Silicon carbide Schottky diode and preparation method thereof

A Schottky diode, silicon carbide technology, applied in semiconductor/solid-state device manufacturing, electrical components, circuits, etc., can solve the problem of high electric field strength at the edge of the injection junction, low reverse withstand voltage of silicon carbide Schottky diode chips, and reliable It can improve the reverse withstand voltage and reliability, protect from damage, and improve uniformity.

Pending Publication Date: 2019-12-17
GLOBAL ENERGY INTERCONNECTION RES INST CO LTD +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the unevenness of the edge of the P-type junction region caused by the vertical injection method in the prior art, resulting in excessive electric field strength at the edge of the injection junction, and the reverse resistance of the silicon carbide Schottky diode chip. Defects of low voltage and poor reliability, thereby providing a silicon carbide Schottky diode and a preparation method thereof

Method used

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  • Silicon carbide Schottky diode and preparation method thereof
  • Silicon carbide Schottky diode and preparation method thereof
  • Silicon carbide Schottky diode and preparation method thereof

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preparation example Construction

[0054] In addition, the present invention also provides a kind of preparation method of above-mentioned Schottky diode, comprises the following steps:

[0055] Rotate around the blind hole on one side of the substrate and perform ion implantation into the blind hole at the same time to form a P-type junction in the blind hole. During the ion implantation process, the angle between the direction of ion implantation and the substrate is an obtuse angle or acute angles.

[0056] The angle β between the direction of the ion implantation and the substrate is 75°-90°; preferably, the angle β between the direction of the ion implantation and the substrate is 75°.

[0057] The implantation energy of the ion implantation is 30-500KeV, the implantation temperature is 500-600°C, and the rotation angle α of the rotation is 0-270°. Preferably, the rotation angle α is 0°, 90°, 180°, or 270°.

[0058] The depth h of the blind hole is 300-500nm;

[0059] The ions of the ion implantation ar...

Embodiment 1

[0069] This embodiment provides a method for preparing a silicon carbide Schottky diode, such as figure 2 Shown is a process flow diagram of a method for preparing a silicon carbide Schottky diode, and the method specifically includes the following steps:

[0070] Cleaning lithography: cleaning the silicon carbide substrate 2 with the silicon carbide epitaxial layer 3, and then aligning and marking the patterns used in lithography on the silicon carbide epitaxial layer 3;

[0071] Making a mask layer: on the silicon carbide epitaxial layer 3, first make a first mask layer silicon dioxide layer by chemical vapor deposition, the thickness of the silicon dioxide layer is 2um; then on the first mask layer silicon dioxide Spin-coat positive photoresist on the layer as the second mask layer, perform pre-baking at 120°C, and expose under ultraviolet light;

[0072] Photolithography: photolithography is carried out on the above samples, and the pattern is photoetched onto the photor...

Embodiment 2

[0090] This embodiment provides a method for preparing a silicon carbide Schottky diode, such as figure 2 Shown is a process flow diagram of a method for preparing a silicon carbide Schottky diode, and the method specifically includes the following steps:

[0091] Cleaning lithography: cleaning the silicon carbide substrate 2 with the silicon carbide epitaxial layer 3, and then aligning and marking the patterns used in lithography on the silicon carbide epitaxial layer 3;

[0092] Make a mask layer: first make a first mask layer silicon dioxide layer on the silicon carbide epitaxial layer 3 by chemical vapor deposition, the thickness of the silicon dioxide layer is 2.5um; Spin-coat positive photoresist on the silicon layer as the second mask layer, perform prebaking at 120°C, and expose under ultraviolet light;

[0093] Photolithography: photolithography is carried out on the above samples, and the pattern is photoetched onto the photoresist of the second mask layer;

[009...

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Abstract

The invention provides a Schottky diode and a preparation method thereof. The Schottky diode comprises a substrate and a plurality of P-type junctions. Each P-type junction comprises a first end partand a second end part which are opposite to each other, and the P-type junction is embedded in the substrate so that the second end part is located in the substrate, and the adjacent P-type junctionsare arranged at intervals. The connection line connecting the first end part and the second end part and located on the side surface of the P-junctions is a smooth arc line. With application of the structure that the connection line connecting the first end part and the second end part and located on the side surface of the P-type junctions is the smooth arc line, the electric field strength injected into the edge of the P-type junctions is more uniform, and the reverse withstand voltage and the reliability of the silicon carbide Schottky diode chip can be further improved.

Description

technical field [0001] The invention relates to the technical field of power semiconductor devices, in particular to a silicon carbide Schottky diode and a preparation method thereof. Background technique [0002] Silicon carbide is one of the most attractive materials among the third-generation semiconductor materials. It has the advantages of large critical electric field, large band gap, and high electron drift speed at high temperature. Therefore, it is widely used in the production of high-temperature, high-voltage, high-power, radiation-resistant Among them, silicon carbide Schottky diodes have the functions of rectification and freewheeling in power electronics technology, so they are widely used in power conversion circuits. [0003] At present, most silicon carbide Schottky diodes use ion implantation technology, combined with photolithography, etching and other processes to achieve in-plane controllable area implantation; due to the extremely high temperature requi...

Claims

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Application Information

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IPC IPC(8): H01L29/872H01L29/06H01L21/04
CPCH01L29/872H01L29/0619H01L21/046H01L21/047H01L29/6606
Inventor 姜春艳吴昊田亮吴军民潘艳
Owner GLOBAL ENERGY INTERCONNECTION RES INST CO LTD
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