Performance and reliability of post-CMOS metal/oxide MEMS for RF application
Performance and reliability of post-CMOS metal/oxide MEMS for RF application
复制标题
DOI：
10.1088/0960-1317/13/4/322
复制
发表时间：
2003-07-01
影响因子：
2.3
通讯作者：
Mathewson, A
中科院分区：
文献类型：
--
作者：
Hill, M;O' Mahony, C;Mathewson, A
本文介绍了在后 CMOS（互补金属氧化物半导体）金属氧化物工艺中评估微机电 (MEMS) 测试结构弹性性能的工作。静电拉入测量用于提取过程的残余应力、弹性模量和应力梯度。给出了金属结构和复合金属/氧化物结构的结果。将提取的参数与从覆盖膜测量和基于散装材料特性的分析获得的值进行比较。测试结构还经过了循环重复性测试。在连续的静电驱动周期中观察到漂移，该漂移归因于底层 CMOS 工艺的氮化物钝化中的电荷俘获。电荷平衡模型用于估计捕获的电荷，并且还讨论了驱动电压极性的影响。结果表明，机械结构令人满意的弹性性能取决于工艺条件，但可以实现。电工作特性的稳定性主要取决于氮化物电荷捕获效应。这种效应可以使用基本模型来量化。为了最大限度地减少由于电荷俘获介电特性引起的问题，必须研究并修改操作特性。
This paper describes work carried out to assess the elastic performance of microelectromechanical (MEMS) test structures in a post-CMOS (complementary metal oxide semiconductor) metal oxide process. Electrostatic pull-in measurements are used to extract the residual stress, elastic modulus and stress-gradient for the process. Results are presented for metal structures and for composite metal/oxide structures. The extracted parameters are compared with values obtained from blanket film measurements and from analysis based on bulk material properties. Test structures have also been tested for cycling repeatability. A drift is observed in successive cycles of electrostatic actuation and this drift is attributed to charge trapping in the nitride passivation of the underlying CMOS process. A charge-balance model is used to estimate the trapped charge and the effect of actuation voltage polarity is also discussed. The results indicate that satisfactory elastic performance of mechanical structures is dependent on process conditions but can be achieved. The stability of electrical operating characteristics is dominated by nitride charge trapping effects. This effect can be quantified using a basic model. To minimize problems due to charge trapping dielectric properties must be investigated and operating characteristics modified.