Description:
Background
Topological Insulators (TI) have been reported to provide high efficiency of spin-orbit torque to adjacent magnetic layers to cause switching in magnetic states. This is highly applicable for exciting magnetization oscillations and switching in the magnetic layer in nonvolatile memory devices such as Magnetic Random Access Memory (MRAM). Traditionally Molecular Beam Epitaxy (MBE) and Pulsed Laser Deposition (PLD) techniques have been used to grow TI thin films. These processes require temperatures that are higher than Complementary metal-oxide-semiconductor (CMOS) compatible limits. Moreover, the growth rate using these processes is very slow making them impossible to integrate into industrial CMOS device fabrication processes. 
 
Technology Overview
 A sputter growth method for TI material BixTe(1-x) (x>0 and x<1) has been developed in this work which is possible to grow at a CMOS compatible temperature with a fast deposition rate of ~0.2 nm/s. This makes it an attractive process for integration in the conventional CMOS fabrication process for Spin-Orbit Torque (SOT) devices. By controlling the process temperature, the degree of crystallinity of the TI film was controlled. With an increase in the crystallinity of the TI layer, significant enhancement in spin-orbit coupling (SOC) is achieved in these materials coupled with the FM layer as observed in ferromagnetic resonance (FMR) spectroscopy and hysteresis loop measurements.
 
Benefits
- Enhanced efficiency of spin to charge current conversions 
- Higher efficiency of SOT in 3D TI/FM heterostructures 
- Enhanced Rashba effect due to high SOC (Spin-orbit coupling) in the materials 
 
Applications
- Spintronics applications and solid state devices
- Highly efficient SOT memory which is non volatile 
- High density PMA with thicker magnetic layer which can be implemented to MRAM devices 
- High frequency spin torque nano oscillators (STNO) 
 
Opportunity
- License
- Partnering
- Research collaboration
Patent Information:
For Information, Contact:
Colin Sullivan
Commercialization Consultant
Northeastern University
col.sullivan@northeastern.edu
Inventors:
Nian-Xiang Sun
Nirjhar Bhattacharjee
Keywords:
Ferromagnet
Magnetics
Spintronics
Thin film
Topological Insulator