Roll-to-Roll Nanoimprint - 6 회 -

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1 Roll-to-Roll Nanoimprint - 6 회 -

2 목차 Click to add Title 1 Roll to Roll nanoimprint Introduction : Continuous Production System (Roll-to-Roll) Fabrication Processes Fabrication of nano roll mold 2 Case study Integrated optical interconnection for polymeric planar light wave circuit device using roll-to-roll imprint A study on the nano wire grid polarizer film by roll-to-roll imprint Design and development of the functional agricultural film by roll-to-roll imprint

3 Click to add Title 1 Roll to Roll nanoimprint Introduction : Continuous Production System

4 1. 1 Introduction : Continuous Production System 기존공정의한계 ( 고에너지, 고비용 ) 를극복하기위한롤투롤기반나노임프린트 ( 대면적, 연속생산공정 ) 로기술패러다임이변화 Conventional Litho. 전통적방식 High Energy-Consumption High-cost Process Facility Environment - Batch Process( 단계공정 ) - Strict Temp. control( 엄격한온도조절 ) Paradigm Shift Roll stamp based NIL* 차세대방식 Green Technology - Environmentally Friendly Process - Non-toxic, E-saving, Waste-free Low-cost Technology - Cheaper material (Soft vs Hard) - Fewer Process step - Increased Productivity & Scalability Facility Environment - Continuous Process (Time-saving) - Less Temp. control (Energy-saving) Limitations( 제한사항 ) - Area (Substrate size) - Resolution (Optical source) Low Limitations! (100nm, 1200mm) Large-area Displays, Solar Cells, Biomedical Devices, MEMS/NEMS, Flexible devices, Memory devices, Sensors, etc. * NIL : NanoImprint Lithography 4

5 1. 1 Introduction : Continuous Production System System formation deposition imprint etch Vacuum deposition of metals, dielectrics, & semiconductors Multiple mask levels imprinted as single 3D structure Patterning completed w/ wet & dry processes Conventional Photo-Lith deposit 5μ Roll to Roll imprint deposit imprint etch strip/clean spin resist etch develop align/expose etch mask 5

6 1. 1 Introduction : Continuous Production System Iowa Thin Film Technologies is now PowerFilm Solar 출처 : Hewlett-Packard Company 6

7 1. 1 Introduction : Continuous Production System Backplane materials costs for R2R photolith & imprint cost per ft 2 Multiple photoresist applications dominate photolithography process materials costs $18.00 $16.00 $14.00 $12.00 $10.00 $8.00 $6.00 $4.00 $2.00 $0.00 Photolithography Photolith Cost of Patterning SAIL Imprint R2R NIL R2R photolith Web cost Strip-off 2P RIE etch oxide Under-cut Al (1-3 um) RIE etch n+ Wet etch Cr Thin down 2P (clear gate-pad) RIE etch n+&si&sin Pre-Cr-etch Cleaning Thin down 2P (clear gate-pad) Plasma etch Al RIE etch oxide RIE etch n+&si&sin Wet etch Cr Imprint SAIL structure SD metal deposition (Cr) PECVD oxide/nitride/si/n+ deposition Gate metal deposition (Al) Condition web (de-hydro) Web cost Align and Expose Sputter Dep Interconnect Align and Expose Sputter Dep/ ITO Align and Expose Ultrasonic Clean Si RIE & Resist Strip Align and Expose SiN, a-si, N+ dep Align and Expose Sputter Gate 1 Metal Web preparation $0.0 $0.5 $1.0 $1.5 $2.0 $2.5 $0.0 $0.5 $1.0 $1.5 $2.0 $2.5 $3.0 출처 : Hewlett-Packard Company 7

8 1. 1 Introduction : Continuous Production System Imprint Lithography is the Best Choice for R2R Patterning Photolithography Imprint lithography Inkjet Physical mask Laser ablation Throughput Moderate: limited by step & repeat / stitching High: > 5 meters/min Low Limited only by deposition Low Resolution Limited by substrate flatness ~10μ 100nm demonstrated >10μ 10μ -100μ ~10μ Alignment Limited by substrate flatness ~10μ Self alignment possible External sensor required poor ~10μ Issues Scaling to large areas costly New technology Materials must be jettable Cleaning, particles Thermal effects, selectivity 출처 : Hewlett-Packard Company 8

9 1. 1 Introduction : Continuous Production System R2R Patterning 원통금형소재원통금형에나노패턴을새김나노패턴원통금형확보 Thermal or UV 코팅, 증착등후속공정 최종제품생산 롤임프린트공정장비를통해필름에패턴을새김 ( 연속공정 ) 9

10 Click to add Title 1 Roll to Roll nanoimprint Fabrication Processes 10

11 1. 2 Fabrication Processes Roll-to-roll imprint(r2r) process bottle neck Roll stamp Web(substrate & film) Material viscosity Roll pressure Defects in the height Web speed R2R imprint process parameter and system IT resolution Optical device : 2um (PLC) Optical film : 100nm (NWGP) Flexible display : 1um (TFT) Roll pressure Web speed Material viscosity Nano roll stamp Flexible soft mold Seamless roll 11

12 1. 2 Fabrication Processes R2R NIL variants based on resist curing 12

13 1. 2 Fabrication Processes Three main contact types of R2R imprint processes Aspect ratio Web speed Roll pressure Web speed Material viscosity

14 1. 2 Fabrication Processes Thermal R2R and R2P NIL system for a flexible polymer film Mold cooling Substrate Stamp 14

15 Thermal NIL process 15

16 Molding ( Squeeze Flow of Thin Films ) L L hr h0 hr hf <Geometrical definitions used for the description of the flow process> ho : Initial thickness(height) hr : Depth of the micro relief Si : Stamp protrusion with width hf : Final thickness(height) Applying the continuity equation with the assumption that the polymer melt is incompressible (conservation of polymer volume), we get : h N 0 i1 N s w h s w h w i i f i1 i i N r i1 N N hr We derive h f to be: hf h0 w i, s i wi This formula only applies for rigid stamps (no local bending) with a constant fill factor i 1 i i 1 16

17 Molding ( Squeeze Flow of Thin Films ) Height Solving Navier-Stokes equation with nonslip boundary conditions and treating the polymer as an incompressible liquid of constant viscosity at the stamp and substrate surfaces. We find the following expression : Stefan equation 1 1 2F t h ( t ) h Ls 0 0 Inserting the final thickness hf h(tf) For many practical cases, where a constant pressure under each stamp protrusion p=f/(sl) is assumed h0 50% From this expression we can see how strongly s influences the embossing time (t f ~s 3 using a constant force F). It is therefore worthwhile reducing the size of the stamp protrusions as much as possible hf 95% 100% Time t0 tf <Schematics of the squeeze flow of a compressed polymer film into one cavity> 17

18 Model describing the flow process. Left side: Flow element. Right side: Velocity distribution in a Newtonian flow. Only the flow of polymer between the centers of the two stamp protrusions contribute to the filling of the cavity. 18

19 The melt should stick ideally at the plate surfaces and be able to move freely both into the cavity and away from the cavity beyond of the borders of the regarded volume. The embossing time t f is simply the time which is reached when the distance between the two plates is h f. To solve the present squeeze flow problem we make the following assumptions: - ideal viscous liquid - incompressibility of the polymer melt - s >> h(t) - no air trapped in the cavities - no stick-slip effect at the interfaces (v y (t,z=±h/2) 0) 19

20 The two-dimensional description gives rise to / x=0. Therefore in the x-direction, both plates should have the length L s. For an infinitesimally small cuboid of the size L δy 2δz at the axis z=0, from the motion equation (for quasi-stationary flow): j p i ij 0 zy dp( y) dy z ; the shear stress in y direction dv dz y zy 1 o zy 1 o dp dy z 20

21 21 2 ) ( 0.;. ), ( 2 ) ( 2 1 ),, ( 2 2 t h z for v b c dy t y dp t h z t z y v y o y dt t dh Ly dy t y dp t h L t z y v L t y q o t h y ) ( ), ( ) ( 12 ),, ( 2 ), ( 3 2 ) ( 0

22 ) ( 1 ) ( ) ( ), ( h h F Ls t t Ls F h t h t h s dt t dh L dy t y p L F f f s s 0 ) 2, (.;. 2 ) ( ) ( 6 ), ( t s p b c s y dt t dh t h t y p o

23 t p f F ( sl) s 2 p hf h0 23

24 1. 2 Fabrication Processes Thermal R2R and R2P NIL system for a flexible polymer film - Throughput: 0.2~5m/min - Temp: 95~110C - Lamination Temp: 65~80C - Pressure: 8Mpa Roll-to-roll hot embossing, Finland,

25 1. 2 Fabrication Processes Thermal R2R and R2P NIL system for a flexible polymer film Materials : Polystyrene Width: 150mm Length: 15m Pillar Dia.: 200nm Aspect ratio: 1.4 Sheet Nanoimprint : Hitachi, Continuous process of heating, pressing, cooling and parallel separation 25

26 1. 2 Fabrication Processes UV R2R NIL system for a flexible polymer film Residual layer 19

27 1. 2 Fabrication Processes UV R2R NIL system for a flexible polymer film Film splitting region Backup roll Upstream bank Film-splitting menuscus Primary parameters : Applicator roll Ratio of gap to radius(h/r) Capillary number (CP) Residual layer 27

28 1. 2 Fabrication Processes UV R2R NIL system for a flexible polymer film 28

29 1. 2 Fabrication Processes Web Handling for tension control 29

30 1. 2 Fabrication Processes Web Handling for tension control (Multi-face contact) 30

31 1. 2 Fabrication Processes Web Handling for tension control (Single-face contact) 31

32 1. 2 Fabrication Processes Web Handling for tension control 1. 장력의변화 2. 댄서롤의회전각변화 3. 댄서롤의회전각으로부터댄서의위치되먹임 4. 댄서롤의위치를기준점에유지하기위한제어명령생성 5. 모터를이용한롤의속도 ( 또는토크 ) 제어 6. 댄서롤의위치복원 7. 장력의복원 32

33 1. 2 Fabrication Processes Web Handling for tension control 33

34 1. 2 Fabrication Processes Web Handling for tension control 34

35 Click to add Title 1 Roll to Roll nanoimprint Fabrication of nano roll mold 35

36 1. 3 Fabrication of nano roll mold Fabrication of nano roll mold using UV Nanoreplication 36

37 1. 3 Fabrication of nano roll mold Fabrication of polyvinyl alcohol(pva) mold process 37

38 1. 3 Fabrication of nano roll mold Fabrication of polyvinyl alcohol(pva) mold process 38

39 1. 3 Fabrication of nano roll mold Roll-to-Roll Liquid Transfer Imprint Lithography for Patterning on a Large-area Roll Conceptual drawing of a roll-to-roll LTIL process and its step-and-repeat process for a large-area roll 39

40 1. 3 Fabrication of nano roll mold Roll-to-Roll Liquid Transfer Imprint Lithography for Patterning on a Large-area Roll Photographs of (a) the roll-to-roll LTIL system and (b) the patterned results on a large-area substrate roll. (c) shows a SEM image of the nanopattern on the substrate roll. 40

41 1. 3 Fabrication of nano roll mold Fabrication of seamless roll mold using laser thermal litho. 41

42 1. 3 Fabrication of nano roll mold Fabrication of seamless roll mold using laser thermal litho. 42

43 1. 3 Fabrication of nano roll mold Fabrication of seamless roll mold using E-beam litho. 100 kev 전자총노광제어기 (PG) 100 kev 나노노광장비 제진시스템 제진시스템제어기 원통나노금형 ( 패턴노광결과물 ) 고진공시스템 진공시스템제어기 43

44 1. 3 Fabrication of nano roll mold Fabrication of seamless roll mold using E-beam litho. 44

45 1. 3 Fabrication of nano roll mold Rolling Mask Lithography 45

46 1. 3 Fabrication of nano roll mold Rolling Mask Lithography 46