MICROSTRUCTURAL CONTROL OF THE INTERFACE FOR SPIN-VALVE GMR THIN-FILMS BY APPLYING THE ULTRA CLEAN SPUTTERING PROCESS

extremely clean sputtering process (XC process) was newly introduced in The构造过程ultra-thin spin valves to control the microstructure and to establish the excellent magneticproperties. The relation between cleanness during film deposition process and The magneticproperties of spin valve elements has been discussed in connection with their microstructure。Sub./Ta/Ni-Fe/Mn-Ni/Ni-Fe and Sub./Ta/Ni-Fe/Mn-Ir/Ta quadrilayers fabricated under thedifferent purity of the sputtering atmospheres. Strength of the exchange anisotropy measured at roomtemperature was增强in very thin F/AF bilayer fabricated under the XC-process，comparing with the bilayer fabricated under a lower graded (log -) process，which only differed in the base pressure of the sputtering chamber：D1-7 D1 Torr order. From a structural analysis and a temperature dependence of the exchangeanisotropy of the bilayers，grains in the bilayers fabricated under the XC-process were found to be enlarged a…the enhancement of exchange anisotropy was caused by the enlargement ofantiferromagnetic grains,which suppress thermal agitation and lowering the local blocking temperature For the electrontransport,the enlargement of the grains observed in the dc -processed films also played an important role. thedecrease of grain boundaries and impurities in the filmsreduced saturated resistivity of the spin valves, Sub. Ta/Ni-Fe/Co/Cu/Co/Mn-Ir/Ta，with lowering the impurity level in the sputtering atmosphere and resulted in the increase of the MRratios. The MR ratio of tan optimized spin valve fabricated under The XC-process achieved to 9.7%even in the total thickness of 148【encircledA】except for the capping Ta layerwhile that of the LG-processed spin valve dropped to 0.9% due to the vanish of the exchange我们包括extremely clean sputtering process is greatly effective to realizeultra-thin spin valves and that to avoid rumpling interfaces of他们it important to induce theadequate magnetic properties. Less

The extremely clean sputtering process (XC process) was newly introduced in the fabrication of ultra-thin spin valves to control the microstructure and to establish the excellent magnetic properties. The relation between cleanness during film deposition process and the magnetic properties of spin valve elements has been discussed in connection with their microstructure. Sub./Ta/Ni-Fe/Mn-Ni/Ni-Fe and Sub./Ta/Ni-Fe/Mn-Ir/Ta quadrilayers were fabricated under the different purity of the sputtering atmospheres. Strength of the exchange anisotropy measured at room temperature was enhanced in very thin F/AF bilayer fabricated under the XC-process, comparing with the bilayer fabricated under a lower graded (LG-) process, which only differed in the base pressure of the sputtering chamber : 10ィイD1-7ィエD1 Torr order. From a structural analysis and a temperature dependence of the exchange anisotropy of the bilayers, grains in the bilayers fabricated under the XC-process were found to be enlarged a … More nd that the enhancement of exchange anisotropy was caused by the enlargement of antiferromagnetic grains, which suppress thermal agitation and lowering the local blocking temperature. For the electron transport, the enlargement of the grains observed in the XC-processed films also played an important role. The decrease of grain boundaries and impurities in the films, reduced saturated resistivity of the spin valves, Sub. Ta/Ni-Fe/Co/Cu/Co/Mn-Ir/Ta, with lowering the impurity level in the sputtering atmosphere and resulted in the increase of the MR ratios. The MR ratio of tan optimized spin valve fabricated under the XC-process achieved to 9.7%, even in the total thickness of 148 【encircledA】 except for the capping Ta layer, while that of the LG-processed spin valve dropped to 0.9% due to the vanish of the exchange anisotropy. We concluded that the extremely clean sputtering process is greatly effective to realize ultra-thin spin valves and that to avoid rumpling interfaces of them it important to induce the adequate magnetic properties. Less