Methods of according to the present disclosure can include: providing a substrate including: a first semiconductor region, a second semiconductor region, and a trench isolation (TI) laterally between the first and second semiconductor regions; forming a seed layer on the TI and the second semiconductor region of the substrate, leaving the first semiconductor region of the substrate exposed; forming an epitaxial layer on the substrate and the seed layer, wherein the epitaxial layer includes: a first semiconductor base material positioned above the first semiconductor region of the substrate, and an extrinsic base region positioned above the seed layer; forming an opening within the extrinsic base material and the seed layer to expose an upper surface of the second semiconductor region; and forming a second semiconductor base material in the opening.

Methods of according to the present disclosure can include: providing a substrate including: a first semiconductor region, a second semiconductor region, and a trench isolation (TI) laterally between the first and second semiconductor regions; forming a seed layer on the TI and the second semiconductor region of the substrate, leaving the first semiconductor region of the substrate exposed; forming an epitaxial layer on the substrate and the seed layer, wherein the epitaxial layer includes: a first semiconductor base material positioned above the first semiconductor region of the substrate, and an extrinsic base region positioned above the seed layer; forming an opening within the extrinsic base material and the seed layer to expose an upper surface of the second semiconductor region; and forming a second semiconductor base material in the opening.

A semiconductor device includes a semiconductor substrate and first and second bipolar transistors. The semiconductor substrate includes first and second main surfaces opposing each other. The first bipolar transistor is formed on the first main surface of the semiconductor substrate and includes a first emitter layer. The second bipolar transistor is formed on the first main surface of the semiconductor substrate and includes a second emitter layer and a resistor layer. The resistor layer is stacked on the second emitter layer in a direction normal to the first main surface.

A semiconductor device of the present invention achieves improved avoidance of a parasitic operation in a circuit region while achieving miniaturization of the semiconductor device and a reduction in the amount of time for manufacturing the semiconductor device. The semiconductor device according to the present invention includes an IGBT disposed on a first main surface of a semiconductor substrate provided with a drift layer of a first conductivity type; a thyristor disposed on the first main surface of the semiconductor substrate; a circuit region; a hole-current retrieval region separating the IGBT and the circuit region in a plan view; and a diffusion layer of a second conductivity type, the diffusion layer being disposed on a second main surface of the semiconductor substrate. The IGBT has an effective area equal to or less than an effective area of the thyristor in a plan view.

A semiconductor device of the present invention achieves improved avoidance of a parasitic operation in a circuit region while achieving miniaturization of the semiconductor device and a reduction in the amount of time for manufacturing the semiconductor device. The semiconductor device according to the present invention includes an IGBT disposed on a first main surface of a semiconductor substrate provided with a drift layer of a first conductivity type; a thyristor disposed on the first main surface of the semiconductor substrate; a circuit region; a hole-current retrieval region separating the IGBT and the circuit region in a plan view; and a diffusion layer of a second conductivity type, the diffusion layer being disposed on a second main surface of the semiconductor substrate. The IGBT has an effective area equal to or less than an effective area of the thyristor in a plan view.

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−).

An apparatus includes a protection circuit electrically connected to first and second voltage domains. The protection circuit includes a first silicon-controlled rectifier (SCR) and a second SCR connected in anti-parallel configuration. The first SCR is configured to connect the first voltage domain and the second voltage domain based on detection of a first triggering condition. The second SCR is configured to connect the second voltage domain and the first voltage domain based on detection of a second triggering condition. The protection circuit is configured to isolate the first and second voltage domains without the triggering conditions.

An apparatus includes a protection circuit electrically connected to first and second voltage domains. The protection circuit includes a first silicon-controlled rectifier (SCR) and a second SCR connected in anti-parallel configuration. The first SCR is configured to connect the first voltage domain and the second voltage domain based on detection of a first triggering condition. The second SCR is configured to connect the second voltage domain and the first voltage domain based on detection of a second triggering condition. The protection circuit is configured to isolate the first and second voltage domains without the triggering conditions.

A semiconductor device has transistor portions and diode portions. The transistor portions have a semiconductor substrate of a first conductivity type, a first semiconductor region of a second conductivity type, second semiconductor regions of the first conductivity type, gate insulating films, gate electrodes, a first semiconductor layer of the first conductivity type, a third semiconductor region of the second conductivity type, a first electrode, and a second electrode. The diode portions have the semiconductor substrate, the first semiconductor region, the first semiconductor layer, a fourth semiconductor region of the first conductivity type, the first electrode, and the second electrode. The first semiconductor layer has a predetermined region, a depth of the predetermined region from a second main surface of the semiconductor substrate is greater than a depth of a region of the first semiconductor layer excluding the predetermined region, from the second main surface of the semiconductor substrate.