NUV Lightsource

NUV Light Source — Bachur LS-100-3 Near UV Exposure System

Model: Bachur LS-100-3 NUV Lightsource

SOP

Collimated near-UV exposure system using a mercury arc lamp for photolithography and UV processing. Provides uniform, high-intensity UV output with precise intensity control and repeatable exposure performance.

This tool will develop a pattern using a UV exposure on the substrate dictated by the mask that is used for the specific research. This is a small single-wafer unit.

NUV Light Source — Bachur LS-100-3 Near UV Exposure System

The Bachur LS-100-3 NUV Light Source is a high-intensity, collimated ultraviolet exposure system designed for photolithography and UV-based processing. It utilizes a mercury arc lamp with precision optics to deliver uniform UV radiation in the near-UV spectral range (~350–450 nm) for consistent and repeatable exposure.

Key Features

  • High-intensity collimated UV output (Near UV: ~350–450 nm)
  • Mercury arc lamp (200W–500W class) with intensity control
  • Uniform exposure beam (±5–6% typical uniformity)
  • Optical integrator for beam homogenization
  • Dielectric mirrors to filter IR and enhance UV efficiency
  • Compatible with constant intensity or constant power operation

Operating Principle

  • UV radiation generated from a mercury arc lamp
  • Elliptical reflector collects and directs light
  • Dielectric mirrors reflect UV while filtering heat (IR)
  • Optical integrator homogenizes beam for uniform exposure
  • Collimating optics project a uniform beam onto the sample plane

Operation Workflow

  • Power on system and allow lamp warm-up (~10–15 minutes)
  • Set operating mode (constant power or constant intensity)
  • Measure and calibrate UV intensity at exposure plane
  • Align (Z-adjust) lamp for peak intensity
  • Place sample and initiate timed exposure using shutter system

Applications

  • Photolithography (photoresist exposure and patterning)
  • UV curing and resist stabilization
  • Microfabrication and MEMS processing
  • Edge bead removal and flood exposure

Training and Usage

Users are trained on:

  • Safe UV system operation (radiation, ozone, electrical hazards)
  • Lamp handling and installation procedures
  • Intensity calibration and exposure control
  • Routine maintenance and optical cleaning

Detailed Safety Considerations – NUV Light Source (Bachur LS-100-3 Near UV Exposure System)

The NUV light source involves hazards related to high-intensity ultraviolet (UV) radiation, high-voltage lamp operation, thermal output, ozone generation, and optical exposure systems. Improper operation can result in eye and skin injury, electrical hazards, burns, and equipment damage. Only trained and authorized users may operate the system.

UV Radiation Safety

  • The system emits high-intensity near-UV radiation (~350–450 nm) that can cause serious eye and skin damage.
  • Never look directly at the UV source or reflected beam
  • Ensure all protective covers, shields, and enclosures are in place before operation
  • Avoid exposure of skin to UV radiation
  • Use UV-blocking safety glasses or face protection when required
  • Do not operate the system with open exposure paths or disabled interlocks

Optical and Reflection Hazards

  • UV light can reflect from surfaces and cause unintended exposure.
  • Be aware of reflective surfaces near the exposure area
  • Minimize exposure time and avoid unnecessary alignment under active UV
  • Use proper shielding and alignment procedures
  • Ensure samples and holders do not create hazardous reflections

High Voltage and Electrical Safety

  • The mercury arc lamp operates at high voltage and power levels.
  • Do not open system panels or access internal electrical components
  • Ensure proper grounding before operation
  • Do not operate with damaged cables or exposed wiring
  • Turn off power before performing maintenance or lamp replacement
  • Only trained personnel may service electrical components

Thermal and Burn Hazards

  • The lamp and optical components generate significant heat.
  • Do not touch lamp housing or optical components during or immediately after operation
  • Allow sufficient cooling time before handling or maintenance
  • Ensure proper airflow and cooling during operation
  • Be cautious when adjusting or accessing nearby components

Mercury Lamp Safety

  • The system uses a mercury arc lamp, which presents chemical and physical hazards.
  • Handle lamps carefully to avoid breakage
  • Do not touch lamp surface with bare hands
  • In case of lamp breakage, follow hazardous material cleanup procedures
  • Dispose of used lamps according to hazardous waste regulations
  • Only trained personnel should replace lamps

Ozone Generation and Ventilation

  • UV systems may generate ozone (O₃), especially in air operation.
  • Ensure proper ventilation or exhaust during operation
  • Avoid inhalation of ozone or accumulated vapors
  • Do not operate in confined or poorly ventilated spaces
  • Report strong odors or unusual air conditions immediately

Process and Exposure Safety

  • Improper exposure settings can damage samples or cause hazards.
  • Verify exposure time and intensity before operation
  • Avoid overexposure of materials that may degrade or release fumes
  • Ensure proper alignment of sample and exposure plane
  • Use calibrated intensity measurements for consistent operation

Mechanical and Handling Hazards

  • The system may include adjustable optical components and sample stages.
  • Secure samples properly before exposure
  • Avoid movement during active exposure
  • Use caution when adjusting lamp position (Z-adjust)
  • Do not force mechanical adjustments

Contamination Control

  • Clean optical and exposure conditions are critical.
  • Keep optical components clean and free of dust
  • Use only approved cleanroom-compatible samples
  • Avoid contamination of exposure surface
  • Clean sample stage regularly

PPE Requirements

  • Cleanroom garments (as required for the area)
  • UV-blocking safety glasses or face shield
  • Gloves when handling samples or lamps

Operational Safety Checks (Pre-Run)

  • Protective covers and shields are in place
  • Lamp is properly installed and aligned
  • Cooling and ventilation systems are active
  • Exposure parameters (time, intensity) are set correctly
  • Sample is properly positioned
  • System interlocks are functioning

Post-Operation Safety

  • Turn off UV source and allow lamp to cool
  • Avoid immediate handling of hot components
  • Remove samples safely
  • Close system and secure exposure area
  • Log usage and report any abnormalities

Waste Handling and Hazardous Materials

  • Dispose of mercury lamps as hazardous waste
  • Handle broken lamps using proper safety procedures
  • Dispose of contaminated materials in designated containers
  • Do not dispose of hazardous materials in regular trash or drains

Emergency Procedures

  • UV exposure incident → seek medical attention and report immediately
  • Lamp failure or breakage → shut down system and follow hazardous cleanup procedures
  • Electrical fault → power down system and notify staff
  • Excessive heat or odor → stop operation and ventilate area
  • Do not resume operation until the system has been inspected and cleared.

General Cleanroom Conduct

  • Use only approved processes and materials
  • Maintain cleanliness of optical and exposure areas
  • Avoid unnecessary exposure or adjustments
  • Report system issues promptly
  • Follow all cleanroom safety protocols