Novel silicon carbide MOSFET (Metal Oxide Semiconductor Field Effect Transistor)

Abstract

The invention relates to a semiconductor device, and in particular discloses a novel silicon carbide MOSFET (Metal Oxide Semiconductor Field Effect Transistor) which is applied to occasions of electrical equipment such as an alternating current motor, a frequency converter, a switch power supply, traction transmission equipment and the like under high-voltage conditions. The novel silicon carbide MOSFET comprises a drain electrode (1) which is arranged at a lower end as well as a source electrode (8) and a gate electrode (9) which are arranged at an upper end, wherein a buffer region (2) and a drift region (3) are sequentially connected above the drain electrode (1), a source region (7) is arranged below the source electrode (8), a gate insulation layer (5) is arranged below the gate electrode (9), a P-type well region (6) is arranged below the source region (7), and a P-type doping region (4) is arranged below the gate insulation layer (5). According to the invention, on the basis of a common MOSFET structure, the doping region with low concentration is additionally arranged on the surface of a substrate below the gate electrode so that an electric field in the gate insulation layer is weakened when the high voltage is applied to the device, thereby lowering the breakdown probability of the insulation layer and improving the integral withstand voltage of the silicon carbide MOSFET.

Description

technical field [0001] The invention relates to a semiconductor device, in particular to a novel silicon carbide MOSFET device used in electrical equipment under high voltage conditions, such as AC motors, frequency converters, switching power supplies, traction drives and the like. Background technique [0002] The main structure of a metal oxide field effect transistor (MOSFET) includes an emitter region, a channel region, and a drift region. By applying an electric field perpendicular to the surface of the material, an inversion layer is formed on the surface close to the gate to form a conductive channel. Due to the principle of unipolar conduction, MOSFET devices have the advantage of high switching speed. [0003] However, during the design and application process of silicon carbide MOSFET devices with higher withstand voltage, the breakdown of the gate insulating material leads to early breakthrough of the device, which limits the design and application of higher with...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the breakdown problem of the gate insulation layer in current high-voltage silicon carbide MOSFET design, the present invention proposes a novel silicon carbide MOSFET

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