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Nano precision X-Y-Rz stage - (Client confidential)
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In close cooperation with Bosch Rexroth a high accuracy stage for wafer alignment has been developed and built.
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The end customer needs this stage for wafer production using an alternative lithographic process. Every cycle the relative position of the wafer w.r.t. mask is measured in three directions (X, Y and Rz). This measurement is done by an external measurement tool, using marks on both wafer and mask. This relative measurement serves as base for generating an accurate alignment set-point. Alignment requirements: - Stroke of ±2.5 mm in X and Y and ±1.5 deg in Rz
- Settled within 50 nm in 30 ms
- drift <10 nm in 10 seconds
- Noise ±60 nm ±3σ over 10 seconds
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Challenges: |
- Integrated air-bearing design in wafer table
- Actuator / sensor layout w.r.t. CoG
- MIMO control strategy
- Force frame design to reduce disturbance from set point reaction forces
- Elastic sensor decoupling
- Design and realization of an external test setup to qualify performance @ tool-point
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Key Competences: |
- Predictive modeling, Dynamic Error Budgeting
- Construction principles for precision engineering
- Advanced Motion Control
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Results: |
- Complete tested prototype, both functional and on performance
- Test tool for qualification @ tool-point
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Cooperation: |
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