一种用于CO2气体传感器的新型MEMS红外光源

A New Design of MEMS Infrared Source for CO2 Gas Sensor

摘要:

基于CO₂红外气体传感器微型化、智能化、低功耗的发展要求,创新性地提出一种中心温度为407℃的CO₂检测用微电子机械系统(MEMS)红外光源芯片。采用X型悬空桥式微热板结构,内部发热区域以环形走线的钨(W)电极为加热丝,以SiO₂和Si₃N₄双层薄膜作为机械支撑保护层,可防止钨电阻丝氧化并提高寿命。电热耦合有限元仿真分析显示,该光源芯片具有发热区温度分布均匀、热响应时间短、功耗低的优点。采用10.16cm(4inch)MEMS工艺完成了芯片的流片制造。测试结果表明,该光源芯片在24ms内即可快速升温至工作温度407℃,功耗低至46mW,工作电压为2.85V,工作电流为16.2mA,具有热响应时间快、功耗低、集成度高的特点。

Abstract:

Based on the requirements of miniaturization, intelligence and low power of CO₂ infrared gas sensor, a special MEMS infrared source chip for CO₂ detection is innovatively proposed with the center temperature of 407℃. The chip is a micro hot plate with X-type suspending bridge structure. And the internal heating area is tungsten heater with ring routing structure, SiO₂ and Si₃N₄ dielectric thin films as the mechanical support film. The infrared source chip is optimized with uniform temperature distribution in heating zone, short thermal response time and low power by the finite element simulation analysis. The chip is fabricated by 10.16cm (4inch) MEMS process. The results show that, the temperature of this chip can quickly rise to 407℃ within only 24ms, the power consumption is as low as 46mW, the working voltage is 2.85V, and the current is 16.2mA. The chip has the advantages of fast thermal response, low power dissipation and high integration.