Patent ID: 9337414
Filing Date: 2016-05-10
CPC Classification: G01R,G11B,H01L

Claim Text:
1. A TMR read sensor comprising: a horizontal lower shield; a horizontal upper shield; a horizontally layered TMR sensor stack formed between said lower shield and said upper shield, wherein said TMR sensor stack has a patterned portion containing an upper layer that is a free layer having a trackwidth defined by said pattern; and symmetrically opposed, horizontal junction shields abutting said patterned portion and extending upward no further than an upper surface of said free layer with which they form a coplanar surface; and wherein said TMR sensor stack comprises: said patterned portion is defined by symmetrically opposed lateral sides, wherein said sides laterally bound said ferromagnetic free layer and laterally bound said tunneling barrier layer and wherein a maximum width of said free layer defines a trackwidth; wherein said sides laterally bounding said ferromagnetic free layer and said sides laterally bounding said tunneling barrier layer are coplanar and make an angle θ wherein portions of said pinned layer laterally disposed to either side of said patterned portion are uniformly reduced in thickness to produce an upper surface that is horizontal, smooth and planar by the removal of all portions of said pinned layer above said penetration amount; wherein said pinned layer and said pinning layer extend laterally and symmetrically, with a constant thickness, beyond said lateral coplanar sides of said patterned portion; and wherein said extended pinned and pinning layers provide a magnetic stability to said narrowly patterned free layer; wherein a layer of isolating oxide conformally covers said horizontal, smooth and planar upper surface of said pinned layer and said coplanar lateral sides of said patterned portion, forming a junction thereat; and wherein said symmetrically disposed pair of junction shields are conformally and contiguously positioned between said upper shield and said layer of isolating oxide and abut said junction forming a coplanar surface with said upper surface of said free layer.