Lateral double-diffused transistor and manufacturing method thereof

Abstract

The invention relates to the technical field of semiconductors, and provides a lateral double-diffused transistor and a manufacturing method thereof. The formed lateral double-diffused transistor comprises: a buried layer, a first epitaxial layer and a second epitaxial layer which are sequentially formed on a substrate, and a plurality of isolation layers transversely arranged between the first epitaxial layer and the second epitaxial layer at intervals; a first drift region located in the second epitaxial layer, high-voltage well regions located on the two sides of the first drift region, anda plurality of floating doped regions transversely distributed in the first drift region at intervals; a plurality of grooves formed in the upper surface of the second epitaxial layer at intervals; and a plurality of body regions transversely distributed between two adjacent grooves on the second epitaxial layer at intervals, wherein each body region is in contact with isolation layers corresponding to the upper position and the lower position through the floating doped regions with the same doping type to form a body region with a super junction structure. According to the invention, the effects of enhancing body region depletion and RESURF can be realized in the device so as to obtain higher withstand voltage and lower on resistance, and the current capability of the device can be enhanced.

Description

technical field [0001] The present disclosure relates to the technical field of semiconductors, in particular to a lateral double-diffused transistor and a manufacturing method thereof. Background technique [0002] The BCD (Bipolar-CMOS-DMOS) process manufactures bipolar devices and CMOS devices on the same chip at the same time. It combines the advantages of high transconductance and strong load driving capability of bipolar devices with high integration and low power consumption of CMOS, so that they learn from each other and give full play to their respective advantages. More importantly, it integrates DMOS power devices, and DMOS can work in switch mode with extremely low power consumption. High power can be delivered to the load without expensive packaging and cooling systems. Low power consumption is one of the main advantages of the BCD process. [0003] Lateral double-diffused MetalOxide Semiconductor Field-Effect Transistor (LDMOSFET) is a good semiconductor, wh...

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Problems solved by technology

[0007] However, in the above-mentioned TRIPLE RESURF NLDMOS device structure, if the concentration of the floating P region is too high, the additional electric field on the surface near the drain terminal will increase, which will easily cause breakdown of the drain terminal; if the concentration of the floating P region is too low, it will Makes the on-resistance increase and the auxiliary depletion is also affected, resulting in reduced reliability of TRIPLE RESURF NLDMOS

At the same time, the RESURF in this scheme is realized by only using the P-type floating area, and it is difficult to further improve the performance of NLDMOS devices

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