Method for manufacturing a magnetic write head using novel mask structure

A method for manufacturing a magnetic write head, comprising:

• depositing a layer of write pole material;
• depositing a series of mask layers over the write pole material, the series of mask layers comprising:
• an under-layer;
• a bi-layer hard mask structure formed over the under-layer, the bi-layer hard mask structure further comprising a layer of silicon dielectric and a layer of carbon formed over the layer of silicon dielectric;
• and a layer of photoresist deposited over the bi-layer hard mask structure;
• photolithographically patterning the photoresist layer to form a photoresist mask;
• performing a reactive ion etching to remove portions of the bi-layer hard mask structure that are not protected by the photoresist mask;
• and
• performing an ion milling to remove a portion of the magnetic write pole layer that is not protected by the under-layer to define a write pole;
• wherein the layer of silicon dielectric is deposited to a thickness of 50-150 nm and the layer of carbon is deposited to a thickness of 2-10 nm.