Low magnetic damping in an ultrathin CoFeB layer deposited on a 300 mm diameter wafer at cryogenic temperature

We deposited an ultrathin CoFeB(1.1 nm) layer, which functions as a storage layer of MgO-based magnetic tunnel junctions for spin-transfer-torque (STT) magnetoresistive random-access memory (MRAM), on phi 300 mm wafers at 100 K and investigated its effect on the magnetization dynamics of CoFeB. We observed clear reductions in both the inhomogeneous linewidth and total magnetic damping parameter for the CoFeB layer deposited at 100 K compared to those deposited at 300 K through the improvement in the interfacial quality. The results show that deposition at cryogenic temperatures is an effective manufacturing process for high-quality magnetic thin films with low magnetic damping.

Automated summary

We deposited a 1.1 nm ultrathin CoFeB layer as the storage layer for MgO-based magnetic tunnel junctions in spin-transfer-torque (STT) magnetoresistive random-access memory (MRAM) on phi 300 mm wafers at 100 K, and investigated its effect on the magnetization dynamics of CoFeB. The results show that deposition at cryogenic temperatures is an effective manufacturing process for high-quality magnetic thin films with low magnetic damping, achieved through the improvement in the interfacial quality.