PATTERN PLACEMENT METROLOGY ON X-RAY MASKS

Metrology is a key function in the evaluation of new manufacturing tec hnology and processes. Meeting the pattern placement requirements for the 256 Mbit DRAM technology with 0.25 mum minimum feature size on 1:1 x-ray masks is a development challenge. Pattern placement measurement s on structures in the range between 0.25 mum and 15 mum are reported using the Leitz LMS 2000 slightly modified to be able to handle x-ray masks automatically without using a special mask holding frame.