Broad-band-gap semiconductor lateral super-junction double-diffused transistor with multi-ring electric field modulation substrate

Abstract

The invention discloses a broad-band-gap semiconductor lateral super-junction double-diffused transistor with a multi-ring electric field modulation substrate. According to the structure, the substrate below a drifting region adopts a charge compensation multi-ring structure; by virtue of the multi-ring charge compensation of the substrate, a longitudinal space charge region of a lateral double-diffused metal oxide semiconductor field effect transistor can be expanded; meanwhile, by virtue of the multi-ring structure, a new electric field peak can be introduced to a surface lateral electric field and an in-vivo longitudinal electric field separately, so that the problem of substrate-assisted depletion existing the lateral super junction can be eliminated; and the surface lateral electric field and the in-vivo longitudinal electric field can be modulated synchronously through an electric field modulation effect, so that the surface lateral electric field and the in-vivo longitudinal electric field can be optimized synchronously. By virtue of the structure, the problem of breakdown voltage saturation caused by limited longitudinal voltage withstand of the lateral double-diffused transistor can be broken through, and the problem of substrate-assisted depletion existing the lateral super junction can be eliminated; and in addition, the surface lateral electric field and the in-vivolongitudinal electric field can be optimized synchronously, so that the breakdown voltage of a device can be highly improved.

Description

technical field [0001] The invention relates to the technical field of semiconductor power devices, in particular to a lateral superjunction double-diffused metal oxide semiconductor field effect transistor. Background technique [0002] Lateral Double-diffused MOSFET (LDMOS) has the advantages of easy integration, good thermal stability, good frequency stability, low power consumption, multi-subconduction, small power drive, and switching speed Advanced advantages are at the heart of smart power circuits and high-voltage devices. However, due to the limitations of the first two generations of semiconductor materials represented by Si and GaAs, the third generation of wide-bandgap semiconductor materials has developed rapidly because of its excellent performance. Wide bandgap semiconductor materials have the characteristics of large bandgap width, high electron drift saturation velocity, small dielectric constant, and good electrical conductivity. Their superior properties ...

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Problems solved by technology

However, there are three problems in the super junction applied to LDMOS: 1) The P-type substrate of N-channel LDMOS assists in depleting the N-type region of the super junction, resulting in substrate-assisted depletion (SAD) Problem; 2) The traditional SJ-LDMOS only forms electric field modulation between the N region and the P region of the super junction, but there is no electric field modulation on the surface; 3) Although the SJ-LDMOS that eliminates the substrate-assisted depletion can completely deplete the drift region However, due to the influence of the longitudinal electric field, the surface electric field distribution is not uniform

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