[NanoIC topic] Novel materials for magnetic tunnelling junctions towards high-performance MRAM devices

Background and Motivation:

The rapid growth of artificial intelligence (AI), edge computing, and data-intensive applications has created a strong demand for fast, energy-efficient, and scalable memory technologies. Conventional memory solutions such as SRAM, DRAM, and Flash increasingly face limitations related to power consumption, scalability, and performance. Magnetic Random Access Memory (MRAM) has emerged as a promising next-generation non-volatile memory technology due to its low latency, high endurance, non-volatility, and compatibility with CMOS processes. Despite these advantages, MRAM technologies, regardless of the employed switching mechanisms such as spin-transfer torque (STT), spin-orbit torque (SOT), or voltage-control of magnetic anisotropy (VCMA), continue to face challenges including high switching energy and reliability issues. These limitations are strongly linked to material quality, interface properties, and scattering mechanisms within Magnetic Tunnelling Junctions (MTJs), which form the fundamental building blocks of MRAM devices. This master’s thesis proposes a materials-driven approach to address these challenges by focusing on the development of novel materials for MTJs, such as FePd, FePt, RuAl. By exploring new material systems and improving crystalline quality, highly crystalline MTJs can reduce scattering during read and write operations and enhance the tunnelling magnetoresistance (TMR) ratio. Developing high-performance MTJs that are compatible with standard MRAM fabrication processes is expected to accelerate MRAM commercialization and support the evolving needs of the semiconductor industry.

Objectives of the Thesis:

The main objective of this thesis is to investigate and optimize MTJ thin films for MRAM applications through an in-depth materials and process study. The specific objectives are:

• To develop a thorough understanding of magnetron sputtering processes used for magnetic thin-film deposition.
• To study and optimize the growth of thin film with improved crystallinity and interface quality.
• To establish correlations between structural and compositional properties and magnetic performance metrics such as anisotropy, coercivity, and TMR.
• To contribute material and process insights relevant for scaling MTJ fabrication toward 300 mm industrial deposition tools.

Experimental Methodology:

The experimental work will be carried out in imec, providing access to state-of-the-art industrial research facilities. Exploratory thin film for MTJ stacks will be deposited using advanced magnetron sputtering systems dedicated to materials research. Emphasis will be placed on controlling deposition parameters and understanding their influence on growth and interface formation.

Structural and compositional characterization of the deposited thin films will be performed using imec’s extensive suite of analytical techniques such as XRD, AFM, enabling detailed analysis of crystallography, composition, and interfaces. Magnetic characterization will be conducted using advanced measurement techniques like VSM, FMR and CIPT to evaluate key magnetic properties. The magnetic results will be systematically correlated with the structural and interfacial characteristics of the exploratory MTJs.

Expected Outcomes and Impact:

This thesis is expected to provide a deeper understanding of the relationship between sputtering conditions, crystalline quality, and magnetic performance in magnetic thin film in MTJs. The results will help identify material and interface engineering strategies to enhance TMR and reduce switching energy. The findings will support imec’s ongoing MRAM research efforts and contribute to the development of scalable, reliable, and high-performance MRAM technologies compatible with industrial manufacturing.

Skills and Knowledge Development:

During this master’s thesis, the student will develop:

• In-depth knowledge of magnetron sputtering processes and magnetic materials.
• Expertise in crystallographic, compositional, and interface analysis of sputtered thin films.
• A detailed understanding of magnetic characterization techniques and their correlation with structural properties.