Magnetic field sensing element and device having magnetoresistance element and integrated circuit formed on the same substrate

A magnetic field sensing element comprising:

• an integrated circuit;
• an underlayer, and a metal pad formed on a substrate in the order stated;
• a second level difference buffer layer formed on the underlayer and the metal pad to absorb the level difference between the surface of the underlayer and the surface of the metal pad;
• and
• a giant magnetoresistance element formed on the second level difference buffer layer, wherein the giant magnetoresistance element is formed by repeatedly laminating a Fe (x) Co (1−x) layer (0≦x≦0.3) and a Cu layer, film thickness of the Cu layers per layer being set to such a film thickness that causes a change rate of magnetoresistance in a layer of the Cu layers to be around a second peak, and protective films on the giant magnetoresistance element are formed by spin coating or by means of low-thermal plasma CVD method.

A magnetic field sensing element comprising:

• an integrated circuit formed on a substrate and having a capacitor portion;
• an underlayer formed on the integrated circuit;
• a second metal layer formed on the underlayer;
• and
• a giant magnetoresistance element formed on the capacitor portion of the integrated circuit, wherein the giant magnetoresistance element is formed by repeatedly laminating a Fe (x) Co (1−x) layer (0≦x≦0.3) and a Cu layer, film thickness of the Cu layers per layer being set to such a film thickness that causes a change rate of magnetoresistance in a layer of the Cu layers to be around a second peak, and protective films on the giant magnetoresistance element are formed by spin coating or by means of low-thermal plasma CVD method.