Innovative positioning solution for DUV lithography

Ultra-compact, highly precise positioning solution for wafer exposure in dry, oxygen-free nitrogen atmosphere. (Image: Steinmeyer Group)

For DUV lithography, Steinmeyer has developed an ultra-compact, highly precise positioning solution for wafer exposure in a dry, oxygen-free nitrogen atmosphere at its Dresden location, Europe's largest ICT/microelectronics center. The innovative assembly is designed as an optional add-on for integration into an existing machine and sets standards in terms of compactness, reliability, and particle cleanliness.

Thanks to its broad technological expertise, comprehensive engineering know-how, deep application understanding, and extensive experience, the Steinmeyer Group is a sought-after partner in the design, development, and manufacturing of sophisticated positioning solutions for wafer and chip production. A prime example of the high solution competence at the Dresden site is the complementary polarization filter for miniaturization and automation in DUV lithography.

Complementary polarization filter for DUV lithography

The DUV polarization filter is built with dimensions of approximately 120 x 180 x 31 mm, making it extremely compact. Three flat filters are housed within a height of just 15 mm, which can be shifted in the optical path of the system and positioned independently of each other. The relative positioning of the three filters determines the desired filter property. The drive is via a lead screw (stroke 75 mm) and electronically commutated DC motors. Each filter has its own drive train, protected by a steel sheet to shield against DUV radiation. The system runs dry, allows accuracies of up to 1.5 µm, and offers maintenance-free, flexible 24/7 operation over many 1,000 positioning cycles (spread over 10 years).

Extremely particle-minimized lead screw drive

The miniature lead screw drive is the core of the assembly. It was developed at the Suhl location specifically for applications in DUV lithography and, with a spindle diameter of only 3 mm and a spindle length of 112 mm, is among the smallest on the market in this precision. The innovative material pairing – the nut made from high-performance plastic PEEK and the spindle from stainless steel – enables optimal sliding capability, heat dissipation, and mechanical stability even under extreme environmental conditions in DUV lithography.

Sought-after partner in the semiconductor industry

Whether handling, inspection, or assembly, whether HV, UHV, or EUV positioning: Steinmeyer has decades of experience in designing and manufacturing positioning systems for semiconductor applications and possesses specialized know-how in tribology and lubrication in dry, oxygen-free atmospheres such as vacuum and pure nitrogen. As a result, the group is capable of implementing reliable, cost-effective solutions even for challenging tasks. The proven systems are customized to meet application-specific requirements – from test laboratories to automated semiconductor factories up to ISO 14644-1 Class 1. All manufacturing parts are designed for vacuum compatibility and are cleaned separately after production. Assembly takes place in a certified ISO Class 6 cleanroom. Variable room capacities of over 3,900 m² ensure exceptional flexibility. An expansion of the cleanroom will be completed next year. A cleanroom-compatible packaging with nitrogen inert gas filling protects the finished product during transport.