Lambda Physik introduces the Lithotex excimer laser, which utilises a novel opto-mechanical architecture to deliver critical advantages for the next generation of lithography scanners
Compared to earlier lithography lasers, this high power, 193nm laser provides improvements in three performance areas: greater spectral purity, higher power (including scalability), and longer pulse length (TIS).
LithoTex delivers output power of 50watts at a pulse repetition rate of 4kHz.
This high average power enables faster processing, and the high pulse repetition rate permits close control of dosing.
This new laser also features a longer pulse length with a TIS (time integral square) of over 32nsec - directly from the laser tube - as compared to 18nsec from other dual-chamber excimer lasers.
This inherently long pulsewidth reduces the requirement for additional stretching optics within the laser head, and between the laser and the scanner.
The benefit of a long pulsewidth is reduced peak power, which increases the lifetime of the stepper objective lens.
Lithotex also produces a narrow bandwidth (<0.2pm, FWHM) and very high spectral purity (<0.5pm@95%).
This enables the scanner to project a better image with a higher contrast.
The Lithotex utilises a unique Morra (master oscillator regenerative ring amplifier) architecture, which naturally eliminates the drawbacks inherent to earlier excimer laser designs, such as Mopo (master oscillator power oscillator) and Mopa (master oscillator power amplifier).
For example, Morra delivers superior spectral purity compared to Mopo lasers and longer pulsewidths than Mopa designs.
