Method of making a magnetoresistive device having improved Barkhausen noise suppression

A method for forming a magnetoresistive device comprising the steps of:

• forming a magnetoresistive mesa from a magnetoresistive structure, said magnetoresistive mesa having two physically spaced sidewall portions;
• overlying said two sidewall portions of said magnetoresistive mesa with a first and a second separation layer, respectively;
• and
• producing a permanent magnet layer adjoining said first and second separation layers to provide longitudinal bias to said magnetoresistive mesa.

A method for forming a magnetoresistive device comprising the steps of:

• providing a magnetoresistive structure;
• forming a magnetoresistive conductive region from said magnetoresistive structure by removing said magnetoresistive structure surrounding said magnetoresistive region to provide a maqnetoresistive region having first and second exposed surfaces;
• overlying a first and a second separation layer on said first and second exposed surfaces respectively of said magnetoresistive conductive region;
• producing a first and a second permanent magnet layer adjoining said first and second separation layers, respectively;
• and
• removing portions of said first and second separation layers and said first and second permanent magnet layers whereby remaining portions of said first and second permanent magnet layers provide longitudinal bias to said magnetoresistive conductive region.

A method for forming a magnetoresistive device comprising the steps of:

• producing a magnetoresistive structure on a device substrate;
• forming a magnetoresistive conductive region within said magnetoresistive structure by removing said magnetoresistive structure surrounding said magnetoresistive conductive region leaving exposed and opposing end portions thereof;
• overlying said substrate and said magnetoresistive conductive region with a separation layer;
• forming a permanent magnet region contiguous with said separation layer;
• and
• removing said separation layer and said permanent magnet region from said magnetoresistive conductive region except at said exposed opposing end portions thereof
• whereby portions of said permanent magnet region adjoining said exposed opposing end portions of said magnetoresistive conductive region provide a longitudinal bias thereto.