Overlay(OVL)for patterns placed at two different layers during microchip production is a key parameter that controls the manufacturing process.The tolerance of OVL metrology for the latest microchip needs to be at nan...Overlay(OVL)for patterns placed at two different layers during microchip production is a key parameter that controls the manufacturing process.The tolerance of OVL metrology for the latest microchip needs to be at nanometer scale.This paper discusses the influence on the accuracy and sensitivity of diffraction-based overlay(DBO)after developing inspection and after etching inspection by the asymmetrical deformation of the OVL mark induced by chemical mechanical polishing or etching.We show that the accuracy and sensitivity of DBO metrology can be significantly improved by matching the measuring light wavelength to the thickness between layers and by collecting high-order diffraction signals,promising a solution for future OVL metrology equipment.展开更多
基金supported by the Science and Technology Commission of Shanghai Municipality(No.22DZ1100300)。
文摘Overlay(OVL)for patterns placed at two different layers during microchip production is a key parameter that controls the manufacturing process.The tolerance of OVL metrology for the latest microchip needs to be at nanometer scale.This paper discusses the influence on the accuracy and sensitivity of diffraction-based overlay(DBO)after developing inspection and after etching inspection by the asymmetrical deformation of the OVL mark induced by chemical mechanical polishing or etching.We show that the accuracy and sensitivity of DBO metrology can be significantly improved by matching the measuring light wavelength to the thickness between layers and by collecting high-order diffraction signals,promising a solution for future OVL metrology equipment.
