摘要
本文提出的一种纹膜结构单硅片微麦克风，采用了硅微机械技术，且实现了麦克风电容两电极之间的自对准，大大提高了麦克风的生产效率，降低了成本．纹膜结构有降低和消除膜内应力的作用，而纹膜的三维结构使麦克风电容的有效面积有所增加，这些都显著地提高了麦克风的灵敏度，是该项新结构的关键．本文从理论和实验上对纹膜结构机械性能与结构尺寸参数之间的关系，及结构的优化进行了研究．通过对制作出的不同结构参数ｑ值的麦克风的测试，得到了与初步理论分析基本相符的实验结果．实验证明，纹膜结构具有比相应的平膜结构高得多的机械灵敏度和麦克风灵敏度，是一种硅麦克风走向实用化的很有效的结构．
Abstract Silicon condenser microphone with corrugated diaphragm has been designed and tested. The introduction of a well--performed corrugation has deeply increased the mechanical sensitivity of the microphone diaphragm due to the reduction of the initial stress in thinfilms. Corrugations with different q values have been investigated, showing a strong relationship between the ratio of the depth of the corrugation to the diaphragm thickness andthe mechanical sensitivity of the diaphragm. Three types of corrugation placements andfive corrugation depths in a diaphragm area of lmm by lmm have been designed and fabricated. Microphones with a flat frequency response between 300Hi and 10kHz and a sensitivity of typically 5-28. 3mV/Pa under a relatively low bias voltage of about 5--15V havebeen fabricated.The application of corrugated diaphragms to silicon condenser microphone offers thepossibility of reducing the initial stress and controlling the sensitivity of thin diaphragmsaccurately by geometrical parameters due to the eliminating of the effect of the initialstress.Therefore, high performance microphones with high sensitivities and high reproducibility are available. The experimental results also proved that the corrugation technique is promising for silicon condenser microphone.
基金
国家自然科学基金
关键词
硅微麦克风
纹膜结构
电容式
麦克风
Capacitors
Corrugated materials
Semiconducting films
Semiconductor devices
