氮化硅薄膜传感器的平面加工工艺研究

Study on process of surface-manufacturing nitride-diaphragm sensor

介绍一种以氮化硅薄膜为压力敏感膜、多晶硅为电阻应变计的压力传感器。该压力传感器先后采用2种不同的平面加工工艺进行加工,实际结果表明:改进后的工艺比较好。通过采用对称分布在一个敏感膜上的4只多晶硅电阻应变计串联组成惠斯通电桥的一个桥臂,减少桥臂电阻的制作误差。制作传感器样品并对传感器的电压输出特性进行了测试。测试结果表明:恒流激励的传感器的电压输出特性非常好,传感器具有过载保护功能。

A nitride-diaphragm sensor with polysilicon piezoresistors is introduced. The sensor is manufactured with two different surface-micromachined processes, and the result indicates the improved process is better. The resistance error of Wheatstone bridge is decreased because every bridge is made up with four series-wound resistance on a diaphragm arranged symmetrically. Sample is made and the characteristic of voltage output is tested. The results show that the linearity of voltage output of the sensor is good when the sensor is supplied with invariable current. The sensor has self-protection ability when overloaded.