Wafer handling apparatus and method of manufacturing thereof
View Patent ↗A wafer processing device or apparatus, i.e., a heater or an electrostatic chuck, comprises a planar support platen, a support shaft having centrally located bore, and a pair of electrical conductors located in the shaft. In one embodiment, the electrical conductors are concentrically located within the bore of the shaft, with the first electrical lead being in the form of a pyrolytic graphite rod and separated from the outer second graphite electrical lead by means of a pyrolytic boron nitride (pBN) coating. In a second embodiment, the support platen and the support shaft are formed from a single unitary body of graphite. In yet another embodiment of the device of the invention, the connection posts comprise a carbon fiber composite and the exposed ends of the electrical connectors are coated with a protective ceramic paste for extended life in operations.
1. A wafer processing device comprising:
a platform for supporting an object to be heated, the platform comprises a substrate having upper and lower relatively flat surfaces, the platform is comprised of graphite;
a shaft extending substantially transverse to the platform, the shaft is comprised of graphite;
a first coating on at least one of the flat surfaces, with said first coating composed of at least a material selected from the group consisting of a nitride, carbide, carbonitride or oxynitride of elements selected from a group consisting of B, Al, Si, Ga, refractory hard metals, transition metals, and combinations thereof;
a second coating layer composed of pyrolytic graphite disposed on the first coating in a patterned arrangement of predetermined geometry, the layer having at least two separate ends adapted for forming at least an electrode; and
a top coating of a dielectric material superimposed on said first and second coatings, the top coating is composed of at least a material selected from the group consisting of a nitride, carbide, carbonitride or oxynitride of elements selected from a group consisting of B, Al, Si, Ga, refractory hard metals, transition metals, and combinations thereof;
wherein the graphite shaft and the graphite platform form a single unitary body, and wherein the graphite shaft is a rod with a hollow core,
wherein the graphite shaft further includes at least two electrical conductors for connecting the electrode to an external source of power, each electrical conductor being in contact with, and surrounded by, dielectric material,
wherein the two electrical conductors are symmetrically disposed on opposite sides of an exterior surface of the graphite shaft.
2. The wafer processing device of claim 1 , wherein the device is an electrostatic chuck and the electrode is a chuck electrode.
3. The wafer processing device of claim 1 , wherein the device is a heater and the electrode is a heating element electrode.
4. The wafer processing device of claim 1 , wherein the graphite platform is one of a disk, a platen, and a cylinder.
5. The wafer processing device of claim 1 , wherein the second coating is patterned to form a continuous elongated strip of pyrolytic graphite arranged in at least one of electrical flow path has at least one of a spiral pattern, a serpentine pattern, a helical pattern, a zigzag pattern, a continuous labyrinthine pattern, a spirally coiled pattern, a swirled pattern, a randomly convoluted pattern, and combinations thereof.
6. The wafer processing device of claim 5 , wherein the patterned second coating is formed on said lower surface of said platform.
7. The wafer processing device of claim 1 , wherein said pyrolytic graphite second coating layer is encapsulated in at least a nitride, carbide, carbonitride or oxynitride of elements selected from a group consisting of B, Al, Si, Ga, refractory hard metals, transition metals, and rare earth metals, or complexes and/or combinations thereof.
8. The wafer processing device of claim 7 , wherein said pyrolytic graphite second coating layer is encapsulated in AlN or pyrolytic boron nitride.
9. The wafer processing device of claim 1 , wherein:
each electrical conductor has an end adapted for connecting to the external source of power, and the end of each of the electrical conductors is coated with at least a ceramic paste comprising at least one of a piezoelectric ceramic paste, a plasticiser, a conductor, and combinations thereof.
10. A wafer processing device comprising:
a platform for supporting an object to be heated, the platform comprises a substrate having upper and lower relatively flat surfaces, the platform is comprised of graphite;
a shaft extending substantially transverse to the platform, the shaft is comprised of graphite;
a first coating on at least one of the flat surfaces, with said first coating composed of at least a material selected from the group consisting of a nitride, carbide, carbonitride or oxynitride of elements selected from a group consisting of B, Al, Si, Ga, refractory hard metals, transition metals, and combinations thereof;
a second coating layer composed of pyrolytic graphite disposed on the first coating in a patterned arrangement of predetermined geometry, the layer having at least two separate ends adapted for forming at least an electrode; and
a top coating of a dielectric material superimposed on said first and second coatings, the top coating is composed of at least a material selected from the group consisting of a nitride, carbide, carbonitride or oxynitride of elements selected from a group consisting of B, Al, Si, Ga, refractory hard metals, transition metals, and combinations thereof;
wherein the graphite shaft and the graphite platform form a single unitary body, and
wherein the graphite shaft further includes at least two electrical conductors for connecting the electrode to an external source of power,
wherein said two electrical conductors are coated layers of pyrolytic graphite symmetrically disposed on opposite sides of said graphite shaft wherein said two electric conductors each extend lengthwise along the graphite shaft and are integral therewith.
11. A wafer processing device comprising:
a platform for supporting an object to be heated, the platform comprises a substrate having upper and lower relatively flat surfaces, the platform is comprised of graphite;
a shaft extending substantially transverse to the platform, the shaft is comprised of graphite;
a first coating on at least one of the flat surfaces, with said first coating composed of at least a material selected from the group consisting of a nitride, carbide, carbonitride or oxynitride of elements selected from a group consisting of B, Al, Si, Ga, refractory hard metals, transition metals, and combinations thereof;
a second coating layer composed of pyrolytic graphite disposed on the first coating in a patterned arrangement of predetermined geometry, the layer having at least two separate ends adapted for forming at least an electrode; and
a top coating of a dielectric material superimposed on said first and second coatings, the top coating is composed of at least a material selected from the group consisting of a nitride, carbide, carbonitride or oxynitride of elements selected from a group consisting of B, Al, Si, Ga, refractory hard metals, transition metals, and combinations thereof;
wherein the graphite shaft and the graphite platform form a single unitary body, and wherein the graphite shaft is a rod with a hollow core,
wherein the graphite shaft further includes at least two electrical conductors for connecting the electrode to an external source of power, each electrical conductor being in contact with, and surrounded by, dielectric material,
wherein said first electrical conductor is in a form of a graphite rod, the second electrical conductor is a hollow graphite rod, and wherein the first and second electrical conductors are separated by means of a coating layer comprising a material selected from the group of least a nitride, carbide, carbonitride or oxynitride of elements selected from a group consisting of B, Al, Si, Ga, refractory hard metals, transition metals, and rare earth metals, or complexes and/or combinations thereof.