Method for producing tight pitched coil with reduced processing steps
View Patent ↗Methods for fabricating thin film magnetic head coil structures are disclosed. The methods disclose deposition of a first thick seed layer, followed by deposition of an ultra-thin second seed layer. Coil structures having sub-micron pitch and high aspect ratios are deposited on the second ultra-thin seed layer, which is removed from between the coil windings via an isotropic etch process such as wet etching or RIE. Subsequent to selective removal of the ultra-thin second seed layer, the first thick seed layer is utilized to deposit pole and backgap structures, eliminating the need to deposit (and remove) a subsequent seed layer on the coil structure.
1. A method for fabricating a thin film magnetic head comprising:
depositing a first seed layer on a surface of a partially completed thin film head structure;
removing a first portion of said first seed layer, exposing a portion of said surface;
depositing a first portion of a second seed layer over a second portion of said first seed layer and a second portion of said second seed layer over said portion of said surface;
depositing a photo resist layer over said second portion of said second seed layer;
removing a portion of said photo resist layer;
electroplating a coil structure over said second portion of said second seed layer by conducting electrical current from said second portion of said first seed layer to said second portion of said second seed layer, wherein said first seed layer is greater than 200 angstroms in thickness and said second seed layer is less than 70 angstroms in thickness;
removing remaining portions of said photo resist layer subsequent to electroplating said coil structure;
removing exposed portions of said second seed layer subsequent to removing said remaining portions of said photo resist layer; and,
electroplating a lower pole pedestal structure and a backgap structure on a lower return pole layer subsequent to removing said exposed portions of said second seed layer, by conducting electrical current from a remaining portion of said first seed layer to said lower return pole layer.
2. The method as recited in claim 1 , wherein said second seed layer comprises copper having a thickness between 10 and 20 angstroms.
3. The method as recited in claim 2 , wherein said exposed portions of said second seed layer are removed by wet etching.
4. The method as recited in claim 1 , wherein said second seed layer comprises chromium having a thickness between 10 and 20 angstroms.
5. The method as recited in claim 4 , wherein said exposed portions of said second seed layer are removed by wet etching.
6. The method as recited in claim 1 , wherein said second seed layer comprises a first layer and a second layer, said first layer comprising tantalum having a thickness between 10 and 50 angstroms, said second layer comprising rhodium having a thickness between 10 and 20angstroms.
7. The method as recited in claim 6 , wherein said exposed portions of said second seed layer are removed by RIE.
8. The method as recited in claim 1 , wherein said second seed layer comprises titanium having a thickness between 10 and 50 angstroms.
9. The method as recited in claim 8 , wherein said exposed portions of said second seed layer are removed by RIE.
10. The method as recited in claim 9 , wherein said second seed layer comprises titanium having a thickness between 10 and 20 angstroms.
11. The method as recited in claim 1 , wherein said exposed portions of said second seed layer are removed by ion milling.
12. The method as recited in claim 1 , wherein said exposed portions of said second seed layer are removed by sputter etching.