PULUODY PMT-2-G Laser-Based Liquid Particle Counter for Photoresist

Overview

The PULUODY PMT-2-G Laser-Based Liquid Particle Counter is a high-sensitivity, laboratory-grade instrument engineered for quantitative particulate contamination analysis in photoresist formulations and other ultra-pure process liquids used in semiconductor manufacturing. It operates on the principle of light extinction and forward-scattered laser detection—leveraging an 8th-generation dual-laser narrow-beam sensor architecture to resolve sub-micron particles with enhanced signal-to-noise ratio and minimized optical interference. Unlike conventional single-wavelength systems, the dual-laser configuration enables simultaneous differential scattering response across two optimized wavelengths, improving discrimination of refractive-index-sensitive particles (e.g., polymer residues, metallic oxides, silica agglomerates) commonly found in photolithographic fluids. Designed specifically for low-conductivity, low-viscosity organic solvents—including PGMEA, ethyl lactate, and proprietary resist blends—the PMT-2-G maintains stable hydrodynamic flow control via a precision metering piston pump and ultra-stable electromagnetic flow regulation, ensuring consistent sample presentation during measurement. Its core application domain spans R&D validation, QC release testing, and process stability monitoring in Class 1–10 cleanroom environments.

Key Features

• 8th-generation dual-laser narrow-beam optical sensor with real-time background compensation and automatic gain adjustment
• Wet dispersion system with integrated degassing module and recirculating flow path to prevent particle settling or aggregation
• Precision metering piston pump delivering volumetric accuracy better than ±1% across full dynamic range
• Embedded V8.3 analysis software supporting dual-mode operation: standalone touchscreen interface and PC-hosted advanced analytics
• Compliant analog output (4–20 mA) with programmable alarm thresholds for integration into facility SCADA or MES platforms
• ISO 21501-2 traceable calibration using NIST-traceable polystyrene latex (PSL) standards; optional certified reference materials available per USP and ChP 2020 Annex VI
• Modular design enabling rapid sensor exchange and field-upgradable firmware without hardware replacement

Sample Compatibility & Compliance

The PMT-2-G is validated for use with non-aqueous, low-dielectric liquids typical in photomask and wafer fabrication workflows—including photoresists, developer solutions, spin-coating solvents, and post-etch rinse fluids. It accommodates viscosity ranges up to 20 cP and conductivity below 1 µS/cm without dilution or surfactant addition. All measurement protocols adhere to internationally recognized regulatory frameworks: ISO 21501-2 (determination of particle size distribution by light extinction), USP (subvisible particle testing), European Pharmacopoeia 2.9.19, and Chinese Pharmacopoeia 2020 Edition Volume IV. The system supports audit-ready data integrity features including electronic signatures, time-stamped raw data logging, and user-access-level controls aligned with FDA 21 CFR Part 11 requirements when operated in networked PC mode. Calibration records and performance verification reports are generated in accordance with JJG 1061–2010 (Chinese national metrological verification regulation for liquid particle counters).

Software & Data Management

PULUODY V8.3 software provides a unified platform for acquisition, visualization, statistical analysis, and reporting. It separates analytical computation from calibration management—eliminating cross-contamination of baseline references during routine testing. Key capabilities include multi-sample comparative histograms, trend analysis over time-series batches, automatic contamination grade assignment per ISO 4406:2017 and NAS 1638, and customizable report templates exportable as PDF, CSV, or XML. Raw scatter pulse data is stored in vendor-neutral HDF5 format, enabling third-party algorithm integration for advanced clustering or machine learning–based anomaly detection. Audit trails record all parameter changes, user logins, calibration events, and report generation actions with immutable timestamps—fully compliant with GLP and GMP documentation expectations.

Applications

• Quantitative assessment of metallic, polymeric, and colloidal contaminants in photoresist lots prior to wafer coating
• In-process monitoring of filtration efficiency in resist recirculation loops
• Verification of cleaning efficacy after solvent-based residue removal steps
• Stability evaluation of formulated resists under thermal or UV stress conditions
• Supporting root-cause analysis of defect excursions in lithography yield loss investigations
• Qualification of new solvent suppliers or alternative resist chemistries against internal cleanliness specifications

FAQ

What particle size ranges does the PMT-2-G support for photoresist analysis?

The standard configuration measures particles from 0.1 µm to 1.0 µm, with optional firmware-defined channels extending down to 0.065 µm or up to 100 µm depending on application-specific validation requirements.
Can the instrument be integrated into an automated wet bench or inline process line?

Yes—it supports continuous unattended sampling via external trigger input and analog output integration; optional flow-cell adapters enable direct connection to recirculation manifolds with minimal dead volume.
Is software validation documentation available for regulated environments?

PULUODY provides IQ/OQ protocol templates, software design specifications, and source code traceability matrices upon request for GMP-compliant deployment.
How is sensor drift compensated during extended operation?

The system performs automatic zero-check cycles between measurements using filtered carrier fluid and applies real-time baseline correction algorithms based on dark-current monitoring and reference pulse normalization.
Does the PMT-2-G meet requirements for pharmaceutical-grade particle counting?

While optimized for semiconductor fluids, its compliance with USP , EP 2.9.19, and ISO 21501-2 permits adaptation to parenteral-grade solvent testing when validated per ICH Q5C and Q9 principles.