The present application teaches, among other innovations, power semiconductor devices in which breakdown initiation regions, on BOTH sides of a die, are located inside the emitter/collector regions, but laterally spaced away from insulated trenches which surround the emitter/collector regions. Preferably this is part of a symmetrically-bidirectional power device of the B-TRAN type. In one advantageous group of embodiments (but not all), the breakdown initiation regions are defined by dopant introduction through the bottom of trench portions which lie within the emitter/collector region. In one group of embodiments (but not all), these can advantageously be separated trench portions which are not continuous with the trench(es) surrounding the emitter/collector region(s).

A bidirectional transient voltage suppressor is constructed as an NPN bipolar transistor incorporating optimized collector-base junction realizing avalanche mode breakdown. In some embodiments, the bidirectional transient voltage suppressor is constructed as an NPN bipolar transistor incorporating individually optimized collector-base and emitter-base junctions with the optimized junctions being spatially distributed. The optimized collector-base and emitter-base junctions both realize avalanche mode breakdown to improve the breakdown voltage of the transistor. Alternately, a unidirectional transient voltage suppressor is constructed as an NPN bipolar transistor with a PN junction diode connected in parallel in the reverse bias direction to the protected node and incorporating individually optimized collector-base junction of the bipolar transistor and p-n junction of the diode.

The present application relates to a turn-off power semiconductor device having a wafer with an active region and a termination region surrounding the active region, a rubber ring as an edge passivation for the wafer and a gate ring placed on a ring-shaped gate contact on the termination region for contacting the gate electrodes of a thyristor cell formed in the active region of the wafer. In the turn-off power semiconductor device, the outer circumferential surface of the gate ring is in contact with the rubber ring to define the inner border of the rubber ring. The area consumed by the ring-shaped gate contact on the termination or edge region can be minimized. The upper surface of the gate ring and the upper surface of the rubber ring form a continuous surface extending in a plane parallel to the first main side of the wafer.

A bidirectional transient voltage suppressor is constructed as an NPN bipolar transistor incorporating optimized collector-base junction realizing avalanche mode breakdown. In some embodiments, the bidirectional transient voltage suppressor is constructed as an NPN bipolar transistor incorporating individually optimized collector-base and emitter-base junctions with the optimized junctions being spatially distributed. The optimized collector-base and emitter-base junctions both realize avalanche mode breakdown to improve the breakdown voltage of the transistor. Alternately, a unidirectional transient voltage suppressor is constructed as an NPN bipolar transistor with a PN junction diode connected in parallel in the reverse bias direction to the protected node and incorporating individually optimized collector-base junction of the bipolar transistor and p-n junction of the diode.

A power transistor assembly and method of operating the assembly are provided. The power transistor assembly includes integrated transient voltage suppression on a single semiconductor substrate and includes a transistor formed of a wide band gap material, the transistor including a gate terminal, a source terminal, and a drain terminal, the transistor further including a predetermined maximum allowable gate voltage value, and a transient voltage suppression (TVS) device formed of a wide band gap material, the TVS device formed with the transistor as a single semiconductor device, the TVS device electrically coupled to the transistor between at least one of the gate and source terminals and the drain and source terminals, the TVS device including a breakdown voltage limitation selected to be greater than the predetermined maximum allowable gate voltage value.

A semiconductor controlled rectifier (FIG. 4A) for an integrated circuit is disclosed. The semiconductor controlled rectifier comprises a first lightly doped region (100) having a first conductivity type (N) and a first heavily doped region (108) having a second conductivity type (P) formed within the first lightly doped region. A second lightly doped region (104) having the second conductivity type is formed proximate the first lightly doped region. A second heavily doped region (114) having the first conductivity type is formed within the second lightly doped region. A buried layer (101) having the first conductivity type is formed below the second lightly doped region and electrically connected to the first lightly doped region. A third lightly doped region (102) having the second conductivity type is formed between the second lightly doped region and the third heavily doped region. A fourth lightly doped region (400) having the second conductivity type is formed between the second lightly doped region and the third heavily doped region and electrically connected to the second and third lightly doped regions.

A semiconductor controlled rectifier (FIG. 4A) for an integrated circuit is disclosed. The semiconductor controlled rectifier comprises a first lightly doped region (100) having a first conductivity type (N) and a first heavily doped region (108) having a second conductivity type (P) formed within the first lightly doped region. A second lightly doped region (104) having the second conductivity type is formed proximate the first lightly doped region. A second heavily doped region (114) having the first conductivity type is formed within the second lightly doped region. A buried layer (101) having the first conductivity type is formed below the second lightly doped region and electrically connected to the first lightly doped region. A third lightly doped region (102) having the second conductivity type is formed between the second lightly doped region and the third heavily doped region. A fourth lightly doped region (400) having the second conductivity type is formed between the second lightly doped region and the third heavily doped region and electrically connected to the second and third lightly doped regions.

A semiconductor controlled rectifier (FIG. 4A) for an integrated circuit is disclosed. The semiconductor controlled rectifier comprises a first lightly doped region (100) having a first conductivity type (N) and a first heavily doped region (108) having a second conductivity type (P) formed within the first lightly doped region. A second lightly doped region (104) having the second conductivity type is formed proximate the first lightly doped region. A second heavily doped region (114) having the first conductivity type is formed within the second lightly doped region. A buried layer (101) having the first conductivity type is formed below the second lightly doped region and electrically connected to the first lightly doped region. A third lightly doped region (102) having the second conductivity type is formed between the second lightly doped region and the third heavily doped region. A fourth lightly doped region (400) having the second conductivity type is formed between the second lightly doped region and the third heavily doped region and electrically connected to the second and third lightly doped regions.

A bidirectional transient voltage suppressor is constructed as an NPN bipolar transistor incorporating optimized collector-base junction realizing avalanche mode breakdown. In some embodiments, the bidirectional transient voltage suppressor is constructed as an NPN bipolar transistor incorporating individually optimized collector-base and emitter-base junctions with the optimized junctions being spatially distributed. The optimized collector-base and emitter-base junctions both realize avalanche mode breakdown to improve the breakdown voltage of the transistor. Alternately, a unidirectional transient voltage suppressor is constructed as an NPN bipolar transistor with a PN junction diode connected in parallel in the reverse bias direction to the protected node and incorporating individually optimized collector-base junction of the bipolar transistor and p-n junction of the diode.

A semiconductor controlled rectifier (FIG. 4A) for an integrated circuit is disclosed. The semiconductor controlled rectifier comprises a first lightly doped region (100) having a first conductivity type (N) and a first heavily doped region (108) having a second conductivity type (P) formed within the first lightly doped region. A second lightly doped region (104) having the second conductivity type is formed proximate the first lightly doped region. A second heavily doped region (114) having the first conductivity type is formed within the second lightly doped region. A buried layer (101) having the first conductivity type is formed below the second lightly doped region and electrically connected to the first lightly doped region. A third lightly doped region (102) having the second conductivity type is formed between the second lightly doped region and the third heavily doped region. A fourth lightly doped region (400) having the second conductivity type is formed between the second lightly doped region and the third heavily doped region and electrically connected to the second and third lightly doped regions.