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 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 disposed at the semiconductor layer, the voltage-regulator diode having an n type portion connected to the p type source region through a first conductive path and a p type portion electrically connected to the gate electrode by a metal member through a second conductive path electrically separated from the first conductive path, the p type portion being in direct contact with the metal member without any pn junction,
wherein the transistor structure and the voltage-regulator diode are unified into a single-chip configuration.
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 p type portion and the n type portion are each formed in an annular shape surrounding the active region, and
a pn junction portion between the p type portion and the n type portion has an integral structure formed in an annular shape surrounding the active region.
4. The semiconductor device according to claim 3 , wherein the p type portion and the n type portion each have a width equal to each other.
5. The semiconductor device according to claim 3 , wherein, in the outer peripheral diode, the n type portion is disposed at a more inward side than the p type 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 1 , wherein
the metal member includes a gate finger surrounding the active region, and
the p type 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 p type source region and the n type body region, and
the metal member includes a gate finger surrounding the source metal.