1 July 2002 Manufacturing sub-50-nm gratings using E-beam lithography and electroplating
Author Affiliations +
In this paper we present a new method for manufacturing steeply profiled grating structures composed of narrow lines and spaces embedded in transition metal layers. We focus on making EUV transmittive grating structures typically consisting of rectangular lines that are down to 40 nm wide, around 100 nm tall, up to 100 nm long, spaced at a 1-2 micrometers pitch, and embedded in 100 nm thick nickel-iron alloy absorber layers. The method comprises the use of a molybdenum plating base deposited on a silicon nitride coated silicon wafer, electron beam writing of down to 40 nm wide and 100 nm tall lines in negative tone hydrogen silsesquioxane (HSQ) resist, and electroplating of the desired metal absorber layer in between the resist lines, using the molybdenum layer as plating base. After processing both the HSQ resist and the thin plating base can remain respectively between and below the grating structure because these materials are relatively transparent to EUV radiation. The presence of HSQ in the plated metal spaces results in a flat top surface, preventing the adhesion of contaminants. Our measurements reveal the presence of rectangular HSQ lines, characterized by near vertical side walls, a high line-width uniformity and a low line-edge roughness. These structures are subsequently embedded in a homogeneously grown absorber, characterized by a low small-scale surface roughness and high-quality overall flatness. The process window, in terms of exposure dose and pre-exposure resist treatment, has been well established for various line width and line pitch settings.
© (2002) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Mark Kroon, Mark Kroon, Falco C.M.J.M. van Delft, Falco C.M.J.M. van Delft, Bas Ketelaars, Bas Ketelaars, } "Manufacturing sub-50-nm gratings using E-beam lithography and electroplating", Proc. SPIE 4688, Emerging Lithographic Technologies VI, (1 July 2002); doi: 10.1117/12.472278; https://doi.org/10.1117/12.472278


Electroplated nickel mold insert for LIGA
Proceedings of SPIE (September 18 1995)
Microriblets for drag reduction
Proceedings of SPIE (May 25 1995)
Direct spray coating of photoresist for MEMS applications
Proceedings of SPIE (September 27 2001)

Back to Top