in a-IZO. The fabricated TFT exhibited a saturated mobility of 12.9 cm2/(V·s), a subthreshold voltage of 0.28 V/dec and a threshold voltage of -0.6 V.