Schottky layer structure, chip and diode

Abstract

The utility model provides a Schottky layer structure, a chip and a diode, and the Schottky layer structure comprises a main body section and an epitaxial section, and the main body section and the epitaxial section are integrally constructed into a pi-shaped structure. According to the Schottky layer structure, the Schottky layer with the pi-shaped structure is redesigned, so that the edge of the Schottky layer is prolonged, the weakest and easy-to-break place of the barrier region can be protected, and the rectification effect of the main body section can be ensured. According to the chip with the Schottky layer structure, the edge end of the Schottky layer extends to the center line position of the groove, so that the weakest edge position of the barrier region can be protected, the quality of the chip is improved, and the performance parameters of the chip are ensured.

Description

Technical Field

[0001] The present application belongs to the technical field of power device manufacturing, and in particular relates to a Schottky-based structure, a chip having the Schottky-based structure, and a diode manufactured using the chip equipped with the Schottky-based structure. Background Art

[0002] The Schottky structure is a key component of the Schottky barrier diode. Due to its extremely short reverse recovery time and low forward voltage drop, it is often used as a high-frequency, low-voltage, high-current rectifier diode, freewheeling diode, and protection diode. It is commonly found in telecommunication power supplies and inverters.

[0003] SBD Schottky diodes utilize a metal-semiconductor junction as a Schottky barrier to produce a rectifying effect, unlike the PN junction created by a semiconductor-semiconductor junction in conventional diodes. The existing Schottky layer structure consists of a horizontal segment grown along the epitaxial layer. Electric field lines are most concentrated at the edges, making them susceptible to breakdown. This can lead to leakage in the diode and directly affect product performance stability. Summary of the Invention

[0004] The present application provides a Schottky-based structure, a chip, and a diode, which solve the technical problem that the existing structure is easily broken down at its edge, thus affecting the stability of product performance.

[0005] To solve at least one of the above technical problems, the technical solution adopted in this application is:

[0006] A Schottky-based structure comprises a main section and an epitaxial section, wherein the main section and the epitaxial section are integrally constructed into a "π"-shaped structure.

[0007] Furthermore, the extension segments are placed at both ends of the main segment and are symmetrically arranged relative to the main segment.

[0008] Furthermore, the main body segment is a straight segment, and the extension segment is a curved surface structure that bends outward.

[0009] Furthermore, the length of the main section is greater than the length of the extension section.

[0010] A chip having the Schottky layer structure, wherein the Schottky layer is located between adjacent grooves on the front side of the epitaxial wafer, and the epitaxial segments are placed in the grooves.

[0011] Furthermore, the width of the epitaxial section is smaller than the width of the groove, and the depth thereof is smaller than the depth of the groove; wherein the width of the groove is 30-80 um; and the depth of the groove is 0.5-1.5 um.

[0012] Furthermore, the end of the extension segment is located at the centerline of the groove.

[0013] Furthermore, the trench further includes a PN junction located below the epitaxial segment; the epitaxial segment is located at one end of the PN junction close to the main segment.

[0014] Furthermore, a metal layer is provided above the Schottky layer; an oxide layer is provided between the metal layer and the epitaxial wafer, and a portion of the oxide layer is opposite to a portion of the metal layer and is provided on the PN junction.

[0015] A diode is provided with the Schottky-based structure and is manufactured from a chip adapted to the Schottky-based structure.

[0016] Using a Schottky layer structure designed in this application, a "π"-shaped Schottky layer is redesigned with its edges extended. This not only protects the weakest and most susceptible to breakdown areas of the barrier region, but also ensures the rectification effect of its main section. This application also proposes a chip with this Schottky layer structure, in which the edge of the Schottky layer is extended to the centerline of the trench, thereby protecting the weakest edge of the barrier region, improving chip quality, and ensuring its performance parameters. This application also proposes a diode made using a chip equipped with this Schottky layer structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of the Schottky-based structure in this application;

[0018] Figure 2 is a schematic diagram of a chip having the Schottky-based structure in this application;

[0019] Figure 3 yes Figure 2 Enlarged view of part A in the middle.

[0020] In the picture:

[0021] 10. Schottky layer 11. Main section 12. Epitaxial section

[0022] 20, epitaxial layer 30, oxide layer 40, trench

[0023] 50, PN junction 60, metal layer DETAILED DESCRIPTION

[0024] The present application is described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] This embodiment proposes a Schottky-based structure, such as Figure 1As shown, the Schottky layer 10 includes a main section 11 arranged horizontally and a peripheral section 12 extending outward, and the main section 11 and the peripheral section 12 are integrally constructed into a "π"-shaped structure. The peripheral sections 12 are located at both ends of the main section 11 and are symmetrically arranged relative to the main section 11.

[0026] In this embodiment, the main segment 11 is a straight segment, and the extension segment 12 is a curved structure that bends outward. The extension segment 12 includes a curved portion near one side of the main segment 11 and a horizontally arranged horizontal portion. Thus, the extension segments 12 at both ends and the main segment 11 in the middle together form a "π"-shaped Schottky-based structure. Furthermore, the length of the main segment 11 is greater than the length of any of the extension segments 12.

[0027] Because the electric field lines are most concentrated at the edges of the main section 11 at both ends of the Schottky layer 10, these locations are most susceptible to breakdown. Extending a curved surface structure outward from these edges not only reduces the density of electric field lines at these locations but also improves its ability to withstand breakdown. The curved surface of the epitaxial section 12 of this "π"-shaped Schottky layer 10 not only protects the electric field at the weakest point in the Schottky layer 10, improving its safety, but also reduces the probability of breakdown.

[0028] A chip having the Schottky-based structure, such as Figure 2 As shown, the Schottky layer 10 is located between adjacent trenches 40 on the front side of the epitaxial wafer, with the main segment 11 positioned closely against the epitaxial layer 20, and the epitaxial segments 12 on both sides positioned above the PN junction 50 within the trench 40. Specifically, the Schottky layer 10 includes the main segment 11 located on the surface of the epitaxial layer 20 and the epitaxial segment 12 located in the middle of the trench 40. The epitaxial segments 12 on both sides form a "π"-shaped gold semiconductor contact structure with the main segment.

[0029] like Figure 3 As shown, the epitaxial segment 12 positioned within the PN junction 50 has a lateral width W1 less than the lateral width W of the trench 40, and a depth H1 within the trench 40 less than the depth H of the trench 40. The width W of the trench 40 is 30-80 μm, and the depth H of the trench 40 is 0.5-1.5 μm. Preferably, the end of the epitaxial segment 12 is located at the centerline of the trench 40. The curved structure of the epitaxial segment 12 not only protects the electric field at the weakest point in the Schottky layer 10, improving its safety, but also reduces the probability of breakdown, ensuring the overall performance parameters of the chip.

[0030] Furthermore, trench 40 includes a PN junction 50 below epitaxial segment 12. Epitaxial segment 12 is positioned entirely above PN junction 50 and closely adheres to the inner side of the PN junction. Epitaxial segment 12 is positioned near one side of PN junction 50, near main segment 11. Main segment 11 and epitaxial segments 12 on either side of the main segment 11 form a "π"-shaped Schottky layer 10.

[0031] Furthermore, a metal layer 60 and an oxide layer 30 are provided above the Schottky layer 10, wherein the oxide layer 30 is disposed between the metal layer 60 and the epitaxial layer 20. Furthermore, within the trench 40, only portions of the oxide layer 30 and the metal layer 60 are positioned opposite each other and on the PN junction 50. This is because a "π"-shaped screen is first etched onto the oxide layer 30, and then metal Ni / NiPt is sputtered onto the surface of the epitaxial layer 20 and the PN junction 50 in the trench 40, forming the "π"-shaped Schottky layer 10. Furthermore, a metal layer 60 is deposited and grown on the basis of the "π"-shaped Schottky layer 10 and the oxide layer 30, thereby forming a chip structure having a terminal region field plate with a front electrode.

[0032] A diode is provided with the Schottky-based structure and is manufactured from a chip adapted to the Schottky-based structure.

[0033] Using a Schottky layer structure designed in this application, a "π"-shaped Schottky layer is redesigned with its edges extended. This not only protects the weakest and most susceptible to breakdown areas of the barrier region, but also ensures the rectification effect of its main section. This application also proposes a chip with this Schottky layer structure, in which the edge of the Schottky layer is extended to the centerline of the trench, thereby protecting the weakest edge of the barrier region, improving chip quality, and ensuring its performance parameters. This application also proposes a diode made using a chip equipped with this Schottky layer structure.

[0034] The above embodiments of the present application are described in detail. The contents described are only preferred embodiments of the present application and should not be considered to limit the scope of implementation of the present application. All equivalent changes and improvements made within the scope of the present application should still fall within the scope of the patent application.

Claims

1. A Schottky-based structure, characterized in that: It includes a main section and an extension section, and the main section and the extension section are integrally constructed into a "π"-shaped structure.

2. A Schottky-based structure according to claim 1, characterized in that: The extension segments are placed at both ends of the main segment and are symmetrically arranged relative to the main segment.

3. A Schottky-based structure according to claim 1 or 2, characterized in that: The main body segment is a straight line segment, and the extension segment is a curved surface structure that bends outward.

4. The Schottky-based structure according to claim 3, characterized in that: The length of the main body segment is greater than the length of the extension segment.

5. A chip having a Schottky-based structure according to any one of claims 1 to 4, characterized in that: The Schottky layer is located between adjacent trenches on the front side of the epitaxial wafer, and the epitaxial segment is placed in the trenches.

6. A chip according to claim 5, characterized in that: The width of the epitaxial section is smaller than the width of the trench, and the depth of the epitaxial section is smaller than the depth of the trench; wherein the width of the trench is 30-80 um; and the depth of the trench is 0.5-1.5 um.

7. A chip according to claim 6, characterized in that: The end of the extension segment is located at the center line of the trench.

8. A chip according to claim 6 or 7, characterized in that: The trench also includes a PN junction located below the epitaxial segment; the epitaxial segment is located at one end of the PN junction close to the main segment.

9. A chip according to claim 8, characterized in that: A metal layer is provided above the Schottky layer; an oxide layer is provided between the metal layer and the epitaxial wafer, and a portion of the oxide layer is opposite to a portion of the metal layer and is provided on the PN junction.

10. A diode, characterized in that: The device is provided with a Schottky-based structure according to any one of claims 1 to 4 and is manufactured from a chip adapted to the Schottky-based structure.

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