Effect of nanotopography in direct wafer bonding: modeling and measurements
Effect of nanotopography in direct wafer bonding: modeling and measurements
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DOI：
10.1109/tsm.2005.845009
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发表时间：
2005-05
影响因子：
2.7
通讯作者：
K. Turner;S. Spearing;W. Baylies;M. Robinson;R. Smythe
中科院分区：
文献类型：
--
作者：
K. Turner;S. Spearing;W. Baylies;M. Robinson;R. Smythe
纳米形貌是指在毫米级波长范围内延伸的数十至数百纳米的表面高度变化，是晶圆几何特征，可能导致直接晶圆键合过程失败。在这项工作中，直接键合中可接受的纳米形貌是使用基于力学的模型来确定的，该模型将键合过程中硅片中积累的弹性应变能与粘附功进行比较。建模结果以设计地图的形式呈现，显示了作为空间波长函数的可接受的高度变化幅度。然后通过测量和分析相结合的方法来评估纳米形貌对优质硅片键合的影响。本文报道并分析了采用不同抛光工艺制备的三片150mm硅片的纳米形貌测量结果。采用了几种不同的策略来比较晶圆的可粘合性，并评估测量的纳米形貌对直接粘合的影响。本文报道的测量和分析技术为评估纳米形貌对直接键合的影响提供了一般途径，并可用于评估用于键合器件或基板的晶圆制造的不同工艺。
Nanotopography, which refers to surface height variations of tens to hundreds of nanometers that extend across millimeter-scale wavelengths, is a wafer geometry feature that may cause failure in direct wafer bonding processes. In this work, the nanotopography that is acceptable in direct bonding is determined using mechanics-based models that compare the elastic strain energy accumulated in the wafer during bonding to the work of adhesion. The modeling results are presented in the form of design maps that show acceptable magnitudes of height variations as a function of spatial wavelength. The influence of nanotopography in the bonding of prime grade silicon wafers is then assessed through a combination of measurements and analysis. Nanotopography measurements on three 150-mm silicon wafers, which were manufactured using different polishing processes, are reported and analyzed. Several different strategies are used to compare the wafers in terms of bondability and to assess the impact of the measured nanotopography in direct bonding. The measurement and analysis techniques reported here provide a general route for assessing the impact of nanotopography in direct bonding and can be employed when evaluating different processes to manufacture wafers for bonded devices or substrates.