Xue Dan, Wang Jiachou, Li Xinxin
State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
Micromachines (Basel). 2020 Feb 17;11(2):205. doi: 10.3390/mi11020205.
In this paper, we present a novel thermoresistive gas flow sensor with a high-yield and low-cost volume production by using front-side microfabricated technology. To best improve the thermal resistance, a micro-air-trench between the heater and the thermistors was opened to minimize the heat loss from the heater to the silicon substrate. Two types of gas flow sensors were designed with the optimal thermal-insulation configuration and fabricated by a single-wafer-based single-side process in (111) wafers, where the type A sensor has two thermistors while the type B sensor has four. Chip dimensions of both sensors are as small as 0.7 mm × 0.7 mm and the sensors achieve a short response time of 1.5 ms. Furthermore, without using any amplification, the normalized sensitivity of type A and type B sensors is 1.9 mV/(SLM)/mW and 3.9 mV/(SLM)/mW for nitrogen gas flow and the minimum detectable flow rate is estimated at about 0.53 and 0.26 standard cubic centimeter per minute (sccm), respectively.
在本文中，我们展示了一种采用正面微加工技术进行高产量、低成本批量生产的新型热阻式气体流量传感器。为了最大程度地提高热阻，在加热器和热敏电阻之间开通了一个微空气槽，以尽量减少从加热器到硅衬底的热损失。设计了两种具有最佳隔热配置的气体流量传感器，并通过基于（111）晶圆的单晶圆单面工艺制造，其中A型传感器有两个热敏电阻，B型传感器有四个。两种传感器的芯片尺寸均小至0.7毫米×0.7毫米，且传感器实现了1.5毫秒的短响应时间。此外，在不使用任何放大的情况下，对于氮气流量，A型和B型传感器的归一化灵敏度分别为1.9毫伏/（标准升每分钟）/毫瓦和3.9毫伏/（标准升每分钟）/毫瓦，估计最小可检测流量分别约为每分钟0.53和0.26标准立方厘米（sccm）。
