High Sensitivity for SOA Etch Improves Endpoint Detection

For high aspect ratio 3D NAND and critical dimension advanced node logic contacts, reliably detecting endpoint well below 1% open area is critical to yield and overall productivity.

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End point detection of contact etch through field oxide (silicon dioxide) needs to be performed to minimize contact resistance and ensure a good electrical contact with transistor source or drain, but without excessive over-etch, which can cause shorts to the gate region or substrate damage.

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For 3D NAND, etching through hundreds of alternate SiO2 and Si3N4 layers requires high speed quantitative end point detection.

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To ensure consistent and optimized contact etch, high sensitivity in-situ molecular diagnostics is needed, to provide real-time measurement and quantification of the etch by-products and to enable a clearly-defined endpoint to be detected.

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With reducing contact open area (OA%), legacy metrology solutions like Optical Emission Spectroscopy (OES) lack the sensitivity to accurately detect etch end point.

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With OA% sensitivity demonstrated to <0.25%, Aston delivers accurate and actionable detection up to an order of magnitude better than OES (~2.5%).

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Learn more about Aston and download our Application Brief below for more details on how Aston supports industry-leading sensitivity in helping to improve end point detection.