We demonstrate electrically functional 0.099μm 2 6T-SRAM cells using full-field EUV lithography for contact and M1 levels. This enables formation of dense arrays without requiring any OPC/RET, while exhibiting substantial process latitudes & potential lower cost of ownership (single-patterning). Key enablers include: 1) highk/metal gate FinFETs with L g~4 0nm, 12-17nm wide Fins, and cell β ratio~1.3; 2) option for using an extension-less approach, advantageous for reducing complexity with 2 less I/I photos, and for enabling a better quality, defect-free growth of Si-epitaxial raised S/D; 3) use of double thin-spacers and ultra-thin silicide; 4) optimized W metallization for filling high aspect-ratio, ≥30nm-wide contacts. SRAM cell with SNM>10%V DD down to 0.4V, and healthy electrical characteristics for the cell transistors [SS~80mV/dec, DIBL~50-80mV/V, and V Tlin ≤0.2V (PMOS), V Tlin~0 .36V (NMOS)] are reported.
We report on a major advancement in full-field EUV Lithography technology. A single patterning approach for contact level by EUVL (NA=0.25) was used for the fabrication of electrically functional 0.186µm 2 6T-SRAMs, with W-filled contacts. Alignment to other 193nm immersion litho levels shows very good overlay values ≤20nm. Other key features of the process are: 1) use of high-k/Metal Gate FinFETs with good gate CD control: 3σ≤7nm after double-dipole 193nm immersion litho (NA=0.85) and 3σ≤9nm after double-Hard Mask gate etch; and 2) use of an ultra-thin NiPt-silicide for S/D and an optimized spacers module without Si recess at dense FINs pitch. Excellent SRAM V DD scalability down to 0.6V (SNM>0.1V DD ) and healthy electrical characteristics (V T , σ(∆V T ), I-V) for the cell transistors are obtained.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.