Semiconductor with unified transistor structure and voltage regulator diode
A semiconductor device includes a semiconductor layer that has a transistor structure including a p type source region, a p type drain region, an n type body region between the p type source region and the p type drain region, and a gate electrode facing the n type body region and a voltage-regulator diode that is disposed at the semiconductor layer and that has an n type portion connected to the p type source region and a p type portion connected to the gate electrode, in which the transistor structure and the voltage-regulator diode are unified into a single-chip configuration.
1. A semiconductor device comprising:
a semiconductor layer that has a transistor structure including a source region of a first conductivity type, a drain region of the first conductivity type, a body region of a second conductivity type between the source region and the drain region, and a gate electrode facing the body region; and
a voltage-regulator diode disposed at the semiconductor layer, the voltage-regulator diode having a first portion of the second conductivity type connected to the source region through a first conductive path made of a first metal member and a second portion of the first conductivity type electrically connected to the gate electrode through a second conductive path made of a second metal member electrically separated from the first conductive path, the voltage-regulator diode having a capability allowing a reverse current to flow only in a first direction,
wherein the transistor structure and the voltage-regulator diode are unified into a single-chip configuration, and
the first metal member and the second metal member are in direct contact with the first portion and the second portion, respectively.
2. The semiconductor device according to claim 1 , wherein the semiconductor layer includes an active region including the transistor structure and an outer peripheral region surrounding the active region, and
the voltage-regulator diode includes an outer peripheral diode disposed along the outer peripheral region.
3. The semiconductor device according to claim 2 , wherein, in the outer peripheral diode, the second portion and the first portion are each formed in an annular shape surrounding the active region, and
a pn junction portion between the second portion and the first portion has an integral structure formed in an annular shape surrounding the active region.
4. The semiconductor device according to claim 3 , wherein the second portion and the first portion each have a width equal to each other.
5. The semiconductor device according to claim 3 , wherein, in the outer peripheral diode, the first portion is disposed at a more inward side than the second portion.
6. The semiconductor device according to claim 1 , wherein the voltage-regulator diode is made of polysilicon stacked on the semiconductor layer.
7. The semiconductor device according to claim 6 , wherein the transistor structure includes a trench gate structure made of polysilicon as the gate electrode embedded in a gate trench which is formed at the semiconductor layer.
8. The semiconductor device according to claim 1 , wherein the voltage-regulator diode is made of an impurity region disposed in the semiconductor layer.
9. The semiconductor device according to claim 1 , wherein a breakdown voltage of the voltage-regulator diode is 8 V or less.
10. The semiconductor device according to claim 1 , the semiconductor device having a length-breadth chip size of 0.6 mm×0.4 mm or less.
11. The semiconductor device according to claim 2 , wherein
the second metal member includes a gate finger surrounding the active region, and
the second portion is in direct contact with the gate finger.
12. The semiconductor device according to claim 1 , wherein
the first conductive path includes a source metal connected to the source region and the body region, and
the second metal member includes a gate finger surrounding the source metal.
13. A semiconductor device comprising:
a semiconductor layer that has a transistor structure including a source region of a first conductivity type, a drain region of the first conductivity type, a body region of a second conductivity type between the source region and the drain region, and a gate electrode facing the body region; and
a voltage-regulator diode disposed at the semiconductor layer, the voltage-regulator diode having a first portion of the second conductivity type connected to the source region through a first conductive path and a second portion of the first conductivity type electrically connected to the gate electrode by a metal member through a second conductive path electrically separated from the first conductive path,
wherein the transistor structure and the voltage-regulator diode are unified into a single-chip configuration,
the first conductive path includes a source metal connected to the source region and the body region and the source metal is in direct contact with the first portion, and
the metal member includes a gate finger surrounding the source metal and the gate finger is in direct contact with the second portion.
14. The semiconductor device according to claim 13 , wherein the semiconductor layer includes an active region including the transistor structure and an outer peripheral region surrounding the active region, and
the voltage-regulator diode includes an outer peripheral diode disposed along the outer peripheral region.
15. The semiconductor device according to claim 14 , wherein, in the outer peripheral diode, the second portion and the first portion are each formed in an annular shape surrounding the active region, and
a pn junction portion between the second portion and the first portion has an integral structure formed in an annular shape surrounding the active region.
16. The semiconductor device according to claim 13 , wherein the voltage-regulator diode is made of polysilicon stacked on the semiconductor layer.
17. The semiconductor device according to claim 13 , wherein the voltage-regulator diode is made of an impurity region disposed on the semiconductor layer.