Dual Free Layer Reader with Rear Soft Bias Design with Improved Soft Bias Stability

A read head, comprising:

• a first shield comprising:
• an anti-ferromagnetic (AFM) layer;
• a first shield layer disposed on the AFM layer;
• an anti-ferromagnetically coupled (AFC) layer disposed on the first shield layer;
• and
• a magnetic seed layer disposed on the AFC layer;
• a dual free layer (DFL) sensor disposed on the first shield at a media facing surface (MFS);
• soft bias (SB) side shields disposed adjacent to the DFL sensor, each of the SB side shields comprising:
• a first SB layer disposed in contact with the magnetic seed layer;
• a non-magnetic layer disposed in contact with the first SB layer;
• and
• a second SB layer disposed in contact with the non-magnetic layer;
• a second shield disposed over the DFL sensor and SB side shields;
• and
• a rear soft bias (RSB) structure disposed adjacent to the DFL sensor and SB side shields, the RSB structure being recessed from the MFS.

A read head, comprising:

• a first shield comprising:
• an anti-ferromagnetic (AFM) layer;
• and
• a magnetic seed layer disposed over the AFM layer;
• a dual free layer (DFL) sensor disposed on the first shield at a media facing surface (MFS);
• soft bias (SB) side shields disposed adjacent to the DFL sensor, each of the SB side shields comprising:
• a first SB layer disposed in contact with the magnetic seed layer;
• a non-magnetic spacer disposed on the first SB layer;
• and
• a second SB layer disposed on the non-magnetic spacer;
• a second shield disposed over the DFL sensor and SB side shields, the second shield comprising:
• a first shield layer;
• an anti-ferromagnetically coupled (AFC) layer disposed on the first shield layer;
• and
• a second shield layer disposed on the AFC layer;
• and
• a rear soft bias (RSB) structure disposed adjacent to the DFL sensor and SB side shields, the RSB structure being recessed from the MFS.