In this study, we comparatively investigated thermal- and plasma-enhanced atomic layer deposition (Th- and PE-ALD) of MgO on a CoFeB layer. MgCp 2 (Bis(cyclopentadienyl)magnesium) was used as a Mg precursor and H2O and O2 plasma were employed as reactants for the Th- and PE-ALD process, respectively. Th- and PE-ALD MgO formed interlayer between MgO and CoFeB layer due to the oxidation of CoFeB by H2O and O 2 plasma during the Th- and PE-ALD process. While interlayer formation was observed to be less than 1 nm for Th-ALD MgO, the PE-ALD MgO process resulted in an approximately 5 nm thick, predominantly FeOx oxidation of CoFeB. This was due to the high reactivity of the O radicals and the higher driving force of Fe for oxidation when compared with Co. Our results show that the Th-ALD MgO process has a better potential as a deposition technique to form tunnel barrier of magnetic tunneling junctions (MTJs).
Bibliographical noteFunding Information:
This work was supported by the Industrial Strategic technology development program (10041926, Development of high-density plasma technologies for the thin-film deposition of nanoscale semiconductors and flexible-display processing) funded by the Ministry of Knowledge Economy (MKE, Korea).
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry