Magnetic Memory Pinned Pattern Boron Diffusion Barrier
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Magnetic memory devices face challenges in achieving improved tunnel magnetoresistance (TMR) characteristics and exchange coupling characteristics, particularly at high temperatures, due to deterioration of crystallinity and magnetoresistance when subjected to high-temperature processes.
Innovation Solution
The magnetic memory device incorporates a first pinned pattern with cobalt and platinum, along with a non-magnetic element, and a blocking pattern with tungsten and molybdenum, which prevents boron diffusion and maintains crystallinity, enhancing heat tolerance and TMR characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If high-temperature processes are applied to magnetic memory devices, then manufacturing and processing are facilitated, but TMR characteristics and exchange coupling characteristics deteriorate due to crystallinity degradation
Solution Approach 1:
A blocking pattern comprising tungsten and molybdenum is introduced as an intermediary layer between the first pinned pattern and the polarization enhancement pattern. This blocking pattern serves as a diffusion barrier that prevents boron from diffusing into the pinned pattern during high-temperature processes, thereby maintaining the crystallinity and magnetic properties of the pinned pattern while allowing the high-temperature manufacturing process to proceed
Solution Approach 2:
The blocking pattern is constructed from a composite material system comprising tungsten and molybdenum in a specific ratio (tungsten: 5-40 at%, molybdenum: 60-95 at%). This composite material provides both diffusion barrier properties and thermal stability, enabling the structure to withstand high-temperature processing while preventing degradation of the magnetic tunnel junction characteristics
2Device complexity
If conventional pinned patterns are used, then device structure is simplified, but exchange coupling characteristics and heat tolerance are insufficient
Solution Approach 1:
The first pinned pattern is segmented into multiple sub-layers: a first magnetic pattern, a second magnetic pattern, and a third magnetic pattern, with the blocking pattern positioned between the first and second magnetic patterns. This segmentation allows each layer to perform specific functions - the blocking pattern prevents diffusion, while the magnetic patterns maintain exchange coupling - thereby improving heat tolerance and exchange coupling characteristics without excessive complexity
Solution Approach 2:
Different regions of the pinned pattern structure are assigned different material compositions and properties. The blocking pattern region contains tungsten and molybdenum for diffusion barrier properties, while the magnetic pattern regions contain cobalt, platinum, and non-magnetic elements for magnetic properties. This local differentiation of material quality enables simultaneous achievement of diffusion protection and magnetic functionality
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration improves the TMR and exchange coupling characteristics, ensuring high-temperature reliability and maintaining resistance and coupling performance even at temperatures of 400°C or higher.
Implementation Method 1
an exchange coupling pattern (ECP) extending between the first pinned pattern and the second pinned pattern. This ECP is configured to antiferromagnetically couple the first pinned pattern and the second pinned pattern to each other
Implementation Method 2
a blocking pattern between the reference magnetic pattern and the polarization enhancement pattern... which prevents boron diffusion and maintains crystallinity, enhancing heat tolerance
Data Source
AI summary
A magnetic memory device includes: (i) a reference magnetic pattern and a free magnetic pattern stacked in vertical alignment relative to a surface of a substrate, and (ii) a tunnel barrier pattern extending between the reference magnetic pattern and the free magnetic pattern. The reference magnetic pattern includes: a first pinned pattern, and a second pinned pattern extending between the first pinned pattern and the tunnel barrier pattern, and an exchange coupling pattern, which extends between the first pinned pattern and the second pinned pattern and antiferromagnetically couples the first pinned pattern and the second pinned pattern to each other. The first pinned pattern includes a first magnetic pattern and a second magnetic pattern extending between the first magnetic pattern and the exchange coupling pattern. One of the first magnetic pattern and the second magnetic pattern includes: cobalt, platinum, and a first non-magnetic element comprising at least one of Nb, Cr, Mo, W, Zr, Hf, and Ti, whereas the other one of the first magnetic pattern and the second magnetic pattern includes cobalt.