Method for making a perpendicular magnetic recording write head with write pole having thin side gaps and thicker leading gap

A method for forming a main pole of a magnetic recording disk drive write head comprising:

• providing a substrate having a trench with a bottom and outwardly sloped sidewalls;
• depositing into the trench, by ionized physical vapor deposition, material selected from a nonmagnetic metal and a nonmagnetic metal alloy to form a bottom layer of said material and sidewall layers of said material, said sidewall layers having a thickness and said bottom layer is having a thickness at least 1.5 times the thickness of said sidewall layers;
• depositing a seed layer of ruthenium (Ru) on said bottom layer and said sidewall layers;
• depositing a smoothing layer of Ru on said Ru seed layer by atomic layer deposition using RuO4 and H2, wherein the RuO4 acts as a precursor that reduces to RuO2 on said Ru seed layer and the H2 acts to reduce RuO2 to Ru;
• depositing a metallic pole seed layer comprising Co and Fe on the Ru smoothing layer;
• and
• electroplating a ferromagnetic pole layer comprising Co and Fe on the pole seed layer.

A method for depositing a layer of material in a substrate having a trench with a bottom and outwardly sloped sidewalls comprising:

• depositing into the trench, by ionized physical vapor deposition, material selected from a metal and a metal alloy to form a bottom layer of said material and sidewall layers of said material, wherein said sidewall layers are thinner than said bottom layer;
• depositing a smoothing layer of Al2O3 on said bottom layer and said sidewall layers by atomic layer deposition, said Al2O3 smoothing layer having a thickness greater than or equal to 1 nm and less than 5 nm;
• and
• depositing a metallic pole seed layer comprising Co and Fe on the Al2O3 smoothing layer and electroplating a ferromagnetic pole layer comprising Co and Fe on the pole seed layer.