High Accuracy Beam Placement for Local Area Navigation

Abstract

The present invention relates to high precision beam placement for local area navigation. An improved method for high precision beam placement for local area navigation in the field of semiconductor chip fabrication is described. Preferred embodiments of the present invention can also be used to quickly navigate to an individual bit cell in a memory array or similar structure, for example, to characterize or correct a defect in that individual bit cell. Use high-resolution scanning to scan (along either the X and Y axes) a "strip" of cells on one edge of the array to locate the row containing the desired cell, followed by A similar high-speed scan in the direction of ) until the desired cell position is reached. This allows pattern recognition tools to be used to automatically "count" the cells necessary to navigate to the desired cell without spending the considerable time required to image the entire array.

Description

technical field [0001] The present invention relates to stage navigation and beam placement in particle beam systems, and in particular to high precision to a site of interest on a sample surface using the acquisition of high resolution images by a FIB or SEM device. degree local area navigation. Background technique [0002] Semiconductor fabrication, such as integrated circuit fabrication, is often accompanied by the use of photolithography. A semiconductor substrate (typically a silicon wafer) on which circuitry is being formed is coated with a material such as photoresist that changes solubility when exposed to radiation. A lithographic tool, such as a mask or reticle, positioned between the radiation source and the semiconductor substrate casts a shadow to control which regions of the substrate will be exposed to the radiation. After exposure, the photoresist is removed from the exposed or unexposed areas, leaving a patterned photoresist layer on the wafer that protec...

AI Technical Summary

Problems solved by technology

Such a high-resolution scan (64K) of a 100µm x 100µm array (with a 500ns dwell time) would take approximately 34 minutes

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