Elemental semiconductor lateral super-junction double-diffused transistor with multi-ring electric field modulation substrate

Abstract

The invention discloses an elemental semiconductor lateral super-junction double-diffused transistor with a multi-ring electric field modulation substrate. A substrate under a drift region in the structure is of a charge compensation multi-ring structure. The substrate multi-ring charge compensation can help expand the longitudinal space charge region of a lateral double-diffused metal oxide semiconductor field effect transistor. Moreover, the multi-ring structure can introduce a new electric field peak to the distribution of the surface transverse electric field and the inside longitudinal electric field, and can eliminate the substrate assisted depletion problem of super junction. The surface transverse electric field and the inside longitudinal electric field are simultaneously modulated using the electric field modulation effect, so that the surface transverse electric field and the inside longitudinal electric field can be simultaneously optimized. The structure not only breaks through the breakdown voltage saturation problem due to the limited longitudinal withstand voltage of the lateral double-diffused transistor, but also can eliminate the substrate assisted depletion problem of super junction, make the surface transverse electric field and the inside longitudinal electric field simultaneously optimized and greatly improve the breakdown voltage of the device.

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] One of the most critical technologies for realizing power integrated circuit PIC (power integrated circuit) is that LDMOS (lateral double-diffused MOSFET) must have low on-resistance to reduce the power loss of PIC integrated circuit, while MOS devices are off-state. The 2.5th power relationship between the breakdown voltage and the on-state on-resistance limits the high-power application range of MOS devices. The super junction structure alleviates this contradiction to the 1.33th power, so the super junction technology is applied Forming SJ-LDMOS from LDMOS is an effective way to realize ultra-low power loss PIC. However, there are three problems in the super junction applied to LDMOS: 1) The P-type substrate of N-channel LDMOS assists in...

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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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