Trench type insulated gate bipolar transistor and preparation method thereof

Abstract

The invention provides a trench type insulated gate bipolar transistor and a preparation method thereof, which belong to the technical field of power semiconductors. According to the invention, a narrow bandgap semiconductor material is used to form a conductive channel and form ohmic contact with emitter metal due to the characteristics of high channel mobility of a narrow bandgap material such as silicon and small ohmic contact resistance with the emitter metal; channel resistance and ohmic resistance are reduced; the forward conduction voltage drop of a device is reduced; in addition, due to the characteristic of high critical breakdown field strength of a wide bandgap material such as silicon carbide, the device is not limited by a gate oxide layer and prevented from avalanche breakdown; the position of a breakdown point is changed; the breakdown voltage of the device is improved to a certain extent, so that the thickness of a drift region can be appropriately reduced at a certainvoltage level; the forward conduction voltage drop and the turn-off loss are further reduced; and the trade-off relationship between the turn-on voltage drop and the turn-off loss is optimized. In addition, the invention further provides a preparation method of the trench type insulated gate bipolar transistor.

Description

technical field [0001] The invention belongs to the technical field of power semiconductors, and in particular relates to a trench type insulated gate bipolar transistor and a preparation method thereof. Background technique [0002] figure 1 It shows a semi-cellular structure of a traditional trench type all-silicon-based IGBT device. Although the IGBT has a conductance modulation effect, which reduces the forward conduction voltage drop to a certain extent, in order to achieve a higher withstand voltage, it must not The thickness of the drift region is not increased, but this increases the conduction voltage drop. Therefore, it is necessary to increase the back injection efficiency to reduce the conduction voltage drop. The increase in injection efficiency causes the unbalanced carrier extraction during the turn-off process. The number increases, thereby increasing the turn-off time, increasing the turn-off loss, and deteriorating the trade-off relationship between the co...

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Problems solved by technology

[0002] figure 1 It shows a semi-cellular structure of a traditional trench type all-silicon-based IGBT device. Although the IGBT has a conductance modulation effect, which reduces the forward conduction voltage drop to a certain extent, in order to achieve a higher withstand voltage, it must not The thickness of the drift region is not increased, but this increases the conduction voltage drop. Therefore, it is necessary to increase the back injection efficiency to reduce the conduction voltage drop. The increase in injection efficiency causes the unbalanced carrier extraction during the turn-off process. The number increases, thereby increasing the turn-off time, increasing the turn-off loss, and deteriorating the trade-off relationship between the conduction voltage drop and the turn-off loss

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