Primelite’s UV-LED light sources replace mercury arc lamps in Wafer Edge Exposure.

Wafer Edge Exposure (WEE) is a prevalent process step in high-volume semiconductor fabrication using lithography steppers and scanners. Optimizing yield in advanced packaging setups (e.g., using 1X stepper technology) is the primary driver to install this additional high-intensity exposure step, which processes the wafer edge separately.

WEE equipment may be connected to a semiconductor wafer track as an independent unit or may be integrated directly into stepper equipment. It consists of a scanning and a wafer spinning device, as well as an optical system in combination with a powerful spot light source for shaped exposure.

Primelite Advanced UV-LED Light Engines for Wafer Edge Exposure
Primelite Advanced UV-LED Light Engines for Wafer Edge Exposure

Primelite’s ALE/1 systems are the perfect UV-LED solution for these wafer edge exposure applications, being the only UV-LED spot light source with high-power polychromatic output matching the relevant i-, h-, and g-line spectrum (365/405/435 nm) of a mercury arc lamp.

The multispectral properties of our UV-LED light source allow replacing mercury lamps with eco-friendly LED technology. Furthermore, our closed-loop feedback control system with instant ON/OFF (0 to 100% below 1 millisecond) ensures consistent and highly accurate exposure results. Tool downtime is reduced to a minimum, as the modular design of all our light sources make maintenance fast and easy.

ALE/1.3 for Wafer Edge Exposure

This version of the ALE/1 combines all wavelengths of the i-, h-, and g-line spectrum (365/405/435 nm) for broadband applications. Whether you want to switch between wavelengths or want to use a broader spectrum, the ALE/1.3 can provide you with the highest radiation output in the spectrum between 350 and 450 nm.

Primelite Advanced UV-LED Light Engine ONE Spectrum (ALE/1.3 365/405/435 nm)
Primelite Advanced UV-LED Light Engine ONE: Spectrum (ALE/1.3 365/405/435 nm)

Radiation output of ALE/1 UV-LED light sources

The ALE/1 can provide intensities that match and exceed 200 W, 350 W and 500 W lamps used in conventional Wafer Edge Exposure systems.

Emitters3 LEDs (365, 405, and 435 nm)1
Radiation output2 in mWALE/1ALE/1+ALE/1+
Light guideØ5.0 mmØ6.5 mmØ6.5 mm AR3
365 nm6,5009,0009,500
405 nm6,5009,50010,000
435 nm4,5006,5007,000
1 CWL of emitters: 367.5±2.5 nm, 402.5±2.5 nm, and 435.0±2.5 nm; 2 Full spectrum of each emitter measured at end of light guide (length 1.5 m), deviation of ±10% possible; 3 Light guides with antireflective coating available.

Highlights – Why ALE/1 for UV-LED Wafer Edge Exposure Equipment

  • Fiber-coupled UV-LED light source for easy integration
  • Highest intensities up to 100,000 mW/cm²
  • Single wavelength and broadband exposure / i-, h-, and g-line (350-450 nm)
  • Stable, precise, consistent output due to closed-loop feedback control system
  • Long lifetime and TCO benefits of UV-LED technology
  • Improved operating safety unlike discharge lamps
  • Future-proof mercury-free light source, no expensive waste disposal