Method for fabricating a magnetic write pole having an improved sidewall angle profile

A method for fabricating magnetic transducer having air-bearing surface (ABS) location comprising:

• depositing a first silicon oxide layer;
• depositing an aluminum oxide layer on the first silicon oxide layer;
• providing a mask covering a first portion of the aluminum oxide layer, the first portion of the aluminum oxide layer including at least part of the ABS location;
• ion milling a second portion of the aluminum oxide layer at a nonzero angle from the ABS location, a remaining portion of the aluminum oxide layer forming a first sublayer of an intermediate having a rear surface, the first sublayer including the at least the part of the ABS location, the rear surface being at an angle of at least sixty degrees and not more than seventy degrees from a surface perpendicular to the ABS location;
• depositing a second silicon oxide layer on the first sublayer and an exposed portion of the first silicon oxide layer;
• planarizing the second silicon oxide layer, a remaining portion of the second silicon oxide layer forming a second sublayer adjoining the first sublayer, at least a part of the first sublayer residing between the ABS location and the second sublayer;
• providing a mask having an aperture therein, the aperture having a shape and location corresponding to a trench for a main pole;
• performing a first etch, the first etch removing a portion of the second sublayer;
• and
• performing a second etch, the second etch removing at least a portion of the first sublayer, the trench being formed by the first etch and the second etch, the trench having a bottom, a top and a plurality of sidewalls, the plurality of sidewalls forming a first angle with a direction perpendicular to the bottom at the ABS location, the first angle being at least ten degrees and not more than twenty degrees, the plurality of sidewalls forming a second angle with the direction perpendicular to the bottom in a portion of the second sublayer, the second angle being at least zero degrees and not more than five degrees, a sidewall angle between the plurality of sidewalls and the bottom varying along the rear surface of the first sublayer;
• providing a main pole in the trench;
• and
• providing at least one side shield.