Acton Optics & Coatings has developed a 193nm XL high-reflectance coating for low-fluence, high-repetition-rate excimer laser applications, particularly those associated with semiconductor R&D and test. The new coating, which offers ≥96 per cent reflectance (45° angle of incidence) to ≥97 per cent reflectance (normal incidence) at 193nm, is also suited to micromachining and materials processing applications.
The Acton 193nm XL is a multilayer dielectric coating that combines a hybrid structure with balanced stress optimised for excimer laser repetition rates of 4kHz to 5kHz. Its design minimises the possibility of catastrophic damage due to micro-defects and thermal stress fractures, as well as preventing dehydration effects from high-repetition-rate operation. This ultraviolet-wavelength coating passes MIL-SPEC adhesion, abrasion, and humidity tests.
The 193nm XL coating can be applied to Acton standard mirror blanks, custom substrates, and customer-supplied material. Reflectance and phase shift can be modified per customer request.
Alternatively, Acton Optics & Coatings offers a 193nm mirror coating optimised for high-fluence, low-repetition-rate (~200 Hz) excimer laser applications. This special ‘e’ design takes electrical field intensity (EFI) correction to the next level by positioning and distributing EFI peaks within several layers, thus reducing the intensity within any single layer in the stack. Subsequently, the effect of EFI-related damage is diminished, resulting in increased laser-damage resistance and longer coating lifetimes.