Super junction and manufacturing method thereof

Abstract

The invention discloses a super junction, comprising grooves which are formed in a first epitaxial layer of a first conductivity type, second epitaxial layers of a second conductivity type which are formed in the grooves, do not completely fill the grooves and define V-shaped openings, and first dielectric layers and non-doped semiconductor layers which fill the V-shaped openings, wherein the non-doped semiconductor layers are located on the tops of the first dielectric layers and seal the first dielectric layers inside. Second conductivity type columns are formed by the second epitaxial layers filling the grooves, first conductivity type columns are formed by the first epitaxial layer between the grooves, and the first conductivity type columns and the second conductivity type columns arealternately arranged to form the super junction. The invention further discloses a manufacturing method of the super junction. By adopting the structure in which the grooves are filled with the epitaxial layers and the dielectric layers, the breakdown voltage of the device and the in-plane uniformity of the breakdown voltage can be improved, the dielectric layers in the grooves can be prevented from being damaged, and the problems of unstable process and device failure caused by damage can be avoided.

Description

technical field [0001] The invention relates to the field of manufacturing semiconductor integrated circuits, in particular to a super junction; the invention also relates to a method for manufacturing the 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. The latter ...

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Problems solved by technology

[0011] However, due to the large number of oxide layer wet etching steps in the subsequent process after the formation of the super junction, the oxide layer 106 filled in the V-shaped port 105 is easily damaged, resulting in process instability and even directly leading to device failure.

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