Electrochemical etching

1. A method, comprising:

disposing a workpiece within an etchant solution having a composition comprising a dilute acid and an adsorbate, wherein the adsorbate comprises 2-benzimidazole proprionic acid;

generating an electric field within the etchant solution; and

anisotropically etching a pattern in a NiP surface of the workpiece.

2. The method of claim 1 , wherein the dilute acid of the etchant solution has a pH value between about 2 to 4 and a pK value greater than 2.

3. The method of claim 1 , wherein disposing further comprises submerging the workpiece in a bath of the etchant solution, the bath also having an electrode disposed adjacent to the workpiece, the electrode and workpiece coupled to a power supply.

4. The method of claim 3 , wherein generating the electric field further comprises applying a current between about 0.05 amp to 2.0 amp to the electrode and workpiece.

5. The method of claim 3 , wherein generating the electric field further comprises applying a current between about 0.05 amp to 2.0 amp to the electrode and workpiece.

6. The method of claim 5 , wherein applying the current further comprises generating an etch rate between about 5 nm/sec to about 20 nm/sec.

7. The method of claim 5 , wherein applying the current produces an aspect ratio value of greater than 1 for an etch depth relative to an etch width on the surface of the workpiece.

8. The method of claim 3 , wherein submerging further comprises forming a space of about 1 mm to about 10 mm between the workpiece and the electrode.

9. The method of claim 1 , wherein the workpiece comprises a disk substrate, and wherein the method, before disposing the workpiece within the etchant, further comprises:

plating the NiP layer over the disk substrate;

depositing an embossable layer over the NiP layer; and

imprinting the embossable layer with a stamper having a template of an etch pattern to be formed on the NiP layer.

10. The method of claim 9 , wherein the etch pattern comprises a discrete track recording (DTR) pattern.

11. The method of claim 1 , wherein the etchant solution further comprises a non-ionic surfactant.

12. The method of claim 11 , wherein the non-ionic surfactant comprises an alkyl ethoxylate or an alkyl ethoxylate blend.

13. The method of claim 12 , wherein the alkyl ethoxylate includes a C7-C10 alkyl chain and a molecular weight of about 550.

14. A method, comprising:

disposing a workpiece within an etchant solution having a composition comprising a dilute acid and an adsorbate, wherein the workpiece comprises a disk substrate having a plated Nip layer over the disk substrate;

generating an electric field within the etchant solution; and

anisotropically etching a pattern in a surface of the workpiece.

15. The method of claim 14 , wherein the dilute acid is selected from the group consisting of citric acid and oxalic acid.

16. The method of claim 14 , wherein the dilute acid of the etchant solution has a pH value between about 2 to 4 and a pK value greater than 2.

17. The method of claim 14 , wherein disposing further comprises submerging the workpiece in a bath of the etchant solution, the bath also having an electrode disposed adjacent to the workpiece, the electrode and workpiece coupled to a power supply.

18. The method of claim 17 , wherein generating the electric field further comprises applying a current between about 0.05 amp to 2.0 amp to the electrode and workpiece.

19. the method of claim 18 , wherein applying the current further comprises generating an etch rate between about 5 nm/sec to about 20 nm/sec.

20. The method of claim 18 , wherein applying the current produces an aspect ratio value of greater than 1 for an etch depth relative to an etch width on the surface of the workpiece.

21. the method of claim 17 , wherein generating the electric field further comprises applying a current between 0.05 amp to the electrode and workpiece.

22. The method of claim 17 , wherein submerging further comprises forming a space about 1 mm to about 10 mm between the workpiece and the electrode.

23. The method of claim 14 , wherein plating further comprises depositing an embossable layer over the NiP layer.

24. The method of claim 23 , wherein depositing further comprises imprinting the embossable layer with a stamper having a template of a etch pattern to be formed on the NiP layer.

25. The method of claim 24 , wherein the etch pattern comprises a discrete track recording (DTR) pattern.

26. The method of claim 25 , wherein stamping further comprises ashing the embossable layer to expose the NiP layer in the recessed areas.

27. The method of claim 26 , wherein generating the electric field further comprises forming a plurality of recessed areas on the surface of the NiP layer corresponding to the DTR pattern.

28. the method of claim 14 , wherein the etchant solution further comprises a non-ionic surfactant.

29. the method of claim 28 , wherein the non-ionic surfactant comprises an alkyl ethoxylate or an alkyl ethoxylate blend.

30. The method of claim 29 , wherein the alkyl ethoxylate includes a C7-C10 alkyl chain and a molecular weight of about 550.

31. A method, comprising:

disposing a workpiece within an etchant solution having a composition comprising a dilute acid and an adsorbate, wherein the adsorbate comprises 2-benzimidazole proprionic acid;

generating an electric field within the etchant; and

anisotropically etching a pattern in a surface of the workpiece, wherein the workpiece comprises a disk substrate, and wherein the method, before disposing the workpiece within the etchant, further comprises:

plating a NiP layer over the disk substrate;

depositing an embossable layer over the NiP layer; and

imprinting the embossable layer with a stamper having a template of an etch pattern to be formed on the NiP layer.

32. The method of claim 31 , wherein the etch pattern comprises a discrete track recording (DTR) pattern.