Directed Self Assembly of Block Copolymers

Transcription

1 Directed Self Assembly of Block Copolymers for CMOS technology R. Tiron, S.Tedesco, C.Couderc, J.Pradelles, S.Gaugiran, C.Lapeyre, L.Pain, CEA-LETI LoreaOrea, Francesc Perez-Murano, CNM AlaitzRuiz de Luzuriaga, Juan A.Alduncin CIDETEC X.Chevalier, C.Navarro, S.Magnet, ARKEMA T.Chevolleau, G.Cunge, LTM G.Fleury, G.Hadziioannou, LCPO

2 Outline Directed Self Assembly for Microelectronics Lithography limitations Block copolymers definitions State of the art Directed Self Assembly and alignment control Chemical surface modification Graphoepitaxy Defectivity in DSA Outlook SEMICON Europa 2011, Dresden Germany R.TIRON et al. Octobre 12th

3 The Sub-Wavelength gap The big Jump from 193 nm to 13.5 nm Courtesy to S.Tedesco 10 Above wavelength Near wavelength Below wavelength Mi icrons g-line λ=436nm i-line λ=365nm 0.25 DUV λ=248nm 0.18 Pulling in feature size DUV λ=193nm Year λ =EUV 13.5 nm The real big jump could be to use self-assembly SEMICON Europa 2011, Dresden Germany R.TIRON et al. Octobre 12th

4 Impossible d'afficher l'image. Votre ordinateur manque peut-être de mémoire pour ouvrir l'image ou l'image est endommagée. Redémarrez l'ordinateur, puis ouvrez à nouveau le fichier. Si le x rouge est toujours affiché, vous devrez peut-être supprimer l'image avant de la réinsérer. Block copolymers : definitions Different morphologies function of weight fractions f A & f B of each BCP sequence A & B L 0 f A = N A N + A N B f A L 0 : characteristic domain length scale N : number of chain segment Domains orientation controlled by surface properties Mandatory for lithographic applications Modified by chemical treatment, exposure, statistic block copolymers SEMICON Europa 2011, Dresden Germany R.TIRON et al. Octobre 12th

5 BCP Self assembly with 193 nm lithography Chemical surface modification Graphoepitaxy Via shrink and rectification Cheng et al, ACS Nano,VOL. 4, NO. 8, , 2010, IBM Almaden Research Center SEMICON Europa 2011, Dresden Germany R.TIRON et al. Octobre 12th

6 Block copolymers : Long range ordering PS-b-PMMA PS-b-PDMS Jeong et al, ACS Nano,VOL. 4, NO. 9, , 2010, KAIST, Republic of Korea Jung et al, Nano Letters, 2010, 10, , Massachusetts Institute of Technology, Cambridge SEMICON Europa 2011, Dresden Germany R.TIRON et al. Octobre 12th

7 Directed Self Assembly for Microelectronics Block copolymers self assembly capabilities Very high resolution Low intrinsic Line Edge Roughness Easy process Low cost C-MOS Lithography constraints Control the domain orientations (1D-2D) Alignment control with respect to a preview level Integration capabilities Low defectivity Respect of design rules SEMICON Europa 2011, Dresden Germany R.TIRON et al. Octobre 12th

8 Block copolymers : alignment control Two ways to control alignment : graphoepitaxy & chemical surface modification D = ( n + 1/ 2) L 0 ) 0 L 0 D 0 LETI approach CNM approach In the frame of LENS European project SEMICON Europa 2011, Dresden Germany R.TIRON et al. Octobre 12th

9 CNM approach: Chemical Surface Modification PS-OH graphting (5 nm) E-beam lithography and O 2 plasma PMMA mask removal A B L 0 X C Block copolymer deposition Self-assembly after annealing in unmodified areas MMA domain removal 35-38nm D E F L 0 X PS-OH brush layer PMMA 950k PMMA domain Silicon surface PS-OH modified section PS-b-PMMA layer PS domain SEMICON Europa 2011, Dresden Germany L.ORIA, F.PEREZ-MURANO R.TIRON et al. Octobre 12th

10 MULTIPLE PATTERNING PROCESS 155 nm width 217 nm width 310 nm width 465 nm width 2x 3x 6x 11x 200nm SEMICON Europa 2011, Dresden Germany L.ORIA, F.PEREZ-MURANO R.TIRON et al. Octobre 12th

11 1 BRUSH PS-OH 2 BRUSHES PS-OH mod PS-OH PS-rPMMA 1.5L0=57nm 200nm 200nm High roughness on hydrophobic High roughness on hydrophobic PS-OH PS-OH mod PS-OH PS-rPMMA 2L0=68nm 200nm High and low roughness SEMICON Europa 2011, Dresden Germany on hydrophilic 200nm Low roughness on hydrophilic R.TIRON et al. Octobre 12th 2011 L.ORIA, F.PEREZ-MURANO 11

12 LETI approaches : Graphoepitaxy Graphoepitaxy : use a first litho level to guide BCP self assembly lithography BCP spin coating BCP self assembly Constraints : First litho patterns must be resistant to solvent & bake BCP orientation with respect to the substrate must be controlled Integration SEMICON Europa 2011, Dresden Germany R.TIRON et al. Octobre 12th

13 Graphoepitaxy of BCP: versatile process 193nm PCAR 193nm PCAR SiO2 trenches 193nm NTD HSQ e-beam resist SADP -Spacer Self assembly of BCP : versatile process and device orientation SEMICON Europa 2011, Dresden Germany R.TIRON et al. Octobre 12th

14 BCP Etch transfer of silicon using SiO2 hard mask BCP SiO2 rcp Si Fluorocarbon plasma After random opening HBr/Cl2/O2 plasma Before polymer remove After polymer removal Good etch transfer capability CD 15nm, h 70nm SEMICON Europa 2011, Dresden Germany R.TIRON et al. Octobre 12th

15 Defectivity study: Delaunay triangulation Cylindrical block copolymer : hexagonal packaging Delaunay triangulation: method to characterize and quantify cristalinity defect levels SEMICON Europa 2011, Dresden Germany R.TIRON et al. Octobre 12th

16 A potential strategy for defectivity reduction? Process guiding litho : HSQ e-beam resist (inert to solvent and bake) Block copolymers PS-b-PMMA PMMA 70/ nm Increasing BCP film thickness the number of (resist-polymer 500 nm 500 nm interaction) defect decrease SEMICON Europa 2011, Dresden Germany R.TIRON et al. Octobre 12th

17 Zero defect configuration => Minimum of defects attended commensurability respected (L and S integer of ( 3/2) L 0 ) 500 nm This methodology may be easily scale up from laboratory environment to a large scale industrial process SEMICON Europa 2011, Dresden Germany R.TIRON et al. Octobre 12th

18 Overview Good integration perspective of BCP self assembly with conventional lithography By graphoepitaxy orby chemical surfacemodification With e-beam&193nm resist patterns, NTD process, Spacer technology Our methodology, based on lithographic optimization and CD- SEM analysis allow to easily optimize parameters required for long-range order structuration maybe easily scale up fromlabto tofab Final goal : improve BCP process by following defectivity SEMICON Europa 2011, Dresden Germany R.TIRON et al. Octobre 12th

19 Thank you!

20 How to find optimum guiding litho process => Counting defects by keeping the BCP process constant and changing L and S A B 200 nm C Minimum of defects attended commensurability respected (N integer) 200 nm SEMICON Europa 2011, Dresden Germany R.TIRON et al. Octobre 12th