1. ITRS Winter Conference 2008 Seoul, Korea 1 Work in Progress: Not for Distribution 2008 ITRS Emerging Research Materials [ERM] December 6, 2008 Michael Garner – Intel Daniel Herr – SRC

2. ITRS Winter Conference 2008 Seoul, Korea 2 Work in Progress: Not for Distribution ERM Workshops

3. ITRS Winter Conference 2008 Seoul, Korea 3 Work in Progress: Not for Distribution ERM Workshops

4. ITRS Winter Conference 2008 Seoul, Korea 4 Work in Progress: Not for Distribution Alternate Channel Materials WS III-V & Ge Channel Structures and Materials: Heterostructure Integration Issues –Current Approaches Direct growth of III-V Heterostructures on Silicon III-V Growth on GeOI on Silicon (MIT) Aspect Ratio trapping in III-V growth on silicon (Amber Wave, Takagi) III-V Growth on GaAs-GeOI (Dual Logic) Issues & Challenges N- (III-V) and P- (Ge) channels growth of low-defect, strain-controlled films with acceptable mobilities after integration to silicon platforms Reduction of dislocation densities – how low can we go? Unusual crystallographic orientations are needed (best epi vs lowest DOS) How do twins in ELO layers affect the carrier transport? Are antiphase domains in III-V’s a problem for carrier transport? Thickness level and control for lateral overgrowth and Ge condensation methods Scaling of strain effects – for ultra-thin layers, can III-V’s support the elastic strain levels required without dislocating?

5. ITRS Winter Conference 2008 Seoul, Korea 5 Work in Progress: Not for Distribution Alternate Channel Materials WS III-V & Ge Channel surface passivation and high-k dielectric deposition options –Current Approaches (III-V): MBE Growth of III-V/Ga2O3/GdGaO Stack (Freescale) As Cap/ In situ As decap +ALD HfO2 (Stanford) NH4OH-ALD Al2O3 or HfO2 on III-V (Purdue) InAlAs Barrier (MIT) –Current Approaches (Ge): GeOxNy Nitridation (Stanford) Ozone Oxidized Ge + ALD High κ dielectric HfO2 (Stanford) LaGeOx-ZrO2(Ge) High K (Dual Logic)

6. ITRS Winter Conference 2008 Seoul, Korea 6 Work in Progress: Not for Distribution High K Integration Issues –Wet (NH4S) vs dry (amorphous As cap) – shows importance of controlling surface oxidation effects on III-V’s to get lower Dit and unpinned interfaces. Sulfur passivation is not complete or stable compared to As cap. –Comparison of NH4OH to atomic H surface preparation during ALD of HfO2? –Comparison of a-Si cap vs a-As cap vs atomic hydrogen for III-V surface passivation and preparation? –GeOx nonstoichiometry is a major issue and can be controlled by either lower temperature ozone oxidation or forming gas anneals, or nitridation, or ----, before HfO2 deposition

7. ITRS Winter Conference 2008 Seoul, Korea 7 Work in Progress: Not for Distribution S/D & Contact Formation Current Approaches: –Ge P-MOS: Boron with many ohmic metal contact options N-MOS: Dopants have high diffusivity & metals schottky barriers –III-V W contact/InGaAs cap/InAlAs (MIT) –Are barriers needed to keep dislocations out of the channel?

8. ITRS Winter Conference 2008 Seoul, Korea 8 Work in Progress: Not for Distribution Carrier Transport Physics How close are we to the theoretical ballistic scatting limit where all the channel mobilities are comparable? What are the scattering mechanisms in ultra-thin channels? –are there new scattering sources (such as Coulomb scattering) other than phonon scattering that have yet to be discovered? –What role does alloy scattering play in III-V ternary and quaterenary alloys (e.g. InGaAs and AlInGaAs)?

9. ITRS Winter Conference 2008 Seoul, Korea 9 Work in Progress: Not for Distribution Graphene Workshops

10. ITRS Winter Conference 2008 Seoul, Korea 10 Work in Progress: Not for Distribution Summary of Graphene Workshop I (i) Prof. Ando, Theory of electric states and transport - Metallic transport! A universal conductivity at zero point due to scatterings. Bandgap opening is difficult. (ii) Dr. Tsukagoshi, Conduction control by gate voltage - Zero conduction (bandgap) observed in bilayer! (iii) Prof. Suemitsu, growth on Si substrate - Two layers of graphene films on SiC(111)/Si(110) (iv) Dr. Hibino, Evaluation of number of layers - Observation by nanogap (v) Prof. Kim, Graphene based nanoelectronics - High µ, edge effect, non-conventional devices Toshiro Hiramoto, University of Tokyo

11. ITRS Winter Conference 2008 Seoul, Korea 11 Work in Progress: Not for Distribution Inducing a Bandgap in Graphene Applying an electric field to a multilayer graphene film can induce a bandgap Ambipolar conduction peak can be shifted with high back gate voltage –Rate of the shift decreases exponentially with increasing graphene thickness –Gate induced charge density decreases with exponentially with screening thickness (λ~1.2nm) K. Tsukagoshi

12. ITRS Winter Conference 2008 Seoul, Korea 12 Work in Progress: Not for Distribution Bilayer Graphene Next target wafer level multi layer graphene Hiroki Hibino, NTT

13. ITRS Winter Conference 2008 Seoul, Korea 13 Work in Progress: Not for Distribution Epitaxial graphene on Si substrate mediated by an ultra-thin SiC layer Prof. Suemitsu, Tohoku University

14. ITRS Winter Conference 2008 Seoul, Korea 14 Work in Progress: Not for Distribution Scaling of Energy Gaps in Graphene Nanoribbons E g = E 0 /(W-W 0 ) Han, Oezyilmaz, Zhang and Kim PRL (2007)

15. ITRS Winter Conference 2008 Seoul, Korea 15 Work in Progress: Not for Distribution Crystallographic Directional Dependence Son, et al, PRL. 97, 216803 (2006) 2  m 030 60 90 0 20 40 E g (meV)  (degree) Graphene Nanoribbons Edge Effect Rough Graphene Edge Structures

16. ITRS Winter Conference 2008 Seoul, Korea 16 Work in Progress: Not for Distribution Mobility n (10 12 cm -2 ) Mobility (cm 2 /V sec) TC17 TC12 TC145 TC130 Mechanically exfoliated graphene Tan et al. PLR (2007) Highest mobility for suspended graphene

17. ITRS Winter Conference 2008 Seoul, Korea 17 Work in Progress: Not for Distribution Graphene Bi Layer Films enable field induced bandgap –Requires a high field (~10 9 V/cm) Substrate effects reduce mobility

18. ITRS Winter Conference 2008 Seoul, Korea 18 Work in Progress: Not for Distribution Graphene WS 2 Integrable Deposition CVD Growth of Graphene on Metal Substrates Exfoliation –Tape –Graphene Oxidation –Solvent SiC decomposition

19. ITRS Winter Conference 2008 Seoul, Korea 19 Work in Progress: Not for Distribution Graphene CVD The best substrates for high quality graphene are Pt 111 or Ni 111 and possibly Ir 111. –Graphene on Ni 111 was strongly chemisorbed onto a lattice matched substrate and had an undistorted structure that was aligned to the Ni Both Pt 111 and Ir 111 (5d metals) are lattice mismatched to graphene –Graphene was undistorted in Pt and not aligned to the Pt surface –Graphene on Ir was slightly distorted

20. ITRS Winter Conference 2008 Seoul, Korea 20 Work in Progress: Not for Distribution CVD Growth of Graphene on Ir CVD growth of graphene on Iridium appears to be initiated at steps on surfaces resulting in island formation –The graphene appears to be continuous over steps –When the islands merge, this results in defects –Very slow growth (close to equilibrium) is required to produce high quality graphene

21. ITRS Winter Conference 2008 Seoul, Korea 21 Work in Progress: Not for Distribution Scale up issues Graphene can be transferred from Ni to an oxide substrate. –APPLIED PHYSICS LETTERS 93, 113103 (2008) –Bonded the graphene with silicone to a glass plate and etched away the metal substrate A key challenge is that graphene is grown on high quality single crystal metal substrates (Pt, Ir, or Ni) and large diameter crystals are not available –Since nucleation occurs at steps, it may be difficult to grow high quality graphene on polycrystalline substrates. –Since the graphene is physisorbed onto Pt, this may be the most promising candidate for a polycrystalline substrate

22. ITRS Winter Conference 2008 Seoul, Korea 22 Work in Progress: Not for Distribution Graphene Oxide Deposition C Gomez-Navarro and Vincent Tung The conductivity of the graphene oxide increased 1000X upon exposure to: –Hydrazine for 24 hours –Hydrogen plasma 5 seconds The mobility was measured to be between 10 and 1000cm2/V-sec. (~400-500 for UCLA) –Conduction was found to be dominated by hopping transport (CGN) Graphene was found to have regions of highly ordered graphene surrounded by disordered graphene. UCLA demonstrated the ability to selectively stack (physical transfer) layers of graphene on top of each other. Maximum graphene flakes achieve to date are in the size range of 10μm to 100μm Critical future work is to reduce the defect regions in the graphene by reducing the damage in the oxidation process.

23. ITRS Winter Conference 2008 Seoul, Korea 23 Work in Progress: Not for Distribution Liquid Phase Exfoliation of Graphene Jonathan Coleman Graphene can be exfoliated in solvents from HOPG with ultrasound, but solvent choices are limited because of solvent surface energy requirements. –The boiling point of the solvents is very high which makes deposition onto a substrate difficult –With NMP, 12% of the flakes in the solvent were monolayer graphene with most of the flakes being 1-3 layers thick. –1% of the graphite was converted to monolayer graphene –The high boiling point of solvents allows graphene to reaggregate when trying to dry on a substrate –Further work is needed to establish a method to deposit the graphene on a surface from surfactant dispersed graphene in water or solvent.

24. ITRS Winter Conference 2008 Seoul, Korea 24 Work in Progress: Not for Distribution Spin Materials Workshops STT Structures Electric Field Control of Spin and Magnetism –Ferromagnetic Semiconductors –Doped Oxides –Magnetoelectric Materials

25. ITRS Winter Conference 2008 Seoul, Korea 25 Work in Progress: Not for Distribution STT Structures MgO was a major breakthough in spin selection efficiency –Requires a 9A film thickness –Must be single crystal –May be limited options on interface materials Major long term scaling issue is sputtering of ferromagnetic materials

26. ITRS Winter Conference 2008 Seoul, Korea 26 Work in Progress: Not for Distribution Ferromagnetic Semiconductors III-V (Mn doped) materials have been verified to have carrier mediated exchange with gated structures –100-200K Ferromagnetic behavior has been reported in GeMn nanostructures –Magnetometer & Anomalous Hall Effect –Not verified with gated structure Is it possible to raise III-V Mn Tc to room temperature –Mark van Schlifgaard: Not with random doping, but possible with superlattices

27. ITRS Winter Conference 2008 Seoul, Korea 27 Work in Progress: Not for Distribution Oxide Doped FM Materials ZnO doped with Co, Mn is FM above room temperature –Ferromagnetism correlated with carrier concentration –Low mobility makes anomalous Hall effect difficult In2O3: 2% Cr is FM with electron concentration above 2E19 cm-3 –Anomalous Hall effect observed

28. ITRS Winter Conference 2008 Seoul, Korea 28 Work in Progress: Not for Distribution Oxide Doped FM Materials Challenges Demonstrate stronger, detailed correlation of FM order with carrier density –Gated structures Directly demonstrate and measure carrier spin polarization –spin-LEDs, TMR device, etc Improve remanent magnetization (currently pathetic) –large remanence is critical –low remanence = weak exchange, low anisotropy, …??? –MFM indicates complex domain structure in Cr:In2O3 Theoretical treatment has improved dramatically, needs to go further –band-gap corrected treatment provides more realistic picture –needs exp input on defect structure, levels r/t CMB,VBM, etc to even begin a detailed treatment

29. ITRS Winter Conference 2008 Seoul, Korea 29 Work in Progress: Not for Distribution Magnetoelectric Materials BiFeO3 Exchange Bias with CoFe couples electric polarization with magnetization –BFO is Ferroelectric and antiferromagnetic –Domain wall orientation and concentration played a key role in exchange bias (109°) 109° domain walls were found to be conductive & possibly metallic Proposed domain wall logic –Changing the FE polarization rotated the FM alignment of the CoFe structure LSMO on BFO had an increased coercive field and shifted exchange bias with change of FE polarization.

30. ITRS Winter Conference 2008 Seoul, Korea 30 Work in Progress: Not for Distribution Emerging Research Materials 2009 Establish ERM Outline and Writing Assignments Refine Critical Assessment Process –CMOS Extension: More detailed –Beyond CMOS: Trends on critical materials & properties –Update Key Challenges Tables Plan Workshops on ERM –All workshops should identify Metrology, Modeling and ESH support as appropriate Finalize new materials needs based on ITWG inputs –ERD, Lithography, FEP, Interconnects, Assembly & Packaging, PIDS –Establish Concrete targets –Functional Diversification

31. ITRS Winter Conference 2008 Seoul, Korea 31 Work in Progress: Not for Distribution ERM Outline Introduction Difficult Challenges Challenges for Multi-application ERM (Back-up?) Materials for Alternate Channel CMOS (PIDS & ERD) –Critical Assessment ERM for Beyond CMOS (ERD) ERM for Lithography –Resist (pixilated, Multi photon resist, novel) –Self Assembled Materials –Transition Table (Molecular glasses, evolutionary resist macromolecular design, etc.) ERM for FEP & PIDS –Deterministic Doping –Self Assembly for Selective Deposition & Etch ERM for Interconnects ERM for Assembly & Package ERM ESH Research Needs ERM Metrology Needs ERM Modeling Needs

32. ITRS Winter Conference 2008 Seoul, Korea 32 Work in Progress: Not for Distribution Challenges for Multi-application ERM LDM –Control of placement & direction –Control of nanostructure, properties & macro properties Macromolecules Self Assembled Materials Complex metal oxides

33. ITRS Winter Conference 2008 Seoul, Korea 33 Work in Progress: Not for Distribution Materials for Alternate Channel CMOS III-V & Ge (John Carruthers) Semiconductor Nanowires(Ted Kamins) Graphene (Daniel Beneshal) Carbon Nanotubes (Jean Dijon)

34. ITRS Winter Conference 2008 Seoul, Korea 34 Work in Progress: Not for Distribution Fundamental Alternate Channel Common Question Does ballistic transport dominate over intrinsic mobility?

35. ITRS Winter Conference 2008 Seoul, Korea 35 Work in Progress: Not for Distribution III-V & Ge Key Messages Gate Dielectric Growth techniques are being developed –Current Approaches (III-V): MBE Growth of III-V/Ga2O3/GdGaO Stack (Freescale) As Cap/ In situ As decap +ALD HfO2 (Stanford) NH4OH-ALD Al2O3 or HfO2 on III-V (Purdue) InAlAs Barrier (MIT) –Current Approaches (Ge): GeOxNy Nitridation (Stanford) Ozone Oxidized Ge + ALD High κ dielectric HfO2 (Stanford) LaGeOx-ZrO2(Ge) High K (Dual Logic) Controlling surface oxide formation is critical for control of interface states –Control of interface stochiometry, structure and defects is critical –GeOx stochiometry control affected by growth temperature

36. ITRS Winter Conference 2008 Seoul, Korea 36 Work in Progress: Not for Distribution III-V & Ge Key Messages Ge dopant activation requires high temperature –Incompatible with III-V process temperatures S/D Contact Formation Current Approaches: –Ge P-MOS: Boron with many ohmic metal contact options N-MOS: Dopants have high diffusivity & metals form Schottky barriers –III-V W contact/InGaAs cap/InAlAs (MIT) Are barriers needed to keep dislocations out of the channel?

37. ITRS Winter Conference 2008 Seoul, Korea 37 Work in Progress: Not for Distribution III-V Ge Heteroepitaxy Challenges Reduction of dislocation densities Control of stress in III-V & Ge integrated on Si –Ultrathin films –Heterostructures to reduce defects Effect of antiphase domains on carrier transport Identify a crystal orientation that favors epitaxy and interface states.

38. ITRS Winter Conference 2008 Seoul, Korea 38 Work in Progress: Not for Distribution Graphene Challenges & Status Ability to deposit graphene on appropriate substrates Producing a bandgap –Fabricating Narrow Graphene Lines –Applying a high electric field to bi-graphene Achieving high mobility in an integrated structure Achieving a high on-off conduction ratio

39. ITRS Winter Conference 2008 Seoul, Korea 39 Work in Progress: Not for Distribution Graphene Deposition CVD of Graphene on Ni, Pt, and Ir –Graphene is strongly bonded to Ni, but has a lattice match –Graphene deposited on Pt is not distorted, is not lattice matched, but is weakly bonded SiC decomposition –Issue: High process temperature (>1100C) Exfoliation Techniques –Graphene Oxide Decomposition (Mobility <1000cm2/V-sec) Oxidation process produced islands of graphene surrounded by disordered material (hoping conduction) –Try less aggressive oxidation process –Solvent exfoliation Solvents capable of separating graphene sheets are difficult to evaporate (high boiling point) –Tape exfoliation

40. ITRS Winter Conference 2008 Seoul, Korea 40 Work in Progress: Not for Distribution Producing a Graphene Bandgap Fabricating Narrow Graphene Lines –Requires patterning sub 20nm lines –Edge defect control is challenging (Eg & Mobility) Applying a high electric field to bi-graphene –Field ~1E9 V/cm

41. ITRS Winter Conference 2008 Seoul, Korea 41 Work in Progress: Not for Distribution Graphene Mobility Mobility on substrates is reduced Graphene Oxide Mobility –Degraded by disordered regions

42. ITRS Winter Conference 2008 Seoul, Korea 42 Work in Progress: Not for Distribution Beyond CMOS M. Garner Molecular State (Alex Bratkovski & Curt Richter) Spin Materials (Kang Wang) –FM Semiconductors –CNT & Graphene –Tunnel Barriers STT-Dr. Yeo –FM metals –Multiferroics Complex Metal Oxides (TBD) –Ferroelectrics (Memory) –Tunnel Barrier

43. ITRS Winter Conference 2008 Seoul, Korea 43 Work in Progress: Not for Distribution Memory Materials –Professor H.S. Hwang

44. ITRS Winter Conference 2008 Seoul, Korea 44 Work in Progress: Not for Distribution ERM Beyond CMOS Scope: 2009 2007Transition InTransition Out2009 Molecules & Interfaces Status FM Semiconductors Curie Temp Table Tc Graph FM Oxide Semiconductors Status, Table or Graph Spin Semiconductor Status Spin BarriersStatus MultiferroicsStatus FM MetalsStatus

45. ITRS Winter Conference 2008 Seoul, Korea 45 Work in Progress: Not for Distribution ERM Beyond MOS Memory: 2009 2007Transition InTransition Out2009 Complex Metal Oxide Resistance Change Status Oxides & Interfaces FE Memory Status Nanotube for Nanomechanical memory Status Molecules & interfaces for Molecular Memory Status MRAM MaterialsStatus

46. ITRS Winter Conference 2008 Seoul, Korea 46 Work in Progress: Not for Distribution Molecular Devices Top contact formation is still a significant issue Determining that switching is due to the molecular energy levels is difficult

47. ITRS Winter Conference 2008 Seoul, Korea 47 Work in Progress: Not for Distribution Spin Materials Ferromagnetic III-V (Mn) semiconductors have verified Curie temperatures 100-200K –Carrier mediated exchange Nanowires of GeMn have reported ferromagnetic properties at 300K+, but carrier mediated exchange with gated structure is difficult to verify Oxides doped with transition metals have ferromagnetic properties –Ferromagnetism is determined by carrier doping, but it isn’t clear whether this can be modulated with electric fields –Ferromagnetism is proposed to be in an impurity band vs. the oxide bands. –It is not clear whether this is useful for device applications

48. ITRS Winter Conference 2008 Seoul, Korea 48 Work in Progress: Not for Distribution Spin Materials (Cont.) Spin Tunnel Barrier Materials –MgO crystalline material is the best spin selective tunnel barrier to date May work with a limited number of materials due to lattice match requirement –Films must be ~9A thick –Al2O3 films work, but with much lower selectivity Multiferroics –BaFeO3 has ferroelectric & ferromagnetic properties coupled Limited degrees of freedom & low coupling

49. ITRS Winter Conference 2008 Seoul, Korea 49 Work in Progress: Not for Distribution ERM for Lithography (Dan Herr & Joe Gordon) ERM for Patterning –Novel Macromolecules for Resist Multi wavelength resist (Dual exposure) (Transition in?) Pixellated resist –Novel Macromolecules for CEL Multi wavelength CEL (Dual Exposure) (Transition in?) –DSA Materials –Imprint molecules Functional materials ERM for Immersion Fluids –Nanoparticles for immersion fluids (Transition Table?)

50. ITRS Winter Conference 2008 Seoul, Korea 50 Work in Progress: Not for Distribution ERM Litho Scope: 2009 2007Transition InTransition Out2009 Resist Molecular Design To Litho TWG Molecular GlassesTo Litho TWG Directed Self Assembly Assess Dual Wavelength Resist Molecules To ERMAssess Dual Wavelength CEL Layer Molecules To ERMAssess High index Immersion Fluids Remove?TBD Imprint MoleculesRemove?TBD

51. ITRS Winter Conference 2008 Seoul, Korea 51 Work in Progress: Not for Distribution ERM Lithography Critical Assessment

52. ITRS Winter Conference 2008 Seoul, Korea 52 Work in Progress: Not for Distribution ERM for FEP Dan Herr Deterministic Doping –Research Equipment Options –Self Assembly Driven Selective Etches & Cleans –Research or Engineering? Selective Deposition

53. ITRS Winter Conference 2008 Seoul, Korea 53 Work in Progress: Not for Distribution ERM FEP 2009 Scope 2007Transition InTransition Out2009 Directed Self Assembly (DSA) for Deterministic Doping Status Shuttered Implant for Deterministic Doping Into ERMStatus & Challenges DSA Selective Deposition Status & Challenges DSA Selective EtchStatus & Challenges DSA Selective Cleans Stats & Challenges

54. ITRS Winter Conference 2008 Seoul, Korea 54 Work in Progress: Not for Distribution Deterministic Doping Approaches Precision ion implantation Scanning Tunneling Microscope Dopant Placement Langmuir self assembly & deposition of dopants

55. ITRS Winter Conference 2008 Seoul, Korea 55 Work in Progress: Not for Distribution Interconnects Yuji Awano ERM for low impedance interconnects & Vias –CNTs –Nanowires –Graphene ERM for Low κ ILD –Macromolecules (Dan check with Scott List) Selective Etch & Deposition

56. ITRS Winter Conference 2008 Seoul, Korea 56 Work in Progress: Not for Distribution ERM Interconnect Scope: 2009 2007Transition InTransition Out2009 Nanotube Interconnects Assess Nanowire Interconnects Assess Nanotube ViasAssess Nanowire ViasAssess 1-2 monolayer barriers ERMAssess Macromolecule Low K ILD ?Status DSA EtchStatus DSA Selective Deposition Status

57. ITRS Winter Conference 2008 Seoul, Korea 57 Work in Progress: Not for Distribution Emerging Interconnect Applications  Vias Multi-wall CNT Higher density Contact Resistance Adhesion  Interconnects Metallic Alignment Contact Resistance  Dielectrics Novel Polymer ILDs Y. Awano, Fujitsu H. Dai, Stanford Univ. Quartz Crystal Step Alignment Ref. 2005 ITRS, INT TWG, p. 22 ERMs Must Have Lower Resistivity Cu

58. ITRS Winter Conference 2008 Seoul, Korea 58 Work in Progress: Not for Distribution Assembly & Packaging Nachiket Raravikar ? ERM for Thermal Heat Spreading Low Temperature Assembly –Lead free Chip to Package Electrical Interconnects Controlled polymer properties –Application –Process –Operation –Bromine Free High Performance Package Capacitors Energy & Bio Application requirement & status will be descriptive in 2009

59. ITRS Winter Conference 2008 Seoul, Korea 59 Work in Progress: Not for Distribution ERM A&P Scope: 2009 2007Transition InTransition Out2009 Nanotube Electrical Interconnects Status Nano soldersStatus Nanocomposite package polymers Status High density, high performance capacitors Status Nanotube thermal interface materials Status Low assembly temperature materials (ACF?) Add to ERMStatus Ag Nano ACF Nanowires for Power & Detectors Add to ERMStatus

60. ITRS Winter Conference 2008 Seoul, Korea 60 Work in Progress: Not for Distribution ITRS 2008 ERM A&P Workshops: key learnings Nachiket Raravikar Intel Corporation September 2008

61. ITRS Winter Conference 2008 Seoul, Korea 61 Work in Progress: Not for Distribution Title: CNT Interconnects & Thermal Challenges –Focus: Update the progress in assembly compatible integration & contact resistance control of CNT for interconnect and thermal applications –Teleconference [Apr-May’08] Prof. Banerjee, UCSB [May’08] Prof. Majumdar, UC-Berkeley [Aug’08] Focus area 1: CNT Organizer: Nachiket Raravikar

62. ITRS Winter Conference 2008 Seoul, Korea 62 Work in Progress: Not for Distribution CNT Interconnects-challenges

63. ITRS Winter Conference 2008 Seoul, Korea 63 Work in Progress: Not for Distribution CNT Interconnects workshop summary : lowest T for CVD ~ 350-500 C : lowest ~ 34.4 

64. ITRS Winter Conference 2008 Seoul, Korea 64 Work in Progress: Not for Distribution CNT TIM-challenges ERM & ApplicationKey Challenges CNT thermal interconnect-Integrating a high density of aligned CNTs in a polymer matrix -Achieving a low thermal contact resistance -Functionalizing and integrating the CNTs in the polymer without degrading thermal conductivity

65. ITRS Winter Conference 2008 Seoul, Korea 65 Work in Progress: Not for Distribution CNT TIM workshop summary The following two still remain challenges in CNT TIM applications: 1.Controlling CNT array density -Best density up to ~ 10 10 – 10 11 /cm 2 achieved by optimizing the catalyst under-layer thickness; -It’s not clear what the target density should be and whether an array density higher than the above could be achieved 2.Increasing bonding or wetting of CNT with Si, SiO 2 and metals to lower thermal interface resistance -Lowest thermal interface resistance achieved by In coating of CNT: Interfacial conductance [glass-In-CNT-Si]: 3.1±1.5 MW/m 2 ∙K as compared to Glass-CNT-Si: 0.075±0.005 MW/m 2 ∙K -Issue of In wetting on CNT remain -Not many strategies exist on improving thermal interface conductance between CNT-Si or CNT-metals -Realistic targets of experimentally achievable interfacial thermal conductance need to be defined

66. ITRS Winter Conference 2008 Seoul, Korea 66 Work in Progress: Not for Distribution CNT summary The following has been achieved... Low electrical contact resistance, close to theoretical value, has been achieved experimentally High frequency response of nanotubes (impedance, inductance, skin effect) has been modeled and skin effect is predicted to be negligible Some progress towards achieving high density CNT arrays 10 10 – 10 11 /cm 2 In-CNT interface shown to reduce thermal interface resistance The following challenges or unknowns still remain... Low T CVD growth of CNT Increasing CNT array density Reducing CNT electrical and thermal contact resistance

67. ITRS Winter Conference 2008 Seoul, Korea 67 Work in Progress: Not for Distribution Title: Polymer nano-composites mechanical, rheological challenges Focus: 1. Adhesion: Update progress in interfacial adhesion control between nanoparticles and matrix as well as between polymers and metals; –2. Multifunctionality: high toughness, low CTE, high/low modulus, flow properties etc. using nano-fillers; –3. Moisture diffusion barriers: block moisture diffusion for regular as well as MEMS packages –Teleconference Prof. Giannelis, Cornell [Aug’08] Focus area 2: Polymer Nano-composites Organizer: Nachiket Raravikar

68. ITRS Winter Conference 2008 Seoul, Korea 68 Work in Progress: Not for Distribution ApplicationPotential ValueKey Challenges Package Polymer Adhesion Improved package reliability Low viscosity in application Increased adhesion to heterogeneous materials including Cu, silica, etc. after cure Package polymer properties Improved mechanical properties, reduced moisture absorption Controlled CTE, modulus and toughness Low electrical loss Low moisture absorption and transport Nano-material Functionalization Reliable integration of nano-materials Good nanomaterial to polymer adhesion No degradation of nanomaterial properties (e.g., thermal conductivity) Macromolecules/nano-composites Challenges Taken from ITRS ERM 2007 chapter Multi-functionality (high toughness, low CTE, high/low modulus, flow properties etc.) using nano-fillers

69. ITRS Winter Conference 2008 Seoul, Korea 69 Work in Progress: Not for Distribution Macromolecules/nano-composites workshop summary Adhesion improvement with nano-composites –Adhesion enhancement is shown with nanocomposites, however the mechanism is not well understood Nano-composite mechanical property enhancement [modulus, CTE, toughness, elongation] –Decoupling of properties (stiffness-toughness) is a very attractive feature of nano-composites and has been demonstrated with various composite systems –Hypotheses of toughening of nano-composites are in place: nano- particle migration to crazes to prevent crack propagation; hypothesis validation is not done yet Nano-composite moisture absorption –Relative permeability is shown to drop significantly at very small volume fractions of nanoparticles [silicates] Dispersion, interface tailoring of nano-fillers with polymer matrix –Various surface chemistries demonstrated to improve dispersion of nano-silica (particles or clays) in composites: epoxy silica, amino silica, HMDS silica –Dispersion issues still remain such as intercalation or exfoliation of clay or nano-particle clusters, delamination at filler-matrix interface

70. ITRS Winter Conference 2008 Seoul, Korea 70 Work in Progress: Not for Distribution ERM for Low Assembly Temperature 10nm SnAg Melting point reduced to 194C –Surfactant passivation required –Formed good solder joint with 230C reflow 10nm SnAgCu melting point reduced to 199C –Surfactant passivation required Nanosilver based ACF sinters at <200C –Improved contact resistance –Increased current carrying capability –Integrated self assembled monolayer improved adhesion

71. ITRS Winter Conference 2008 Seoul, Korea 71 Work in Progress: Not for Distribution ERM ESH Needs M. Garner & J. Jewett Write a Background Paper on NanoEHS

72. ITRS Winter Conference 2008 Seoul, Korea 72 Work in Progress: Not for Distribution Metrology Needs Yaw Obeng & Alain Diebold

73. ITRS Winter Conference 2008 Seoul, Korea 73 Work in Progress: Not for Distribution ERM Metrology Gaps and Requirements  Generic Gaps  Standards and Requirements for rapidly evolving materials and techniques.  Dopant activation Metrology for USJ  Interface Metrology  Surface/film analysis on vertical surfaces  In-situ monitoring of multi-component oxides  In-Line work function measurements – band gap engineering for flash and gates  Nanowires  3-D Atom mapping for compositional analysis / doping mapping  Non-Destructive local strain/stress measurement  Graphitic Materials  Defects / Substrate Interface Characterization and Stress / Thickness control  Understand substrate effects on Raman spectroscopy (see Das et al bull. Mater. Sci. 31(3), 2008 pp579-584)  Understand angle resolved XPS Data  Harmonize and Understand Mobility data  New channel material or structures challenges  SiGe & III-V  Trigate FinFET,  Complex Oxides / Multiferroics  Better Characterization of Domain Walls  Better understanding of PFM and XMCD Data  Lithography  Precise and accurate overlay metrology  Metrology for charactering double patterning  Characterization of Immersion fluids  3-D packaging (TSV /Nanowire Interconnects  Standards  Thermomenchical stability metrology

74. ITRS Winter Conference 2008 Seoul, Korea 74 Work in Progress: Not for Distribution Modeling Needs Sadasivan Shankar

75. ITRS Winter Conference 2008 Seoul, Korea 75 Work in Progress: Not for Distribution Interfaces & Heterointerfaces John Carruthers

76. ITRS Winter Conference 2008 Seoul, Korea 76 Work in Progress: Not for Distribution ERD/ERM Korea ERD & ERM Korea –Include Band to Band Devices in ERD ’09 –Include Mass Storage Memory Devices?