Primelite offers several solutions for UV-LED exposure in mask aligner systems.
Back-end lithography applications in the semiconductor, MEMS, LED, power devices, and microfluidics industry use a large variety of mask alignment systems. A growing number of advanced packaging technologies like Wafer-Level Chip-Scale Packaging (WLCSP), Fan-Out Wafer-Level Packaging (FOWLP), Flip-Chip Packaging, 3D-IC/Through-Silicon Via (TSV), Bumping, and 2.5D Interposer facilitates the fabrication of increasingly integrated microstructures.
Manual, semi- and fully automated mask aligner systems meet the requirements for any production environment: from low volume R&D setups to high-volume mass production. Primelite’s UV-LED lithography products (ALE/1 and ALE/1C) have been successfully integrated into a broad range of mask alignment systems, replacing 200 W, 350 W, 500 W, and 1 kW mercury arc lamps.
Mask aligners using our UV-LED light engines have proven to produce superior results in contact (soft/hard/vacuum) as well as proximity exposure applications. We have seen exceptional uniformity, excellent collimation properties (<2°) and high resolution down to 0.7 µm on 4-inch, 6-inch, and 8-inch substrates. Due to long service life, enhanced output stability, and no need to warm-up or cool-down, our UV-LED solution comes with minimal cost of ownership and provides superior throughput performance.
Broadband for Full Power
Many photolithography applications rely on broadband exposure encompassing i-, h-, and g-line (365/405/435 nm) radiation. We designed our ALE/1 UV-LED light sources to provide a very similar spectral output. This way, an upgrade of your existing photolithography process to UV-LED exposure requires as little adaptation as possible. Apart from our broadband UV-LED exposure units, configurations with single (365 nm) or dual peak wavelengths (365/405 nm and 405/435 nm) are also available.
Exposure Intensity on the Wafer
The ALE/1C can provide intensities of up to 100 mW/cm² on 150 mm and 60 mW/cm² on 200 mm wafers.
| Wafer | 150 mm / 6” | 200 mm / 8” | ||
| Exposure area | 230 cm² | 380 cm² | ||
| Spectrum | Broadband | I-line | Broadband | I-line |
Radiation on surface in mW/cm² | ||||
| ALE/1C* | 100 | 45 | 60 | 27 |
Mercury Arc Lamp | ||||
| 350 W type | 30 | 15 | 18 | 10 |
| 500 W type | 45 | 22 | 27 | 13 |
| 1000 W type | 90 | 44 | 55 | 27 |
| * Standard version without external cooling | ||||
Integration of ALE/1 and ALE/1C in Mask Aligner Setups
Our UV-LED exposure solution replaces conventional lamp houses based on mercury discharge lamp technology. There are two different designs to choose from:
- Our fiber-coupled system ALE/1, featuring flexible liquid light guides to be coupled into the integration optics of the mask aligner.
- Our built-in solution ALE/1C, which follows a distributed design approach with a Control Subsystem (CSS) separated from the Exposure Subsystems (ESS).
Both systems may be customized to perfectly fit into your mask aligner. Also retrofitting – replacing a conventional lamp house in an existing system – is possible.
Highlights – Why ALE/1 and ALE/1C for Mask Aligners
- Single spot UV-LED light source for easy integration
- Stable, precise, consistent, high-intensity radiation output
- Flexible, polychromatic coverage of i-, h-, and g-line (350-450 nm), no need for optical filters
- Long lifetime and TCO benefits of UV-LED technology
- Improved operating safety unlike discharge lamps
- No extensive cooling needed (e.g., no nitrogen or CDA)
- No mechanical shutter needed (fast switching times below 1 millisecond)