highly precise, fast and effective Wolfram Meyer Technical Sales · SIOS Meßtechnik GmbH –Am Vogelherd 46 –D-98693 Ilmenau –Germany Tel.: +49 (0) 3677-6447-47 Fax: +49 (0)

SIOS Meßtechnik GmbH – Am Vogelherd 46 – D-98693 Ilmenau – Germany

Tel.: +49 (0) 3677-6447-47 Fax: +49 (0) 3677-6447-8 E-Mail: [email protected]

Modern homodyne interferomer – highly precise, fast and effective

Wolfram Meyer

Technical Sales

Modern homodyne interferometers – Wolfram Meyer

2List of contents

1. Speaker and Company Introduction

2. Basics of homodyne laser interferometer

3. Uncertainty of laser measurement

4. Applications in the laser interferometry


List of contents 3






4

Education:

Study of precision engineering with focus on precision

mechanics, optics, electronics and informatics at university

of applied science Jena (Germany)

Work experience:

2 years developer engineer in the field of semiconductor industry equipment (stepper, implanter)

7 years metrology manager (length, shape, raughness, gear and spline as well as CMM

measurements)

9 years technical manager for gear and spline inspection technology (responsible for developemnt

and manufacturing of mechanics, electronics, software, and services)

6 years managing director (start up of an engineering and service company for machine tool builder

focused on volumetric compensation of machine tools with laserinterferometer)

3 years R&D manager for drive technologies (gear motors)

SIOS:

10 months Technical consultant, training and sales (all products, national and international)

Signalment

Profile: Wolfram Meyer - SIOS


ILMENAUFrankfurt

Munich

SIOS Meßtechnik GmbH 5

1991 Foundation of SIOS Meßtechnik GmbH by Prof. G. Jäger and employees of the Institute for Process Measurement and Sensor Technology of TU Ilmenau.

The main focus is the development of laser-interferometric fiber-coupled sensors for length, angular and vibration measurement.

Development and production to 100% in Germany at one location.

SIOS offers standard and customer-specific solutions of the highest precision and dynamics in 4 business areas.

Science Industry OEM Products Service


International Representatives

24 international representatives

6


STABILIZED HE-NE-LASER

- Stabilized He-Ne-Laser

- Fiber coupling and fiber coupled He-Ne laser

ONE AXIS DISPLACEMENT MEASURING SYSTEMS

- High precision measuring devices

- Displacement calibration or closed loop control of one axis

SIMULTANEOUS MEASUREMENTS OF DISPLACEMENT AND TILT

- Measurement of displacement and tilt in one measuring step

- Multi-beam systems for simultaneous measurements of

displacement and tilt

SIMULTANEOUS MULTI-AXIS MEASURING SYSTEMS

- Measurement and calibration of multi-axis positioning systems

- Position control

- Simultaneous measurement of displacement and tilt

DIFFERENTIAL DISPLACEMENT MEASUREMENTS

- High stable long term measurements

- Material science

Products of the SIOS Meßtechnik GmbH 7


VIBRATION MEASUREMENT SYSTEMS

- Fiber coupled interferometer for vibration analysis

- High resolution displacement and vibration measurements

8

COMPLETE SYSTEMS

- 5 DOF calibration interferometer

- Nanopositioning and Nanomeasuring Machine

- Thickness measurement devices

- Gauge block measuring station

- Tactile probe

1kg ComparatorBalance

TEMPERATURE & ENVIROMENTAL MEASUREMT SYSTEMS

- Climate measurement system

- wired ans wireless temperature sensors

Products of the SIOS Meßtechnik GmbH


9

SERVICES

- Maintenance service for hardware and software (in house, on site)

- Calibration of laser wave lenght (retraceble to German PTB)

- Calibration of enviromental sensors (pressure, humidity, temperature)

- Training (basics and applications)

- Commissioned measurements with NMM-1 (one system permanently available)

- Machine tool calibration (on site MTB)

- Equipment hire service (mainly for application tests)

- Customized solutions (soft- and hardware as well as mechanic and optic)

SOFTWARE

- Infas NTC (configurable measuring task for any SIOS interferometer)

- Infas VIBRO (Vibration measurement including online FFT, Filter, Remote control)

- InfasALIGN (quick and easy alignment of axex and guides)

- Infas AXIS (Calibration according ISO 230, VDI 2617, DGQ 3441)

- Infas GAUGE (databased Gauge block calibration software)

- NMM Control (3D measurering software for NMM)

- SIOS DLL für Windows & Linux

(selfmade software support including examples for LabView, MathLab, C++)

Products of the SIOS Meßtechnik GmbH


10






Fiber-coupled Interferometer 11

He-Ne-Laser

Δs = 2sopt

Design of a plane-mirror interferometer

Kollimatorcollimator

LWLoptical fibre

LASER Planspiegelplane mirror

Strahlteilerbeam splitter

Empfängerdetector

λAir =λVacuum

nAir

λAir

2


Interferometer with Plane Mirror Reflector 12

SIOS Meßtechnik GmbH Other solutions

• Measuring beam defines measuring direction

• Abbe-error free measurement are possible

• Additional optics can be placed into the laser beam

• Multi-beam arrangements are possible

• Wide range of reflectors possible

Concept advantages

Concept comparison


Interferometer with tilt invariant reflectors 13

Interferometer SP-Series with ball reflector

Interferometer SP-Serieswith hollow reflector


SIOS Fiber -Coupled Interferometer Concept 14

He-Ne-Laser

Data processing unit

Stabilized or unstabilizedlaser in 19” rack

• Compact measuring arrangements (laser

source is not part of the setup)

• Modular system design

• Easy to adjust in any direction

• Different materials of interferometer

sensor head are possible

• The cable lengths between the sensor

head and data processing unit from

3 to 15 meters

• Modular interface and data processing unit

• Ultra high vacuum, cryo and clean variants

Fiber coupled InterferometerIn any direction

Features


15






Laser Wavelength in Air 16

Laser wavelength in air

Refractive index in air

Laser wavelength as length measurement standard

Laser wavelength in vacuum

The absolute accuracy of the laser-interferometric measurement in air essentially depends on the accuracy of the determination of air refractive index along the measuring path.

nn

0

Edlen Formula for determination of the refractive index in air

Air pressure

Temperature

Humidity

wcptp pct

pn

w

8)77

,,, 1063,310)300(4,51(003671,01

108793,2)1(


1610929,0/ Knn - Change of air temperature

pPann 1910682,2/ p - Change of air pressure

FpPann 1101084,3/ Fp - Change of water vapor pressure of the air

Influences on the refractive index of air 17

If we measure at 60% instead of 50% relative humidity, we measure -0.09 μm wrong.

If we measure a air pressure of 1014 hPa instead of 1013 hPa, we measure wrong by +0.27 μm.

If we measure at 21 ° C instead of 20 ° C, we measured -1.0 µm incorrectly at 1 meter.


Exemplarily Certificate from PTB for MI 5000 18

Result of Calibration for MI 5000

2921012040 LnmUL

Systematic measurement uncertainty 120 nm/m


Influence of the dead path 19

Reference and measuring beams have same lengths at Pos. 1

Laser

Pos. 1

Dead path of laser interferometer is a difference of lengths of measuring and reference beams in air at the moment of setting the interferometer value to zero

Pos. 2

Lt

Dead path = 0, if the interferometer is set to zero at Pos. 1

Dead path correction

Air refractive index at the moment of setting interferometer value to zero

Current refractive index of air

Dead path = Lt, if the interferometer is set to zero at Pos. 2


Abbe Error (errors 1. Order) 20

d - Abbe offsetf - Tilt angle

)tan(f dlAbbe

• Abbe offset 1 mm• Dynamic mirror tilt ±8 arcsec (±39 µrad)

Abbe error ± 39 nm

Example 1

• Abbe offset 100 mm• Dynamic mirror tilt ±0,8 arcsec (±3,9 µrad)

Abbe error ± 390 nm

Example 2


Alignment Error (errors 2. Order) 21

• Visible beam offset 0.5 mm• Displacement, long 500 mm

Angle 3.4 arcmin (1 mrad) Error 500 nm/m

Example 1

• Visible beam offset 1 mm• Displacement, short 50 mm

Angle 68 arcmin (20 mrad)Error 2 µm/m

lm - Measuring displacementf - Angle

Direction error

)]cos(1[1cos f mll

Example 2


Measuring Uncertainty Budget 22

ParameterRelative

value Value in nm Description

u_laser 2.00E-08 2.00 Laser frequency

u_index 1.05E-07 10.50Determination of the refractive

index of air

u_demod 0.26 Demodulation error

u_Abbe 24.24 Abbe-error

u_cos1 0.47 Cosine error

u_cos2 0.12 Tilt of measuring mirror

u_deadpath 1.59 Dead path correction

u_total 26.54 nm**

Measuring displacement: 100 mm

* Temperature change has been included only for dead path calculation error** Combined standard uncertainty

• Abbe-offset 1 mm• Cosine error 30 arcsec• Dynamic mirror tilt ±8 arcsec• Dead path 10 mm ± 1 mm• Change of temperature* 0.5 °C

Example calculation for interferometer with plane mirror reflector

Assuming setup conditions :


23






SP-Series Interferometers for Plane Mirror Reflector

Measuring range 2 mResolution 20 pm

single beam length measurement

SP series

double beam interferometer for length and angle measurement

Resolution 0,1’’ …0,001’’

SP-DS series

triple beam interferometerfor simultaneous length, pitchand yaw angle measurement

SP-TR series

Resolution 0,002’’

Angular measuring range ± 1.5’ Angular measuring range ± 1.5’

OVERVIEW


CUSTOMER APPLICATION FOR CLOSED LOOP CONTROL

Design and performance evaluation of an interferometric controlled planar nanopositioning system, S Hesse et al 2012 Meas. Sci. Technol. 23

Travel range Ø 100 mmMeasuring resolution 0,02 nmMeasuring resolution Phi z 0,8 nrad

Planar table

Achieved 2D servo error (RMS) 0,4 nm

SP SeriesPlane-Mirror Interferometer


Piezosystem JenaCustomer

Serie SP 2000 TR

3D – Calibration of piezo actuators

Anwendung der Interferometer der Serie SP-TR 26

3D Piezoaktuators TRITOR 102 SG

Measurement of z-axis positioning error and

simultaneously measurement of pitch and yaw angle

Measurement of x – y – z – axis positioning error

Tolerances according data sheet:

• Position resolution: 1.0 nm

• Repeatability: 10 nm


Differential Interferometer with Plane Mirror Reflector 27

Compensated distance

• Difference measurements between two objects• Long term measurements• Minimization of the dead path influence• Compensation of thermal behavior of mechanical assembly

Reference mirror

Measuring mirror

Interferometer with external reference beam SP-DI Series

Principle of operationDisplacement to be measured


Differential Interferometer with Plane Mirror Reflector 28

SP-DI Series

• Symmetrical construction• High stability• Optical beam alignment

Principle of operation

Beam separation ~20 mmResolution <0.1 nmTemperature sensitivity <20 nm/°C

Other beam separations as option

Interferometer with external reference beam

L = lR - lm


Serie SP-DIS

Range ≤ 2 mResolution 20 pm

Position independing interferometer 29

• Measurement against one external reference surface like a plan mirror• Measurement results are independent of interferometer position

s1 s2

Lm = s1 + s2

+ +--

Mirror 1

Mirror 2


High Stable Interferometers 30

Mean value of all channels, air pressure and humidity corrected

Invar interferometer with frequency stabilized laser

± 1 nm

15 h


Calibration Interferometer for 5 DOF 31

Minimization of the direction alignment error by integrated PSD


Calibration Interferometer 32

Sensor head Reflector unit

Deflecting mirror

Straightness mirror

Length measurement: Measuring range 15m /50 m

Resolution 0.1 nm

Angle measurement: Measuring range ± 5°

Resolution 0.0004 arsec

Straightness measurement: Axial range < 6,5 m

Measuring range ± 4 mm

Resolution 10 nm

Simultaneous measurement of 4/5 DOF SP 15000 C5 / SP 50000 C5

Measurement of length, pitch angle, yaw angle and straightness



Long Range Triple-Beam Interferometer

Linear guide system

Fiber coupled interferometer Reflector Straightness mirror

Flexible display unit for quick alignment without software

SP 15000 C5 / SP 50000 C5


0 50 100 150 200 250-10

-5

0

5

10

mm

µm

SP 15000 C5; Straightness Y


0 50 100 150 200 250-4

-2

0

2

4

mm

µm

SP 15000 C5; Straightness X

0 50 100 150 200 250-300

-200

-100

0

100

mm

µra

d

SP 15000 C5; Angle

Yaw angle

Pitch angle

0 50 100 150 200 250-20

-15

-10

-5

0

5

10

mm

µm

SP 15000 C5; Position deviation

Position deviation Pitch and yaw angles

Straightness XStraightness Y


Position deviations

pitch angle

yaw angle

Corrected position deviations

• Simultaneous measurement of displacement and angle

• Measuring points are defined by every measuring beam

• Correction of Abbe-errors is possible

Application SP-DS, SP-TR Interferometers 35

Correction of Abbe-error by simultaneous length and angle measurements

Interferometer Target

Internal measuring system


Laser Vibrometers 36

LSV SeriesSP-S Series

Amplitude resolution 20 pm

Working distance 30…70 mm, 240 mm, 480 mm

Amplitude resolution 20 pm

Working distance(continuously selectable) 240 mm - 2500 mm

Frequency range 0 – 5 MHz

Surface roughness arbitrary

Systems for vibration velocities up to 3 m/s are available


Nanovibration Analyzer 37

High resolution frequency analysis of vibrating

micro objects

Wide positioning range of 50x50 mm, possible

up to 100x50 mm

Object monitoring on PC by means of 1/2“ CCD

camera

Different objectives (10x, 20x, 50x, 100x ) can be

used and exchanged

Laser spot diameter ≤ 1 µm with 100x objective

DC deflection measurements as well as spectral

analysis up to some MHz are possible

Triggering options for data acquisition

Sub - nanometer resolution

Customized configuration is possible

Standard products NA Series

Remote control and script language available


5 pm @2,35 MHz

1pm noise

Application of NA-Analyzer 38

AFM Cantilever

Measuring beamSpot diameter 1 µm

Measurements of cantilever thermal noise

SIOS

Nano

Analyzer


Precision Climate Measuring Station

High-precision temperature, air pressure and air humidity measurements LCS

• In measuring and calibration laboratories

• For documentation and compensation

during calibration procedure

• For monitoring precision measurement

and test setups

• As module for integrating in precision

machines

TT-01 with air temperatur sensor WT-01 with material temperature sensor

Sensor are calibrated digitally together withthe measuring electronic

PT100 air and material temperature sensor,customized design possible

• 5 (up to 15) wired temperature sensor

• up to 15 wireless temperature sensors

• up to 2 air pressure sensors

• up to 2 air humidity sensors


LCS Application: Examinations on TEC-controler 40

• Measurement on TEC controlled aluminum plate (large base of a laser diode)

• 3 Phases:• Start of controlling, with an overshoot• stable phase• rising temperature due to a thermal runaway


LCS Applications: Examinations on TEC-controler 41

• Control quality of TEC controler• 1 grid = 2 mK

± 2 mK


NANOPOSITIONING- AND NANOMEASURING MACHINE

3D nano measuring machine

Resolution 0,1 nm

Measuring range 25 mm x 25 mm x 5 mm

Driving speed, except in measurement modeX-, Y-Achse 2 mm/sZ-Achse 50 mm/s

Probing system multi sensoric (4 different probe

technologies available)

external analog interface for customer spezific probes

TECHNICAL DATA

42

NMM-1


Nanomeasuring and Nanopositioning Machine

Mechanical setup NMM-1

43

3D drive and guide system

Stable granite basement

y-Interferometerx-Interferometer

Metrologyframe (Zerodur)

Cornermirror


Performance of the NMM-1

Moving performance NMM-1

44

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000-0.5

0

0.5

1

1.5

Index

nm

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000-0.5

0

0.5

1

1.5

2

2.5

Index

nm

Step size 1 nm

Step size 0,5 nm


Multisensoric of the NMM 45

NMM-1Probe Systems

Fix Focus SensorWhite Light

Sensor

Atomic Force Microscope

1D Sensors Imaging Sensor Tactile 3D Sensor

3D-Micro Probe


Application of the NMM-1 46

NMM-1Probe Systems


Sensor



3D-Micro Probe


• Non-contact, optical scanning of surfaces

• Sensor measuring range ± 3 µm

• Sensor resolution 1 nm

• Spot diameter ≈ 1 µm

• Working distance 12 mm

Application of the NMM-1

Fix Focus Sensor LFS-1

47


15

V = 370 pl

Courtesy of TU Ilmenau


Other application examples LFS-1

48

Oil drop

Micro structure on Fresnel lens

Hardeness indention



Probe systems NMM-1

49

NMM-1Probe Systems


Sensor



3D-Micro Probe


• The lateral pitch standard consists of 2D lattice of square pyramids with 3000 nm pitch etched into silicon

• Used for the xy-calibration of the scanning mechanism in scanning force microscopes


Calibration of lateral standards AFM

50

Difference in nm

-0,041 nm2999,97 nm0,03 nm (k=2)3000,011 nm2D3000

UncertaintyPitchPitch

NMM-results in nm

(with AFM)PTB results in nmSample

0,28 nm (k=2)

Uncertainty

www.nanosensors.com

Pitch 2999,97 nm



• Probe systems • NMM-1

51

NMM-1Probe Systems


Sensor



3D-Micro Probe


• Non-contact, optical scanning of surfaces

• Low positioning noise and large measuring range due 5 mm z-axis positioning range

• Structure independent stitching with sub pixel accuracy is possible

148 x 148 µm20,65 µm0,148 µm50x

370 x 370 µm20,90 µm0,370 µm20x

740 x 740 µm21,48 µm0,740 µm10x

Field of viewLateral resolution

Pixel spacingObjective magnification


• White Light Sensor • WLI

52


Courtesy of TU Ilmenau


• Measuring results • WLI

53

Step height 20µm

Step height 497nm

Surface measurement



Probe systems NMM-1

54

NMM-1Probe Systems


Sensor



3D-Micro Probe


3D-Micro Probe GannenXP

• Tactile scanning of surfaces

• Silicon chip with integrated piezo resistive elements

• Exchangeable stylus and membrane

• Probe stiffness: 400 N/m

• Tip diameter: 0,12-0,5 mm

• Stylus length 6 mm


Used tactile force0,1 mN


Tactile Micro Probe 56

3D measurements 3D Microprobe


Tactile Micro Probe 57

0 200 400 600 800 1000 1200 1400 1600 1800-10

-8

-6

-4

-2

0

2

4

Number of measurements

nm

STD = 1,7 nm over 2h

Repeatability of tactile probing 3D Microprobe


0 10 20 30 40 50 60-5

-4

-3

-2

-1

0

1

2

3

4

5Repeatability of sphere radius measurement

Number of measurements

nm

RadiusR = 2,500050 mm ± 2,2 nm

Repeatability of sphere radius measurement 3D Microprobe

• Measuring object is a calibrated ruby sphere on a stable invar holder

• The sphere radius is measured by NMM and Gannen XP 3D probe, repeated several times


www.Saphierwerke.com

SIOS Meßtechnik GmbH – Am Vogelherd 46 – D-98693 Ilmenau – Germany

Tel.: +49 (0) 3677-6447-47 Fax: +49 (0) 3677-6447-8 E-Mail: [email protected]

Thank you for your attention!

Documents

highly precise, fast and effective Wolfram Meyer Technical Sales · SIOS Meßtechnik GmbH –Am Vogelherd 46 –D-98693 Ilmenau –Germany Tel.: +49 (0) 3677-6447-47 Fax: +49 (0)