Voltage-Control Spintronics Memory (VoCSM) with Low Write Current using Highly-Selective Patterning Process

A voltage-control spintronics memory (VoCSM) which has a potential of low energy consumption uses the spin Hall effect (SHE) and the voltage-controlled magnetic anisotropy (VCMA) effect for its write operation. In this work, the relationship between the critical switching current (Ic(sw)) and the SHE electrode thickness (IN) is investigated in the range of 5 nm < t(N) < 8 nm. In the fabrication process, we develop highly-selective patterning process to stop MTJ etching precisely on the surface of the SHE electrode. Using the technique, Ic(sw), is reduced by half as t(N) is varied from 8 nm to 5 nm, and Ic(sw), of 112 mA at 20 ns write current pulse is obtained for MTJ size of 50 x 150 nm(2) on Ta(2 nm)/TaB (3 nm) electrode. The results indicate that the decrease in the SHE electrode thickness is a promised method to reduce Ic(sw) which leads VoCSM to a low-energy-consumption device.