Claims
- 1. A semiconductor device having a lateral high-breakdown-voltage transistor comprising:
a first-conductivity-type semiconductor layer; a second-conductivity-type source region formed in the semiconductor layer; a second-conductivity-type drain region formed in or outside the semiconductor layer, separated from the source region; a gate electrode formed above the semiconductor layer between the drain region and the source region, insulated from the semiconductor layer; a second-conductivity-type drain contact region formed in the drain region and having a higher impurity concentration than the drain region; a drain wiring electrically connected to the drain region via the drain contact region; a first-conductivity-type substrate contact region formed adjacent to the source region; and a source wiring electrically connected to the source region, and also connected to the semiconductor layer via the substrate contact region, the source wiring touching a portion of the source region and the substrate contact region, thereby forming a contact surface therebetween, the substrate contact region laterally extending from inside the contact surface to outside the contact surface.
- 2. The semiconductor device having the lateral high-breakdown-voltage transistor according to claim 1, wherein the substrate contact region laterally extends from inside the contact surface of the source wiring to a channel formed below the gate electrode.
- 3. The semiconductor device having the lateral high-breakdown-voltage transistor according to claim 1, wherein a pair of gate electrodes is formed laterally outside the substrate contact region, a plurality of the substrate contact regions are in existence such that the substrate contact regions alternately extend to opposite portions of channels formed below the gate electrodes.
- 4. The semiconductor device having the lateral high-breakdown-voltage transistor according to claim 1, wherein a pair of gate electrodes is formed laterally outside the substrate contact region such that the substrate contact region extends to opposite portions of channels formed below the gate electrodes.
- 5. A semiconductor device having a lateral high-breakdown-voltage transistor comprising:
a first-conductivity-type semiconductor layer; a second-conductivity-type source region formed in the semiconductor layer; a second-conductivity-type drain region formed in or outside the semiconductor layer, separated from the source region; a gate electrode formed above the semiconductor layer between the drain region and the source region, insulated from the semiconductor layer; a second-conductivity-type drain contact region formed in the drain region and having a higher impurity concentration than the drain region; a drain wiring electrically connected to the drain region via the drain contact region; a first-conductivity-type substrate contact region formed adjacent to the source region; a source wiring electrically connected to the source region, and also connected to the semiconductor layer via the substrate contact region; and a first-conductivity-type low resistance layer formed in the semiconductor layer in contact with a bottom of the source region and having a higher impurity concentration than the semiconductor layer.
- 6. A semiconductor device having a lateral high-breakdown-voltage transistor comprising:
a first-conductivity-type semiconductor layer; a second-conductivity-type source region formed in the semiconductor layer; a second-conductivity-type drain region formed in or outside the semiconductor layer, separated from the source region; a gate electrode formed above the semiconductor layer between the drain region and the source region, insulated from the semiconductor layer; a second-conductivity-type drain contact region formed in the drain region and having a higher impurity concentration than the drain region; a drain wiring electrically connected to the drain region via the drain contact region; a first-conductivity-type substrate contact region formed adjacent to the source region; and a source wiring electrically connected to the source region, and also connected to the semiconductor layer via the substrate contact region, a distance from a contact surface of the drain wiring and the drain contact region to an edge of the source region side of the drain contact region being 5 μm or more.
- 7. A semiconductor device having a lateral high-breakdown-voltage transistor comprising:
a first-conductivity-type semiconductor layer; a second-conductivity-type source region formed in the semiconductor layer; a second-conductivity-type drain region formed in or outside the semiconductor layer, separated from the source region; a gate electrode formed above the semiconductor layer between the drain region and the source region, insulated from the semiconductor layer; a second-conductivity-type drain contact region formed in the drain region and having a higher impurity concentration than the drain region; a drain wiring electrically connected to the drain region via the drain contact region; a first-conductivity-type substrate contact region formed adjacent to the source region; and a source wiring electrically connected to the source region, and also connected to the semiconductor layer via the substrate contact region, the drain contact region having a bottom at a level lower than a bottom of the drain region.
- 8. The semiconductor device having the lateral high-breakdown-voltage transistor according to claim 7, wherein a total amount of a second-conductivity-type impurity contained in the drain contact region is 3.0×1012 cm−2 or more.
- 9. The semiconductor device having the lateral high-breakdown-voltage transistor according to claim 7, further comprising a second-conductivity-type semiconductor layer formed in below region of the first-conductivity-type semiconductor layer, the drain contact region is formed in contact with the second-conductivity-type semiconductor layer.
- 10. A semiconductor device having a lateral high-breakdown-voltage transistor comprising:
a first-conductivity-type semiconductor substrate; a second-conductivity-type buried layer formed in the semiconductor substrate; a second-conductivity-type epitaxial layer formed on the buried layer; a first-conductivity-type well layer formed in a surface portion of the epitaxial layer; a second-conductivity-type source region formed in a surface portion of the well layer; a second-conductivity-type drain region formed in a surface portion of the epitaxial layer or the well layer, separated from the source region; a second-conductivity-type deep diffusion layer formed in the drain region but extending to a level lower than a bottom of the drain region in contact with the buried layer, and having a higher impurity concentration than the drain region; a gate electrode formed above the well layer between the drain region and the source region, insulated from the well layer; a first drain electrode formed on the deep diffusion layer and electrically connected to the drain region via the deep diffusion layer; a source electrode formed on and electrically connected to the source region; a second-conductivity-type isolating diffusion layer surrounding the drain region and the source region, separated from the well layer, and extending to the buried layer; and a second drain electrode formed on the isolating diffusion layer and electrically connected to the first drain electrode, a distance between the deep diffusion layer and the source region being greater than a thickness of the epitaxial layer on the buried layer.
- 11. The semiconductor device having the lateral high-breakdown-voltage transistor according to claim 10, wherein the drain region is formed in the well layer.
- 12. The semiconductor device having the lateral high-breakdown-voltage transistor according to claim 10, wherein the distance is 10%-50% greater than the thickness.
- 13. The semiconductor device having the lateral high-breakdown-voltage transistor according to claim 10, wherein the deep diffusion layer has an impurity concentration ranging from 3.0×1012 cm−3 to 5.0×1015 cm−3.
- 14. The semiconductor device having the lateral high-breakdown-voltage transistor according to claim 10, further comprising a second-conductivity-type drain contact region formed in a surface portion of the deep diffusion layer and having a higher impurity concentration than the deep diffusion layer.
- 15. A semiconductor device having a lateral high-breakdown-voltage transistor comprising:
a first-conductivity-type semiconductor substrate; a second-conductivity-type buried layer formed in the semiconductor substrate; a second-conductivity-type epitaxial layer formed on the buried layer; a first-conductivity-type well layer formed in a surface portion of the epitaxial layer; a second-conductivity-type source region formed in a surface portion of the well layer; a second-conductivity-type drain region formed in a surface portion of the well layer, separated from the source region; a second-conductivity-type drain contact region formed in a surface portion of the drain region and having a higher impurity concentration than the drain region; a gate electrode formed above the well layer between the drain region and the source region, insulated from the well layer; a first drain electrode formed on the drain contact region and electrically connected to the drain region via the drain contact region; a source electrode formed on and electrically connected to the source region; a second-conductivity-type isolating diffusion layer surrounding the well layer, separated from the well layer, and extending to the buried layer; and a second drain electrode formed on the isolating diffusion layer and electrically connected to the first drain electrode, a distance between the drain contact region and the source region being greater than a thickness of the epitaxial layer on the buried layer.
- 16. The semiconductor device having the lateral high-breakdown-voltage transistor according to claim 15, wherein the distance is 10%-50% greater than the thickness.
- 17. The semiconductor device having the lateral high-breakdown-voltage transistor according to claim 1, further comprising a diode formed by short-circuiting the source wiring and the gate electrode.
- 18. The semiconductor device having the lateral high-breakdown-voltage transistor according to claim 5, further comprising a diode formed by short-circuiting the source wiring and the gate electrode.
- 19. The semiconductor device having the lateral high-breakdown-voltage transistor according to claim 6, further comprising a diode formed by short-circuiting the source wiring and the gate electrode.
- 20. The semiconductor device having the lateral high-breakdown-voltage transistor according to claim 7, further comprising a diode formed by short-circuiting the source wiring and the gate electrode.
Priority Claims (2)
Number |
Date |
Country |
Kind |
11-371568 |
Dec 1999 |
JP |
|
2000-205070 |
Jul 2000 |
JP |
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of priority from the prior Japanese Patent Applications No. 11-371568, filed Dec. 27, 1999; and No. 2000-205070, filed Jul. 6, 2000, the entire contents of which are incorporated herein by reference.