Nanoindentation, Scratch and nanodma : Innovations for Atomic Force Microscopes. Ryan Stromberg

Transcription

1 Nanoindentation, Scratch and nanodma : Innovations for Atomic Force Microscopes Ryan Stromberg

2 2 Outline Hysitron TriboScope Technology Mechanical Testing Indenter Stylus vs. AFM Cantilever True Load Control and Displacement Control TriboScope Interface on Your Bruker AFM Application Examples

3 Transducer & Digital Controller Core Technology Springs Center Electrode Outer Electrode Outer Electrode Capacitive displacement sensing Small inertia of moved parts <1 g Low intrinsic dampening Indenter Load or Displacement Control 78 khz Feedback Loop Rate 15 khz Data Acquisition Rate Experimental Noise Floor <100 nn (Digital Controller) Enhanced Testing Routines Digital Signal Processor (DSP) + Field Programmable Gate Array (FPGA) + USB Architecture Modular Design Transducer Stability Specs <0.2 nm displacement noise floor <75 nn force noise floor <0.05 nm/sec thermal drift *Specs Guaranteed On-Site* 9/7/2017 Enabling Technology for Ultra-Small Materials Research 3

4 4 Indenter Stylus vs. AFM Cantilever Nanoindenter Capabilities - Indentation, Scratch & Imaging AFM Indentation TriboScope Force & Displacement Measured independently Traceable to SI standards Applied normal to surface with a stylus Resulting Benefits: Dedicated mechanical test instrument True Load or Displacement control Strain Rate Control & dynamic testing Plastic deformation of hardest materials! Dedicated software for automatic analysis SPM Imaging: Contact Mode in-situ SPM imaging only

5 5 AFM Cantilever vs. Indenter Stylus AFM Capabilities Indentation, Scratch & Imaging AFM Indentation TriboScope Force & Displacement Highest force sensitivity by cantilever bending and torque; 2ω, 3ω, Spring constant accuracy 10% Hard to calibrate for scratch Resulting Benefits: Thin soft layer testing / smallest volumes Force-pulling tests SPM Imaging Contact & Dynamic imaging modes Cantilever with highest mechanical bandwidth Contact, tapping mode, etc. imaging Electrical, magnetic, Kelvin probe

6 PeakForce Tapping Force TappingMode Contact Resonance AFM Frequency and Modulus Ranges Force Volume and PeakForce Tapping & Indentation 1. Ramp & Hold Full mechanics spectra 2. FFV Force Curve Mapping Force Spectra and Creep 1 Force Volume 5 3. PFQNM Highest resolution and fast nanomechanical mapping 4. Tapping Phase imaging 5. FFV-CR Combined FC/Sweeping 6. TriboScope Nanoindentation Indenter Stylus Electrostatic Force Actuation Modulus & Hardness Testing Advanced Test Modes 2 Nanoindentation Material Volume Tested / µm Cantilever Diamond Indenter Typical Tip Radius / nm mn µn nn pn 9/7/2017 6

7 7 Transients of Deformation The low inertia of the Hysitron TriboScope s capacitive transducer combined with <30 nn force noise floors, 78 khz feedback loop rate, and 38 khz data acquisition rate provides insight into nanoscale deformation phenomena. W(100) Load Control Al (100) Load Control Displacement Control Annealed and electro-polished single crystal specimen- low dislocation density Mechanically polished specimen no load-displacement discontinuity

8 8 Quantitative Mechanical Testing Load Function Editor with up to 2000 segments Quantitative Measurements by... Transducer Calibration Force / Displacement SI-traceable Area Function Calibrated Tip Geometry Diamond Probes Berkovich Cube Corner Load Control Displacement Control Const. Strain Rate Creep Testing Relaxation Cyclic Indentation/Scratch Conospherical

9 Load, P Nanoindentation Analysis Elastic Modulus (E) E r reduced elastic modulus S 2 A c Hardness (H) H P max A c projected contact area (evaluated at maximum load) Contact Depth (h c ) P max h c h max P S max Contact Area (A c ) A f c h c A c 0 0 h f h c h max Power-law Fit to Unloading P A( h ) h f m Depth, h Initial Unloading Stiffness S dp dh hmax ma( h m 1 max h f ) E vi 1 vs r Ei Es Indenter Sample Poisson s Ratio Sample s Elastic Modulus 9/7/2017 9

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11 11 Hysitron TriboScope on Bruker Platform Easy, non-permanent change to AFM platform

12 9/8/

13 Load, mn Hysitron TriboScope Atomic Step Bunch TERRACE STEP BUNCH Indentation depth, nm Atomic Terrace Load-displacement data for Au(100) when the indenter is centered over an atomically flat terrace or over step bunches. S.G. Corcoran, R.J. Colton, E.T. Lilleodden, and W.W. Gerberich, Phys. Rev. B, vol. 55, no. 24, pp. R R16060, /7/

14 14 Experiments for TriboScopes Wear Test Scratch SPM Image Indentation

15 15 TriboScope Applications Section Quasistatic Indentation Experiments Testing in a Microstructure Thin film Testing Thin Film Scratch-Testing and Wear Advanced Testing modes with nanodma III Creep testing CMX depth profiling DMA dynamic mechanical analysis

16 Light Microscope SEM Micrograph 9/7/ Nanoindentation in a Microstructure Flip Chip interface connection Lead free solder using Ag and Sn Mechanical interface and electrical contact Cu bump with solder cap after annealing

17 µm In-Situ SPM Imaging Topography Chain is as strong as its weakest link Engineering to find best process window for strength of solder Intermetallic phases reduce the diffusion processes (electro-migration) µm 9/7/

18 µm Displacement (nm) Nanoindentation Testing Topography 80 DC Load Function Displacement Time (s) µm 9/7/2017 Surface topography from polishing step Soft and hard materials in one sample Displacement controlled load function 18

19 µm Load (µn) Load (µn) Nanoindentation Analysis Topography Indents IP Solder Cu µm 9/7/ Depth (nm) Depth (nm) 19

20 µm Hardness (GPa) Reduced Modulus (GPa) Mechanical Properties Analysis Solder Cap IP2 IP Si Cu IP1 IP2 Solder 0 Si Cu IP1 IP2 Solder Cu-bump Silicon Cu IP1 IP2 Solder Cu-pad Si-wafer µm Average Stdev Average Stdev Average Stdev Average Stdev Average Stdev Hardness (GPa) Red. Modulus (GPa) /7/

21 Relaxation at Max Displacement Load (µn) µm µm 9/7/2017 Solder Cap Cu-bump Cu-pad Si-wafer IP2 IP Load (µn) Depth (nm) Si Time (s) 21

22 Height (nm) Thin Film Nanoindentation DLC coating on high strength steel Image of film edge on substrate In-situ SPM Metrology on coating: Cross Section profile Position (µm) Surface Roughness Film thickness: 129 nm Steel Substrate: Peak To Valley = 14.8 nm Average Roughness (Ra) = nm RMS Roughness (Rq) = nm DLC-Coating: Peak To Valley = nm Average Roughness (Ra) = nm RMS Roughness (Rq) = nm 9/7/

23 23 Thin Film Nanoindentation Quasistatic indentation with changing force Indentation on Steel Substrate and DLC coating Load Displacement Curves Steel DLC Steel DLC

24 24 Scratch Testing with the TriboScope

25 25 Cyclic Scratching Separate transducer for indentation and lateral force sensing Electrostatic force and capacitive displacement sensing Quantitative and SI-traceable 2D Standard Transducer Normal Force Editor Lateral Displacement Editor Time

26 26 Ramp Force Scratch Testing Easy set-up of scratch testing Calibrated force and displacement Independent Normal/Lateral sensing Force / Friction During Scratch Normal Lateral Profile

27 Displacement Force 9/7/ Cyclic Scratching Time /s Friction Surface Profiles virgin DLC Coating on Steel CC-indenter 250 µn normal load

28 28 Advanced Testing Modes with nanodma III

29 29 nanodma III Time Dependent Properties The Next-Generation of Dynamic Nanoscale Mechanical Property Characterisation Cs Er '' 2 A c Energy loss E r ' k 2 s A c Elastic response tan Er" C E ' k r s s Damping Dynamic Measurement of Hardness, Modulus, Storage Modulus, Loss Modulus, Tan Delta Continuously measure properties as a function of contact depth, frequency and time

30 30 nanodma III Depth Profile CMX algorithm provides a truly Continuous Measurement of X (X= hardness, storage modulus, loss modulus, tan-delta, etc ) Continuously measure properties as a function of contact depth, frequency, and time Hardness Reduced Modulus Depth and Time Profiling Dynamic force superimposed on quasi-static Force

31 Reduced Modulus (GPa) Hardness (GPa) Thin Film Nanoindentation 3 coatings on steel Berkovich Indenter CMX-depth profile Steel Substrate 135nm DLC 75nm DLC 25nm DLC Contact Depth (nm) /7/ Contact Depth (nm) 31

32 32 Frequency Dependence of Soft Materials DMA Measurement of Storage Modulus, Loss Modulus, Tan Delta Continuously measure properties as a function of contact depth, frequency and time Samples and compression DMA testing courtesy of Donna Ebenstein, Department of Biomedical Engineering, Bucknell University.

33 33 Long Term Creep Testing Topographical SPM images used to refine test position and ensure that test was performed on the top of the dome, where surface could be reasonably approximated as flat.

34 Reference Creep Testing Modulus of material is measured during first several seconds of the test, while any error from drift is negligible. Once modulus is known, contact area is calculated continuously from the contact stiffness, with no reliance on raw displacement measurement. Contact area can also be converted to indent depth through the area function. 9/7/

35 35 Test Results Stiffness was measured continuously and used to calculate hardness and contact depth during hold. Material softened as temperature increased, as expected Creep rate increased dramatically between 150 C and 175 C

36 36 Summary: Accurate Nanomechanics Cantilever Based Force Volume most accurate for soft materials PeakForce Tapping for fast, high resolution results Contact Resonance most accurate for stiff materials Tip calibration and deformation models in next software release Hertzian Model for spherical tips where a<<r Conical (Sneddon) Model is good for pyramids and cones with sharp apex Cone-sphere model handles tips that start with spherical apex and transition to a conical shape. Limitation in hardness testing & testing of hard materials δ α δ Indenter Stylus Indentation and nanodma with quantitative force and displacement Calibration routines for tip shape are built into software; a lot of defined tip shapes are available Hardness, modulus, load & displacement control, constant strain rate, creep, relaxation can be tested Scratch testing with quantitative force and displacement along sample surface Contact Mode imaging only - limitation in imaging soft samples

37 9/8/ Upcoming Webinars in 2017 XPM, High Speed Property Mapping September 28 th (Wednesday), Presented by Dr. Eric Hintsala Advanced Dynamic Nanoindentation Modes: Applications of nanodma III October 19 th (Wednesday), Presented by Dr. Ude Hangen

38 38 Contact Information Sales Enquiries: Dedicated Nanoindentation Customer Support: Helpdesk:

39 Copyright Bruker Corporation. All rights reserved.