National Taiwan University Mechanical Engineering Precision Metrology Lab.

Development of a high precision co-planar stage with a multi-degree-of-freedom sensor

Professor Kuang-Chao FanNTU

Dept. of Mechanical EngineeringNational Taiwan University

Nov 8th, 2012 at IFToMM

Hung-Yu Wang, Chung-Hao Lin, Bo-Hsun Liao

National Taiwan University Mechanical Engineering Precision Metrology Lab.

Outline

The need of Micro/Nano Measurements

Components and principles of the Co-planar stage

Multi-Degree-of-freedom Sensor

Experimental tests

Conclusions

National Taiwan University Mechanical Engineering Precision Metrology Lab.

Gap between Micro to Meso Regions

Microgrooves

National Taiwan University Mechanical Engineering Precision Metrology Lab.

Specifications of Traditional and Micro CMMs

Source ： Takamasu Lab. http://www.nano.pe.u-tokyo.ac.jp/

National Taiwan University Mechanical Engineering Precision Metrology Lab.

Evolution of the Co-planar stage

Co-planar stage design maintenance. (Abbé error free)

MDFS measures not only distance but also two angle. (Pitch & Yaw)

Stage motion measurement directly. (Excluded backlash, angle… compensation)

National Taiwan University Mechanical Engineering Precision Metrology Lab.

Abbé principle in Co-planar Stage

Abbé principle for 3D motions

National Taiwan University Mechanical Engineering Precision Metrology Lab.

The configuration of the Multi-Degrees-of-freedom Sensor

Moving Mirror

Displacement

Pitch & Yaw

QuadrantDetector

Laser DiodeReference Mirror

BS1

BS2

BS3Q1

Q2 Q3

Quadrant DetectorFocusing Lens

PBS1 PBS2

PBS3

PD1

PD2

PD3

PD4

FocusingLens

Michelson interferometer

Autocollimator

Wavelength compensator

PBS : Polarized Beam SplitterBS : Beam SplitterQ : Quarter-Wave PlatePD : Photodetector

Moving Mirror

Displacement

Pitch & Yaw

QuadrantDetector

Laser DiodeReference Mirror

BS1

BS2

BS3Q1

Q2 Q3

Quadrant DetectorFocusing Lens

PBS1 PBS2

PBS3

PD1

PD2

PD3

PD4

FocusingLens

Michelson interferometer

Autocollimator

Wavelength compensator

PBS : Polarized Beam SplitterBS : Beam SplitterQ : Quarter-Wave PlatePD : Photodetector

National Taiwan University Mechanical Engineering Precision Metrology Lab.

Multi-Degrees-of-freedom SensorMichelson interferometer

12

1 cos( )PDd

I A

22

1 cos( )PDd

I A

32

1 sin( )PDd

I A

42

1 sin( )PDd

I A

Signal process

National Taiwan University Mechanical Engineering Precision Metrology Lab.

Multi-Degrees-of-freedom SensorAutocollimator

Signal process

Collimating lens

Polarizing beam splitter

Photodiode IC

Laser diode

AB

DC

Focusing lens

θ 0 (Incline angle)Mirror

Y-a

xis

X-axis

Collimating lens

Polarizing beam splitter

Photodiode IC

Laser diode

AB

DC

AB

DC

Focusing lens

θ 0 (Incline angle)Mirror

Y-a

xis

X-axis 2[( ) ( )]x A B C DK V V V V

2[( ) ( )]y B C A DK V V V V

VA VA

VBVB VCVC

VD VD

National Taiwan University Mechanical Engineering Precision Metrology Lab.

Experiment result -- Positioning Error

Accuracy and repeatability of positioning The relationship between SIOS

and Michelson values

National Taiwan University Mechanical Engineering Precision Metrology Lab.

Experiment result -- Abbé Error Compensation

Residual error with and without Abbé error compensation (Ly = 6 mm 、 Lz = 0 mm)

Residual error with and without Abbé error compensation (Ly = 6 mm 、 Lz = 2 mm)

Residual error with and without Abbé error compensation (Ly = 6 mm 、 Lz = 3 mm)

zxyy LLE

Abbé error illustration

National Taiwan University Mechanical Engineering Precision Metrology Lab.

Conclusion

Residual error with and without Abbé error compensation (Ly = 6 mm 、 Lz = 0 mm)

New type of co-planar stage was developed to overcome nonlinear

error.

The positioning error can be controlled to ±30 nm with standard

deviation 20 nm in 20mm travel range.

The NDFS for co-planar stage with high accuracy was developed.

(can achieve 1 nm resolution )

The Abbé error has been compensated due to the MDFS can measure

the yaw and pitch errors of the co-planar stage.

LOW COST.

National Taiwan University Mechanical Engineering Precision Metrology Lab.

Thank you for your attention

National Taiwan University Mechanical Engineering Precision Metrology Lab.

Driver: Ultrasonic Motor (HR-4)

X1

X2

X1

X2u1 ( x1 , x2 , t ) u2 ( x1 , x2 , t )

A

B' A'

B

bending mode longitudinal mode

Elliptical motion of the piezoelectric elements: vector sum of the bending mode and the longitudinal mode AC mode: successive motion with

long stroke of 0.1mm-20mm.

GATE mode: short travel of 20-30nm in steps.

DC mode: nanopositioning motion of within 30nm.

Slide Moving direction

Finger tipPZT element