Abstract: The invention provides a high voltage MOS transistor having a high source/drain breakdown voltage of about 300V and a low on-resistance. An N-type body layer is formed extending from a source layer side to under a gate electrode. A P-type second drift layer is formed in an epitaxial semiconductor layer by being diffused deeper than a first drift layer, extending from under the first drift layer to under the gate electrode and forming a PN junction with the body layer under the gate electrode. A surface of the body layer between this second drift layer and the source layer serves as a channel region. The first drift layer is formed at a distance from a left end of the gate electrode where electric field concentration easily occurs.

Abstract: A semiconductor integrated circuit device according to the present invention includes an N-type embedded diffusion region between a substrate and an epitaxial layer in first and second island regions serving as small signal section. The N-type embedded diffusion region connects to N-type diffusion regions having supply potential. The substrate and the epitaxial layer are thus partitioned by the N-type embedded diffusion region having supply potential in the island regions serving as small signal section. This structure prevents the inflow of free carriers (electrons) generated from a power NPN transistor due to the back electromotive force of the motor into the small signal section, thus preventing the malfunction of the small signal section.

Abstract: A semiconductor device includes a trench formed in a surface of a semiconductor substrate. A conductor is embedded in the trench. A conductive layer is arranged adjacent to the trench on the surface of the semiconductor substrate. Semiconductor elements, which include sources provided by one of the conductor and the conductive layer and drains provided by the other one of the conductor and the conductive layer, are formed in a semiconductor element formation region. A planar wiring layer is embedded in the semiconductor substrate under the entire semiconductor element formation region and connected to the conductor.

Abstract: A semiconductor integrated circuit device according to the present invention includes a diode in a second island region. The anode region of the diode and the dividing region in a first island region having a horizontal PNP transistor are electrically connected to each other; the cathode region of the diode and the collector region of a power NPN transistor are electrically connected to each other. Accordingly, the dividing region in the first island region having a horizontal PNP transistor becomes lower in potential than the dividing regions in the other island regions, so that the inflow of free carriers (electrons) to the horizontal PNP transistor can be prevented.

Abstract: The invention provides a high voltage MOS transistor having a high source/drain breakdown voltage of about 300V and a low on-resistance. An N-type body layer is formed extending from a source layer side to under a gate electrode. A P-type second drift layer is formed in an epitaxial semiconductor layer by being diffused deeper than a first drift layer, extending from under the first drift layer to under the gate electrode and forming a PN junction with the body layer under the gate electrode. A surface of the body layer between this second drift layer and the source layer serves as a channel region. The first drift layer is formed at a distance from a left end of the gate electrode where electric field concentration easily occurs.

Abstract: A semiconductor device includes a trench formed in a surface of a semiconductor substrate. A conductor is embedded in the trench. A conductive layer is arranged adjacent to the trench on the surface of the semiconductor substrate. Semiconductor elements, which include sources provided by one of the conductor and the conductive layer and drains provided by the other one of the conductor and the conductive layer, are formed in a semiconductor element formation region. A planar wiring layer is embedded in the semiconductor substrate under the entire semiconductor element formation region and connected to the conductor.

Abstract: A semiconductor integrated circuit device according to the invention includes an N-type embedded diffusion region between a substrate and a first epitaxial layer in island regions serving as small signal section. The substrate and the first epitaxial layer are thus partitioned by the N-type embedded diffusion region having supply potential in the island regions serving as small signal section. This structure prevents the inflow of free carriers (electrons) generated from a power NPN transistor due to the back electromotive force of the motor into the small signal section, thus preventing the malfunction of the small signal section.

Abstract: A semiconductor integrated circuit device according to the present invention includes a diode in a second island region. The anode region of the diode and the dividing region in a first island region having a horizontal PNP transistor are electrically connected to each other; the cathode region of the diode and the collector region of a power NPN transistor are electrically connected to each other. Accordingly, the dividing region in the first island region having a horizontal PNP transistor becomes lower in potential than the dividing regions in the other island regions, so that the inflow of free carriers (electrons) to the horizontal PNP transistor can be prevented.

Abstract: A semiconductor integrated circuit device according to the invention includes an N-type embedded diffusion region between a substrate and a first epitaxial layer in island regions serving as small signal section. The substrate and the first epitaxial layer are thus partitioned by the N-type embedded diffusion region having supply potential in the island regions serving as small signal section. This structure prevents the inflow of free carriers (electrons) generated from a power NPN transistor due to the back electromotive force of the motor into the small signal section, thus preventing the malfunction of the small signal section.

Abstract: This invention is characterized in that, a gate electrode 27F formed on a P-type well 3 via a gate oxide film 9, a high-concentration N-type source layer and a high-concentration N-type drain layer 15 respectively formed apart from the gate electrode and a low-concentration N-type source layer and a low-concentration H-type drain layer respectively formed so that they respectively surround the N-type source layer and the N-type drain layer 10 and respectively parted by a P-type body layer formed under the gate electrode 27F are provided.

Abstract: A method for the production of a semiconductor integrated circuit device is disclosed, wherein the formation of lateral wall spacers for high voltage MOS transistor is implemented by forming a resist film for covering at least an insulating film formed on a drain region of low impurity concentration in the proximity of a gate electrode, masking the resist film, and etching the parts of the insulating film destined to give rise to the lateral wall spacers.