Electron injection enhanced high voltage IGBT and manufacturing method thereof

Abstract

The invention discloses an electron injection enhanced high voltage IGBT. Gate oxide layers are arranged in a trench in a middle part on an n- silicon substrate and flat surface parts at two sides, and a polycrystalline silicon layer is arranged on the gate oxide layers, which is called a trench-planar gate G; two sides of the trench-planar gate G are each provided with a p base region on the n- silicon substrate, the p base regions are isolated from the trench-planar gate G through the gate oxides, and in each p base region an upper surface of an n+ emitter region and the p base region are short-circuited to form an emitting electrode E; joints of the upper side of an n- drift region and bottoms of the p base regions at the two sides are provided with discrete n carrier storage layers; and an n field stop layer, a p+ collector region and a collector electrode C are arranged in sequence under the n- drift region. The high voltage IGBT structure provided by the invention remarkably improves saturation voltage when a device is turned on, blocking voltage is high, on-state loss is low, and latch current density is relatively high.

Description

technical field [0001] The invention belongs to the technical field of power semiconductor devices, and relates to an electron injection-enhanced high-voltage IGBT, and also relates to a method for manufacturing the electron-injection enhanced high-voltage IGBT. Background technique [0002] One of the key technical issues that need to be solved in the development of high-voltage IGBTs is to reduce the saturation voltage in the on-state. In the existing planar gate IGBT and trench gate IGBT structures, a carrier storage (CS) layer is usually introduced to generate an electron injection enhancement effect, thereby increasing the conductance modulation during the turn-on period and reducing the saturation voltage. [0003] However, for the planar gate IGBT structure, although the CS layer can effectively reduce the saturation voltage and have a high short-circuit capability, it is still prone to latch-up at high temperatures, resulting in a decrease in the reliability of the d...

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Problems solved by technology

[0003] However, for the planar gate IGBT structure, although the CS layer can effectively reduce the saturation voltage and have a high short-circuit capability, it is still prone to latch-up at high temperatures, resulting in a decrease in the reliability of the device.

For the trench gate IGBT structure, although the latch-up effect can be effectively suppressed, in order to obtain a higher short-circuit capability, a wide gate spacing is required, resulting in a decrease in cell density and a decrease in current capacity; at the same time, due to the deep trench, the process higher cost

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