Optics Express · 2009 · 50 citations · 3 references
EngineeringElectrical EngineeringManufacturing EngineeringMetrologyMicrofabricationSemiconductor DevicesDisplacement MeasurementForm MetrologyIndustrial MetrologyMicrofabrication MetrologyOptical MetrologySurface MetrologyCritical Dimension MetrologyDirect MeasurementDisplacementManufacturingMetrology For Semiconductor Process ControlNanometer-scale MetrologyOverlay MetrologySemiconductor Metrology
Optical metrology is widely used in microelectronics process control for its speed and non‑destructive nature, yet it usually requires special measurement structures in scribe lines, limiting lithography characterization; in‑chip measurements can overcome this limitation. This paper introduces an in‑chip optical metrology technique that directly measures critical dimensions and overlay displacement errors in DRAM manufacturing. The method performs measurements on the actual semiconductor devices without the need for special target structures. Experimental results demonstrate that the technique accurately measures critical dimensions and overlay errors in DRAM.
The use of optical metrology techniques in process control for microelectronic manufacturing has become widespread. These techniques are fast and non-destructive, allowing a higher sampling rate than non-optical methods like scanning electron or atomic force microscopy. One drawback of most optical metrology tools is the requirement that special measurement structures be fabricated in the scribe line between chips. This poses significant limitations regarding the characterization of lithography processes that may be overcome via in-chip measurements. In this paper we present experimental results for an in-chip optical metrology technique that allows direct measurement of both critical dimensions and overlay displacement errors in the DRAM manufacturing process. This technique does not require special target structures and is performed on the actual semiconductor devices.
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