【作者】 林宙峰；

【导师】 庄志强；

【作者基本信息】 华南理工大学 ， 材料学， 2010， 硕士

【摘要】 MEMS技术因其具有可大批量生产、成本低、功耗小及集成化等特点,其应用及市场日益增长,发展潜力巨大,而可靠性是MEMS器件能否成功应用的一个关键,因此开展MEMS可靠性研究具有重要意义。在可靠性研究中,失效分析与破坏性物理分析(DPA)是产品可靠性工程的一个重要组成部分,尽管国内外对微电子机械系统(MEMS)的失效机理已有了众多的研究,也提出了相关理论,但由于MEMS结构的复杂性及产品的多样性,以及工艺技术的不断升级更新,仍有很多的失效模式与失效机理需进一步深入研究,并且国内外关于MEMS的DPA技术尚缺乏一定的标准,需要通过对MEMS进行失效及DPA技术研究,来完善和补充相关标准的内容,从而确保MEMS器件的可靠性。本论文是以硅基梳齿式MEMS电容式加速度计为研究对象,利用电子扫描显微镜(SEM)、X射线透视系统、扫描声学显微镜(SAM)、X射线能谱分析(EDX)、金相切片分析、封装气体分析、聚焦离子束(FIB)划痕及电性能测试等分析技术,通过一系列环境试验,对不同结构尺寸样品进行失效与DPA研究。在对工艺中失效的硅基梳齿式MEMS加速度计的失效研究和确定结构与封装的主要失效模式中发现:工艺制造中的机械失效是造成此类器件失效的主要原因,而封装失效主要表现为汽密性失效和装配工艺失效,初步评定粘连、污染、梳齿断裂、梳齿翘曲为标准缺陷。对硅基梳齿式MEMS加速度计在冲击下进行失效分析,阐述了其失效机理,验证了其悬臂梁断裂的主要结构失效模式,其ANSYS模态分析结果与实验结果一致,而封装失效仍表现为汽密性失效和装配工艺失效。实验证明,颗粒碰撞噪声检查(PIND)可应用于MEMS的DPA检测。本文还在高温低温储存、温度冲击、机械振动、机械冲击及耐湿试验等一系列环境试验下分别对特薄悬臂梁和在悬臂梁上有不同尺寸划痕的MEMS样品进行可靠性评价,确定悬臂梁尺寸变薄1/2以上为DPA标准缺陷,并可作为是否失效的一个判据。更多还原

【Abstract】 The application and market of MEMS technology are growing and having huge potential for development because of its characteristics that it can be mass-produced and it is low cost, low power consumption and integrated, while the reliability of MEMS devices is a key to successful application, so it is important to carry out reliability research of MEMS.In reliability studies, failure analysis and destructive physical analysis (DPA) are important part of the produce reliability project. Despite the failure mechanism of Micro Electromechanical System(MEMS)has been numerous studies and related theory has also been presented, there are still a lot of failure mode and mechanism need further study because of the complexity of MEMS structure, the diversity of its product and the constant updates of MEMS technology, and the DPA of MEMS is still lack of standard at home and abroad, it is need to conduct failure analysis on MEMS and study DPA technology to improve relevant standard content and ensure the reliability of MEMS devices .Silicon-based MEMS comb-type capacitive accelerometer was studied in this thesis. By using Scanning Electron Microscopy (SEM), X-Ray Inspection System, Scan Acoustic Microscopy (SAM), Energy Dispersive X-ray spectroscopy (EDX), microsection inspection and analysis, package gas analysis and electrical test, and through a series of environment tests, failure analysis and DPA study were conducted on samples with different dimensions.Failure study on Silicon-based MEMS comb-type capacitive accelerometers that have failed in the process was conducted, its main failure modes of structure and package were determined. The verified failure modes show that main failures of this kind of MEMS products were the failures occurred in process. Moreover, the package failures of this kind of devices were leakage and failures occurred in assembling process. The adhesion, pollution, comb fracture and warping comb were aseessed as standard defect.Failure analysis of Silicon-based MEMS comb-type capacitive accelerometer under shock was conducted, its failure mechanism was analyzed and its main structural failure mode was verified as cantilever fracture, and mode analysis result by ANSYS was the same with the experimental result. While the package failures were still leakage and failures occurred in assembling process. Moreover, experimental results show that the particle impact noise (PIND) testing can be applied to DPA test of MEMS.The reliability of MEMS samples with special thin cantileverand and different sizes’scratch in cantilever respectively were evaluated under a series of environment tests such as high and low temperature, temperature shock, humidity tests mechanical vibration and mechanical shock . At last , thinner than 1 / 2 standard cantilever size was assessed as DPA standard defect, which as a criterion to decide whether failure.更多还原