先进ATHENATM选用策略与对准功能

基于先进科技对准规格的减缩,对准仪量测数据的应用也变得更为重要。不同对准策略的选择所引起的结果,对全部对准预算有很重要的影响。介绍两个主要科技研发项目:先进对准配套和对准标的设计。

Overlay Performance with Advanced ATHENATM Alignment Strategies

To comply with the tightening overlay roadmap, processing effects on overlay need to be reduced to a minimum. For this purpose, ASML has developed the ATHENATM alignment sensor. This phase grating alignment system detects up to seven orders that are diffracted by an alignment grating. Since these higher diffraction orders are less sensitive to mark deformations, alignment has become more accurate and more robust to processing variations. In addition, the robustness for situations where destructive interference or absorption impacts the signal strength is enhanced by incorporating two wavelengths in the alignmernt system: red and green with wavelengths of 633 and 532 nm, respectively. Thus, the sensor provides in total 14 signals per alignment mark to perform a wafer alignment.