Improved throughput and stability of etch tools through root-cause isolation and procedural standardization:

• Performed Root Cause Analysis on multi-factor run-rate loss using DOE across gas flow, RF power, and chamber pressure.

• Collaborated with vendor engineers to identify contributing sub-systems.

• Established Best Known Methods (BKM) and formalized OCAP documentation for recurring run-rate failures.

• Linked outcome to SPC dashboards to monitor run-rate drift and flag early deviations.

• Result: Increased run-rate by 15 % and stabilized chamber performance across fleet.

https://www.researchgate.net/profile/Cong-Wang-130/publication/283350045/figure/fig1/AS:391754751725570@1470413019337/Wafer-handling-robots-inside-a-semiconductor-manufacturing-machine.png

Eliminated persistent idle-state defect source and aligned process performance to golden chamber:

• Conducted segmentation RCA using defect Pareto and DOE to isolate idle component behavior.

• Identified faulty assembly through correlation analysis with idle-time parameters.

• Executed corrective action plan, replaced defective component, and updated OCAP procedures.

• Integrated SPC trace charts to track defect signature trends post-fix.

• Result: Defect count reduced from 2000 → 0, full chamber-to-fleet matching achieved.

Resolved incomplete etch defects through EPD integration and recipe optimization:

• Detected residual material via SEM and post-etch metrology, initiating RCA.

• Tuned recipe timing window using mini-DOE around etch step duration and bias power.

• Enabled EPD system for the affected step and validated cut-off threshold.

• Documented response in OCAP and linked EPD status in SPC for auto-flagging missed endpoints.

• Result: Achieved 100 % defect elimination and improved wafer-to-wafer consistency.

Kim, B.; Im, S.; Yoo, G. Performance Evaluation of CNN-Based End-Point Detection Using In-Situ Plasma Etching Data. Electronics 2021, 10, 49. https://doi.org/10.3390/electronics10010049

Marchack, Nathan, et al. "Control of surface oxide formation in plasma-enhanced quasiatomic layer etching of tantalum nitride." Journal of Vacuum Science & Technology A 38.2 (2020).

Improved across-wafer uniformity through plasma diagnostics and hardware redesign:

• Mapped plasma distribution using OES and Langmuir probe to locate cold zones.

• Designed and ran DOE on gas flow configuration and chuck temperature zones.

• Collaborated with vendor engineering to perform hardware upgrade and chamber retrofit.

• Updated OCAP with new seasoning and qualification steps; linked uniformity control to SPC.

• Result: Reduced across-wafer variation by 40 %, improved MTBC, and stabilized uniformity.

Description: Optimized trench depth and profile uniformity across wafer:

• Applied DOE varying coil power, bias ratio, and pressure to study etch rate response surface.

• Analyzed profile tilt and depth uniformity via SEM cross-sections.

• Implemented recipe correction factors and OCAP-based tuning guide.

• Linked final parameters to SPC limits for depth uniformity tracking.

• Result: Improved within-wafer uniformity from ±10 % → ±3 %, enhancing yield and CD control.

Yoon, Min Young, et al. "Plasma etching of the trench pattern with high aspect ratio mask under ion tilting." Applied Surface Science 595 (2022): 153462.

Song, W.S.; Kang, J.E.; Hong, S.J. Spectroscopic Analysis of CF4/O2 Plasma Mixed with N2 for Si3N4 Dry Etching. Coatings 2022, 12, 1064. https://doi.org/10.3390/coatings12081064

New ICP etchers introduced for next-gen process node. Long qualification cycle and data fragmentation:

• Partnered with equipment vendors on FOK installation and process qualification.

• Executed fingerprinting DOE for baseline and chamber matching across fleet.

• Streamlined data acquisition and analysis scripts.

• Captured qualification protocol in OCAP documentation and linked to SPC dashboards.

• Result: Reduced tool qualification time by 10 % and ensured smooth FOK deployment.

Frequent unplanned downtime from unpredictable plasma shifts:

• Collected OES and ion current data across multiple chambers.

• Built DOE model correlating plasma signatures to etch rate variation.

• Suggested vendors for upgrades and drove implementation.

• Established plasma-performance linkage in SPC; updated OCAP for early-warning triggers.

• Result: Improved predictive maintenance accuracy by 25 % and cut tool downtime.

https://www.vskills.in/certification/tutorial/statistical-process-control-spc/

https://kensobi.com/images/characteristic-dimensional-report_res.png

Manual SPC data review delayed corrective actions. Built automated dashboard for adhoc review:

• Developed Python + JSL automated dashboards integrating SPC, OCAP, and defect Pareto.

• Enabled real-time chamber health visualization and trend detection.

• Deployed dashboards fab-wide, reducing data latency.

• Result: Cut manual analysis time by 20 %, boosted decision speed, and enhanced KPI visibility.