Transfer-ESC based on a wafer
View Patent ↗A mobile transportable electrostatic chuck for clamping thin wafers ( 12 ) without permanent connection to an external power supply unit is described. The mobile chuck allows a safe handling of thin substrates on existing production equipment because the size and thickness of the clamped substrate on the mobile chuck is similar to a standard wafer. The chuck is made from silicon wafers itself as base material ( 11 ) using an IC manufacturing processes. Bipolar electrode-unit-cells ( 10 ), combined into clusters ( 4 ) and linked to an integrated fuse ( 5 ), generate a non-uniform electric field with additional force components. Peak-electrodes ( 1 ) are introduced with the highest field density in the peak region and thus creating a three dimensional non-uniform electric field with each surrounding electrode ( 3 ). Quadratic or hexagonal electrode-unit-cells ( 10 ) enable the highest dense of unit cells, which effectively clamp wafers ( 12 ) in close proximity to the surface ( 8 a ) of the chuck at elevated temperatures.
1. A mobile, transportable electrostatic chuck comprising a first surface ( 8 a ) for electrostatically clamping a thin process-wafer ( 12 ) thereon by applying a clamping voltage, without permanent connection to an external power supply unit for transportation or other process steps, where the size and thickness of the clamped process-wafer and the mobile chuck is similar of size, thickness and shape as a standard wafer comprising:
a semiconductor base-material ( 11 ) with electrodes on top, which create a non-uniform electric field, wherein each said electrode comprises a plurality of clusters built up modularly from a plurality of single, bipolar electrode-unit-cells ( 10 );
each of said electrode-unit-cell ( 10 ) comprising one inside peak-electrode ( 1 ), a lateral insulator layer ( 2 ), a surrounding electrode ( 3 ) and a top dielectric layer ( 8 ).
2. The mobile chuck as set forth in claim 1 , wherein each electrode-unit-cell ( 10 ) has a length of no more than 5 μm and a width of no more than 5 μm.
3. The mobile chuck as set forth in claim 1 , wherein each said cluster ( 4 ) is built up from 4 up to 100,000 said electrode-unit-cells ( 10 ).
4. The mobile chuck as set forth in claim 1 , wherein each said cluster ( 4 ) is linked to one or more integrated fuses ( 5 ).
5. The mobile chuck as set forth in claim 1 , wherein integrated semiconductor-components are integrated within the said semiconductor base-material ( 11 ).
6. The mobile chuck as set forth in claim 1 , wherein active and passive semiconductor-components are supplied self-sufficient with energy, comprising autarky capacitors ( 9 ), batteries or accumulators.
7. The mobile chuck as set forth in claim 1 , wherein solid state switches integrated in the said semiconductor base-material ( 11 ) are applied to switch on or off said electrodes.