Clamp with burls-electrode
View Patent ↗Holding apparatus ( 100 ) for electrostatically holding component ( 1 ), (e.g., a silicon wafer), includes base body ( 10 ) composed of first and second plates ( 11 A, 12 ), the first plate being arranged on upper side ( 10 A) of base body ( 10 ) and second plate ( 12 ) carrying first plate ( 11 A), and second plate ( 12 ) being an electrically insulating material, a plurality of projecting, upper burls ( 13 A) arranged on upper side ( 10 A) and forming a support surface for component ( 1 ), and first electrode device ( 20 A) having first electrodes ( 21 A) arranged on upper side ( 10 A) for receiving a clamping voltage, wherein first plate ( 11 A) is produced from electrically conductive, Si-based ceramic and carries upper plate insulating layer ( 14 A) which covers upper side ( 10 A), having upper burls ( 13 A), and the first electrodes ( 21 A) include electrode layers arranged on upper burls ( 13 A) and each carry upper electrode insulating layer ( 15 A). A method for producing the holding apparatus is also described.
1. A holding apparatus configured to electrostatically hold a component, comprising:
a base body which comprises a first plate and a second plate, the first plate being arranged on an upper side of the base body and the second plate carrying the first plate, and the second plate comprising an electrically insulating material,
a plurality of projecting, upper burls which are arranged on the upper side of the base body and form a support surface for the component, and
a first electrode device having a plurality of first electrodes which are arranged on the upper side of the base body for receiving a clamping voltage, wherein
the first plate comprises an electrically conductive, Si-based ceramic and carries an upper plate insulating layer which covers the upper side of the base body having the upper burls, and
the first electrodes comprise electrode layers which are arranged on the upper burls and each carry an upper electrode insulating layer.
2. The holding apparatus according to claim 1 , which further comprises
a third plate which is arranged on an underside of the base body, carries the second plate and comprises an electrically conductive, Si-based ceramic,
a plurality of projecting, lower burls which are arranged on the underside of the base body and form a carrier surface for the holding apparatus on a carrier platform,
a second electrode device having a plurality of second electrodes which are arranged on the underside of the base body for receiving a clamping voltage, wherein
the second plate carries a lower plate insulating layer which covers the underside of the base body having the lower burls, and
the second electrodes comprise electrode layers which are arranged on the lower burls and each carry a lower electrode insulating layer.
3. The holding apparatus according to claim 1 , wherein
at least one of the first and second electrodes are limited to the upper and lower burls, respectively, and spaces between at least one of the upper and lower burls are free of electrodes for receiving the clamping voltage.
4. The holding apparatus according to claim 1 , having at least one of the features:
at least one of the upper and lower burls have a surface roughness Ra>200 nm,
at least one of the upper and lower burls are connected electrically conductively to the first or second plates,
at least one of the upper and lower burls comprise the electrically conductive, Si-based ceramic, and
at least one of the upper and lower burls are integrally connected to the first or second plates.
5. The holding apparatus according to claim 1 , wherein
at least one of the upper and a lower electrode insulating layers carry at least one of an upper and a lower anti-wear layer on the upper or lower burls.
6. The holding apparatus according to claim 5 , wherein
at least one of the upper and lower anti-wear layer comprises silicon carbide or electrically insulating, amorphous carbon.
7. The holding apparatus according to claim 1 , wherein
at least one of the first and second electrode devices comprises at least one of first and second conductor strips, respectively, which are arranged for connecting at least one of the first and second electrodes to a voltage source.
8. The holding apparatus according to claim 7 , wherein
at least one of the first and second conductor strips and the voltage source are so configured that at least one of the first and second electrodes can selectively receive a specific clamping voltage.
9. The holding apparatus according to claim 1 , wherein
at least one of the first and third plates has at least one electrical contact region for connection with ground potential.
10. The holding apparatus according to claim 1 , having at least one of the features
at least one of the first and third plates comprises SiSiC or SSiC ceramic,
the second plate comprises Si 3 N 4 , SiC ceramic or borosilicate glass, and
at least one of the first and second electrodes comprise Al, TiN or WC.
11. A method for producing a holding apparatus according to claim 1 , comprising the steps
prefabricating the first and second plates,
depositing the upper plate insulating layer on the first plate,
depositing the first electrodes and the upper electrode insulating layers on the upper burls, and
joining the first plate to the second plate.