Magnetic sensor, hall element, hall IC, magnetoresistive effect element, method of fabricating hall element, and method of fabricating magnetoresistive effect element

A Hall IC comprising:

• (a) a substrate;
• (b) a Hall element including;
• (b-1) a GaN layer which is formed on said substrate, an electron concentration of said GaN layer being not more than 1×1012/cm3, a specific resistance of said GaN layer being not lower than 1×106 Ωcm,
• (b-2) an AlGaN layer formed on said GaN layer by AlxGa1-xN(0<x≦0.3),
• (b-3) two input electrodes, and
• (b-4) two output electrodes;
• and
• (c) a control circuit which is formed on said substrate while including HEMT,
• wherein said GaN layer and said AlGaN layer constitute an operating layer having a heterojunction structure,
• said two input electrodes are comprised on each of first end portions of said operating layer, said each of first end portions being opposite to each other when said operating layer is viewed from above, and
• said two output electrodes are comprised on each of second end portions of said operating layer, said each of second end portions being opposite to each other in a direction substantially orthogonal to a direction connecting said each of first end portions.

A magnetoresistive effect element comprising:

• a GaN layer whose electron concentration is not more than 1×1016/cm3;
• an AlGaN layer which is formed by AlxGa1-xN(0<x≦0.3);
• two terminal electrodes;
• and
• a plurality of short-circuit electrodes,
• wherein said GaN layer and said AlGaN layer constitute an operating layer having a heterojunction structure,
• said two terminal electrodes are comprised on each of end portions being opposite to each other on a surface of said operating layer, and
• said plurality of short-circuit electrodes are comprised between said two terminal electrodes.

A method of fabricating a Hall element, comprising steps of:

• (a) forming an operating layer having a heterojunction structure between a GaN layer and an AlGaN layer, including steps of;
• (a-1) epitaxially forming said GaN layer whose electron concentration is not more than 1×1012/cm3 on a predetermined substrate, and
• (a-2) epitaxially forming said AlGaN layer made of AlxGa1-xN(0<x≦0.3) on said GaN layer;
• and
• (b) forming input electrodes on each of first end portions of said operating layer and of forming output electrodes on each of second end portions, said first end portions being opposite to each other when said operating layer is viewed from above, said second end portions being opposite to each other in a direction substantially orthogonal to a direction connecting said each of first end portions.

A method of fabricating a magnetoresistive effect element comprising steps of:

• (a) forming an operating layer having a heterojunction structure between a GaN layer and an AlGaN layer, including steps of;
• (a-1) epitaxially forming said GaN layer whose electron concentration is not more than 1×1016/cm3 on a predetermined substrate, and
• (a-2) epitaxially forming said AlGaN layer made of AlxGa1-xN(0<x≦0.3) on said GaN layer;
• and
• (b) forming terminal electrodes on each of end portions on a surface of said operating layer, said end portions being opposite to each other, and of forming a plurality of short-circuit electrodes between said terminal electrodes.