The emergence of connected electronic devices in the Internet of Things (IoT) era has fueled the need for real-time decision making at the data source, or “edge intelligence”. Coupled with the scaling limitations of conventional CMOS technology, there is a growing need to develop computing elements with energy-efficient, GHz switching as a scalable solution for next-generation infocomm technology. Spin technologies have previously harnessed the electron spin for pathbreaking applications in electronics – used in today’s hard disks and tomorrow’s magnetic random access memory (MRAM). Next-generation spin technologies are further expected to create devices with lower switching power, faster dynamics and higher endurance.
One such avenue is spin transfer torque (STT) – wherein an electrical current can be used to control the magnetization of a memory cell [A*STAR STT BIP]. Indeed, several companies are already developing commercial STT-MRAM solutions on the gigabit scale. Another particularly attractive avenue is spin-orbit coupling (SOC) – the entwining of electron spin and momentum. SOC has recently found to be greatly enhanced at heavy metal (HM) – ferromagnet (FM) interfaces in magnetic thin films within materials used in commercial MRAM stacks [Nature ‘16]. On one hand, interfacial SOC provides a fast, energy-efficient means of magnetization switching – known as spin-orbit torque [A*STAR SOT BIP]. On the other hand, it creates new topological phases, such as topological materials, magnetic skyrmions etc., that are unusually robust in ambient conditions [A*STAR Sk BIP].
At IMRE, we aim to utilize our expertise and capabilities in magnetic thin films and devices to develop emerging and next-generation solutions for a range of nanoelectronic applications.
Emergent spin-orbit phenomena at interfaces of magnetic thin films, which promise a range of nanoelectronic applications. Adapted from A. Soumyanarayanan et al., Nature 2016.
IMRE’s efforts in magnetic thin films build on our well-established capabilities in the areas of 1) Materials and Device Development, 2) Microscopy and Modelling, 3) Electrical Transport Measurements, and 4) 200 mm wafer-level scaling. The fabrication and translational components utilize a well-established 200 mm semiconductor fabrication platform which has been successfully used for multiple industry collaborations.
For 200 mm stack fabrication, we have the Singulus Timaris cluster sputtering system with pre-cleaning, annealing, wedge deposition and multi-target (over 20) process modules at 2 Å thickness uniformity. Cassette-level fabrication is processed using a copper protocol line including spin coating with the SVG 90S track; lithography with (a) DUV stepper (Canon EX5, 248 nm) and (b) DUV mask aligner (EVG …, 1.25 um); etching by (a) dielectric (SPTS Etch), (b) inductively coupled plasma (Oxford PlasmaPro 100 ICP), (c) ion-beam (Oxford Ionfab 300Plus), passivation using OIPT Plasmalab 380, electrode deposition using Singular Rotaris or AMAT Endura PVD system etc.
Our electrical measurements build on custom-made device testing platforms and probe stations with pulsing capabilities <1 ns and noise levels down to ~1nV. Wafer-level capabilities include an ISI Wafer auto-prober capable of conducting device testing modules including TMR, switching voltage, breakdown voltage, endurance, bit error rates etc. We also have custom-made high-frequency spectroscopy setups that can be used for broadband ferromagnetic resonance (FMR) or spin-torque ferromagnetic resonance (ST-FMR) over a large range of frequencies (up to 67 GHz), magnetic fields (up to 2 T vectorial), and temperatures (4 – 325 K).
Further Details are provided here.
Highlights & Achievements
Spin-Transfer Torque Switching
Spin-Orbit Torque Switching
Dr. Anjan Soumyanrayanan, firstname.lastname@example.org
Dr. Lim Sze Ter, Lim_Sze_Ter@imre.a-star.edu.sg
We welcome queries and collaboration partners for both the research and commercialization of spin related materials, technologies and devices.