Method for etching EUV material layers utilized to form a photomask

1. A method of etching an ARC layer or an absorber layer disposed on a photomask, comprising:

transferring a film stack into an etching chamber, the film stack having an ARC layer or an absorber layer partially exposed through a patterned layer;

providing a gas mixture including at least one fluorine containing gas in to a processing chamber;

applying a source RF power to form a plasma from the gas mixture;

applying a first type of RF bias power to the substrate for a first period of time;

applying a second type of RF bias power away from the substrate for a second period of time; and

etching the ARC layer or the absorber layer through the patterned layer in the presence of the plasma.

2. The method of claim 1 , wherein ARC layer or an absorber includes at least one of a tantalum containing layer.

3. The method of claim 1 , wherein the substrate including the ARC layer disposed on the absorber layer.

4. The method of claim 1 , wherein applying the first type of RF bias power comprises:

applying the first type of RF bias power to a substrate support disposed in the processing chamber.

5. The method of claim 1 , wherein applying the second type of RF bias power comprises:

applying the second type of RF bias power through a chamber wall of the processing chamber to ground.

6. The method of claim 1 , wherein a time period ratio of the first period of time to the second period of time is controlled at a ratio between about 1:9 and about 4:1.

7. The method of claim 1 , wherein the first and the second type of the RF bias power is applied in pulsed mode.

8. The method of claim 1 , wherein the absorber layer is a TaN layer or TaBN layer and the ARC layer is a TaO or TaBO layer.

9. The method of claim 1 , wherein applying the source RF power further comprises:

providing a plasma source power of between about 50 Watts to about 3000 Watts.

10. The method of claim 1 , wherein applying the first type of RF bias power further comprises:

providing a first plasma bias power of between about 5 and about 600 Watts.

11. The method of claim 1 , wherein applying the second type of RF bias power further comprises:

providing a second plasma bias power of between about 5 and about 600 Watts.

12. A method of etching an ARC layer or an absorber layer disposed on a photomask, comprising:

transferring a film stack into an etching chamber, the film stack having an ARC layer disposed on an absorber layer partially exposed through a patterned photoresist layer;

providing a first gas mixture including at least one fluorine containing gas in to a processing chamber;

applying a first source RF power to form a plasma from the first gas mixture to etch the ARC layer;

applying a first type of RF bias power to the substrate for a first period of time;

applying a second type of RF bias power away from the substrate for a second period of time; and

etching the ARC layer through the patterned photoresist layer in the presence of the plasma.

13. The method of claim 12 , further comprising:

providing a second gas mixture including at least one chlorine containing gas in to the processing chamber;

applying a second source RF power to form a plasma from the first gas mixture to etch the ARC layer;

applying a third type of RF bias power to the substrate for a third period of time;

applying a fourth type of RF bias power away from the substrate for a fourth of time; and

etching the absorber layer through the patterned photoresist and ARC layer in the presence of the plasma.

14. The method of claim 13 , wherein the first RF bias power is higher than the third RF bias power.

15. The method of claim 13 , wherein the first RF bias power is higher than the third RF bias power between about 50 percent and about 200 percent.

16. The method of claim 12 , wherein the first period of time to the second period of time is controlled at a ratio between about 1:9 and about 4:1.

17. The method of claim 13 , wherein the third period of time to the fourth period of time is controlled at a ratio between about 1:9 and about 4:1.

18. The method of claim 12 , wherein the first type of RF bias power is applied to a substrate support disposed in the processing chamber and the second type of RF bias power is applied through a chamber wall of the processing chamber to ground.

19. The method of claim 13 , wherein the third type of RF bias power is applied to a substrate support disposed in the processing chamber and the fourth type of RF bias power is applied through a chamber wall of the processing chamber to ground.

20. The method of claim 12 , wherein the film stack further includes a capping disposed on a multiple reflective material layers disposed between the substrate and the absorber layer.

21. A method of etching an ARC layer and an absorber layer disposed on a photomask, comprising:

transferring a film stack into an etching chamber, the film stack having an ARC layer disposed on an absorber layer partially exposed through a patterned photoresist layer;

providing a first gas mixture including at least one fluorine containing gas in to a processing chamber;

applying a first type of RF bias power to the substrate for a first period of time;

applying a second type of RF bias power away from the substrate for a second period of time;

etching the ARC layer through the patterned photoresist layer in the presence of the plasma;

providing a second gas mixture including at least one fluorine containing gas in to the same processing chamber;

applying a third type of RF bias power to the substrate for a third period of time;

applying a fourth type of RF bias power away from the substrate for a fourth period of time, wherein first RF bias power is higher than the third RF bias power.