Trench Schottky diode terminal structure and preparation method thereof

A technology of Schottky diode and terminal structure, which is applied in semiconductor/solid-state device manufacturing, electrical components, circuits, etc., can solve problems such as device structural characteristics and unstable process methods, improve withstand voltage and reliability performance, reduce The effect of small leakage current and increased reverse withstand voltage capability

CN104900719AInactive Publication Date: 2015-09-09SHANGHAI GREENPOWER ELECTRONICS
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2015-09-09
Estimated Expiration
Not applicable · inactive patent

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Abstract

The present invention discloses a trench Schottky diode terminal structure which comprises an N-type silicon substrate. One side of the N-type silicon substrate is also provided with an N-type silicon epitaxial layer which is internally provided with a plurality of first trenches, and one side of the trenches is provided with a terminal ring structure. The invention also discloses a preparation method of the trench Schottky diode terminal structure. Due to the depletion of the N-type silicon epitaxial layer by the first trenches, a depletion layer is formed at the surface of the N-type silicon epitaxial layer of each of the first trenches, with the increase of reverse voltage, the depletion layers spread to the depth (horizontal and vertical directions) of a silicon surface, thus depletion layers between adjacent trenches are connected, which is equivalent to the significant increase of the depletion layer in the vertical direction, thus the reverse voltage withstand ability of a device is increased, the leakage current is reduced at the same time, and a terminal ring is added at the edge part of the device to improve the voltage withstand and reliability performance of the device.
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Description

technical field

[0001] The invention relates to a diode terminal structure, more precisely a trench Schottky diode terminal structure, and also relates to a preparation method of the trench Schottky diode terminal structure. Background technique

[0002] Schottky diodes occupy a place in the field of power devices due to their good forward conduction characteristics and fast switching speed, but because they are manufactured using metal-semiconductor contacts, their reverse withstand voltage and reverse leakage conditions are not good.

[0003] In the process conditions of the prior art, the morphology of the polysilicon on the sidewall of the large-sized trench cannot be well controlled, which in turn affects the contact between it and the metal layer, resulting in the instability of the structural characteristics of the terminal ring. At the same time, the sidewall The strip width of polysilicon is too narrow, which is not conducive to the photolithography alignment of the...

Examples

specific Embodiment approach

[0036] Such as figure 1 As shown, a trench Schottky diode termination structure includes an N-type silicon substrate 1, and one side of the N-type silicon substrate 1 is also provided with an N-type silicon epitaxial layer 2, and the N-type silicon epitaxial layer 1 There are several first grooves 21 inside, and a terminal ring structure 4 is arranged on one side of the first grooves 21 .

[0037] The terminal ring structure 4 of the present invention includes a second trench 22 and a third trench 23 disposed in the N-type silicon epitaxial layer, and the size of the third trench is larger than that of the first trench 21, and The size of the second groove 22 is the same as that of the first groove 21. In this embodiment, the first groove 21 and the second groove 22 are arranged at equal intervals, and the first groove 21 and the second groove 22 are small in size. groove, and the third groove 23 is a third groove.

[0038] The present invention also includes a first oxide l...