Optical lithography, the structuring of photosensitive materials by mask-defined light for subsequent semiconductor processes, is a well-known and established technology. Today’s main requirements for optical lithography are defined by several key parameters. Sub-micron alignment accuracy, controlled uniform proximity gap between mask and wafer, as well as a clearly defined and precisely controlled exposure spectrum corresponding to the resist sensitivity, are among the most important criteria taken into account. Additionally, EVG´s customer-focused approach includes customized solutions for dedicated process needs. Understanding special requirements and having the flexibility to adapt our systems accordingly are among the unique core competences that EVG brings to the marketplace while constantly enhancing its lithography portfolio.
Over the years, optical lithography has continued to evolve to meet the scaling requirements for new semiconductor device designs. EVG has also continuously looked ahead at future market requirements and developed new innovations in the field of optical lithography technology – from the invention of the world’s first double-sided mask aligner in 1985 up to today, with the IQ Aligner NT achieving a top-side alignment down to 250 nm. Furthermore, EVG has implemented many advanced alignment features, such as runout control with temperature-controlled toolset, automatic cross correction, full clearfield mask movement, edge alignment and dynamic alignment. The latest implemented technology in EVG’s mask alignment product family is UV-LED technology, which gives users much more flexibility for their applications in terms of UV exposure spectrum setup, as spectral lines are individually tunable and special optical filters are no longer required. Maintenance of UV-LED lamp houses is also minimized. Further capabilities such as bond, transmissive or reflective IR alignment, as well as EVG’s proprietary SmartNIL technology, make EVG’s mask aligners very well equipped and advanced. This technology is well-established in the worldwide market today, covering all essential steps and able to serve various applications, such as wafer bumping, creation of redistribution layer (RDL) and via etching masks, via bottom opening processes, as well as lithography performed on thin or temporary bonded wafers. Such systems can be configured in semi-automated configurations for R&D as well as fully automated system configurations running cassette-to-cassette processes for high-volume production.