Driving UV-LED Integration into High-End Production Mask Aligners with Primelite
Mask alignment systems feature prominently in back-end lithography for MEMS, compound semiconductors, power devices, and microfluidics. With good reason: Increasingly integrated microstructures are so much easier to produce with advanced packaging technologies such as 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.
Manual, semi-automated, and fully-automated mask aligners are found everywhere from low-volume R&D setups to high-volume mass production lines Primelite’s UV-LED Lithography Exposure Systems (ALE/1, ALE/1C, and ALE/2) fully comply with the requirements of any manufacturing scenario and have been integrated into a wide range of mask aligners to replace small (200 W, 350 W, 500 W) and medium-sized (750 W, 1,000 W, 1,500 W) mercury arc lamps in broadband applications. In i-line-only processes, our UV-LED exposure systems match the performance of conventional discharge lamps rated for up to 5,000 W.
Mask aligners using our UV-LED Light Engines produce superior results in contact (soft / hard / vacuum) and proximity exposure use cases, where they provide exceptional uniformity, excellent collimation properties (<2°), and high resolution down to 0.7 µm on 4-inch, 6-inch, 8-inch, 12-inch, and even larger substrates. Less overall maintenance, long LED service life, enhanced output stability, no waiting for the exposure tool to warm up and cool down – our UV-LED solutions drive down the cost of ownership while delivering superior throughput performance.
Integrating Our UV-LED Exposure Systems into Mask Aligners
Our UV-LED exposure solutions replace the conventional lamp house. You no longer need the primary beam-folding mirror, heat sink to absorb radiation beyond 450 nm, shutter, and filters. In many cases, our LED Performance Optics are also an economical alternative for legacy homogenizing / condensing components. You can upgrade from mercury arc lamps to our UV-LED technology in several ways:
- If your design envelope is challenging, be sure to check out our all-in-one fiber-coupled UV-LED light source ALE/1 featuring a flexible high-transmission LED Light Guide.
- Our High-Power UV-LED Exposure System ALE/1C uses a distributed design. The control subsystem (CSS) and the small-footprint exposure subsystem (ESS) are separate components. The ESS integrates directly into the mask aligner.
- You can achieve extreme intensities in i-line and broadband and expose extra-large substrates with our UV-LED Light Engine ALE/2. This is also a distributed setup, with the exposure subsystem (ESS) to be installed in the exposure tool.
All solutions are customizable for a perfect fit in your mask aligner. Retrofitting – that is, replacing a conventional lamp house in a legacy tool – is also an option.
Broadband for Full Power
Our UV-LED exposure systems provide similar spectral output to that of mercury discharge lamps, so upgrading your photolithography process to UV-LED exposure involves minimal adaption. Our broadband UV-LED exposure units are not your only option: we also offer i-line (365 nm) configurations and setups with dual peak wavelengths (365 / 405 nm).
Exposure Intensities Compared
| Wafer size | 6" | 8" | 12" | |||
|---|---|---|---|---|---|---|
| Irradiance [mW/cm2] | Broadband | i-line | Broadband | i-line | Broadband | i-line |
ALE/11 | 90 | 37 | 50 | 22 | — | — |
ALE/1C1,3 | 120 | 50 | 70 | 30 | — | — |
ALE/22,3 | — | — | 130 | 130 | 50 | 50 |
Mercury discharge lamp (typical values) | ||||||
| 350 W | 50 | 25 | 25 | 12 | — | — |
| 500 W | 75 | 37 | 35 | 17 | — | — |
| 1,000 W | 150 | 75 | 70 | 35 | — | — |
| 5,000 W2 | — | — | 250 | 130 | 100 | 50 |
1Round exposure area starting at Ø150 mm
2Square exposure area starting at 200 X 200 mm
3Standard mode; Performance mode with chiller delivers additional 20% output
Why Primelite's UV-LED Exposure Systems for Mask Aligners:
- Easy-to-integrate, high-intensity UV-LED spot light source
- Stable, precise, and consistent radiation output
- Flexible, polychromatic coverage of i-, h-, and g-line (350 - 450 nm), so no need for optical filters
- UV-LED technology for longer life and lower TCO
- Safer than discharge lamps
- Runs much cooler, so no need for nitrogen or CDA
- Switches faster than 1 millisecond
Advanced Light Engine
ONE
Our ALE/1 is the benchmark fiber-coupled UV-LED spot light source if you need reliable output and a customizable broadband exposure spectrum.
Advanced Light Engine
ONE C
Mask aligners equipped with our UV-LED Light Engines deliver superior results for contact and proximity exposure use cases.
Advanced Light Engine
TWO
Expose at 100 mW/cm2 and beyond on round and square 8″ and 12″ substrates with our i-line or broadband ALE/2 UV-LED Light Engine configurations.