Trench type super junction and manufacturing method therefor

Abstract

The invention discloses a trench type super junction. The trench type super junction comprises a plurality of trenches, wherein each trench is filled with a second conductive type first epitaxial layer; the trench with the smallest size is to be fully filled with the first epitaxial layer; the trench, which is not fully filled with the first epitaxial layer, is also filled with a second dielectriclayer; and the second dielectric layer is overlaid on the surface of the first epitaxial layer to fully fill each trench. By adoption of the second dielectric layer, the total doping amount of a second conductive type thin layer is determined by the first epitaxial layer, so that influence to the breakdown voltage of the super junction from the volume difference of the trenches is lowered, and in-plane uniformity of the breakdown voltage of the super junction is improved. The invention also discloses a manufacturing method of the trench type super junction. By virtue of the trench type superjunction and the manufacturing method therefor, the in-plane uniformity of the breakdown voltage of the super junction is improved; and the manufacturing method is simple in process and is of significance meaning to the quantity production of the super junction process platform.

Description

technical field [0001] The invention relates to the field of semiconductor integrated circuit manufacturing, in particular to a trench super junction; the invention also relates to a method for manufacturing the trench super junction. Background technique [0002] The super junction is composed of alternately arranged P-type thin layers (also called P-type pillars) and N-type thin layers (also called N-type pillars) formed in a semiconductor substrate, and the matching is completed by using P-type thin layers and N-type thin layers The formed depletion layer supports the reverse withstand voltage while maintaining a small on-resistance. [0003] The pillar structure of the PN interval of the super junction is the biggest feature of the super junction. Currently, there are mainly two methods for manufacturing the pillar structure of the PN spacer, one is obtained by multiple epitaxy and ion implantation, and the other is made by deep trench etching and epitaxy (EPI) filling....

AI Technical Summary

Problems solved by technology

In the etching of trenches, the morphology of trenches in different regions of the same semiconductor substrate is not exactly the same, and the reverse breakdown voltage of super junction devices is greatly affected by the morphology of trenches, making the same crystal The uniformity of the reverse breakdown voltage of the super junction device on the circle is poor

Images