CPP read sensor fabrication using heat resistant photomask
View Patent ↗A method is disclosed for fabricating a CPP read head for a magnetic disk drive having an electrical isolation layer. The method includes providing a first shield layer, depositing a sensor stack on the first shield layer, a CMP stop layer is deposited on the sensor stack, and a release layer is deposited a on the CMP stop layer. Photoresist material containing Si is deposited on the release layer, and the photoresist material is then patterned and then oxidized by Reactive Ion Etching to form a high temperature photomask. The electrical isolation layer is then deposited to surround the sensor stack using a high temperature deposition process. The read head is then continued as either an in-stack bias sensor with ‘draped shield’ variation, or a hard bias stabilization variation.
1. A method for fabricating a CPP read head for a magnetic disk drive having an electrical isolation layer, comprising:
A) providing a first magnetic shield layer;
B) depositing a sensor stack on said first magnetic shield layer;
C) depositing a first CMP stop layer on said sensor stack;
D) depositing a release layer on said first CMP stop layer;
E) depositing photoresist material containing Si on said release layer;
F) patterning said photoresist material to form protected areas in the underlying materials;
G) oxidizing said photoresist material by use of Reactive Ion Etching to form a high temperature photomask;
H) depositing said electrical isolation layer to surround said sensor stack using a high temperature deposition process, where said high temperature photomask protects said protected areas during said high temperature deposition process;
I) depositing a draped magnetic shield material layer on said electrical isolation layer;
J) depositing a second CMP stop layer on said draped magnetic shield material layer; and
K) planarizing said isolation layer and said draped magnetic shield material layer to the level of said sensor stack to form a planarized structure.
2. The method of fabricating a CPP read head of claim 1 , wherein:
said sensor stack is an in-stack bias sensor.
3. The method for fabricating a CPP read head of claim 1 , further comprising:
L) depositing a second magnetic shield layer upon said planarized structure.
4. The method for fabricating a CPP read head of claim 1 , wherein:
said planarizing of K) is done by CMP processes and said first and second CMP stop layers act to limit the planarizing action.
5. The method for fabricating a CPP read head of claim 1 , wherein:
said first CMP stop layer is diamond-like-carbon.
6. The method for fabricating a CPP read head of claim 1 , wherein:
said release layer also acts as a secondary mask layer.
7. The method for fabricating a CPP read head of claim 1 , wherein:
said release layer is spin-on polymide.
8. The method for fabricating a CPP read head of claim 1 , wherein:
said high temperature deposition process of H) includes a process chosen from the group consisting of Chemical Vapor Deposition, Atomic Layer Deposition, Plasma Enhanced Chemical Vapor Deposition or High Temperature Sputtering.
9. The method for fabricating a CPP read head of claim 1 , wherein:
oxidizing of said photoresist material by use of Reactive Ion Etching of G) is done by using a gas chosen from the group consisting of oxygen and carbon dioxide.