Abstract: The direction of magnetization of a reading ferromagnetic material 5R forming a spin filter when reading is the same as that of a pinned layer 1. In this case, a torque that works on the spin of a free layer 3 due to a spin polarized current becomes “zero.” When the element size is made small so as to improve the integration degree of the magnetic memory, according to the scaling law, the writing current can be made small. In the present invention, the resistance to the spin injection magnetization reversal due to a reading current is high, so that the magnitude of the writing current can be lowered.

Abstract: An optical waveguide is formed on a substrate 11 by the steps of (1) forming an lower clad layer 12, core layer 13, metal mask layer 14 and a photoresist layer 15, (2) patterning the photoresist layer 15 by using a photomask 16, (3) etching and patterning the metal mask layer 14 wider than a core of required width using the patterned photoresist layer 15, (4) removing the photoresist layer and the metal mask layer 14 after patterning the core layer 13 by using the patterned metal mask layer 14 to form core 13a, (5) forming an upper clad layer 17 on the lower clad layer 12 so as to bury the patterned core 13a.