针对非晶铟镓锌氧薄膜晶体管(a-IGZO TFT)的钼/铜源漏电极开展研究。实验证明, 单层Mo源漏电极与栅绝缘层之间的粘附性好、表面粗糙度较小、电阻率较大, 而单层Cu源漏电极与栅绝缘层之间的结合性差且Cu原子扩散问题严重、表面粗糙度较大、电阻率较小。为了实现优势互补, 我们设计了双层Mo(20 nm)/Cu(80 nm)源漏电极,并采用优化工艺制备了包含该电极结构的a-IGZO TFT。器件具有良好的电学特性, 场效应迁移率为 8.33 cm2·V-1·s-1, 阈值电压为6.0 V, 亚阈值摆幅为2.0 V/dec ,开关比为 1.3×107, 证明了双层Mo/Cu源漏电极的可行性和实用性。

Mo/Cu source/drain(S/D) electrodes for amorphous InGaZnO thin film transistors(a-IGZO TFTs) were investigated. The experimental data indicate that the single-layer Mo electrodes have good adhesion to gate insulators, smaller surface roughness, and higher resistivity, whereas the single-layer Cu electrodes possess bad adhesion to gate insulators as well as the serious Cu atom diffusion problems, larger surface roughness, and lower resistivity. To complement each others advantages, the double-layer Mo/Cu electrodes as well as the corresponding a-IGZO TFTs are designed and fabricated, which exhibits good performance parameters(field effect mobility of 8.33 cm2·V-1·s-1, threshold voltage of 6.0 V, subthreshold swing of 2.0 V/dec, and on-off current ratio of 1.3×107 ). This proved the feasibility and practicability of the double-layer Mo/Cu source/drain electrodes for the mass productions of a-IGZO TFTs.