Method for using CVD process to encapsulate coil in a magnetic write head
View Patent ↗A method for fabricating a magnetic write head with a coil with a high aspect ratio using a Chemical Vapor Deposition process such as Atomic Layer Deposition (ALD), High Speed ALD, Plasma Enhanced ALD (PEALD), Plasma Enhanced Chemical Vapor Deposition (PECVD) or Low Pressure Chemical Vapor Deposition (LPCVD) to form encapsulating films over the coils without voids is disclosed. Materials which can be used for encapsulation include Al 2 O 3 , SiO 2 , AlN, Ta 2 O 5 , HfO 2 , ZrO 2 , and YtO 3 . The use of an ultra-conformal deposition process allows the pitch of the coils to be smaller than it is possible in the prior art. The method also allows materials with a smaller coefficient of thermal expansion than hardbake photoresist to be used with resulting improvements in thermal protrusion characteristics.
1. A method of fabricating a thin film magnetic head on a wafer comprising:
patterning turns of a coil on a surface, the turns of the coil having a first thickness;
depositing an encapsulation material on the coil by a chemical vapor deposition process comprising reacting a metal or silicon compound precursor with a surface of the coil in a system, purging the metal or silicon compound precursor from the system and then exposing the surface of the wafer to a precursor in the system to form the encapsulation material as a compound that includes the metal or silicon in addition to oxygen or nitrogen, the encapsulation material being deposited as an ultra-conforming film over the wafer with a minimum second thickness that is less than the first thickness, the encapsulation material having a third thickness between the turns of the coil and filling gaps between the turns of the coil without leaving voids, the third thickness being greater than the first thickness;
depositing an insulating material over the encapsulation material by sputtering, the insulating material having a minimum fourth thickness that is greater than the minimum second thickness filling the wafer to a predetermined level with insulating material; and
planarizing the wafer exposing the encapsulation material between the turns of the coils by removing the insulating material from above the encapsulation material between the turns of the coils.
2. The method of claim 1 wherein the chemical vapor deposition process is an atomic layer deposition process.
3. The method of claim 1 wherein the encapsulation material is YtO 3 .
4. The method of claim 1 wherein the encapsulation material is Al 2 O 3 .
5. The method of claim 1 wherein the encapsulation material is SiO 2 .
6. The method of claim 1 wherein the encapsulation material is AlN.
7. The method of claim 1 wherein the encapsulation material is Ta 2 O 5 .
8. The method of claim 1 wherein the encapsulation material is HfO 2 .
9. The method of claim 1 wherein the encapsulation material is ZrO 2 .