In semiconductor switching devices like IGBTs (insulated gate bipolar transistors) as well as RC-IGBTs (reverse conducting IGBTs) mobile charge carriers flood a low-doped drift zone and form a charge carrier plasma that provides a low on-state resistance. For achieving high short-circuit robustness, source zones are formed only in portions of the cell area in order to limit the maximum short-circuit current. On the other hand, reducing the source zone area may adversely affect the charge carrier plasma in the drift zone. It is desirable to provide semiconductor devices with improved switching characteristics.
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