Development of ultra-low-power consumption MOX sensors with ppb-level VOC detection capabilities for emerging applications
Development of ultra-low-power consumption MOX sensors with ppb-level VOC detection capabilities for emerging applications
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DOI：
10.1016/j.snb.2008.09.002
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发表时间：
2008-12-10
影响因子：
8.4
通讯作者：
Cardinali, G. C.
中科院分区：
文献类型：
--
作者：
Elmi, I.;Zampolli, S.;Cardinali, G. C.
本文论述了发展最先进的金属氧化物半导体（MOX）气体传感器的基础上，超低功耗（ULP）消费的微加工热板和针对VOC检测在ppb级。提出了一种非常简单的单金属正面硅体微机械加工工艺。几种类型的ULP设备，不同的形状和大小，已被设计和制造，以评估最有效的布局几何形状和最佳的制造工艺参数。的ULP热板的功能行为进行了彻底的研究，并报告了典型的热板温度与施加功率的测量结果。对于在加热器和传感层之间具有创新的自绝缘布局的器件，可以突出显示400摄氏度时8.9 mW的非常令人满意的值。还进行了瞬态温度响应和热板热时间常数的评估。采用改进的流变生长和热氧化（M-RGTO）工艺在悬浮加热板结构的中心沉积了一层氧化锡薄膜。一个非常控制量的金纳米粒子最后溅射到传感层上，以提高其响应VOC的催化效应。正如所预期的和通过形态学表征所证实的，氧化锡膜以尺寸非常均匀的纳米团簇结构化。对不同的气体在不同的工作条件下的功能特性的结果报告，证明了检测挥发性有机化合物（VOC）的能力下降到十亿分之几（ppb）。(C)2008 Elsevier B. V.保留所有权利。
This paper deals with the development of state-of-the-art metal oxide semiconductor (MOX) gas sensors based on ultra-low-power(ULP) consumption micro-machined hotplates and targeted to VOC detection at ppb-level. A very simple, single metal, front-side silicon bulk micromachining fabrication technology was conceived and proposed. Several types of ULP devices, differing in shape and size, have been designed and fabricated to assess both the most efficient layout geometry and optimal fabrication process parameters. The ULP hotplates functional behavior was thoroughly investigated, and typical results on measurements of the hotplate temperature vs. applied power are reported. A very satisfactory value of 8.9 mW at 400 degrees C can be highlighted, for a device featuring an innovative self-insulated layout between heater and sensing layer Transient temperature responses and evaluation of the hotplate thermal time constant were also carried out. On the center of the suspended hotplate structures a thin film of tin oxide has been deposited by means of modified rheotaxial growth and thermal oxidation (M-RGTO) process. A very controlled amount of gold nanoparticles is finally sputtered onto the sensing layer to enhance its response to VOC by catalytic effect. As expected and confirmed by morphological characterization the tin oxide film is structured in nanoclusters very uniform in size. Results of functional characterizations towards different gases under different working conditions are reported and prove the capability of detecting volatile organic compounds (VOC) down to few parts a per billion (ppb). (C) 2008 Elsevier B.V. All rights reserved.