US 6,271,545 B1Granted

Asymmetrical thyristor with blocking/sweep voltage independent of temperature behavior

AssigneeSiemens Aktiengesellschaft

InventorHans-Joachim Schulze

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Abstract

Both the blocking voltage as well as the sweep voltage of conventional thyristors exhibit a pronounced temperature behavior, whereby the corresponding voltage values can change by up to 15% within the relevant temperature range (5° C.-120° C.). In the proposed thyristor, the overhead triggering is compelled by the “punch through” effect that is independent of the temperature (expanse of the space charge zone allocated to the p-base/n-base junction 10) up to the neighboring n-base/p-emitter junction 11). Due to the laterally non-uniform distribution of the dopant in the n+ stop zone (7′) of the anode-side base (7), further, it is assured that the central thyristor region always ignites first. Sweep or punch through voltage is not dependent on the temperature in the asymmetrical thyristors.

Claims5

Dependent claims

An asymmetrical thyristor, comprising:

a semiconductor body having a first electrode serving as cathode and a second electrode serving as anode, and the semiconductor body having a plurality of differently doped regions;
the differently doped regions being positioned such that the regions form a cathode-side emitter of a first conductivity type, a cathode-side base of a second conductivity type, an anode-side base of the first conductivity type and an anode-side emitter of the second conductivity type;
a stop zone of the first conductivity type located in the anode-side base;
the stop zone having a central region, lying under one of a trigger contact or a light-sensitive structure, and a region laterally adjoining thereto;
the stop zone being more lightly doped in the central region than in the laterally adjoining region;
and
the anode-side emitter being provided with anode shorts.

4 more elements

Dependencies are inferred from the claim text.