Cell structure of trench gate igbt, its preparation method and trench gate igbt

Abstract

The present disclosure provides a cell structure of a trench gate IGBT, a preparation method thereof, and a trench gate IGBT. The cell structure includes a substrate of a first conductivity type; a drift layer of the first conductivity type located above the substrate; a drift layer of the first conductivity type located on the substrate A first trench gate located in the center of the cellular structure within the drift layer and a second trench gate penetrating through the first trench gate; an emitter metal layer located above the drift layer; wherein, the The first trench gate is connected to the emitter metal layer through a first connection hole, and the second trench gate is isolated from the emitter metal layer by an interlayer dielectric layer. Without changing the area of ​​the cell, the problem of increasing the chip area caused by the false gate is solved by integrating the real and false gates in one cell. Not only does it not affect the spacing between the trenches and the conductive channel, but also increases the contact area of ​​the emitter, improves the conductance modulation effect, and reduces the conduction voltage drop while the blocking voltage remains unchanged.

Description

technical field [0001] The present disclosure relates to the technical field of semiconductor devices, in particular to a cell structure of a trench gate IGBT, its preparation method and the trench gate IGBT. Background technique [0002] Insulated Gate Bipolar Transistor (IGBT) is a composite fully-controlled voltage-driven power semiconductor device composed of BJT (bipolar transistor) and MOSFET (metal oxide semiconductor field effect transistor). In addition to the low on-resistance and high withstand voltage characteristics of BJT and MOSFET, it also has many excellent characteristics such as voltage control, large input impedance, low driving power, small on-resistance, and low switching loss. It is widely used in medium and high power Power Electronics Systems. [0003] However, due to the relatively small size of the trench gate IGBT with the traditional structure, the current density is relatively high and the current is concentrated, so it is easy to cause a short...

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Problems solved by technology

[0004] In view of the above problems, the present disclosure provides a trench gate IGBT cell structure, its preparation method and trench gate IGBT, which solves the problem of increased chip area caused by dummy gates in the prior art

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