Nanoimprinting. Nanoimprint. Spin Coating Imprinting De-molding Etching

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1 Nanoimprinting Nanoimprint Spin Coating Imprinting De-molding Etching 1

2 Nanoimprint Glass Transition Temperatures (Tg) mr-i C mr-i C mr-i PMMA 105 C 2

3 10 nm holes 10 nm holes and 40 nm pitch in PMMA fabricated by nanoimprint lithography Micro- and Nanoimprint C C Chang et. al, A Study of The Thin Film Heat Transfer in a Rapid-heating Nanoimprint Process, EMN04, October 2004, Paris, France 3

4 Rolling Imprint Step and Stamp Imprint Lithography,SSIL University of Texas at Austin, USA 4

5 Step and Flash Imprint Lithography,SFIL 發展常溫常壓下的微影轉印製程 採小面積步進轉印微影紫外光 (UV) 使低黏度光阻硬化成形 Step and Flash Imprint Lithography 5

6 Large scale ultraviolet-based nanoimprint lithography, B. Vratzov, A. Fuchs, M. Lemme, W. Henschel, and H. Kurz, J. Vac. Sci. Technol. B Vol 21, No 6, Nov Dec 2003, Large scale ultraviolet-based nanoimprint lithography, B. Vratzov, A. Fuchs, M. Lemme, W. Henschel, and H. Kurz, J. Vac. Sci. Technol. B Vol 21, No 6, Nov Dec 2003,

7 Microcontact Print, μ-cp (Soft Lithography) PDMS ( 聚二甲基矽氧烷 ) Thiol ( 一種有機高分子硫醇 ) Gold thin file + Thiol Self-Assembly Monolayer, SAM Bottom-up Approach Y. Xia, G. M. Whitesides, Angew. Chem. Int. Vol.37, pp , 1998, Laser-Assisted Direct Imprint, LADI 利用雷射加熱矽基材直接壓印的雷射輔助直接壓印 7

8 Laser-Assisted Direct Imprint, LADI SEM image of the cross-section of samples patterned using LADI. a, A quartz mould. b, Imprinted patterns in silicon. The imprinted silicon grating is 140 nm wide, 110 nm deep and has a 300 nm period, an inverse of the mould. Fabrication of 70 nm channel length polymer organic thin-film transistors using nanoimprint lithography Michael D. Austina and Stephen Y. Chou, APPLIED PHYSICS LETTERS, VOLUME 81, NUMBER 23 2 DECEMBER 2002 OTFT device 於塑膠基板上, 利用高精度印刷技術製作 P- 型與 N 型有機薄膜電晶體 Using precision printing technology to fabricate p type and N type organic TFT on plastic substrate 應用範圍 : 軟性顯示器 軟性有機電子元件 8

9 ITRI Project EVG s Nanoimprint Lithography Products Hot Embossing Micro Contact Printing UV-Nanoimprint Lithography 9

10 Equipment Developers EV Group (EVG) SUSS MicroTec Obducat EVG s Nanoimprint Products EVG520HE The EVG520HE semi-automated hot embossing system is designed for embossing and nanoimprinting applications. This productionproven system from EVG accepts substrates up to 200 mm and is compatible with standard semiconductor manufacturing technologies. The hot embossing system is configured with a universal embossing chamber, high-vacuum and high-contact force capabilities and manages the whole range of polymers suitable for hot embossing. Together with high-aspect ratio embossing and multiple de-embossing options many processes for high quality pattern transfer and nm resolution are offered. 10

11 Dip-Pen Nanolithography Transport of molecules to the surface via water meniscus( 凹面 ) Dip-pen nanolithography heats up with new technique Diagram illustrating thermal dip pen nanolithography. When the cantilever is cold (left) no ink is deposited. When the cantilever is heated (right), the ink melts and is deposited onto the surface. Source: Naval Research Laboratory 11

12 DPN Kit - DPN Pens & Substrates DPN Substrates - patterned alignment oxide-sharpened DPN probe tips DPN Probes singles triples as many W D L D L A W A Wafer Type 1 Wafer Types 2 &

13 DPN Pens NSCRIPTOR user interface leverages InkCAD CAD to create nanoscale patterns 13

14 NSCRIPTOR DPNWriter DPN InkWells 14

15 Dip-Pen Nanolithography Possible applications Recent progress in nanoimprint technology and its applications L Jay Guo, Recent progress in nanoimprint technology and its applications, Journal Of Physics D: Applied Physics, 37 (2004) R123 R

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18 CNP: Combined nanoimprint and photolithography 18

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26 Nanostructing Techniques Severe Plastic Deformation (SPD) 26

27 Severe Plastic Deformation (SPD) Special set-up of thermomechanical processing Rolling Wire-drawing Extrusion High reduction rates or with a combination of different steps during cold deformation Equal Channel Angular Processing (ECAP) 27

28 Equal Channel Angular Processing (ECAP) It is shown that simple shear can be considered as a near ideal deformation method for structure and texture formation in metalworking. It has the advantage of producing extra-large, strictly uniform and unidirectional deformations under relatively low pressure and load. Without macroscopic shape change Equal Channel Angular Processing (ECAP) There are many potential and promising applications of this deformation method in materials synthesis and processing. It should be pointed out that breakdown of cast ingots, consolidation and bonding of powders and grain refinement by ECAP with subsequent recrystallisation treatments can be used to produce submicron-grained structures in various materials. The process can easily be repeated a number of times in the same tool. The process can also be extended from Extrusion to Drawing. 28

29 Grain Size Grain Size 29

30 Accumulative Roll Bonding (ARB) Accumulative Roll Bonding (ARB) Aluminum 30

31 Nanocrystalline Copper Superplastic Extensibility of Nanocrystalline Copper at Room Temperature L. Lu, M. L. Sui, K. Lu1 SCIENCE VOL FEBRUARY 2000 A bulk nanocrystalline (nc) pure copper with high purity and high density was synthesized by electrodeposition. An extreme extensibility (elongation exceeds 5000%) without a strain hardening effect was observed when the nc copper specimen was rolled at room temperature. Microstructure analysis suggests that the superplastic extensibility of the nc copper originates from a deformation mechanism dominated by grain boundary activities rather than lattice dislocation, which is also supported by tensile creep studies at room temperature. This behavior demonstrates new possibilities for scientic and technological advancements with nc materials. 31

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35 Friction and wear behaviors of nanocrystalline surface layer of pure copper Y.S. Zhang, Z. Han, K. Wang, K. Lu Wear 260 (2006) Surface mechanical attrition treatment (SMAT) was employed to fabricate a nanocrystalline surface layer on a pure copper plate. The grain size is about 10 nm in the top layer and increases with an increasing depth from the treated surface. 35

36 Selected area electron diffraction (SAED) 36

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40 Effect of surface nanocrystallization on friction and wear properties in low carbon steel Z.B. Wang, N.R. Tao, S. Li b, W. Wang, G. Liu, J. Luc, K. Lu Materials Science and Engineering A352 (2003) 144/149 40

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44 An abnormal strain rate effect on tensile behavior in nanocrystalline copper 44

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46 原子力顯微鏡 AFM (Atomic Force Microscope) 46

47 web.mit.edu/cortiz/www/nanomechanics.html AFM Tip 47

48 AFM 基本原理 探針與樣品表面的凡得瓦爾力 橫桿 (cantilever) 位移 200 µm with a low spring constant (of the order of 1 Newton/m) 雷射束偵測位移 掃瞄系統 迴饋電路系統 表面圖形 (surface topography) 高度影像 (height image) Piezo-electric Ceramics ( 壓電陶瓷 ) Direct Effect( 直接效應 ) a well-known effect used in microphones, accelerometers etc. Converts mechanical strain into voltage. Reverse Effect( 反相效應 ) a well-known effect used as a limited motion actuator, ultrasound transducer etc. Converts electrical fields into motion. 48

49 Record Player ( 唱片機 ) Z-axis is conventionally perpendicular to the sample. We may think that the AFM is like a record player Feedback Control Modes 迴授控制模式 With feedback control the positioning piezo which is moving the sample (or tip) up and down can respond to any changes in force constant force Without feedback control 49

50 AFM 操作模式 接觸式 (contact mode) 非接觸式 (non-contact mode) 輕敲式 (tapping mode) 接觸式 (Contact Mode) 排斥力 (repulsive) 最早發現 排斥力對距離敏感 解析度高 探針與樣品之作用力 10-6 ~10-10 N 作用力太大損害樣品 解析度 50

51 非接觸式 (Non-contact Mode) 解決接觸式 AFM 損害樣品之缺點 吸引力 ( 凡得瓦爾力 ) 對距離不敏感, 解析度不佳 改善解析度 探針需要與一陶瓷震盪片接觸 偵測振幅或相位 解析度 空氣中 :50nm ( 表面水模之影響 ) 真空 : 原子解析度 輕敲式 (Tapping Mode) 改良非接觸式 側向力減少 拉近探針與樣品距離 探針震盪至波谷時接觸樣品 共振頻率 (resonant frequency, hundreds of kilohertz) 較不受磨擦力之影響 樣品損害降低 硬質樣品損害探針 軟質物體受破壞 51

52 Tip Effects( 探針影響 ) One of the most important factors influencing the resolution Sharpness of the scanning tip The main influences are 寬度 (broadening) 與形狀比例 (aspect ratio) 壓縮 (compression) 交互作用力 (interaction forces) Tip Broadening( 探針寬度 ) Aspect Ratio ( 形狀比例 ) Radius of curvature of the tip Shape of the tip 52

53 Compression( 壓縮 ) Occurs when the tip is over the feature trying to be imaged. Difficult to determine in many cases how important this affect is. It should be born in mind that although the force between the tip and sample may only be nn, the pressure may be MPa. Interaction forces( 交互作用力 ) between the tip and sample The reason for image contrast with the AFM Forces due to the chemical nature of the tip are probably most important Selection of a particular tip for its material can be important 53

54 Specification of Cantilevers Length: 230 ± 5, µm Width: 40± 3, µm Thickness: 3.0 µm Resonant Frequency: 75 khz Force Constant: 3.5 N/m Images of Probe and Single Extratip Typical probe curvature radius : 1 nm Typical height of extratip: 100~200 nm 54

55 Tip Radius 1 nm curvature radius Scan size Height 250 nm 25 nm Conventional silicon probe in Tapping mode. Tip curvature radius Rc < 10 nm. Scan size Height 250 nm 40 nm HI'RES probe in Tapping mode. Individual molecules are resolved. Tip curvature radius Rc < 1 nm. 55