Ozone for selective hydrophilic surface treatment
Processes for surface treatment of a workpiece are provided. In one example implementation, a method can include placing the workpiece on a workpiece support in a processing chamber. The method can include admitting a process gas into the processing chamber. The process gas can include an ozone gas. The method can include exposing the silicon nitride layer and the low-k dielectric layer to the process gas to modify a surface wetting angle of the silicon nitride layer.
1. A method for processing a workpiece, the workpiece comprising a semiconductor material, the workpiece comprising a first layer and a second layer, the process comprising:
placing the workpiece on a workpiece support in a processing chamber;
admitting a process gas into the processing chamber, the process gas comprising an ozone gas;
simultaneously exposing the first layer and the second layer to the process gas to decrease a surface wetting angle of the first layer by at least about 5°, wherein a surface wetting angle of the second layer is decreased by less than about 5°; and
depositing a photoresist layer on the first layer;
wherein modifying the surface wetting angle of the first layer promotes adhesion of the photoresist layer across the first layer;
wherein the first layer is a silicon nitride layer and the second layer is a low-k dielectric layer,
wherein the method comprises conducting an organic radical based surface treatment process on the workpiece to modify a surface wetting angle of the low-k dielectric layer selectively relative to the silicon nitride layer.
2. The method of claim 1 , wherein the low-k dielectric layer is an SiOC layer.
3. The method of claim 1 , wherein the ozone gas is admitted through a separation grid separating a plasma chamber from the processing chamber.
4. The method of claim 3 , wherein the ozone gas is admitted through one or more gas injection ports into the separation grid.
5. The method of claim 1 , wherein the ozone gas is admitted from a gas injection port located below a separation grid separating the processing chamber from a plasma chamber.
6. The method of claim 1 , wherein exposing the first layer and the second layer to the process gas to modify a surface wetting angle of the first layer occurs when the workpiece is at a processing temperature, the processing temperature in a range of about 25° C. to about 500° C.
7. The method of claim 6 , wherein the processing temperature is in a range of about 150° C. to about 500° C.
8. The method of claim 1 , wherein a concentration of ozone gas in the process gas is in a range of about 0.1% by weight to about 20% by weight.
9. The method of claim 1 , wherein a concentration of ozone gas in the process gas is in a range of about 0.5% by weight to 5% by weight.
10. The method of claim 1 , wherein the process gas comprises a carrier gas, the carrier gas being one or more of nitrogen or an inert gas.
11. The method of claim 1 , wherein the process gas comprises an oxygen gas (O 2 gas).
12. The method of claim 1 , exposing the first layer and the second layer to the process gas to modify a surface wetting angle of the first layer occurs for a process period, the process period being in a range of about 5 second to 600 seconds.
13. The method of claim 12 , wherein the process period is in a range of about 3 seconds to 90 seconds.
14. The method of claim 1 , wherein admitting a process gas into the processing chamber and exposing the first layer and the second layer to the process gas to modify a surface wetting angle of the first layer is implemented in a pulsed mode.
15. A method for processing a workpiece, the workpiece comprising a semiconductor material, the workpiece comprising a silicon nitride layer and a low-k dielectric layer, the process comprising:
placing the workpiece on a workpiece support in a processing chamber;
conducting an ozone based hydrophilic surface treatment process on the workpiece, the ozone based hydrophilic surface treatment process comprising:
admitting a process gas into the processing chamber, the process gas comprising an ozone gas;
simultaneously exposing the silicon nitride layer and the low-k dielectric layer to the process gas for a processing period while the workpiece is at a processing temperature to decrease a surface wetting angle of the silicon nitride layer by at least 5°, wherein the surface wetting angle of the low-k dielectric layer is decreased by less than about 5°; and
depositing a photoresist layer on the silicon nitride layer;
wherein modifying the surface wetting angle of the silicon nitride layer promotes adhesion of the photoresist layer across the silicon nitride layer;
wherein a concentration of the ozone gas in the process gas is in a range of about 0.1% by weight to about 20% by weight;
wherein the processing temperature is in a range of about 25° C. to about 500° C.; and
wherein the processing period is in a range of about 5 second to 600 seconds;
wherein the method comprises conducting an organic radical based surface treatment process on the workpiece to modify a surface wetting angle of the low-k dielectric layer selectively relative to the silicon nitride layer.
16. The method of claim 15 , wherein the organic radical based surface treatment process comprises exposing the low-k dielectric layer to one or more methyl radicals.
17. The method of claim 15 , wherein the method comprises conducting a plasma based surface treatment process on the workpiece to modify a surface wetting angle of both the silicon nitride layer and the low-k dielectric layer, the ozone based hydrophilic surface treatment process comprising exposing the workpiece to one or more hydrogen radicals, oxygen radicals, or nitrogen radicals.