| AVS 55th International Symposium & Exhibition | |
| Manufacturing Science and Technology | Monday Sessions |
| Session MS+NC-MoM |
| Session: | CMOS Extension and Metrology |
| Presenter: | J.-F. de Marneffe, IMEC, Belgium |
| Authors: | J.-F. de Marneffe, IMEC, Belgium D. Goossens, IMEC, Belgium A. Vandervorst, IMEC, Belgium S. Demuynck, IMEC, Belgium A.M. Goethals, IMEC, Belgium J. Hermans, IMEC, Belgium F. Van Roey, IMEC, Belgium B. Baudemprez, IMEC, Belgium S. Brus, IMEC, Belgium C. Vrancken, IMEC, Belgium |
| Correspondent: | Click to Email |
In order to overcome patterning challenges brought by dimensional scaling and aggressive pitches, extreme ultra-violet (EUV) lithography has been recently pushed forward as a possible solution for IC manufacturing, allowing extended exposure latitude at sub-50nm dimensions. This work address the technological solutions used for contact holes patterning by means of EUV lithography. A 0.186 μm2 SRAM cell has been used as a test-vehicle, showing down to 55nm circular and boomerang-shaped contacts.1 A metal hard-mask (MHM) approach has been selected, in order to combine the etch of high-aspect ratio features with thin EUV photoresist. The pre-metal dielectric stack covering the active fins was composed of 15nm Si3N4 as an etch-stop liner, covered by 240nm SiO2. The MHM was made of a 30nm TiN film on top of which was spun 20nm of organic underlayer and 100nm of EUV photoresist. This paper will describe in details the various patterning steps (lithography, MHM opening and ash, SiO2 followed by Si3N4 etch, residue cleaning) leading to the successful patterning of small contacts by EUV lithography.
1 Imaging Performance of the EUV Alpha Demo Tool at IMEC, G.F. Lorusso et al., SPIE conference 6921-24 (2008).