Wolfgang Rupp

Photolithography using the AERIAL illuminator in a variable-NA wafer stepper

This paper shows the suitabilily of i-line photolithography for production at 0.30 tm. The process performance is demonstrated through the use of off-axis illumination, high NA projection lens, and a state of the art photoresist system. The minimum required depth of focus for a suitable 0.30 tm process is derived as 0.95 tm over at least a 10% process window. This will result in a 0.60 m common corridor over a square 22 mm imaging feId. In addition to the dense and isolated lines, a preliminary investigation of contact hole performance using chrome and phase shift masks was completed.

Cw-Intracavity Frequency Doubling With Different Crystals

The cw second-harmonic generation (SHG) properties of three nonlinear crystals were in-vestigated: KTP, BBO and LiI03. Therefore we built up a special Nd:YAG laser resonator producing a beam waist at the crystal location by an intracavity focusing lens and so increasing the intensity at the SHG crystal. Another advantage of the used resonator design is the possibility of coupling out the whole generated second-harmonic power. The obtained power outputs at 532 nm were greater than 10 W for KTP and about 1 W for BBO and LiI03.