基于微机电系统技术(Micro electro mechanical system,MEMS),研制了微型高场非对称波形离子迁移谱(High-field asymmetric waveform ion mobility spectrometry,FAIMS)传感器芯片。芯片采用感应耦合等离子体(ICP)刻蚀和两次硅-玻璃键合工艺加工,尺寸为18.8mm×12.4mm×1.2mm,其中迁移区尺寸为10mm×5mm×0.2mm。设计了高场非对称方波电源,可输出最大频率2MHz,电压峰-峰值1000V,占空比20%~50%连续可调的方波射频电压。以乙醇为实验样品,分析了方波射频电压幅值对FAIMS传感器芯片性能的影响。实验表明,随着电压幅值的增加,FAIMS分辨率提高,灵敏度下降,补偿电压绝对值增大,且芯片对乙醇的检出限可达8.9mg/m3。
A miniature high-field asymmetric waveform ion mobility spectrometry ( FAIMS) sensor chip based on micro-electro-mechanical-system ( MEMS) technology was reported. The chip with dimension of 18. 8 mm × 12. 4 mm 1. 2 mm was fabricated by inductively coupled plasma ( ICP) etching on the two sides of silicon and double silicon-glass bonding. The dimension of the drift tube is 10 mm × 5 mm × 0. 2 mm. The high-field rectangular asymmetric power with the peak-to-peak voltage of 1000 V at the maximum frequency of 2 MHz and the duty cycle of 20% 50% was designed. The ethanol was adopted to illustrate the influence of rectangular radio-frequency ( RF) voltage amplitude on the performance of FAIMS sensor chip. The experiment results show that,with the voltage amplitude increasing,the FAIMS resolution and compensation voltage increase while the sensitivity decreases. And the detection of ethanol at concentration as low as 8. 9 mg/m3 has been demonstrated.