Study of Magnetic Tunnel Junctions embedded with Magnetic nanoparticles

• Main Authors: Chia-hao Lin, 林家豪
• Other Authors: Te-ho Wu
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/26491433729818985580

碩士 === 國立雲林科技大學 === 材料科技研究所 === 100 === This study focused on magnetic tunnel junction (MTJ) embedded with magnetic nanoparticles. Studies using the six-target magnetron sputtering system. sputtering parameters were sputtering power and thickness. To form the Fe magnetic particles embedded into the MgO film, using tandem and co-sputtering processes. And then choose the better one to make the MTJ structure. Resistivity tendency with changing Fe film thickness and annealing temperature was by the van der pauw measurement. The micro structure of the samples was measured by atomic force microscopy (AFM) and transmission electron microscopy (TEM). Finally, alternating gradient magnetometer (AGM) and Current Perpendicular to Plane (CPP) were investigated the magnetic and electrical properties. No matter tandem or co-sputtering process, we get the Fe particles embedded into the MgO thin film. The magnetic properties were independent of the Fe sputtering power. In co-sputtering process, Fe particles distribute in MgO thin film, but it’s very small. In tandem process, when the Fe thickness was decreased below 1 nm, the film type change from the continuous film to the island film. The Fe thin film thickness reduced Fe particles getting smaller and spacing shorter. After annealing treatment, the particle size will change. In R-H measurements the Fe thin film thickness 0.1 nm after annealing 250 ° C found that the easy axis in the horizontal direction, MR = 34%. But it also quite easy to make it flip with applied perpendicular magnetic field, MR = 13%.