Haynes and Boone, LLP
Magnetic layer for magnetic random access memory (MRAM) by moment enhancement
A perpendicularly magnetized magnetic tunnel junction (p-MTJ) is disclosed wherein a boron containing free layer (FL) is subjected to a plasma treatment with inert gas, and a natural oxidation (NOX) process to form B2O3 before overlying layers are deposited. A metal layer such as Mg is deposited on the FL as a first step in forming a Hk enhancing layer that increases FL perpendicular magnetic anisotropy, or as a first step in forming a tunnel barrier layer on the FL. One or more anneal steps are essential in assisting B2O3 segregation from the free layer and thereby increasing the FL magnetic moment. A post-oxidation plasma treatment may also be used to partially remove B2O3 proximate to the FL top surface before the metal layer is deposited. Both plasma treatments use low power (<50. Watts) to remove a maximum of 2. Angstroms FL thickness.
TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.
H H G H H H H H
H01F H01L G11C H01L H01F H01L H01L H01L
inventional inventional inventional inventional inventional inventional inventional inventional
Ru-Ying Jian Jodi Mari Yuan-Jen Guenole Huanlong
Tong Zhu Iwata Lee Jan Liu