Rein Boshuisen, PME
description
Transcript of Rein Boshuisen, PME
1Titel van de presentatie
Rein Boshuisen, PME
Analysis and Performance of a lightweight over-actuated 450mm wafer chuck
R. Boshuisen, PME09-06-2010
2Titel van de presentatie
Contents• Introduction
• Problem Description
• Principle of Over-actuation
• Test Setup and Analysis
• Improvements on the Current Setup
• Conclusions
Over-actuation of a wafer chuck
3Titel van de presentatie
Problem descriptionTypically wafer chucks are actuated as rigid bodies. Larger wafers leads to heavier wafer stages:
200 mm Wafer
m kg
300 mm Wafer
> 3 x m kg
450 mm Wafer
> 11 x m kg
Z
Y
X
Width: 1.5Depth 1.5Thickn: 1.5
Width: 1.5Depth 1.5Thickn: 1.5
Modal analysisModal analysisOver-actuation of a wafer chuck
4Titel van de presentatie
Drawbacks of large wafers and chucks:• Larger actuation forces and deformation• Larger power dissipation and thermal load • Internal modes still critical to performance
Z
Y
X
Problem descriptionDesire to have a LARGE chuck with
LOW Mass and HIGH internal modes
Modal analysisModal analysisOver-actuation of a wafer chuck
5Titel van de presentatie
zF
z
ALTERNATIVE means of ACTUATOR placement
Actuation in nodes
zFzFSymmetrical actuation
zF zF zF
Challenge deal with infinitely many modes, without adding as many actuators and control complexity
Alternative: Over-Actuation
Over-actuation of a wafer chuck
6Titel van de presentatieModal analysisModal analysis
Eigenmodes of a chuck
Over-actuation of a wafer chuck
7Titel van de presentatieOver-actuation of a wafer chuck
First eigenmode - Example
8Titel van de presentatieModal analysisModal analysis
Eigenmodes of a chuck
Over-actuation of a wafer chuck
9Titel van de presentatie
• Actuators on nodeline?• Change nodelines?
Modal analysisModal analysis
Eigenmodes of a chuck
Over-actuation of a wafer chuck
10Titel van de presentatie
1Langelaar TU Delft
y
x
Topology optimization1 of chuck
Over-actuation of a wafer chuck
11Titel van de presentatie
5
1
25
1
25
1
2min
f RyTff Rx
Tff z
Tf BBB
Z Rx Ry
00
010
001
2
2
kms
ms
Mechanics
T CB
Modal Coordinates
Physical CoordinatesMinimize the contribution by varying actuator position and cavity diameter :
a d
Optimization Strategy
Over-actuation of a wafer chuck
12Titel van de presentatieModal analysisModal analysisOver-actuation of a wafer chuck
Optimization result I
13Titel van de presentatie
184 Hz 270 Hz 270 Hz
349 Hz 521 Hz
Actuator location
Green zero displacement
Eigenmodes of a chuck
Over-actuation of a wafer chuck
14Titel van de presentatieModal analysisModal analysisOver-actuation of a wafer chuck
Optimization result II
15Titel van de presentatieModal analysisModal analysisOver-actuation of a wafer chuck
Optimization result II
16Titel van de presentatie
Wafer chuck demonstrator motions in Z, Rx, and Ry
Z
Y
X
Three linear encoders
Folded Flexures (3x), Fixing Rz, X and Y Actuator assembly
(5x)
Frame
Modal analysisModal analysis
Realized Test Setup
Over-actuation of a wafer chuck
17Titel van de presentatie
Conventional actuation around COG
Over-actuation around COG
Realized Test Setup
Over-actuation of a wafer chuck
18Titel van de presentatieModal analysisModal analysisOver-actuation of a wafer chuck
Measured Result I
19Titel van de presentatieModal analysisModal analysisOver-actuation of a wafer chuck
Measured Result II
20Titel van de presentatie
Control of the chuck
ChuckDynamics
Loc ->CoGActuation matrix3 PID
controllers
3 Sensors
Z
RX
RY
Control with standard industrial controller Bosch-RexRoth NYCe 4000
Over-actuation of a wafer chuck
21Titel van de presentatie
Performance of the setupConventional Over-Actuated
Bandwidths:ZRXRY
50 Hz60 Hz50 Hz
102 Hz100 Hz100 Hz
Standstill Performance RMS
ZRXRY
30 nm 150 nrad135 nrad
7 nm35 nrad30 nrad
Factor 2 in bandwidth, 4 in stiffness
Factor 5 improvement
Over-Actuation shows clear benefits compared to conventional actuation!
Over-actuation of a wafer chuck
22Titel van de presentatieModal analysisModal analysisOver-actuation of a wafer chuck
Why still excitation of the modes??
23Titel van de presentatie
• Improved model
• No Symmetry – Possible causes• Actuator 5• Gravity Compensators• Plate springs• Chuck
The analysis only partially explains the mode excitations Over-actuation of a wafer
chuck
Mode excitation analysis
24Titel van de presentatie
• Sensor-placement / Over-Sensing
Over-actuation of a wafer chuck
Improvements of the current setup
25Titel van de presentatie
Control of the chuck
ChuckDynamics
Loc ->CoGActuation matrix3 PID
controllers
3 Sensors
Z
RX
RY
Control with: Matlab/Simulink, using xPc Target software
Over-actuation of a wafer chuck
26Titel van de presentatie
Adjust Sensorposition such, that the excitation of the modes is not converted to CoG movement
• Place sensor in a node
• Symmetric sensor placement
Over-actuation of a wafer chuck
Over-Sensing
27Titel van de presentatieOver-actuation of a wafer chuck
Over-Sensing
28Titel van de presentatie
• This sensor placement can distinguish the first and second eigenmode from the rigid body movement
• Active damping of first eigenmode!
Over-actuation of a wafer chuck
Over-Sensing
29Titel van de presentatie
Conventional Over-Actuated + first mode active damping
Bandwidths:ZRXRY
100 Hz100 Hz100 Hz
200 Hz150 Hz150 Hz
Standstill Performance RMS
Sensor 1Sensor 2Sensor 3Sensor 4
4.0 nm5.8 nm4.6 nm4.6 nm
1.8 nm1.9 nm1.9 nm1.9 nm
Over-actuation of a wafer chuck
Over-Sensing - Performance
30Titel van de presentatie
• Over-actuation is succesfully implemented on a wafer chuck with an increased performance as result.
• Symmetry is critical for the positions of the nodelines on the diagonals
• Include sensor position optimization in the design phase
• Use four sensors to be able to actively damp the first eigenmode
Over-actuation of a wafer chuck
Conclusion
31Titel van de presentatie
Rein Boshuisen, PME
Analysis and Performance of a lightweight over-actuated 450mm wafer chuck
R. Boshuisen, PME09-06-2010
32Titel van de presentatieOver-actuation of a wafer chuck
33Titel van de presentatie
Dynamic Analysis – effect of rotated chuck
Over-actuation of a wafer chuck
34Titel van de presentatie
Dynamic Analysis – effect of Gravity Compensator
Over-actuation of a wafer chuck
35Titel van de presentatie
Damping• Chuck is very lightly damped, increasing damping,
reduces maximum peak-hight, leading to less sensitivity of the actuator placement
Over-actuation of a wafer chuck