首页>
外国专利>
Method of Designing Metrology Targets, Substrates Having Metrology Targets, Method of Measuring Overlay, and Device Manufacturing Method
Method of Designing Metrology Targets, Substrates Having Metrology Targets, Method of Measuring Overlay, and Device Manufacturing Method
展开▼
机译:计量目标的设计方法,具有计量目标的基板,覆盖物的测量方法以及器件制造方法
展开▼
页面导航
摘要
著录项
相似文献
摘要
Metrology targets are formed by a lithographic process, each target comprising a bottom grating and a top grating. Overlay performance of the lithographic process can be measured by illuminating each target with radiation and observing asymmetry in diffracted radiation. Parameters of metrology recipe and target design are selected so as to maximize accuracy of measurement of overlay, rather than reproducibility. The method includes calculating at least one of a relative amplitude and a relative phase between (i) a first radiation component representing radiation diffracted by the top grating and (ii) a second radiation component representing radiation diffracted by the bottom grating after traveling through the top grating and intervening layers. The top grating design may be modified to bring the relative amplitude close to unity. The wavelength of illuminating radiation in the metrology recipe can be adjusted to bring the relative phase close to π/2 or 3π/2.
展开▼