Bi-directional trench power switches. At least one example is a semiconductor device comprising: an upper base region associated with a first side of a substrate of semiconductor material; an upper-CE trench defined on the first side, the upper-CE trench defines a proximal opening at the first side and a distal end within the substrate; an upper collector-emitter region disposed at the distal end of the upper-CE trench; a lower base region associated with a second side of substrate; and a lower collector-emitter region associated with the second side.

A power semiconductor device includes an active cell region with a drift region of a first conductivity type, a plurality of IGBT cells arranged within the active cell region, each of the IGBT cells includes at least one trench that extends into the drift, an edge termination region surrounding the active cell region, a transition region arranged between the active cell region and the edge termination region, at least some of the IGBT cells are arranged within or extend into the transition region, a barrier region of a second conductivity type, the barrier region is arranged within the active cell region and in contact with at least some of the trenches of the IGBT cells and does not extend into the transition region, and a first load terminal and a second load terminal, the power semiconductor device is configured to conduct a load current along a vertical direction between.

A method of processing a power semiconductor device includes: providing a semiconductor body with a drift region of a first conductivity type; forming a plurality of trenches extending into the semiconductor body along a vertical direction and arranged adjacent to each other along a first lateral direction; providing a mask arrangement at the semiconductor body, the mask arrangement having a lateral structure according to which some of the trenches are exposed and at least one of the trenches is covered by the mask arrangement along the first lateral direction; forming, below bottoms of the exposed trenches, a plurality of doping regions of a second conductivity type complementary to the first conductivity type; removing the mask arrangement; and extending the plurality of doping regions in parallel to the first lateral direction such that the plurality of doping regions overlap and form a barrier region of the second conductivity type adjacent to the bottoms of the exposed trenches.

A compound semiconductor device includes a heterojunction bipolar transistor and a bump. The heterojunction bipolar transistor includes a plurality of unit transistors. The bump is electrically connected to emitters of the plurality of unit transistors. The plurality of unit transistors are arranged in a first direction. The bump is disposed above the emitters of the plurality of unit transistors while extending in the first direction. The emitter of at least one of the plurality of unit transistors is displaced from a center line of the bump in the first direction toward a first side of a second direction which is perpendicular to the first direction. The emitter of at least another one of the plurality of unit transistors is displaced from the center line of the bump in the first direction toward a second side of the second direction.

The present application contemplates a method for manufacturing a power semiconductor device. The method comprises: providing a wafer of a first conductivity type, the wafer having a first main side and a second main side opposite to the first main side, and the wafer including an active cell area, which extends from the first main side to the second main side, in a central part of the wafer and a termination area surrounding the active cell area in an orthogonal projection onto a plane parallel to the first main side; forming a metallization layer on the first main side to electrically contact the wafer in the active cell area, wherein the surface of the metallization layer, which faces away from the wafer, defines a first plane parallel to the first main side; forming an isolation layer on the first main side in the termination area, wherein the surface of the isolation layer facing away from the wafer defines a second plane parallel to the first main side; after the step of forming the metallization layer and after the step of forming the isolation layer, mounting the wafer with its first main side to a flat surface of a chuck; and thereafter thinning the wafer from its second main side by grinding while pressing the second main side of the wafer onto a grinding wheel by applying a pressure between the chuck and the grinding wheel, wherein the first plane is further away from the wafer than a third plane, which is parallel to the second plane and arranged at a distance of 1 μm from the second plane in a direction towards the wafer.

On a single-crystal semiconductor substrate with an upper surface including a first direction in which an inverted mesa step extends and a second direction in which a forward mesa step extends in response to anisotropic etching in which an etching rate depends on crystal plane orientation, a bipolar transistor including a collector layer, a base layer, and an emitter layer that are epitaxially grown, and a base wire connected to the base layer are arranged. A step is provided at an edge of the base layer, and the base wire is extended from inside to outside of the base layer in a direction intersecting the first direction in a plan view. An intersection of the edge of the base layer and the base wire has a disconnection prevention structure that makes it difficult for step-caused disconnection of the base wire to occur.

A semiconductor device includes a drift region of a first conductivity type, an anode region of a second conductivity type situated below the drift region, an inversion region of the second conductivity type situated above the drift region, an enhancement region of the first conductivity type situated between the drift region and the inversion region, first and second control trenches extending through the inversion region and the enhancement region into the drift region, each control trench being bordered by a cathode diffusion region of the first conductivity type, and a superjunction structure situated in the drift region between the first and the second control trenches so that the superjunction structure does not extend under either the first or the second control trench. The superjunction structure is separated from the inversion region by the enhancement region and includes alternating regions of the first and the second conductivity types.

Various embodiments of the present disclosure are directed towards a method for forming a bipolar junction transistor (BJT). A dielectric film is deposited over a substrate and comprises a lower dielectric layer, an upper dielectric layer, and an intermediate dielectric layer between the lower and upper dielectric layers. A first semiconductor layer is deposited over the dielectric film and is subsequently patterned to form an opening exposing the dielectric film. A first etch is performed into the upper dielectric layer through the opening to extend the opening to the intermediate dielectric layer. Further, the first etch stops on the intermediate dielectric layer and laterally undercuts the first semiconductor layer. Additional etches are performed to extend the opening to the substrate. A lower base structure and an emitter are formed stacked in and filling the opening, and the first semiconductor layer is patterned to form an upper base structure.

Provided is a semiconductor device comprising: a semiconductor substrate; a gate trench section that is provided from an upper surface to an inside of the semiconductor substrate and extends in a predetermined extending direction on the upper surface of the semiconductor substrate; a mesa section in contact to the gate trench section in an arrangement direction orthogonal the extending direction; and an interlayer dielectric film provided above the semiconductor substrate; wherein the interlayer dielectric film is provided above at least a part of the gate trench section in the arrangement direction; a contact hole through which the mesa section is exposed is provided to the interlayer dielectric film; and a width of the contact hole in the arrangement direction is equal to or greater than a width of the mesa section in the arrangement direction.

A bipolar transistor includes a stack of an emitter, a base, and a collector. The base is structured to have a comb shape including fingers oriented in a plane orthogonal to a stacking direction of the stack.