题名 | 低张力振动膜硅微电容传声器的研究 |
作者 | 张晓辉 |
学位类别 | 博士 |
答辩日期 | 2007-06-08 |
授予单位 | 中国科学院声学研究所 |
授予地点 | 声学研究所 |
关键词 | MEMS 硅微电容传声器 降低张力 |
其他题名 | A Silicon Condenser Microphone With A Lower Stress Diaphragm |
学位专业 | 信号与信息处理 |
中文摘要 | 基于MEMS技术的硅微传声器是当今的一个研究热点。以往我们所制备的一般硅微电容传声器为了减小硅微电容器的体积,而需要缩减振动膜的面积;导致其灵敏度大幅度降低。在我们实验室,振动膜直径由1.8mm降到0.7mm时,灵敏度由-44dB下降到-60dB(ref.1V/Pa)。传声器的灵敏度与振动膜的张力成正比,降低振动膜上的张力,是提高传声器灵敏度较为可行的办法。本文的目的就是探讨降低振动膜张力的硅微传声器结构,提出它们的设计和制备工艺。 一类结构是振动膜外围部分进行减薄,通过膜沿径向的变化来使振动膜中央部分的应力降低;另一类方法是在振动膜外围开一些孔和或槽来释放张应力。经过分析,特别进行测试表明:其中二类结构取得比较好的结果。一种以用ICP刻蚀减薄振动膜外围的硅微传声器,它比普通均匀振动膜结构灵敏度提高6dB,即由-60dB提高到-54dB,9V偏置电压下达到-49dB,即4mV/Pa。另外一种结构是振动膜外围开槽的结构,他比普通振动膜结构提高7dB,即由-60dB提高到-53dB,9V偏置电压下达到-48.5dB。实验与理论分析是大致相符的,这表明降低振动膜张力是提高传声器灵敏度的一个有效方法。 这两种传声器达到的灵敏度已基本满足一般的需求,经过本论文的工作,作为进一步展望,我们提出一些可行的改进措施,可望进一步提高6dB或更高,届时硅微传声器灵敏度将完全满足实际的需求。 |
英文摘要 | Silicon microphone which is based upon MEMS technology is a hotspot in the past decade years. In order to reduce the volume of the regular silicon condenser microphones, we need to reduce the area of the vibration diaphragm, which leads to the great reducing of the sensitivity. In our lab, the diameter of the vibration diaphragm of the silicon condenser microphone has reduced from 1.8mm to 0.7mm, then the sensitivity has reduced from -44dB to -60dB(ref.1V/Pa). Since the sensitivity of the microphone is inversely proportional to the stress of the diaphragm, reducing the stress of the diaphragm, is a effective way to increase the sensitivity of the microphone. Objective of the dissertation is to investigate the structure of the silicon microphone, which can reduce the stress of the diaphragm, designs and manufactures. One of these structures is that the outer part of the vibration diaphragm reduced the thickness; the other structure is that the diaphragm opened some holes or grooves at the edge, which can release the stress. After the analyzing and measuring, the two structures are proved to has a good result. One kind of the silicon microphone uses ICP to reduce the thickness of the outer area of the diaphragm, whose sensitivity increased from -60dB to -54dB at bias of 6V. And at bias of 9V the sensitivity is about -49dB. Another structure of the silicon microphone is that the edge at the vibration diaphragm has 8 grooves, whose sensitivity increased from -60dB to -53dB at a bias of 6V. And at bias of 9V the sensitivity is about -48.5dB. The measured results approximately conform to the analysis, which means that the stress reducing of the diaphragm is an effective way to heighten the sensitivity of the microphone. Both the types of silicon condenser microphone already basically satisfied the general requirements for the sensitivity. As a prospect, we suggest forward some feasible improvement, that the sensitivity of silicon condenser microphone can increase 6dB or more higher once again, and will have been satisfied completely the practical requirements. |
语种 | 中文 |
公开日期 | 2011-05-07 |
页码 | 75 |
内容类型 | 学位论文 |
源URL | [http://159.226.59.140/handle/311008/132] ![]() |
专题 | 声学研究所_声学所博硕士学位论文_1981-2009博硕士学位论文 |
推荐引用方式 GB/T 7714 | 张晓辉. 低张力振动膜硅微电容传声器的研究[D]. 声学研究所. 中国科学院声学研究所. 2007. |
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