Bipolar transistors and MOS transistors are formed in a common process. A semiconductor layer is arranged on an insulating layer. On a side of the bipolar transistors: an insulating region including the insulating layer is formed; openings are etched through the insulating region to delimit insulating walls; the openings are filled with first epitaxial portions; and the first epitaxial portions and a first region extending under the first epitaxial portions and under the insulating walls are doped. On the side of the bipolar transistors and on a side of the MOS transistors: gate structures are formed; second epitaxial portions are made; and the second epitaxial portions covering the first epitaxial portions are doped.

A multi-transistor configuration including a first transistor having a first terminal that is configured to control the flow of current between, a second terminal of the first transistor and a third terminal of the first transistor; a second transistor, that is a bipolar junction transistor comprising a base terminal, an emitter terminal, and a collector terminal, wherein the third terminal of the first transistor and the collector terminal of the second transistor are electrically connected; and a first voltage source having a first terminal at a first voltage and a second terminal at a second voltage.

A semiconductor device includes a semiconductor body having first and second surfaces opposite to each other. The semiconductor body includes a first well region having a first conductivity type, second and third well regions spaced apart from each other in a first direction with the first well region interposed therebetween and having a second conductivity type, first doped regions spaced apart from each other in a second direction intersecting the first direction in the first well region, a second doped region, which is adjacent to the second well region and has the second conductivity type, and a third doped region, which is adjacent to the third well region and has the second conductivity type. The second surface of the semiconductor body includes bottom surfaces of the first to third well regions, the plurality of first doped regions, the second doped region, and the third doped region.

Power semiconductor devices can often be expensive to produce and/or expensive to operate (i.e. inefficient). The present structure seeks to overcome these problems by providing a double-sided vertical power transistor structure that poses a unipolar path and a second parallel bipolar path.

Rectifiers are used in power systems, but surges are commonly encountered in the power grid, which can damage switches used to drive the active rectifiers. An active rectification system is proposed in which a thyristor type path is enabled through a transistor device such that surges bypass the driving switches.

Considering ease of electrical conduction tests and the like, electrodes provided mainly above an active region are desirably continuous on a single plane. A semiconductor device is provided, including: a semiconductor substrate; a first top surface electrode and a second top surface electrode that are provided above a top surface of the semiconductor substrate and contain a metal material; and a first connecting portion that electrically connects to the first top surface electrode and contains a semiconductor material, wherein the second top surface electrode has: a first region and a second region that are arranged being separated from each other with the first connecting portion as a boundary in a top view of the semiconductor substrate, and a second connecting portion that connects the first region and the second region above the first connecting portion.

Bipolar transistors and MOS transistors are formed in a common process. A semiconductor layer is arranged on an insulating layer. On a side of the bipolar transistors: an insulating region including the insulating layer is formed; openings are etched through the insulating region to delimit insulating walls; the openings are filled with first epitaxial portions; and the first epitaxial portions and a first region extending under the first epitaxial portions and under the insulating walls are doped. On the side of the bipolar transistors and on a side of the MOS transistors: gate structures are formed; second epitaxial portions are made; and the second epitaxial portions covering the first epitaxial portions are doped.

An insulated gate turn-off (IGTO) device, formed as a die, has a layered structure including a P+ layer (e.g., a substrate), an N epi layer, a P-well, vertical insulated gates formed in the P-well, and N+ regions between at least some of the gates, so that vertical NPN and PNP transistors are formed. A source/emitter electrode is on top, and a drain/cathode electrode is on the bottom of the substrate. The device is formed of a matrix of cells. To turn the device on, a positive voltage is applied to the gates, referenced to the source/emitter electrode. Some of the cells are passive, having gates that are either not connected to the active gates or having gates that are shorted to their associated N+ regions, to customize the input capacitance and lower the saturation current. Other techniques are described to form the passive cells.

Double sided versions of several power transistor types are devices that are already known in the literature. Devices built in this configuration are generally required to have a separate driver circuit to control the front and rear control electrodes and provide the gate or base voltage and/or currents for the power switch. This is because there may be of the order of 1000V potential-difference between the frontside and rearside potentials when the transistor is in the off conditionand a single integrated circuit cannot generally sustain this within a single package. The NPN configuration is preferred in this case to benefit from electron conduction for the main power path between the emitters. However, problems arising when using a P-type wafer. The present invention seeks to avoid the use of P-type wafers while still getting the higher conduction performance of NPN operation.

It is prevented that when a predetermined number of semiconductor chips having transistors are manufactured from one semiconductor wafer, manufacturing cost of a semiconductor device is increased due to excess semiconductor chips manufactured from the semiconductor wafer. A first bipolar transistor including a first emitter region having a first area is formed in a first chip formation region in an exposure region that can be exposed by one exposure step, and a second bipolar transistor including a second emitter region having a second area different from the first area is formed in a second chip formation region in the exposure region.