Process for making PMR writer with constant side wall angle
View Patent ↗A process for manufacturing a writer main pole for a perpendicular magnetic recording system is provided. The writer pole may have a constant sidewall angle from the ABS to yoke and may be formed out of an insulating material and a magnetic material. The sidewall angle of the yoke region may be adjusted during manufacture. The ABS region may correspond to the magnetic material and the yoke region may correspond to the insulating material. The insulating material may comprise Alumina. The magnetic material may comprise a NiFe alloy.
1. A method, comprising:
forming over a substrate a layer comprising insulating material and magnetic material, wherein the insulating material and magnetic material are planar at a top surface of the layer;
depositing a first hard mask and a second hard mask over the top surface of the layer;
forming an air-bearing surface (ABS) region in the magnetic material with a first sidewall angle;
forming a yoke region in the insulating material with a second sidewall angle; and
decreasing the second sidewall angle by performing a reactive ion etch (RIE) on the insulating material using the first hard mask.
2. The method of claim 1 wherein the ABS region and yoke region are formed using the second hard mask.
3. The method of claim 2 , wherein forming the ABS region and the yoke region comprises:
forming a resist pattern over a portion of the second hard mask;
depositing a third hard mask over the resist pattern;
removing a portion of the third hard mask deposited over the resist pattern to form a patterned third hard mask;
performing a RIE on the second hard mask using the third hard mask; and
performing a RIE on the first hard mask, insulating material, and magnetic material using the second hard mask.
4. The method of claim 3 wherein the third hard mask comprises at least one of chromium (Cr) or ruthenium (Ru).
5. The method of claim 3 wherein the resist pattern is a writer main pole photo pattern.
6. The method of claim 2 , wherein the magnetic material comprises nickel-iron (NiFe).
7. The method of claim 2 , wherein the insulating material comprises alumina (Al 2 O 3 ).
8. The method of claim 7 , wherein the second sidewall angle is decreased to within 2 degrees of the first sidewall angle.
9. The method of claim 8 wherein the first and second sidewall angles are between 11 and 13 degrees.
10. The method of claim 2 wherein the first hard mask comprises nickel chromium (NiCr).
11. The method of claim 2 wherein the second hard mask comprises tantalum (Ta).
12. The method of claim 2 wherein the yoke region is 20 to 250 nm behind the ABS.