Magnetic sensor having vertical hall device and method for manufacturing the same

A vertical Hall device comprising:

• a substrate;
• a semiconductor region having a first conductive type and disposed in the substrate;
• and
• a magnetic field detection portion disposed in the semiconductor region, wherein:
• the magnetic field detection portion is capable of detecting a magnetic field parallel to a surface of the substrate in a case where a current flows through the magnetic field detection portion in a vertical direction of the substrate;
• the semiconductor region is a diffusion layer including a conductive impurity doped and diffused therein;
• the semiconductor region has an impurity concentration changing in the vertical direction of the substrate;
• the semiconductor region has a maximum impurity concentration at a predetermined portion of the substrate, which has a predetermined depth from the surface of the substrate;
• and
• the impurity concentration of the semiconductor region is decreased toward a bottom and the surface of the substrate.

A vertical Hall device comprising:

• a substrate;
• a semiconductor region having a first conductive type and disposed in the substrate;
• a magnetic field detection portion disposed in the semiconductor region;
• and
• a diffusion stopper layer disposed under a bottom of the semiconductor region, wherein:
• the magnetic field detection portion is capable of detecting a magnetic field parallel to a surface of the substrate in a case where a current flows through the magnetic field detection portion in a vertical direction of the substrate;
• the semiconductor region is a diffusion layer including a conductive impurity doped and diffused therein;
• the semiconductor region has an impurity concentration changing in the vertical direction of the substrate;
• the semiconductor region has a maximum impurity concentration at a portion adjacent to the diffusion stopper layer;
• and
• the impurity concentration of the semiconductor region is decreased toward the surface of the substrate.

A vertical Hall device comprising:

• a substrate;
• a semiconductor region having a first conductive type and disposed in the substrate;
• a magnetic field detection portion disposed in the semiconductor region;
• and
• a separation wall having a second conductive type and disposed in the semiconductor region for separating the magnetic field detection portion electrically, wherein:
• the magnetic field detection portion is capable of detecting a magnetic field parallel to a surface of the substrate in a case where a current flows through the magnetic field detection portion in a vertical direction of the substrate;
• the semiconductor region is a diffusion layer including a conductive impurity doped and diffused therein;
• the separation wall provides a current path in such a manner that the separation wall selectively narrows near a bottom of the semiconductor region;
• an impurity concentration of a portion of the semiconductor region that contacts the substrate is lower than an impurity concentration of a surface portion of the semiconductor region;
• and
• an impurity concentration of a bottom portion of the semiconductor region under the separation wall is lower than the surface portion of the semiconductor region.

A vertical Hall device comprising:

• a substrate;
• a semiconductor region having a first conductive type and disposed in the substrate;
• a magnetic field detection portion disposed in the semiconductor region;
• and
• a separation wall having a second conductive type and disposed in the semiconductor region for separating the magnetic field detection portion electrically, wherein:
• the magnetic field detection portion is capable of detecting a magnetic field parallel to a surface of the substrate in a case where a current flows through the magnetic field detection portion in a vertical direction of the substrate;
• the semiconductor region is a diffusion layer including a conductive impurity doped and diffused therein;
• the separation wall is shallower than the semiconductor region;
• the separation wall has an impurity concentration changing in the vertical direction of the substrate;
• the separation wall has a maximum impurity concentration at a surface portion of the substrate;
• and
• the impurity concentration of the separation wall is decreasing toward a bottom of the substrate.

A vertical Hall device comprising:

• a substrate;
• a semiconductor region having a first conductive type and disposed in the substrate;
• a magnetic field detection portion disposed in the semiconductor region;
• and
• a separation wall having a second conductive type and disposed in the semiconductor region for separating the magnetic field detection portion electrically, wherein:
• the magnetic field detection portion is capable of detecting a magnetic field parallel to a surface of the substrate in a case where a current flows through the magnetic field detection portion in a vertical direction of the substrate;
• the semiconductor region is a diffusion layer including a conductive impurity doped and diffused therein;
• the separation wall is shallower than the semiconductor region;
• the separation wall is disposed from the surface of the semiconductor region to a predetermined depth of the semiconductor region so that a current path is formed between a bottom of the separation wall and a bottom of the semiconductor region;
• an impurity concentration of a portion of the semiconductor region that contacts the substrate is lower than an impurity concentration of a surface portion of the semiconductor region;
• and
• an impurity concentration of a bottom portion of the semiconductor region under the separation wall is lower than the surface portion of the semiconductor region.

A vertical Hall device comprising:

• a substrate;
• a semiconductor region having a first conductive type and disposed in the substrate;
• a magnetic field detection portion disposed in the semiconductor region;
• a first, a second and a third current supply terminals disposed on a surface of the semiconductor region;
• and
• a first and a second voltage output terminals disposed on the surface of the semiconductor region, wherein:
• the magnetic field detection portion is capable of detecting a magnetic field parallel to a surface of the substrate in a case where a current flows through the magnetic field detection portion in a vertical direction of the substrate;
• the semiconductor region is a diffusion layer including a conductive impurity doped and diffused therein;
• the first and the second current supply terminals flow the current through the magnetic field detection portion in the vertical direction of the substrate;
• the first and the third current supply terminals flow the current through the magnetic field detection portion in the vertical direction of the substrate;
• the first and the second voltage output terminals output a Hall voltage signal corresponding to the magnetic field parallel to the surface of the substrate;
• the first current supply terminal is disposed between the first and the second voltage output terminals;
• the second and the third current supply terminals are disposed symmetrically on either side of a line between the voltage output terminals;
• and
• the first, the second and the third current supply terminals are disposed on a line, which is perpendicular to a line between the voltage output terminals.

A vertical Hall device comprising:

• a substrate;
• a semiconductor region having a first conductive type and disposed in the substrate;
• and
• a magnetic field detection portion disposed in the semiconductor region, wherein:
• the magnetic field detection portion is capable of detecting a magnetic field parallel to a surface of the substrate in a case where a current flows through the magnetic field detection portion in a vertical direction of the substrate;
• the semiconductor region is a diffusion layer including a conductive impurity doped and diffused therein;
• and
• the surface of the substrate is parallel to a predetermined surface orientation of crystal, which shows a resistance change in accordance with a stress application caused by a Piezo resistance effect, the resistance change of the predetermined surface orientation is smallest among those of other surface orientations.