Advancements in High-end Lithography Process

Creating High-Quality Large Area Diffraction Gratings Using Diode Laser-Driven Interference Lithography

Lasers are commonly utilized in many manufacturing processes. However, in order to achieve sustainable and eco-friendly production, it is vital to minimize the impact on the environment caused by the use of lasers. One significant step towards this goal is replacing gas lasers with diode lasers.

Switching from gas lasers to diode lasers can significantly decrease the energy consumption of the light source by up to 1000 times. Gas lasers also typically require significant cooling systems which can lead to excessive water usage or a rise in energy consumption when using a closed cooling circuit.

This application note discusses the use of large scale interference lithography as a crucial technique in micro- and nanotechnology, where gas lasers were commonly used until the advent of solid-state lasers and new diode laser solutions in recent years.

First published: 24 November 2022, PhotonicsViews , Volume 20, Issue 1Feb 2023, https://doi.org/10.1002/phvs.202200054

Benedikt Bl?si / Fraunhofer Institute for Solar Energy Systems ISE, Martina Müller / 3D AG, Harald Rossmeier / TOPTICA Photonics AG

Lasers are key for innovative products

Interference lithography can create uniform and high-quality structures on large surfaces with ease, leading to the development of new and innovative products in fields like display technology, lighting and solar energy conversion. Frequency-doubled high-power diode lasers with their high coherence length, stability and power provide the critical parameters for interference lithography.

While the TA-SHG pro system, which is part of the TOPTICA UV/RGB solutions, allows more choice in wavelength, tunability and even higher output powers through optional fiber amplifiers (FA), the TopWave 405 is the system of choice for easy system integration in industrial environments.

TopWave 405: cost-efficient, gas laser replacement

For applications that require an easy, hands-off operation with a low cost of operation, a high power diode laser is the perfect solution. The TopWave 405 provides 1 Watt of output power at 405 nm, making it an ideal replacement for the bulky and power hungry Krypton ion gas lasers (406.7 nm and 413.1 nm) still commonly used in lithographic and holographic applications. The savings in operating costs are typically well above 80%. Beam diameter and M2 (typ. 1.15) are designed to match the established gas laser parameters, hence allow for an easy integration without significant changes to the optical system. The noticeably higher coherence length (> 100 m) results in a clear advantage with regard to stable pattern generation in interference lithography or holography .