MRAM Shift-Adjustment Layer Grain Control

The patent applies local quality by creating distinct regions within the shift-adjustment layer with different grain sizes. Specifically, it forms a first region with finer grains and a second region with coarser grains, allowing each region to contribute differently to the overall function. The finer-grained region provides better magnetic anisotropy uniformity while the coarser-grained region can accommodate larger thickness without excessive grain growth, thus resolving the contradiction between thickness for shielding and grain size uniformity.

The patent employs composite materials by combining multiple materials in the shift-adjustment layer, specifically using a CoFeB-based alloy with controlled composition gradients. By varying the atomic percentages of Co, Fe, and B across different regions, the patent creates a composite structure that optimizes both magnetic shielding and grain size control. This compositional grading allows the layer to achieve thick design for shielding while maintaining uniform perpendicular magnetic anisotropy through localized compositional optimization.

The patent applies local quality by creating distinct regions within the shift-adjustment layer with different grain sizes. Specifically, it forms a first region with finer grains and a second region with coarser grains, allowing each region to contribute differently to the overall function. The finer-grained region provides better magnetic anisotropy uniformity while the coarser-grained region can accommodate larger thickness without excessive grain growth, thus resolving the contradiction between thickness for shielding and grain size uniformity.

The patent employs parameter changes by systematically varying the composition parameters (atomic percentages of Co, Fe, and B) across different regions of the shift-adjustment layer. By changing these compositional parameters, the patent controls grain growth behavior and surface morphology. The compositional gradient allows the layer to achieve the desired thickness for magnetic shielding while maintaining surface flatness through localized compositional optimization that suppresses excessive grain growth.