Paper
22 August 2001 Experimental determination of the impact of polysilicon LER on sub-100-nm transistor performance
Kyle Patterson, John L. Sturtevant, John R. Alvis, Nancy Benavides, Douglas Bonser, Nigel Cave, Carla Nelson-Thomas, William D. Taylor, Karen L. Turnquest
Author Affiliations +
Abstract
Photoresist line edge roughness (LER) has long been feared as a potential limitation to the application of various patterning technologies to actual devices. While this concern seems reasonable, experimental verification has proved elusive and thus LER specifications are typically without solid parametric rationale. We report here the transistor device performance impact of deliberate variations of polysilicon gate LER. LER magnitude was attenuated by more than a factor of 5 by altering the photoresist type and thickness, substrate reflectivity, masking approach, and etch process. The polysilicon gate LER for nominally 70 - 150 nm devices was quantified using digital image processing of SEM images, and compared to gate leakage and drive current for variable length and width transistors. With such comparisons, realistic LER specifications can be made for a given transistor. It was found that subtle cosmetic LER differences are often not discernable electrically, thus providing hope that LER will not limit transistor performance as the industry migrates to sub-100 nm patterning.
© (2001) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Kyle Patterson, John L. Sturtevant, John R. Alvis, Nancy Benavides, Douglas Bonser, Nigel Cave, Carla Nelson-Thomas, William D. Taylor, and Karen L. Turnquest "Experimental determination of the impact of polysilicon LER on sub-100-nm transistor performance", Proc. SPIE 4344, Metrology, Inspection, and Process Control for Microlithography XV, (22 August 2001); https://doi.org/10.1117/12.436808
Lens.org Logo
CITATIONS
Cited by 18 scholarly publications.
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Line edge roughness

Transistors

Semiconducting wafers

Optical lithography

Critical dimension metrology

Etching

Scanning electron microscopy

Back to Top