Patent ID: 9153676
Filing Date: 2015-10-06
Classification: H01L

Abstract:
1. An insulated gated bipolar transistor having layers between an emitter electrode on an emitter side and a collector electrode on a collector side opposite to the emitter side, the insulated gated bipolar transistor comprising: a lowly doped drift layer of a first conductivity type; a collector layer of a second conductivity type different than the first conductivity type, the collector layer being arranged between the drift layer and the collector electrode and electrically contacting the collector electrode; a base layer of the second conductivity type arranged between the drift layer and the emitter electrode, the base layer electrically contacting the emitter electrode and being completely separated from the drift layer, first and second source regions of the first conductivity type arranged on the base layer towards the emitter side and electrically contacting the emitter electrode, the first and second source regions having a higher doping concentration than the drift layer; at least two first trench gate electrodes arranged lateral to the base layer and extending deeper into the drift layer than the base layer, the at least two first trench gate electrodes being separated from the base layer, the first source region and the drift layer by a first insulating layer, wherein a first channel is formable from the emitter electrode, the first source region, the base layer and the drift layer between two of the first trench gate electrodes, the first source region being arranged between two of the first trench gate electrodes; a second insulating layer arranged on the emitter side on top of the first trench gate electrodes; an enhancement layer of the first conductivity type arranged between the base layer and the drift layer, the enhancement layer separating the base layer from the drift layer at least in a plane parallel to the emitter side and having a higher doping concentration than the drift layer; a gate electrode including a second trench gate electrode and an electrically conducting layer, both of which are electrically connected to the emitter electrode, the second trench gate electrode being arranged lateral to the base layer and extending deeper into the drift layer than the base layer, the second trench gate electrode being separated from the base layer, the enhancement layer and the drift layer by a third insulating layer, wherein a second channel is formable from the emitter electrode, the second source region, the base layer and the drift layer between one of the first trench gate electrodes and the second trench gate electrode, the second source region being arranged between one of the first trench gate electrodes and the second trench gate electrode, wherein the electrically conductive layer covers and laterally extends outside the second trench gate electrode at least to a region above the base layer, wherein the electrically conductive layer is separated from the base layer by a fourth electrically insulating layer, wherein the electrically conductive layer contacts the second trench gate electrode, and wherein the insulated gated bipolar transistor comprises a fifth insulating layer arranged on the emitter side on top of the electrically conductive layer, the fifth insulating layer having a recess such that the electrically conducting layer electrically contacts the emitter electrode.