Bonding silicon silicon carbide to glass ceramics
A wafer chuck for use in a lithographic apparatus, which includes a low-thermal expansion glass ceramic substrate, a silicon silicon carbide layer, and a bonding layer comprising silicate having a strength of at least about 5 megapascals, the bonding layer attaching the silicon silicon carbide layer to the substrate is described. Also, a method of forming a wafer chuck for use in a lithographic apparatus, which includes coating a portion of one or both of a low-thermal expansion glass ceramic substrate and a silicon silicon carbide layer with a bonding solution, and contacting the substrate and the silicon silicon carbide layer to bond the substrate and the silicon silicon carbide layer together is described.
1. A chuck for use in a lithographic apparatus, comprising:
a low-thermal expansion glass ceramic substrate;
a silicon silicon carbide layer; and
a bonding layer comprising silicate having a strength of at least about 5 megapascals, the bonding layer attaching the silicon silicon carbide layer to the substrate.
2. The chuck of claim 1 , wherein chuck is a wafer chuck and the substrate comprises fluid channels.
3. The chuck of claim 2 , wherein the silicon silicon carbide layer is at least partially in contact with the fluid channels.
4. The chuck of claim 3 , wherein the bonding layer is configured to seal the fluid channels using the silicon silicon carbide layer and the substrate.
5. The chuck of claim 4 , wherein the bonding layer is configured to seal the fluid channels under fluid pressure of at least about 2.5 megapascals.
6. The chuck of claim 1 , wherein the substrate comprises silicon oxide and aluminum oxide.
7. The chuck of claim 1 , wherein the substrate comprises β-quartz and β-eucryptite.
8. The chuck of claim 1 , wherein a surface of the silicon silicon carbide layer opposite the substrate is polished to a smoothness of about 2-5 nm.
9. The chuck of claim 1 , wherein a surface of the silicon silicon carbide layer adjacent the substrate further comprises a surface layer of silicon dioxide or aluminum oxide.
10. The chuck of claim 9 , wherein the surface layer has thickness of about 20-100 nm.
11. The chuck of claim 10 , wherein the surface layer has thickness of about 50 nm.
12. The chuck of claim 1 , wherein the bonding layer further comprises bonds between silicon atoms and oxygen atoms.
13. The chuck of claim 1 , wherein the bonding layer further comprises aluminate.