单硅片单面硅微机械加工的热温差式流量传感器

The Single-Wafer Single-Side Silicon Bulk-Micromachined Thermal Flow Sensor

在（111）硅片上研制了一种单硅片单面硅微机械加工的热温差式流量传感器。利用Comsol仿真软件对敏感结构参数进行优化设计,最大程度降低了传感器的热损耗,提高了传感器灵敏度和响应时间。此外,得益于MEMS微创手术MIS（Micro-openings Inter-etch＆Sealing）工艺技术使得加工后的芯片尺寸仅为0.7 mm×0.7 mm,测试结果表明：传感器灵敏度为107.88m V/（m/s）W（无放大处理）,检测响应时间仅为1.53 ms,综合精度为±4%。

A novel thermal flow sensor is proposed and developed,which is fabricated only from the front side of（ 111） silicon wafer through bulk-micromachining process. COMSOL Multiphysics software is employed to optimize some sensitive parameters,which gives a promise to isolating the generating heat from the silicon wafer totally and reduces the device thermal loss at utmost. Furthermore,being benefit from the MEMS Micro-openings Inter-etchSealing（ MIS） process,the fabricated sensor chip size is as small as 0.7 mm×0.7 mm. The testing results show that the flow sensor achieves an ultrahigh normalized sensitivity of 107.88 m V/（ m/s）/W with respect to heating power and gain for nitrogen gas flow. Furthermore,the response time of the sensor is 1.53 ms and the accuracy is ±4%.