Magnetoresistive sensor with stop-layers

A method comprising:

• forming a first stop layer on a shield element;
• removing material of the first stop layer to form a depression in the shield element;
• and
• depositing an alumina insert within the depression;
• and
• forming a reader stack above the alumina insert such that a width of the reader stack is at least partially co-extensive with a corresponding width of the alumina insert.

A method comprising:

• depositing an alumina insert within a depression formed in a shield element of a reader;
• depositing a stop layer on the alumina insert;
• side milling to remove the stop layer and an upper portion of the alumina insert, and
• forming a reader stack above a remaining lower portion of the alumina insert such that a width of the reader stack is at least partially co-extensive with a corresponding width of the remaining lower portion of the alumina insert.