HIGH-PERFORMANCE PATTERN PLACEMENT METROLOGY ON DYNAMIC RANDOM-ACCESSMEMORY LAYERS OF 0.25 MU-M TECHNOLOGY

Pattern placement metrology is a key function in the evaluation of new manufacturing technology and processes. For future dynamic random acc ess memory (DRAM) generations, ground rules of less than 0.25 mum must be achieved. This paper presents the results of an investigation of t he Leitz LMS 2020 laser metrology system from Leica for pattern placem ent metrology for different layers of DRAM and X-ray mask fabrication processes. The results demonstrate clearly that the new Leitz LMS 2020 tool is well suited for pattern placement control of typical CMOS pro cess wafers and X-ray masks with 30 nm accuracy.