基于有序阵列硅纳米线纳米孔嵌套构筑同质集成高性能气体传感器件的研究

Integrated nano-sensor is becoming a hot focus and tendency of research in the field of modern sensors. Considering the research trend and actuality on gas sensor and aiming at the exploratory of integrated and high-speed nano-gas sensor with high performance and lower power consumption, an applied basic study on a new type of room-temperature gas sensor,which has solid performance and is easy to integrate with silicon technology, based on silicon nanowire array with porous substructure will be performed. The nanowires-based gas senor will be realized through the construction in situ of an aligned porous silicon nanowires array with double features of one-dimensional (1D) and porous structure, and the porous silicon nanowires array will be formed from the nesting of porous substructure in the aligned silicon nanowires. Due to the nanosynergies resulted from the nesting of 1D and porous features, an enhanced gas-sensing performances for the porous silicon nanowires array-based sensor will be expected. On the one hand, the sensitivity will be increased obviously by the enhanced nano-effect which is originated from the nesting of porous substructure in 1D nanowires. On the other hand, the poor ability for gas diffusion in the body of 3D porous silicon will be promoted markedly by the 1D construcition of nanowires array, possibly resulted a rapid response-recovery for the porous silicon nanowires array-based sensor. During the execution of the project, the key techniques for the controlled preparation of porous substructure and the optimized designment and further realizaiton for the electrical contact with high performance and reliability, as well as the gas-sensing and nano-effect mechanism will be explored and investigated, and the interdisciplinary research will provide the opportunity to realize homogenous integrated gas sensors with high performance and low power consumption.

集成化纳米传感器是信息传感领域的研发趋势和研究重点。本项目针对新一代气敏传感器的性能特征和研究现状，围绕集成化高速化的高性能低功耗纳米气敏传感器探索这一主要目标，提出开展面向硅基同质集成应用的、基于有序阵列硅纳米线纳米孔嵌套构筑高性能室温气体传感器件的应用基础研究，以一维有序硅纳米线嵌套二级多孔结构形成一种兼具一维/多孔双重纳米特征的多孔结构硅纳米线有序阵列原位构筑高性能硅基同质硅纳米线传感元件。通过有序阵列的两级纳米结构可控嵌套获得气敏性能的协同增强：以二级多孔结构增强纳米效应实现器件的结构增敏；以纳米线阵列一维化有序化特征弱化二级多孔硅多孔结构对气体扩散的不利影响，实现器件的快速响应与恢复。本项目通过兼容性独立可调控纳米孔嵌套关键技术研究、纳米线阵列高效可靠电接触的优化设计与实现以及气敏与纳米效应机制的积极探索，以多学科交叉性研究推进硅基同质集成的高性能低功耗气敏传感器目标的实现。

集成化低功耗纳米传感器是信息传感领域的研发趋势和研究重点。本项目提出并开展了基于有序阵列硅纳米线纳米孔嵌套构筑同质集成高性能气体传感器件的研究课题，基于单晶硅wafer原位化学刻蚀形成有序硅纳米线阵列构筑硅基同质集成传感器的核心敏感元，通过纳米线结构多孔化和表面粗糙化增强纳米效应与气体吸附，进一步基于纳米线有序阵列的有机/无机异质（协同）改性，实现了气敏响应、选择性、抗环境湿度干扰稳定性的显著改善与提升，同时在探索新型改性结构和改性工艺、改性机理方面形成了技术和理论创新。具体包括：探讨了原位实现多孔性硅纳米线阵列的MACE关键技术，发展了基于KOH/TMAH各向异性后刻蚀、dual-MACE制备粗糙硅纳米线、实现类“多孔化”的创新结构增感路线；提出并建立了一种基于硅纳米线簇状阵列电学自组装的新颖高效多通道气体传感器新结构，解决了纳米线有序阵列构筑高性能气体传感器的电学接触与气敏信号的高效引出问题；基于MACE副产物Ag发展了银纳晶修饰创新工艺，构筑了超灵敏超快速气体传感器，室温下实现了对10ppb NO2的瞬态响应；基于OTS官能团疏水改性对抗湿干扰性能的调控，将多孔硅纳米线在75%RH下的NO2探测下限降至小于50ppb；基于硝酸银氧化剂的吡咯气相聚合实现了银纳晶&聚吡咯shell一步协同改性的工艺技术创新，形成了对氨敏响应、选择性和高湿度稳定性的有效调控，在80%RH下获得了对30ppb NH3的室温响应及优异的氨敏选择性；建立了改性硅纳米线气敏响应调控增强的“电阻效应”模型并推导出了改性增敏的普适性理论公式，基于DFT计算形成了对硅纳米线MACE机理以及贵金属修饰“溢出效应”的理论解析。项目研究实现了预期研究目标，研究内容涉及多学科多前沿技术的交叉，具有重要的学术意义；项目研究成果为进一步推进硅基同质集成的高性能低功耗气体传感器的研究与开发奠定了很好的实验与理论基础。