Trench type super junction and method of making the same

Abstract

The invention discloses a trench type super junction. The trench type super junction comprises a plurality of trenches formed in a first conductive type first epitaxial layer, wherein each trench is filled with a second conductive type second epitaxial layer which is not full of the trench; the gaps of the trenches are fully filled with first conductive type third epitaxial layers; and the sizes of the second epitaxial layers of respective super junction units are the same, while the sizes of the first epitaxial layers and the third epitaxial layers are also the same, so that the sum of the total doping amount of the first conductive type of the first and third epitaxial layers in the respective super junction units is matched with the sum of the total doping amount of the second conductive type of the second epitaxial layers. The invention also discloses a manufacturing method of the trench type super junction. Charge matching of respective super junction units can be realized in a self-alignment manner, in-plane uniformity of the reverse breakdown voltage of a super junction device can be improved, and the process window range of the reverse breakdown voltage can be enlarged.

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

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