HIGH-PERFORMANCE PATTERN PLACEMENT METROLOGY ON DYNAMIC RANDOM-ACCESS MEMORY 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 access memory (DRAM) generations, ground rules of less than 0.25 mum must be achieved. This paper presents the results of an investigation of the Leitz LMS 2020 laser metrology system from Leica for pattern placement 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 process wafers and X-ray masks with 30 nm accuracy.