A device includes a first region, a second region disposed on the first region, a third region and a fourth region abutting the third region disposed in the second region, a fifth region disposed in the third region and coupled to a collector disposed above, and a sixth region disposed in the fourth region and coupled to an emitter disposed above. A first isolation is disposed between the collector and the emitter. A seventh region is disposed in the fifth region and coupled to the collector is spaced apart from the first isolation. The first region, the third region, the fifth region, the collector and the emitter have a first conductivity type different from a second conductivity type that the second region, the fourth region, the sixth region and the seventh region have.

A device includes a first region, a second region disposed on the first region, a third region and a fourth region abutting the third region disposed in the second region, a fifth region disposed in the third region and coupled to a collector disposed above, and a sixth region disposed in the fourth region and coupled to an emitter disposed above. A first isolation is disposed between the collector and the emitter. A seventh region is disposed in the fifth region and coupled to the collector is spaced apart from the first isolation. The first region, the third region, the fifth region, the collector and the emitter have a first conductivity type different from a second conductivity type that the second region, the fourth region, the sixth region and the seventh region have.

An electrostatic discharge (ESD) protection circuit (FIG. 3C) is disclosed. The circuit includes a bipolar transistor (304) having a base, collector, and emitter. Each of a plurality of diodes (308-316) has a first terminal coupled to the base and a second terminal coupled to the collector. The collector is connected to a first terminal (V+). The emitter is connected to a first power supply terminal (V−).

An electrostatic discharge (ESD) protection circuit (FIG. 3C) is disclosed. The circuit includes a bipolar transistor (304) having a base, collector, and emitter. Each of a plurality of diodes (308-316) has a first terminal coupled to the base and a second terminal coupled to the collector. The collector is connected to a first terminal (V+). The emitter is connected to a first power supply terminal (V−).

A method of subdividing a semiconductor wafer is described with trenches in order to provide separate, electrically isolated regions that can be used to hold components that operate at different voltages. There is also described a masking and etching process of forming collector and emitter regions of a lateral bipolar transistor, from a layer of polysilicon deposited on a patterned later of silicon dioxide.

A method of subdividing a semiconductor wafer is described with trenches in order to provide separate, electrically isolated regions that can be used to hold components that operate at different voltages. There is also described a masking and etching process of forming collector and emitter regions of a lateral bipolar transistor, from a layer of polysilicon deposited on a patterned later of silicon dioxide.

A device includes a first region, a second region disposed on the first region, a third region and a fourth region abutting the third region disposed in the second region, a fifth region disposed in the third region and coupled to a collector disposed above, and a sixth region disposed in the fourth region and coupled to an emitter disposed above. A first isolation is disposed between the collector and the emitter. A seventh region is disposed in the fifth region and coupled to the collector is spaced apart from the first isolation. The first region, the third region, the fifth region, the collector and the emitter have a first conductivity type different from a second conductivity type that the second region, the fourth region, the sixth region and the seventh region have.

A device includes a first region, a second region disposed on the first region, a third region and a fourth region abutting the third region disposed in the second region, a fifth region disposed in the third region and coupled to a collector disposed above, and a sixth region disposed in the fourth region and coupled to an emitter disposed above. A first isolation is disposed between the collector and the emitter. A seventh region is disposed in the fifth region and coupled to the collector is spaced apart from the first isolation. The first region, the third region, the fifth region, the collector and the emitter have a first conductivity type different from a second conductivity type that the second region, the fourth region, the sixth region and the seventh region have.

A semiconductor device is provided in which a zener diode having a desired breakdown voltage and a capacitor in which voltage dependence of capacitance is reduced are mounted together, and various circuits are realized. The semiconductor device includes: a semiconductor layer; a first conductivity type well that is arranged in a first region of the semiconductor layer; a first conductivity type first impurity diffusion region that is arranged in the well; a first conductivity type second impurity diffusion region that is arranged in a second region of the semiconductor layer; an insulating film that is arranged on the second impurity diffusion region; an electrode that is arranged on the insulating film; and a second conductivity type third impurity diffusion region that is arranged at least on the first impurity diffusion region.

A semiconductor device is provided in which a zener diode having a desired breakdown voltage and a capacitor in which voltage dependence of capacitance is reduced are mounted together, and various circuits are realized. The semiconductor device includes: a semiconductor layer; a first conductivity type well that is arranged in a first region of the semiconductor layer; a first conductivity type first impurity diffusion region that is arranged in the well; a first conductivity type second impurity diffusion region that is arranged in a second region of the semiconductor layer; an insulating film that is arranged on the second impurity diffusion region; an electrode that is arranged on the insulating film; and a second conductivity type third impurity diffusion region that is arranged at least on the first impurity diffusion region.