Design of a compact AFM scanner Compact high

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Design of a compact AFM scanner Compact, high speed and high accuracy AFM scanner

Design of a compact AFM scanner Compact, high speed and high accuracy AFM scanner K. J. Kamp June 26, 2013 Committee: Prof. Ir. R. H. Munnig Schmidt Dr. Ir. S. Kuiper Dr. Ir. J. L. Herder Dr. Ir. J. F. L. Goosen

K. J. Kamp Design of a compact AFM scanner Outline Introduction to Atomic Force

K. J. Kamp Design of a compact AFM scanner Outline Introduction to Atomic Force Microscopes (AFM) Research questions Requirements and specifications Concept 1 Concept 2 Detailed Design Conclusion 2

K. J. Kamp Design of a compact AFM scanner Introduction Research Questions Requirements specifications

K. J. Kamp Design of a compact AFM scanner Introduction Research Questions Requirements specifications Concept 1 Introduction Concept 2 Detailed Design Conclusion 3

K. J. Kamp A compact AFM scanner Introduction The atomic force microscope (AFM) Basic

K. J. Kamp A compact AFM scanner Introduction The atomic force microscope (AFM) Basic operation principle Probe tip attached to a cantilever is scanned over a sample Cantilever deflects due to the atomic forces The cantilever deflection measures the surface topography 4

K. J. Kamp A compact AFM scanner Introduction The AFM scanner Lateral scanning Triangular

K. J. Kamp A compact AFM scanner Introduction The AFM scanner Lateral scanning Triangular pattern Constant tip speed z x y 5

K. J. Kamp A compact AFM scanner Introduction The AFM scanner Vertical scanning Feedback

K. J. Kamp A compact AFM scanner Introduction The AFM scanner Vertical scanning Feedback loop Cantilever deflection signal minimal The probe tip tracks the topography DOI wafer AFM measurement 6

K. J. Kamp A compact AFM scanner Introduction AFM system specifications Surface area (x,

K. J. Kamp A compact AFM scanner Introduction AFM system specifications Surface area (x, y) < 15 mm x 15 mm Measurement range (x, y, z) > 10 x 2 microns Imaging time <1 s Measurement uncertainty < 1 nm 7

K. J. Kamp A compact AFM scanner Top View Introduction Concept 1: The tripod

K. J. Kamp A compact AFM scanner Top View Introduction Concept 1: The tripod scanner z y x Sensor u 3 Actuator 1 u 2 Actuator 2 Sensor 8

K. J. Kamp A compact AFM scanner Introduction Research Questions Requirements specifications Concept 1

K. J. Kamp A compact AFM scanner Introduction Research Questions Requirements specifications Concept 1 Research Questions Concept 2 Detailed Design Conclusion 9

K. J. Kamp A compact AFM scanner Research questions 1. How do the specifications

K. J. Kamp A compact AFM scanner Research questions 1. How do the specifications of the AFM system translate to the requirements of the AFM scanner? 2. Does the first scanner concept meet the requirements? 3. Does the second scanner concept meet the requirements? 4. Is the second scanner concept valid as a real world design? 10

K. J. Kamp A compact AFM scanner Introduction Research Questions Requirements specifications Concept 1

K. J. Kamp A compact AFM scanner Introduction Research Questions Requirements specifications Concept 1 Requirements Concept 2 Detailed Design Conclusion 11

K. J. Kamp A compact AFM scanner Requirements Research question 1: How do the

K. J. Kamp A compact AFM scanner Requirements Research question 1: How do the specifications of the AFM system translate to the requirements of the AFM scanner? Measurement uncertainty < 1 nm Translate to scanner roll angles Imaging time <1 s Translate to scanner resonance frequencies 12

K. J. Kamp A compact AFM scanner Requirements Measurement uncertainty to roll angle Misalignment

K. J. Kamp A compact AFM scanner Requirements Measurement uncertainty to roll angle Misalignment sensors and probe tip: 0, 5 mm Scanner will rotate (roll angle) → This causes an Abbe error (measurement uncertainty) 13

K. J. Kamp A compact AFM scanner Requirements Abbe error Platform roll angle φ

K. J. Kamp A compact AFM scanner Requirements Abbe error Platform roll angle φ Sensor offset δ Abbe error: eabbe = δ tan(φ) Assumptions: δ = 0, 5 mm eabbe < 1, 0 nm φ < 2 microrad 14

K. J. Kamp A compact AFM scanner Requirements Imaging time to resonance frequencies Lateral

K. J. Kamp A compact AFM scanner Requirements Imaging time to resonance frequencies Lateral resonance frequency > 10 k. Hz Triangular wave frequency content z x y Vertical resonance frequency > 30 k. Hz Tracking error, scanning speed 15

K. J. Kamp A compact AFM scanner Introduction Research Questions Requirements specifications Concept 1

K. J. Kamp A compact AFM scanner Introduction Research Questions Requirements specifications Concept 1 Concept 2 Detailed Design Conclusion 16

Design of a compact AFM scanner Concept 1 Analysis of the tripod concept 1.

Design of a compact AFM scanner Concept 1 Analysis of the tripod concept 1. Kinematics related to scanner stroke 2. Statics related to scanner roll angles (Abbe error) 3. Dynamics related to scanner resonance frequencies 17

K. J. Kamp A compact AFM scanner Concept 1 Kinematics analysis Required stroke: 10

K. J. Kamp A compact AFM scanner Concept 1 Kinematics analysis Required stroke: 10 x 2 microns z y x Relation is found between x, y, z (platform position) u 1, u 2, u 3 (actuators) u 3 u 1 u 2 18

K. J. Kamp A compact AFM scanner Concept 1 Example Ten scan lines 10

K. J. Kamp A compact AFM scanner Concept 1 Example Ten scan lines 10 x 10 microns Actuator displacement ~ 6 microns Mechanical amplification 10 / 6 = 1. 66 19

K. J. Kamp A compact AFM scanner Concept 1 Scanner roll angle Hinges are

K. J. Kamp A compact AFM scanner Concept 1 Scanner roll angle Hinges are not perfect Lateral motion will cause the scanner to roll z y x u 3 u 1 u 2 20

Titel van de presentatie Concept 1 2 D Statics analytical model 21

Titel van de presentatie Concept 1 2 D Statics analytical model 21

K. J. Kamp A compact AFM scanner Concept 1 Main cause of AFM scanner

K. J. Kamp A compact AFM scanner Concept 1 Main cause of AFM scanner roll Stiffness ratio between longitudinal and lateral stiffness of a rod Normalized stiffness ratio [] 22

K. J. Kamp A compact AFM scanner Concept 1 Statics Flexure notch hinges Increase

K. J. Kamp A compact AFM scanner Concept 1 Statics Flexure notch hinges Increase longitudinal to lateral stiffness ratio Decreases the roll angle 23

K. J. Kamp A compact AFM scanner Concept 1 Statics FEM analysis 3 D

K. J. Kamp A compact AFM scanner Concept 1 Statics FEM analysis 3 D FEM model 24

K. J. Kamp A compact AFM scanner Concept 1 Statics FEM results u 1

K. J. Kamp A compact AFM scanner Concept 1 Statics FEM results u 1 = 5 microns x = 5 microns φ = ~ 460 microrad 25

K. J. Kamp A compact AFM scanner Concept 1 Statics FEM results Roll angle

K. J. Kamp A compact AFM scanner Concept 1 Statics FEM results Roll angle is lower φ = ~ 360 microrad 26

K. J. Kamp A compact AFM scanner Concept 1 Statics FEM results Circular notch

K. J. Kamp A compact AFM scanner Concept 1 Statics FEM results Circular notch hinge Roll angle even lower φ = ~ 60 microrad 27

K. J. Kamp A compact AFM scanner Concept 1 Dynamics First four resonances: 28

K. J. Kamp A compact AFM scanner Concept 1 Dynamics First four resonances: 28

K. J. Kamp A compact AFM scanner Concept 1 FEM Modal analysis Eigenmode results

K. J. Kamp A compact AFM scanner Concept 1 FEM Modal analysis Eigenmode results Lateral 9, 3 k. Hz Yaw 9, 8 k. Hz Roll 42 k. Hz Vertical 48 k. Hz 29

K. J. Kamp A compact AFM scanner Concept 1 Summary Can the requirements be

K. J. Kamp A compact AFM scanner Concept 1 Summary Can the requirements be met? Trade-off low roll angle vs. high resonance frequencies Low roll angles require a high stiffness ratio (low lateral stiffness) High resonance frequencies require high stiffness overall Conclusion: The individual requirements can not all be met. Concept 1 is not feasible 30

K. J. Kamp A compact AFM scanner Introduction Research Questions Requirements specifications Concept 1

K. J. Kamp A compact AFM scanner Introduction Research Questions Requirements specifications Concept 1 Concept 2 Detailed Design Conclusion 31

K. J. Kamp A compact AFM scanner Concept 2 Orthogonal scanning concept Lateral motion

K. J. Kamp A compact AFM scanner Concept 2 Orthogonal scanning concept Lateral motion Side view Top view Probe tip Sensor Actuator 32

K. J. Kamp A compact AFM scanner Concept 2 Orthogonal scanning concept Vertical motion

K. J. Kamp A compact AFM scanner Concept 2 Orthogonal scanning concept Vertical motion Side view Top view Probe tip Sensor Actuator 33

K. J. Kamp A compact AFM scanner Concept 2 Kinematics Lateral stroke: mechanical amplification

K. J. Kamp A compact AFM scanner Concept 2 Kinematics Lateral stroke: mechanical amplification = lever ratio b to a b ulever x a 34

K. J. Kamp A compact AFM scanner Concept 2 Statics analysis Analytical model adapted

K. J. Kamp A compact AFM scanner Concept 2 Statics analysis Analytical model adapted to the orthogonal concept L uφ ux z uφ K 1 uz φ ux x uz L 2 K 2 ulever 35

K. J. Kamp A compact AFM scanner Concept 2 Analytical model and FEM analysis

K. J. Kamp A compact AFM scanner Concept 2 Analytical model and FEM analysis Pure lateral input (no lever) ux = 5 microns Analytical model: φ = 21, 7 microrad FEM result φ = 22, 9 microrad The roll angle φ is positive 36

K. J. Kamp A compact AFM scanner Concept 2 uφ ux Including the lever

K. J. Kamp A compact AFM scanner Concept 2 uφ ux Including the lever uz b Input ux results in a positive roll angle Input uφ results in a negative roll angle positive ux a ulever negative uφ 37

K. J. Kamp A compact AFM scanner Concept 2 Analytical model and FEM results

K. J. Kamp A compact AFM scanner Concept 2 Analytical model and FEM results The length of the vertical rods is varied: Vertical rod length φ Analytical φ FEM 10 mm -82, 1 μrad -17, 8 μrad 6 mm -28, 4 μrad +19, 5 μrad 3 mm +123, 1 μrad +73, 2 μrad The roll angle shifts from negative to positive 38

K. J. Kamp A compact AFM scanner Concept 2 The analytical model is used

K. J. Kamp A compact AFM scanner Concept 2 The analytical model is used to find zero roll angle Vertical rod length [m] 39

K. J. Kamp A compact AFM scanner Concept 2 Resulting roll angle Final iteration

K. J. Kamp A compact AFM scanner Concept 2 Resulting roll angle Final iteration L 1 = 3, 0 mm L 2 = 4, 0 mm ulever = 10 microns x= 4, 9 microns Roll angle φ= -0, 63 microrad 40

K. J. Kamp A compact AFM scanner Concept 2 Dynamics FEM modal results Lateral:

K. J. Kamp A compact AFM scanner Concept 2 Dynamics FEM modal results Lateral: Lateral eigenmodes (x, y): ~12, 3 k. Hz Vertical mode (z): ~36, 5 k. Hz Vertical: 41

K. J. Kamp A compact AFM scanner Concept 2 Summary The orthogonal scanner concept

K. J. Kamp A compact AFM scanner Concept 2 Summary The orthogonal scanner concept meets all the requirements The stroke of 10 x 2 microns can be achieved The roll angle is ~ 0, 64 microrad The resonance frequencies are 12, 3 k. Hz lateral 43, 4 k. Hz vertical 42

K. J. Kamp A compact AFM scanner Introduction Research Questions Requirements specifications Concept 1

K. J. Kamp A compact AFM scanner Introduction Research Questions Requirements specifications Concept 1 Detailed design Concept 2 Detailed Design Conclusion 43

K. J. Kamp A compact AFM scanner Detailed design Component selection Piezo actuators Triangulation

K. J. Kamp A compact AFM scanner Detailed design Component selection Piezo actuators Triangulation sensors AFM chip holder 44

K. J. Kamp A compact AFM scanner Detailed design Piezo actuators PI (Physik Instrumente)

K. J. Kamp A compact AFM scanner Detailed design Piezo actuators PI (Physik Instrumente) Type Dimensions Nom. displ. P 885. 11 5 x 9 mm ~6, 5 micron P 883. 31 3 x 13, 5 mm ~13 micron 5 x 9 mm for vertical motion 3 x 13, 5 mm for lateral motion 45

K. J. Kamp A compact AFM scanner Detailed design Triangulation sensors Lion Precision capacitive

K. J. Kamp A compact AFM scanner Detailed design Triangulation sensors Lion Precision capacitive sensors Type C 3 R-0, 8 Dimensions Ø 3 x 15 mm Range 25 microns 46

K. J. Kamp A compact AFM scanner Detailed design AFM chip holder Bruker DAFMCH

K. J. Kamp A compact AFM scanner Detailed design AFM chip holder Bruker DAFMCH probe holder Piezo holder measures 4 x 5 mm at the base. 47

K. J. Kamp A compact AFM scanner Detailed design Final design overview Probe holder

K. J. Kamp A compact AFM scanner Detailed design Final design overview Probe holder Lever Sensor Piezo actuator Outer dimensions (x, y): 26 x 26 mm 48

K. J. Kamp A compact AFM scanner Detailed design Cross-section view (no piezo actuators)

K. J. Kamp A compact AFM scanner Detailed design Cross-section view (no piezo actuators) 49

K. J. Kamp A compact AFM scanner Detailed design 50

K. J. Kamp A compact AFM scanner Detailed design 50

K. J. Kamp A compact AFM scanner Detailed design Summary Specifications Dimensions (x, y)

K. J. Kamp A compact AFM scanner Detailed design Summary Specifications Dimensions (x, y) 26 x 26 mm Stroke (microns) 16 x 6, 5 Roll angle 5, 4 microrad Resonances lateral 9, 8 k. Hz Resonances vertical 30, 4 k. Hz 51

K. J. Kamp A compact AFM scanner Detailed design Summary Specifications Requirements Dimensions (x,

K. J. Kamp A compact AFM scanner Detailed design Summary Specifications Requirements Dimensions (x, y) 26 x 26 mm 15 x 15 mm Stroke (microns) 16 x 6, 5 10 x 2 Roll angle 5, 4 microrad < 2 microrad Resonances lateral 9, 8 k. Hz > 10 k. Hz Resonances vertical 30, 4 k. Hz > 30 k. Hz 52

K. J. Kamp A compact AFM scanner Introduction Research Questions Requirements specifications Concept 1

K. J. Kamp A compact AFM scanner Introduction Research Questions Requirements specifications Concept 1 Conclusion Concept 2 Detailed Design Conclusion 53

K. J. Kamp A compact AFM scanner Conclusion The requirements have been set up

K. J. Kamp A compact AFM scanner Conclusion The requirements have been set up for the AFM scanner The first concept is not feasible The second concept meets all the requirements and is feasible The detailed design is limited by the selected components: 1. The required size can not be achieved 2. The required roll angle is exceeded by a factor 2 54

K. J. Kamp A compact AFM scanner Introduction Research Questions Requirements specifications Concept 1

K. J. Kamp A compact AFM scanner Introduction Research Questions Requirements specifications Concept 1 Questions? Concept 2 Detailed Design Questions? 55