Title :
Resist roughness limits in EUV lithography for 1 G to 16 G DRAMs
Author :
Scheckler, E.W. ; Ogawa, T. ; Yamanashi, H. ; Soga, T. ; Ito, M.
Author_Institution :
Central Res. Lab., Hitachi Ltd., Tokyo, Japan
Abstract :
Pattern fluctuation in EUV lithography is analyzed using new theoretical models, molecular-scale simulation and experiment. For /spl plusmn/5% 3/spl sigma/ linewidth control in 100 nm PMMA, the dose must exceed 0.18 mJ/cm/sup 2/ for 180 nm lines and 51.8 mJ/cm/sup 2/ for 70 nm lines. Roughness in novolac chemical amplification resists is dependent on the cross-linker density, and the extent of cross-linking. Current resists might be suitable for 4 G DRAMs (120 nm) and cannot be applied to 16 G DRAMs (70 nm) in EUV lithography.<>
Keywords :
DRAM chips; VLSI; integrated circuit technology; photoresists; polymer films; 1 to 16 Gbit; 70 to 180 nm; DRAMs; EUV lithography; PMMA; cross-linker density; extreme UV; molecular-scale simulation; novolac chemical amplification resists; pattern fluctuation; resist roughness limits; Absorption; Chemicals; Fluctuations; Indium tin oxide; Laboratories; Lithography; Pattern analysis; Random access memory; Resists; Ultraviolet sources;
Conference_Titel :
VLSI Technology, 1994. Digest of Technical Papers. 1994 Symposium on
Conference_Location :
Honolulu, HI, USA
Print_ISBN :
0-7803-1921-4
DOI :
10.1109/VLSIT.1994.324418
