Magnetoresistive effect element and memory device using the same

Abstract

One block SB serving as a fundamental unit constituting a data reading circuit is constituted by four memory cells MSto MSconnected electrically in series, four FETs Sto Sconnected in parallel with the memory cells MSto MSin one-to-one correspondence, and an FET Sconnected to one of series connection ends of the memory cells MSto MS. Each memory cell MS-MSis formed out of a TMR element having two TMR element portions connected electrically in series. The two TMR element portions are connected in series to thereby form a series connection body. A sensing current flows in only through one end of the series connection body of the two TMR element portions, passes through the TMR element portions in turn, and then flows out only through the other end of the series connection body. Further, the TMR elementhas two TMR element portionsA andB. The TMR element portionsA andB are disposed in a direction parallel with their laminated surfaces with respect to each other. The TMR element portionsA andB are electrically connected in series to thereby form a series connection body. A sensing current for detecting a change in magnetoresistance flows in only through one end of the series connection body of the two TMR element portionsA andB, passes through the TMR element portionsA andB in turn, and then flows out only through the other end of the series connection body. The sensing current flows through an effective area effective in changing the magnetoresistance in each TMR element portionA,B, and in a direction substantially perpendicular to the laminated surface.