Liu Lin, Wang Yingyi, Sun Fuqin, Dai Yanbing, Wang Shuqi, Bai Yuanyuan, Li Lianhui, Li Tie, Zhang Ting, Qin Sujie
Department of Health and Environmental Sciences, Xi'an Jiaotong-Liverpool University, 111 Ren'ai Road, Suzhou, Jiangsu 215123 P. R. China.
Department of Environmental Science, University of Liverpool, Brownlow Hill, Liverpool, L69 7ZX UK.
Microsyst Nanoeng. 2020 May 4;6:31. doi: 10.1038/s41378-020-0144-4. eCollection 2020.
Manufacture of large-scale patterned nanomaterials via top-down techniques, such as printing and slurry coating, have been used for fabrication of miniaturized gas sensors. However, the reproducibility and uniformity of the sensors in wafer-scale fabrication are still a challenge. In this work, a "top-down" and "bottom-up" combined strategy was proposed to manufacture wafer-scaled miniaturized gas sensors with high-throughput by in-situ growth of Ni(OH) nanowalls at specific locations. First, the micro-hotplate based sensor chips were fabricated on a two-inch (2") silicon wafer by micro-electro-mechanical-system (MEMS) fabrication techniques ("top-down" strategy). Then a template-guided controllable de-wetting method was used to assemble a porous thermoplastic elastomer (TPE) thin film with uniform micro-sized holes (relative standard deviation (RSD) of the size of micro-holes <3.5 %, > 300), which serves as the patterned mask for in-situ growing Ni(OH) nanowalls at the micro-hole areas ("bottom-up" strategy). The obtained gas microsensors based on this strategy showed great reproducibility of electric properties (RSD < 0.8%, = 8) and sensing response toward real-time HS detection (RSD < 3.5%, = 8).
通过自上而下的技术，如印刷和浆料涂覆来制造大规模图案化纳米材料，已被用于制造小型气体传感器。然而，在晶圆级制造中传感器的可重复性和均匀性仍然是一个挑战。在这项工作中，提出了一种“自上而下”和“自下而上”相结合的策略，通过在特定位置原位生长氢氧化镍纳米壁来高通量制造晶圆级小型气体传感器。首先，通过微机电系统（MEMS）制造技术（“自上而下”策略）在两英寸（2"）硅晶圆上制造基于微热板的传感器芯片。然后，使用模板引导的可控去湿方法组装具有均匀微孔（微孔尺寸的相对标准偏差（RSD）<3.5%，>300）的多孔热塑性弹性体（TPE）薄膜，该薄膜用作在微孔区域原位生长氢氧化镍纳米壁的图案化掩膜（“自下而上”策略）。基于该策略获得的气体微传感器在电学性能方面表现出很高的可重复性（RSD<0.8%，=8），并且对实时硫化氢检测具有传感响应（RSD<3.5%，=8）。
