DUV mirrors: 98 percent reflectivity is state-of-the-art
Alzenau, 03/2005
LEYBOLD OPTICS has a long tradition of manufacturing coating equipment for lithography applications. APS 1104, a well-known system in the past, has now been followed by the new SYRUSpro platform. The SYRUSpro 1100 DUV has proved successful for coatings down to the 157 nm range. Consequently, some of the leading players in optical lithography now use it as their main tool for 248/193 nm DUV coatings.
When moving from a range of 248 nm down to 193 nm, the production of high-performance coatings becomes more and more essential. Great importance is attached to the optical performance and the durability of the coated components. Substrate material and treatment, surface roughness, coating materials, film stress and contaminations are only some of the critical issues involved.
In highly reflective mirror coatings for DUV there are a much greater number of layers than in AR coatings. For that reason, they demand extremely low absorption. While fluoride materials are typically deposited in a conventional hot process, leading to issues of stress and columnar growth structures, oxides are an important alternative, provided low absorption and high laser damage threshold are achieved. Here, LEYBOLD OPTICS' SYRUSpro 1110 DUV coating system uses Advanced Plasma Source (APS) technology to produce first-class results with Al2O3 and SiO2. A reflectivity of almost 98 percent at 193 nm is state-of-the-art. APS produces highly reactive oxygen which is a key factor in achieving fully oxidized films with extremely low absorption.
About LEYBOLD OPTICS
As a prominent manufacturer of vacuum coating systems and developer of processes for the thin film technology, LEYBOLD OPTICS is represented in thirteen countries worldwide. The main focus of our processing technologies is on evaporation, sputtering and plasma-assisted coating processes for display technology, ophthalmics, precision optics, reflective and protective coatings, web coating, R&D, and special applications.
The basis of our success was laid in Germany 150 years ago by Ernst Leybold and Wilhelm Carl Heraeus. They addressed their pioneering spirit to the search for new manufacturing processes and founded our internationally recognized vacuum-technology company, which has set market standards ever since.
