The trench insulating gate bipolar transistor which possesses the safe operational field which is improved

摘要

(57) Abstract The trench insulating gate bipolar transistor (IGBT) which possesses the safe operational field (SOA) which is improved includes the many trench IGBT structure (250) which is combined with bipolar transistor (BJT) structure (252) mutually in drift formation (254), the trench gate (258) has separated these structures. When the shallow P field (264) the span does the cartridge head corner of the respective trench gate, the device is conversely biased, conservation trench oxide from the high peak electric field which it occurs. Responding to gate voltage, because there are no times when the reversal channel is formed in the BJT mesa, based Drive, therefore, saturation current level of the device decreases, that short circuit SOA is improved. Ratio of the IGBT structure for BJT structure is adjusted according to need you obtain with the saturation current level and short circuit SOA of desire. Originating in introducing BJT structure, rather than occurring, rather than voltage drop of big forward direction augments the depth of the trench gate, improves the injection efficiency of the device and reducing the voltage drop of forward direction the long cumulative channel it is suppressed by making form alongside the side wall of the gate. The N die formation (230, 232 and 242) which is expanded in the top and bottom of the shallow P field, suppresses the augmentation of on resistance which it occurs with the erosion to in the mesa of IGBT and BJT.