Temperature Gradient ZnO Deposited via ALD for High-Performance Transistor Applications

IEEE Journal of the Electron Devices Society

Hao Zhang¹  Bowen Che²  Jianhua Zhang²  Xingwei Ding²  Jun Yang²  Jie Qi³ 

[1] College of Electronics and Information Science, Organic Optoelectronics Engineering Research Center of Fujian’s Universities, Fujian Jiangxia University, Fujian, China;Key Laboratory of Advanced Display and System Application, Ministry of Education, Shanghai University, Shanghai, China;Research and Development Department, Air Liquide Innovation Campus Shanghai, Shanghai, China;

关键词: Thin-film transistors;    temperature gradient ZnO;    atomic layer deposition;    oxygen vacancy;   

DOI  :  10.1109/JEDS.2020.3015030

来源: DOAJ

【 摘 要 】

This work reports an alternative atomic layer deposition (ALD) method to fabricate ZnO thin-film transistors (TFTs). The ZnO film is deposited with temperature naturally-cooling process from 200 to 100°C, called a “temperature gradient ZnO (TG-ZnO)”). After optimized annealing treatment at 300°C, the TG-ZnO TFT shows an excellent performance compared to those fabricated with traditional constant temperature deposition, including a high saturation mobility $\left(\mu_{\text {sat }}\right)$ of 11.8 cm²/Vs, which is 5 times higher than the ZnO TFT, a good on/off-state current ratio $\left(I_{\mathrm{on}} / I_{\mathrm{off}}\right)$ of $1.9 \times 10^{7}$ , a small subthreshold swing ( $SS$ ) of 175 mV/decade and a threshold voltage $\left(V_{\mathrm{th}}\right)$ of 1.1 V. Meanwhile, the TG-ZnO TFT has better crystallization than 100°C-ZnO and lower oxygen vacancies than 200°C-ZnO. These characters enable the TG-ZnO TFT not only to maintain a high mobility, but also to present a satisfactory $I_{\mathrm{on}} / I_{\mathrm{off}}$ ratio. This promising deposition technique provides a new idea for fabricating TFTs with high mobility.

【 授权许可】

Unknown