Split-gate structure in trench-based silicon carbide power device

Abstract

An integrated structure includes a plurality of split-gate trench MOSFETs. A plurality of trenches are formed within the silicon carbide substrate composition, and each trench is lined with a passivation layer, each trench being substantially filled with a first conductive region a second conductive region and an insulating material having a dielectric constant similar to a dielectric constant of the silicon carbide substrate composition. The first conductive region is separated from the passivation layer by the insulating material. The first and second conductive regions form gate regions for each trench MOSFET. The first conductive region is separated from the second conductive region by the passivation layer. A doped body region of a first conductivity type formed at an upper portion of the substrate composition and a doped source region of a second conductivity type formed inside the doped body region.

Description

technical field [0001] Embodiments of the present invention relate to power integrated circuits, and more specifically to integrated structures including split-gate trench MOSFETs in silicon carbide substrates. Background technique [0002] Most semiconductor power devices are fabricated using silicon as the substrate. Currently, the research and development trend is moving towards the use of silicon carbide (SiC) to fabricate power devices, especially high-voltage power devices. Silicon carbide has many favorable properties compared to silicon and can operate at high temperature, high power, and high frequency. In addition, SiC power devices have very low on-resistance (R DSon ) and high thermal conductivity, which is 500 to 1000 times higher than that of silicon power devices, so it can be used to prepare power devices. [0003] Despite these favorable properties, SiC also has many less-than-ideal properties that make it difficult to fabricate trench-based power devices...

AI Technical Summary

Problems solved by technology

This high electric field stress can lead to catastrophic breakdown of the oxide

Although there are many processes that can reduce this field stress, these processes either reduce the on-resistance of the device or are not practical in the actual manufacturing process.

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