| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To obtain a high TMR ratio while securing low coercive force and RA value. <P>SOLUTION: On a tunnel barrier layer 17 comprised of MgOx, a free layer 18 comprised of CoB<SB>X</SB>with low magnetostriction (λ=-5×10<SP>-6</SP>-0) is formed. The free layer 18 may be formed as a bilayer structure of FeCo<SB>Y</SB>/CoB<SB>X</SB>(Y is 0 to 100 atomic%) or as a trilayer structure of FeCo<SB>Y</SB>/Co<SB>U</SB>Fe<SB>W</SB>B<SB>Z</SB>/CoB<SB>X</SB>, FeCo<SB>Y</SB>/CoB<SB>X</SB>/Co<SB>U</SB>Fe<SB>W</SB>B<SB>Z</SB>, FeCo<SB>Y</SB>/CoFe<SB>W</SB>/CoB<SB>X</SB>, or FeCo<SB>Y</SB>/FeB<SB>V</SB>/CoB<SB>X</SB>. In this case, CoB<SB>X</SB>may be replaced with CoNiFeB or CoNiFeBM, where M is one of V, Ti, Zr, Nb, Hf, Ta and Mo. While securing the low coercive force and RA value, the TMR ratio is improved by 15 to 30% compared to the conventional free layer of CoFe/NiFe structure. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
