Electrochemical etching

1. A method, comprising:

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

generating an electric field within the etchant solution to cause an anisotropic etch pattern to form on a surface of the workpiece.

2. The method of claim 1 , wherein the dilute acid is selected from a group consisting of citric acid and oxalic acid.

3. The method of claim 1 , wherein the non-ionic surfactant comprises an alkyl ethoxylate or an alkyl ethoxylate blend.

4. The method of claim 3 , wherein the alkyl ethoxylate includes a C7-C10 alkyl chain and a molecular weight of about 550.

5. The method of claim 1 , wherein the etchant solution comprises a citric acid and an alkyl ethoxylate blend.

6. 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.

7. 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.

8. The method of claim 7 , wherein generating the electric field further comprises applying a current between about 0.05 amp to 2.0 amp to the electrode and workpiece.

9. The method of claim 7 , wherein generating the electric field further comprises applying a current density between about 50-150 mA/cm2.

10. The method of claim 8 , wherein applying the current further comprises generating an etch rate between about 5 nm/sec to about 20 nm/sec.

11. The method of claim 7 , wherein submerging further comprises forming a space about 1 mm to about 10 mm between the workpiece and the electrode.

12. The method of claim 8 , 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.

13. The method of claim 1 , wherein the workpiece comprises a disk substrate having a plated NiP layer over the disk substrate.

14. The method of claim 13 , further comprising:

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, wherein the etch pattern comprises a DTR pattern, and 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.

15. The method of claim 14 , wherein imprinting further comprises ashing the embossable layer to expose the NiP layer in the recessed areas.