1 Titel van de presentatie Rein Boshuisen, PME Analysis and Performance of a lightweight over-actuated 450mm wafer chuck R. Boshuisen, PME

2 Titel 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

3 Titel van de presentatie Problem description Typically 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: 1.5 Depth 1.5 Thickn: 1.5 Width: 1.5 Depth 1.5 Thickn: 1.5 Modal analysis Over-actuation of a wafer chuck

4 Titel 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 description Desire to have a LARGE chuck with LOW Mass and HIGH internal modes Modal analysis Over-actuation of a wafer chuck

5 Titel van de presentatie ALTERNATIVE means of ACTUATOR placement Actuation in nodes Symmetrical actuation Challenge deal with infinitely many modes, without adding as many actuators and control complexity Alternative: Over-Actuation Over-actuation of a wafer chuck

6 Titel van de presentatie Modal analysis Eigenmodes of a chuck Over-actuation of a wafer chuck

7 Titel van de presentatie Over-actuation of a wafer chuck First eigenmode - Example

8 Titel van de presentatie Modal analysis Eigenmodes of a chuck Over-actuation of a wafer chuck

9 Titel van de presentatie • Actuators on nodeline? • Change nodelines? Modal analysis Eigenmodes of a chuck Over-actuation of a wafer chuck

10 Titel van de presentatie 1 Langelaar TU Delft y x Topology optimization 1 of chuck Over-actuation of a wafer chuck

11 Titel van de presentatie ZRxRy Mechanics Modal Coordinates Physical Coordinates Minimize the contribution by varying actuator position and cavity diameter : Optimization Strategy Over-actuation of a wafer chuck

12 Titel van de presentatie Modal analysis Over-actuation of a wafer chuck Optimization result I

13 Titel van de presentatie 184 Hz 270 Hz 349 Hz521 Hz Actuator location Green zero displacement Eigenmodes of a chuck Over-actuation of a wafer chuck

14 Titel van de presentatie Modal analysis Over-actuation of a wafer chuck Optimization result II

15 Titel van de presentatie Modal analysis Over-actuation of a wafer chuck Optimization result II

16 Titel 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 analysis Realized Test Setup Over-actuation of a wafer chuck

17 Titel van de presentatie Conventional actuation around COG Over-actuation around COG Realized Test Setup Over-actuation of a wafer chuck

18 Titel van de presentatie Modal analysis Over-actuation of a wafer chuck Measured Result I

19 Titel van de presentatie Modal analysis Over-actuation of a wafer chuck Measured Result II

20 Titel van de presentatie Control of the chuck Chuck Dynamics Loc ->CoG Actuation matrix 3 PID controllers 3 Sensors Z RX RY Control with standard industrial controller Bosch-RexRoth NYCe 4000 Over-actuation of a wafer chuck

21 Titel van de presentatie Performance of the setup ConventionalOver-Actuated Bandwidths: Z RX RY 50 Hz 60 Hz 50 Hz 102 Hz 100 Hz Standstill Performance RMS Z RX RY 30 nm 150 nrad 135 nrad 7 nm 35 nrad 30 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

22 Titel van de presentatie Modal analysis Over-actuation of a wafer chuck Why still excitation of the modes??

23 Titel 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

24 Titel van de presentatie •Sensor-placement / Over-Sensing Over-actuation of a wafer chuck Improvements of the current setup

25 Titel van de presentatie Control of the chuck Chuck Dynamics Loc ->CoG Actuation matrix 3 PID controllers 3 Sensors Z RX RY Control with: Matlab/Simulink, using xPc Target software Over-actuation of a wafer chuck

26 Titel 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

27 Titel van de presentatie Over-actuation of a wafer chuck Over-Sensing

28 Titel 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

29 Titel van de presentatie Conventional Over-Actuated + first mode active damping Bandwidths: Z RX RY 100 Hz 200 Hz 150 Hz Standstill Performance RMS Sensor 1 Sensor 2 Sensor 3 Sensor nm 5.8 nm 4.6 nm 1.8 nm 1.9 nm Over-actuation of a wafer chuck Over-Sensing - Performance

30 Titel 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

31 Titel van de presentatie Rein Boshuisen, PME Analysis and Performance of a lightweight over-actuated 450mm wafer chuck R. Boshuisen, PME

32 Titel van de presentatie Over-actuation of a wafer chuck

33 Titel van de presentatie Dynamic Analysis – effect of rotated chuck Over-actuation of a wafer chuck

34 Titel van de presentatie Dynamic Analysis – effect of Gravity Compensator Over-actuation of a wafer chuck

35 Titel 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