A semiconductor structure for a DRAM is described having multiple layers of arrays of thyristor memory cells with silicon-germanium base regions. Memory cells in a vertical string extending through the layers have an electrical connection to one terminal of the memory cells in that string. Word lines couple the strings together. Each layer of the array also includes bit line connections to memory cells on that layer. Select transistors enable the use of folded bit lines. Methods of fabricating the array are described.

A semiconductor structure for a DRAM is described having multiple layers of arrays of thyristor memory cells with silicon-germanium base regions. Memory cells in a vertical string extending through the layers have an electrical connection to one terminal of the memory cells in that string. Word lines couple the strings together. Each layer of the array also includes bit line connections to memory cells on that layer. Select transistors enable the use of folded bit lines. Methods of fabricating the array are described.

Bidirectional thyristor device comprising a semiconductor body extending in a vertical direction between a first main surface and a second main surface opposite the first main surface, a first main electrode arranged on the first main surface, and a second main electrode arranged on the second main surface, is specified, wherein the semiconductor body comprises a first base layer of a first conductivity type, a second base layer of the first conductivity type, and a third base layer of a second conductivity type different than the first conductivity type arranged between the first base layer and the second base layer. The first main electrode acts as a cathode for a first thyristor functional element and as an anode for a second thyristor functional element of the bidirectional thyristor device. The bidirectional thyristor device is configured asymmetrically with respect to the first thyristor functional element and the second thyristor functional element.

A semiconductor structure for a DRAM is described having multiple layers of arrays of thyristor memory cells with silicon-germanium base regions. Memory cells in a vertical string extending through the layers have an electrical connection to one terminal of the memory cells in that string. Word lines couple the strings together. Each layer of the array also includes bit line connections to memory cells on that layer. Select transistors enable the use of folded bit lines. Methods of fabricating the array are described.

A bypass thyristor device includes a semiconductor device providing a thyristor with a cathode electrode on a cathode side, a gate electrode on the cathode side surrounded by the cathode electrode and an anode electrode on an anode side; an electrically conducting cover element arranged on the cathode side and in electrical contact with the cathode electrode on a contact side; and a gate contact element electrically connected to the gate electrode and arranged in a gate contact opening in the contact side of the cover element; wherein the cover element has a gas expansion volume in the contact side facing the cathode side, which gas expansion volume is interconnected with the gate contact opening for gas exchange.

A Bipolar Junction Transistor (BJT) comprises an emitter, a collector, and a base between the emitter and the collector. The BJT also comprises an emitter contact on a first side of the BJT, a base contact on the first side of the BJT, and a collector contact on a second side of the BJT. The BJT further comprises a Deep Trench Isolation (DTI) region extending from the first side of the BJT to the second side of the BJT.

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 Bipolar Junction Transistor (BJT) comprises an emitter, a collector, and a base between the emitter and the collector. The BJT also comprises an emitter contact on a first side of the BJT, a base contact on the first side of the BJT, and a collector contact on a second side of the BJT. The BJT further comprises a Deep Trench Isolation (DTI) region extending from the first side of the BJT to the second side of the BJT.

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 semiconductor structure for a DRAM is described having multiple layers of arrays of thyristor memory cells with silicon-germanium base regions. Memory cells in a vertical string extending through the layers have an electrical connection to one terminal of the memory cells in that string. Word lines couple the strings together. Each layer of the array also includes bit line connections to memory cells on that layer. Select transistors enable the use of folded bit lines. Methods of fabricating the array are described.