N type longitudinal silicon carbide MOS (metal oxide semiconductor) tube with high breakdown voltage

Abstract

An N type longitudinal silicon carbide MOS tube with high breakdown voltage comprises an N type substrate, wherein drain electrode metal and an N type drift region are arranged at two ends of the N type substrate respectively; a P type base region layer is arranged on the N type drift region; N type source regions and P type body contact regions distributed according to an array are arranged on the P type base region layer; N type drift region bulges are arranged between adjacent N type source regions; boundaries of the N type source regions extend into corresponding breakdown voltage improving regions; the breakdown voltage improving regions are rectangular regions formed by inner side boundary extension cords of four adjacent N type source regions; gate oxide layers are arranged on the N type drift region bulges, and boundaries of the gate oxide layers extend outwards and stop at the boundaries of the N type source regions; poly-silicon gates are arranged on the gate oxide layers; field oxide layers arranged on the poly-silicon gates and the N type source regions; the N type source regions and the P type body contact regions are connected with source electrode metal; and the surfaces of the poly-silicon gates are connected with gate metal.

Description

technical field [0001] The invention mainly relates to the field of high-voltage power semiconductor devices, specifically, an N-type vertical silicon carbide metal oxide semiconductor tube with high breakdown voltage, which is suitable for aerospace, aviation, oil exploration, nuclear energy and other fields. Background technique [0002] Silicon carbide material is a wide bandgap semiconductor material with large band gap, high breakdown voltage, high thermal conductivity, high electron saturation drift velocity, high electron mobility, high thermal conductivity, strong radiation resistance and chemical stability Excellent physical and chemical properties, such as good performance and compatibility with silicon integrated circuit technology, have become the preferred materials for manufacturing high-temperature, high-frequency, high-power, radiation-resistant, non-volatile memory devices and optoelectronic integrated devices. At present, developed countries represented by ...

AI Technical Summary

Problems solved by technology

However, in practice, the breakdown voltage of the vertical silicon carbide metal oxide semiconductor tube is smaller than the theory. On the one hand, because the P-type base region is in the shape of a spherical surface at the corner, when it is in the off state, the electric field lines at the spherical surface are very dense. , causing the electric field at the spherical surface of the P-type base region to be very strong. On the other hand, because each P-type base region is far away from the P-type base region at the adjacent diagonal, when it is in the cut-off state, even if the leakage voltage The depletion layer in the larger N-type drift region cannot be completely connected together, so the gate oxide and the P-type base region are not shielded from the high electric field, resulting in premature breakdown of the device

Images