A 4h-sic side gate integrated sbd MOSFET device and its preparation method

Abstract

The invention relates to a 4H-SiC side-gate integrated SBD MOSFET device and a preparation method thereof. The MOSFET device comprises: a substrate layer; a drift layer located on the upper surface of the substrate layer; a masking layer and a base region respectively located on the upper surface of the drift layer; The Tertyl electrode is located on the upper surface of the masking layer; the first source is located on the upper surface of the masking layer and the upper surface of the Schottky electrode; the gate dielectric layer is located on the upper surface of the first source electrode, the upper surface of the masking layer and the second The upper surface of the three regions; the polysilicon gate layer, located on the inner surface of the gate dielectric layer; the first source region and the second source region, both located on the upper surface of the base region; the second source electrode, located on the first source region and the second source region The surface; the gate, located on the upper surface of the polysilicon gate layer; the drain, located on the lower surface of the substrate layer. The invention eliminates the bipolar degeneration effect by forming the SBD diode on the side wall of the groove gate structure, reduces the turn-on voltage of the device diode in the working mode, increases the switching speed of the device, reduces the switching power consumption of the device, and improves the performance of the device .

Description

technical field [0001] The invention belongs to the technical field of microelectronics, and in particular relates to a 4H-SiC side-gate integrated SBD MOSFET device and a preparation method thereof. Background technique [0002] Silicon carbide, a wide bandgap semiconductor material, has excellent physical and chemical properties such as large bandgap width, high critical breakdown electric field, high thermal conductivity and high electron saturation drift velocity, and is suitable for high temperature, high pressure, high power, and radiation resistance semiconductor devices. In the field of power electronics, power MOSFET devices have been widely used. It has the characteristics of simple gate drive and short switching time. [0003] In traditional trench-gate structure MOSFET devices, the electric field concentration at the corner of the gate oxide layer leads to the breakdown of the gate dielectric layer, causing the device to break down below the rated breakdown volt...

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Problems solved by technology

[0003] In traditional trench-gate structure MOSFET devices, the electric field concentration at the corner of the gate oxide layer leads to the breakdown of the gate dielectric layer, causing the device to break down below the rated breakdown voltage, which seriously affects the forward blocking characteristics of the device. Due to the high turn-on voltage of the parasitic diode of the device, the slow switching speed, the large switching power consumption, the large amount of reverse recovery charge, and the introduction of bipolar degradation effects, which seriously affect the performance of the device, the traditional structure is often used in parallel with SBD diodes, but this structure Will increase module area and cost

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