PULUODY PMT-2J Optical Liquid Particle Counter for Photoresist and Ultrapure Fluids

Overview

The PULUODY PMT-2J Optical Liquid Particle Counter is an engineered solution for quantitative micro- and sub-micron particle analysis in ultra-clean process fluids—specifically formulated for photoresist formulations, semiconductor cleaning agents, ultrapure water (UPW), and other low-conductivity organic and aqueous media used in advanced lithography and wafer fabrication. It operates on the principle of dual-laser narrow-beam light obscuration (LO), where two spatially separated laser beams intersect the fluid stream to minimize coincidence error and enhance sizing resolution below 0.5 µm. Unlike conventional single-beam counters, this 8th-generation sensor architecture enables robust discrimination of near-diffraction-limit particles while maintaining high signal-to-noise ratio and dynamic linearity across a broad concentration range. The instrument is designed for both online integration into recirculating UPW loops or chemical delivery systems and offline benchtop analysis—supporting real-time trending, pass/fail threshold alerts, and compliance-driven reporting for cleanroom and fab-line quality assurance protocols.

Key Features

• Dual-laser narrow-beam detection system optimized for sub-0.5 µm particle resolution in low-scatter media such as photoresists and solvent-based chemistries
• High-fidelity volumetric sampling via precision metering piston pump with electromagnetic flow stabilization—achieving <±1% volumetric accuracy and ±3% counting accuracy (typical)
• Configurable detection thresholds: standard 0.1–0.5 µm range; extended options include 1–100 µm or 4–70 µm(c), with 0.1 µm(c) selectable mode for critical nucleation studies
• Embedded V8.3 analysis software with physically segregated calibration and measurement modules—eliminating software-induced drift during long-term monitoring
• Real-time analog output (4–20 mA) with programmable alarm triggers for integration into SCADA, DCS, or MES platforms
• Touchscreen HMI with optional wireless keyboard/mouse support for flexible lab or cleanroom deployment
• Compliance-ready architecture: supports electronic signatures, audit trails, and role-based access control when deployed with validated IT infrastructure

Sample Compatibility & Compliance

The PMT-2J is validated for use with non-aqueous photoresist solvents (e.g., PGMEA, ethyl lactate), aqueous UPW (≥18.2 MΩ·cm), dilute acid/base cleans (SC1, SC2), and polymer solutions requiring insoluble particulate quantification. Its wetted path employs chemically inert materials—including sapphire flow cells and PFA/ETFE tubing—to ensure minimal leachables and compatibility with aggressive chemistries. Calibration traceability follows ISO 21501-4 (light extinction particle counters) and JJG 1061 (Chinese national metrological verification regulation), with optional NIST-traceable latex sphere validation. For regulated environments, the system can be configured to meet FDA 21 CFR Part 11 requirements through secure user authentication, immutable data logging, and electronic signature workflows—enabling use in GMP-compliant semiconductor material release testing and qualification of filtration integrity.

Software & Data Management

PULUODY V8.3 is a dual-mode software platform comprising an embedded real-time acquisition engine and a standalone PC-based analysis suite. The embedded module handles continuous sampling, alarm logic, and raw pulse processing without host dependency—ensuring uninterrupted operation during network outages. The PC version provides advanced statistical tools: time-series trend analysis, histogram binning, multi-channel overlay comparison, and automated report generation compliant with ISO 4406, NAS 1638, and SAE AS4059 contamination coding standards. All calibration parameters are digitally signed and stored separately from test data to prevent inadvertent overwrite. Audit logs record every operator action, parameter change, and calibration event—with timestamps synchronized to NTP servers for regulatory review readiness.

Applications

• In-line monitoring of photoresist dispense lines to detect filter breakthrough or nozzle wear-induced particulates
• Qualification of point-of-use (POU) filters in UPW distribution networks using sequential sampling before/after membrane stages
• Offline verification of cleaning agent purity prior to wafer immersion—critical for sub-7 nm node defect control
• Insoluble microparticle quantification in polymer spin-coating solutions to correlate haze formation with batch variability
• Trending of particle load in reclaimed solvent streams to optimize regeneration cycle intervals
• Supporting IEST-STD-CC1246D cleanliness certification for photomask handling environments

FAQ

What particle size ranges can the PMT-2J resolve in photoresist solvents?
The instrument achieves reliable detection down to 0.1 µm(c) in low-viscosity photoresist carriers (e.g., PGMEA), with optimal performance between 0.1–0.5 µm. Custom calibration extends upper limits to 100 µm for macro-defect screening.
Is the system compatible with ISO 14644-1 Class 1 cleanroom installation?
Yes—the enclosure meets IP54 ingress protection, and all external cabling uses shielded, low-outgassing connectors suitable for Class 1 environments when installed with appropriate air filtration and vibration isolation.
Can the PMT-2J interface with factory MES systems?
It supports Modbus TCP and OPC UA protocols via optional communication modules, enabling direct integration with Siemens PCS7, Rockwell FactoryTalk, or Yokogawa CENTUM VP.
How is calibration maintained during extended unattended operation?
Automated zero-check routines run every 24 hours; scheduled recalibration intervals are configurable per ISO/IEC 17025 internal quality procedures—and logged with full traceability.
Does the system meet semiconductor industry fluid certification standards?
Yes—it satisfies SEMI F63 (ultrapure water) and SEMI F57 (chemical purity) test method requirements when operated with certified reference materials and documented SOPs.