Superjunction device and method of manufacturing the same

Abstract

The invention discloses a super-junction device. At least one of an N type column and a P type column in each super-junction unit is of a vertical three-section structure having doping concentrations;the vertical three-section structure includes a bottom section, a middle section, and a top section along a vertical direction; the doping concentration of the middle section is lower than the dopingconcentration of the bottom section; the doping concentration of the middle section is lower than the doping concentration of the top section; after the column of the vertical three-section structureis depleted, impurity ions of the middle section, the bottom section, and the top section form an electric field trap in the middle section; and the electric field trap enhances the difficulty of being extracted of residual minority carries, and therefore, the softness factor of the reverse recovery of the device can be increased. The invention also discloses a manufacturing method of the super-junction device. With the manufacturing method of the invention adopted, the reverse recovery characteristic of the body diode of the device and the output capacitance characteristic of the device canbe significantly improved, the breakdown voltage of the device can be increased, and the output capacitance characteristic of the device can be adjusted.

Description

technical field [0001] The invention relates to the field of manufacturing semiconductor integrated circuits, in particular to a super junction device; the invention also relates to a method for manufacturing the super junction device. Background technique [0002] The super junction structure is composed of alternately arranged N-type pillars and P-type pillars. If the superjunction structure is used to replace the N-type drift region in the vertical double-diffused MOS transistor (Vertical Double-diffused Metal-Oxide-Semiconductor, VDMOS) device, the conduction path is provided through the N-type column in the conduction state, and when the conduction The P-type column does not provide a conduction path; in the off state, the PN column jointly bears the reverse bias voltage, forming a super-junction metal-oxide-semiconductor field-effect transistor (Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET). The super-junction MOSFET can greatly reduce the on-resistance o...

AI Technical Summary

Problems solved by technology

However, in the trench-filling device, during the reverse recovery process of the body diode of the device, since the P-type column 4 and the N-type column 3 are completely depleted at a lower Vds, so in the recovery process There is no remaining carrier in it, which makes the di / dt of reverse recovery very large, which is easy to cause voltage oscillation, and the device is also easy to damage

At the same time, the nonlinearity of the output capacitance of the device is also difficult to adjust

Images