MOSFET device with silicon carbide single-side deep L-shaped base region structure and preparation method of MOSFET device

Abstract

The invention relates to an MOSFET device with a silicon carbide single-side deep L-shaped base region structure and a preparation method of the MOSFET device. The MOSFET device comprises a gate dielectric layer, a base region which comprises a first base region and a second base region located on the two sides of the gate dielectric layer respectively, a current diffusion layer located between the gate dielectric layer and the second base region, a drift layer located on the lower surfaces of the base region and the current diffusion layer, a substrate layer located on the lower surface of the drift layer, a drain electrode located on the lower surface of the substrate layer, a polycrystalline silicon layer positioned on the inner surface of the gate dielectric layer, a gate electrode located on the upper surface of the polycrystalline silicon layer, a first source region located on the upper surface of a preset region of the base region, a second source region located on the upper surface of the rest region of the base region, and a source electrode located on the upper surfaces of the first source region and the second source region. According to the MOSFET device, by changing the structure of the single-side P-type base region, under the condition that the cell area of the device is not enlarged, the electric field aggregation at the groove-gate corner is reduced, and the breakdown voltage of the device is improved.

Description

technical field [0001] The invention belongs to the technical field of microelectronics, and in particular relates to a MOSFET device with a silicon carbide single-side deep L-shaped base structure 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 the traditional groove gate structure MOSFET, the electric field concentration at the corner of the gate dielectric layer leads to the breakdown of the gate dielectric layer, causing the breakdown of the d...

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Problems solved by technology

[0003] In the traditional groove gate structure MOSFET, the electric field concentration at the corner of the gate dielectric 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

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