Method of forming a continuous free layer spin valve sensor with patterned exchange underlayer stabilization

A method of forming a spin valve device comprising:

• forming a gap layer,
• forming a buffer layer having a top surface and which comprises a single layer of a refractory material formed on the surface of the buffer layer,
• forming patterned underlayers including a magnetic material for providing trackwidth and longitudinal bias on the buffer layer selected from the group consisting of as follows:
• a) a first antiferromagnetic layer stacked with a ferromagnetic layer, and
• b) a chromium layer stacked with a permanent magnetic layer,
• forming an inwardly tapered depression in the patterned underlayers down to the surface of the buffer layer by a method selected from the steps as follows:
• c) ion milling through a mask and
• d) forming a lift off stencil where the depression is to be located prior to forming the patterned underlayers and lifting off the stencil after forming the patterned underlayers,
• e) forming a stack of layers formed covering the patterned underlayers and reaching down to cover the inwardly tapered depression including:
• forming a free layer,
• forming a pinned layer,
• forming a spacer layer, and
• forming a second antiferromagnetic layer, and
• forming conductors either on a surface of the second antiferromagnetic layer aside from said depression or between the buffer layer and the patterned underlayers.