CV

My academic CV.

Contact Information

Name Xiaosi Zhang
Professional Title Senior Software Systems Engineer
Email
Location San Jose, California

Professional Summary

Senior Software Systems Engineer with a Ph.D. from Vanderbilt University, working at the intersection of semiconductor systems, computer vision, and machine learning. Designs scalable end-to-end solutions for registration, defect detection, and robust matching in structured environments.

Experience

  • 2023 -

    Senior Software Systems Engineer
    PDF Solutions
    GAN-based SEM ↔ Layout Translation System (Jan 2026 - Present)
    • Built a GAN-based machine learning image-to-image translation system (U-Net + PatchGAN) for SEM ↔ layout simulation domain translation in semiconductor inspection.
    • Designed multi-objective loss functions (adversarial + L1 + cycle consistency) to preserve geometric fidelity while improving visual realism.
    • Deployed the model as a RESTful API (FastAPI) for scalable inference and integration into inspection and analysis workflows.
    • Designed a closed-loop ML system with drift detection and human-in-the-loop feedback, enabling continuous improvement via automated fine-tuning and evaluation gating.
    1D Registration Location Discovery – Geometry-based Pattern Search (Sep 2025 – Jan 2026)
    • Designed a geometry-aware search system to identify robust registration locations from semiconductor layouts using edge-based spatial analysis.
    • Built efficient candidate generation and filtering mechanisms with spatial indexing and rule-based isolation constraints for structured layout patterns.
    • Developed scoring strategies to evaluate pattern quality and robustness under highly noisy conditions.
    • Designed and integrated an end-to-end pipeline from layout parsing to candidate search and result generation, deployed on HPC (SGE clusters) for scalable large-scale layout processing.
    Image-based Registration & Template Matching Pipeline (Apr 2025 – Sep 2025)
    • Designed an end-to-end image-based pipeline for registration location selection in huge chip design layout(~mm^2), including layout rasterization, candidate sampling, template matching, and quality scoring.
    • Applied computer vision techniques (template matching and correlation analysis) to identify robust patterns under noise, ambiguity, and repetitive structures.
    • Developed data-driven quality metrics (e.g., peak ratio, feature coverage) for pattern ranking and selection.
    • Improved pipeline efficiency by ~3×, leading to substantial reductions in compute cost and infrastructure usage, while enhancing code maintainability and debuggability by replacing legacy black-box EDA components with transparent, modular implementations.
    • Built scalable and production-ready workflows, deployed across HPC (SGE) and AWS with debugging and validation pipelines for large-scale semiconductor inspection.
    Automated 1D Registration Ranking & Selection System (May 2024 - Oct 2024)
    • Designed an automated pipeline for registration candidate ranking and selection in semiconductor inspection workflows.
    • Modeled the problem as a candidate scoring task using edge-based features (Sobel gradient, signal contrast) to evaluate registration quality.
    • Implemented a multi-stage pipeline (generate → score → rank → select) to replace failed or low-quality locations with optimal alternatives.
    • Improved registration accuracy from 98% to 99% across ~1M locations, reducing error cases by ~50% (~10K fewer failures).
    • Enhanced system robustness by filtering false-pass and weak-signal candidates under noisy and repetitive conditions.
    Data-Driven 2D Registration Tuning System (June 2023 - Dec 2023)
    • Built a data-driven system for registration tuning and candidate filtering in semiconductor inspection workflows,resulting in 99% system registration pass rate for CPU and GPU chip defect detection
    • Modeled the problem as a scoring and ranking task using 2D spatial features and 1D signal statistics to identify high-quality alignment locations under noise.
    • Designed adaptive thresholding and failure-type classification (e.g., false pass, multi-peak ambiguity) to improve robustness and generalization.
    • Reduced manual tuning effort by >90% (~20 min → <1 min) while improving consistency and interpretability through intermediate outputs.
    Customer Collaboration & Technical Leadership
    • Acted as a customer-facing engineer, delivering live demos of e-beam inspection systems to customers.
    • Provided on-site and remote technical support, diagnosing complex registration and inspection issues in real production environments.
    • Partnered with product managers and application engineers to translate customer requirements into scalable and testable technical solutions.
    • Authored reproducible documentation and guided offshore teams in model deployment, debugging, and system validation.
  • 2018 - 2023

    Graduate Research Assistant
    Vanderbilt University
    Ph.D. research in optoelectronic characterization, signal processing, and data-driven analysis
    • Performed optoelectronic characterization using scanning photocurrent microscopy (SPCM), generating spatially-resolved signal maps for device behavior and defect patterns.
    • Analyzed photocurrent and electrical signals to characterize carrier transport, device variability, and pattern-level anomalies across spatial regions.
    • Developed signal and image processing pipelines (MATLAB/Python) for noise reduction, feature extraction, and spatial pattern recognition.
    • Explored data-driven approaches for pattern analysis and feature extraction from high-dimensional measurement data.

Education

  • 2018 - 2023

    Nashville, TN, USA

    Ph.D.
    Vanderbilt University
    Electrical Engineering and Computer Science
  • 2014 - 2018

    Wuhan, China

    B.Sc.
    Huazhong University of Science and Technology
    Materials Forming and Control Engineering

Awards

  • 2018
    Hamilton Fellowship
    Vanderbilt University

    Fellowship awarded to support doctoral studies.

Languages

Chinese : Native speaker
English : Fluent