Short-channel semiconductor power device and preparation method therefor

Abstract

The invention discloses a short-channel semiconductor power device. The short-channel semiconductor power device comprises a silicon carbide wafer with a heavily doped layer, a first base region and asecond base region, a mask layer, a silicon dioxide layer, and a heavily doped source region, wherein a lightly doped epitaxial layer is arranged on the wafer; the first base region and the second base region are arranged in the epitaxial layer and isolated by a part of the epitaxial layer; the mask layer is arranged on the part, used for isolating the first base region and the second base region, of the epitaxial layer; the silicon dioxide layer is arranged on the outer surface of the mask layer; the heavily doped source region is positioned in the first base region and the second base region separately; a channel is formed between the heavily doped source region and a part of the epitaxial layer, wherein the doping concentrations of the first base region and the second base region are gradually increased from the upper surface of the channel part downwardly; by virtue of the downwardly and gradually increased channel width, the distance between the source region and a drift region is prolonged; and when the device is in a switch-off state, a drain junction depletion region can reach higher width, thereby improving voltage withstand of the device.

Description

technical field [0001] The invention relates to the field of electronic devices, in particular to a short-channel semiconductor power device. The invention also relates to methods of fabricating short-channel semiconductor power devices. Background technique [0002] Silicon carbide is an important semiconductor material. Silicon carbide power devices have high switching speed and low energy loss, so they are widely used in many fields. [0003] For SiC power devices such as MOSFETs, the channel resistance is an important component of the device on-resistance, especially when the device drift layer resistance is small. The reduction of channel resistance can be achieved by increasing the channel mobility or reducing the channel length, but due to the quality of the interface between silicon carbide and the oxide layer, it is difficult to effectively improve the channel mobility, so reduce the channel length It has become the main way to reduce the channel resistance. [...

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Problems solved by technology

In the case of short channel lengths, this results in very low withstand voltage of the power device

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