A high voltage power device with ultra-low on-resistance

Abstract

The application relates to the technical field of power devices, and discloses a high-voltage power device with an ultralow specific on-resistance characteristic, which comprises a silicon wafer body and a substrate layer, the substrate layer is located in the interior of the silicon wafer body, a drift layer is arranged in the interior of the silicon wafer body, the drift layer is located at the bottom of the substrate layer, the inner wall of the drift layer is electroplated with silicon oxide, a capacity expansion groove is arranged at the bottom of the drift layer, a substrate is fixedly installed at the bottom of the drift layer, a groove is arranged in the interior of the silicon wafer body, a drain metal layer is fixedly installed at the bottom of the substrate, and a source metal layer is fixedly installed at the top of the substrate layer. The capacity expansion groove is arranged in the inner wall of the drift layer, so that the area of the drift layer is increased, the size of the silicon wafer body is not increased, and the effect that the size of the silicon wafer body is not increased is ensured under the premise that the power device has the ultralow specific on-resistance characteristic.

Description

Technical Field

[0001] This invention relates to the field of power device technology, specifically to a high-voltage power device with ultra-low specific on-resistance characteristics. Background Technology

[0002] Power devices are electronic components with relatively high output power. They are a general term for electronic elements and devices, and include power amplifiers. Power amplification utilizes the current control of transistors or the voltage control of field-effect transistors to convert the power from a power source into a current that varies according to the input signal.

[0003] During operation, power devices can break down when the drain terminal voltage is too high. To protect them, power devices need to have ultra-low specific on-resistance characteristics. This requires a long drift layer, but a long drift layer leads to a larger overall size of the high-voltage power device, making it inconvenient for installation and use.

[0004] To address the issues of excessively long drift layers leading to large overall device size and inconvenience in installation and use, we propose a high-voltage power device with ultra-low specific on-resistance characteristics. Summary of the Invention

[0005] To address the issue of power devices breaking down under excessive drain voltage during operation, ultra-low specific on-resistance characteristics are required for their protection. This necessitates a long drift layer, but a long drift layer leads to a larger overall size, hindering installation and use. To achieve ultra-low specific on-resistance characteristics in the power device while avoiding excessively long drift layers that result in a large overall size and inconvenient installation, this invention provides the following technical solution: A high-voltage power device with ultra-low specific on-resistance characteristics, comprising a silicon wafer body and a substrate layer, wherein the substrate layer is located inside the silicon wafer body;

[0006] A drift layer is formed inside the silicon wafer body. The drift layer is located at the bottom of the substrate layer. The drift layer contains free electrons. The inner wall of the drift layer is electroplated with silicon oxide. An expansion groove is formed at the bottom of the drift layer. A substrate is fixedly installed at the bottom of the drift layer. A trench is formed inside the silicon wafer body. The trench is located above the drift layer. A drain metal layer is fixedly installed at the bottom of the substrate. A source metal layer is fixedly installed at the top of the substrate layer.

[0007] Furthermore, the upper and lower sidewalls of the drift layer are parallel, and the connection between the expansion groove and the drift layer is provided with an arc transition section. The length of the drift layer is increased by the expansion groove, and the problem of the silicon wafer body size being too large is avoided. At the same time, the arc transition section on the expansion groove facilitates the electroplating effect inside the expansion groove.

[0008] Furthermore, the drift layer is arc-shaped, and the diameter of the left and right sides of the drift layer is larger than the internal diameter of the drift layer. By increasing the diameter of the drift layer on both sides, it is easier to electroplate the inner wall of the drift layer.

[0009] Furthermore, the expansion groove is arc-shaped and located on the left and right sides of the bottom wall of the drift layer. By reasonably designing the position of the expansion groove, it is convenient to achieve the coating effect on the inner wall of the expansion groove. The inner wall of the expansion groove is also coated with silicon oxide material.

[0010] This invention provides a high-voltage power device with ultra-low specific on-resistance characteristics. It possesses the following advantages:

[0011] 1. This high-voltage power device with ultra-low specific on-resistance characteristics increases the area of ​​the drift layer by opening expansion grooves on the inner wall of the drift layer, without increasing the size of the silicon wafer. This achieves the effect of ensuring that the size of the silicon wafer does not increase while the power device has ultra-low specific on-resistance characteristics.

[0012] 2. This high-voltage power device with ultra-low specific on-resistance characteristics facilitates the coating process of the drift layer by setting the diameters on both sides of the drift layer to be larger than the diameter at the middle position of the drift layer. At the same time, the expansion grooves opened on the drift layer are located near the diameters on the left and right sides of the drift layer, which facilitates the silicon oxide coating process of the expansion grooves. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the parallel drift layer power device of the present invention;

[0014] Figure 2 This is a schematic diagram of the curved drift layer power device of the present invention.

[0015] In the figure: 1. Silicon wafer body; 2. Substrate layer; 3. Drift layer; 31. Capacitance expansion trench; 4. Substrate; 5. Trench; 6. Drain metal layer; 7. Source metal layer. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] An example of this high-voltage power device with ultra-low specific on-resistance characteristics is as follows:

[0018] Example 1:

[0019] Please see Figure 1 A high-voltage power device with ultra-low specific on-resistance characteristics includes a silicon wafer body 1 and a substrate layer 2, wherein the substrate layer 2 is located inside the silicon wafer body 1.

[0020] A drift layer 3 is formed inside the silicon wafer body 1. The drift layer 3 is located at the bottom of the substrate layer 2. The drift layer 3 contains free electrons. The inner wall of the drift layer 3 is electroplated with silicon oxide. An expansion groove 31 is formed at the bottom of the drift layer 3. The upper and lower sidewalls of the drift layer 3 are parallel. An arc transition section is formed at the connection between the expansion groove 31 and the drift layer 3. The length of the drift layer 3 is increased by the expansion groove 31, and the problem of the silicon wafer body 1 being too large is avoided. At the same time, the arc transition section formed on the expansion groove 31 facilitates the electroplating effect inside the expansion groove 31. A substrate 4 is fixedly installed at the bottom of the drift layer 3. A trench 5 is formed inside the silicon wafer body 1. The trench 5 is located above the drift layer 3. A drain metal layer 6 is fixedly installed at the bottom of the substrate 4. An source metal layer 7 is fixedly installed at the top of the substrate layer 2.

[0021] The working principle is that by opening an expansion groove 31 on the inner wall of the drift layer 3, the area of ​​the drift layer 3 is increased, and the size of the silicon wafer body 1 does not increase. This achieves the effect of ensuring that the size of the silicon wafer body 1 does not increase while the power device has ultra-low specific on-resistance characteristics. At the same time, by setting the drain metal layer 6 and the source metal layer 7, the possibility of the silicon wafer body 1 being broken down is reduced.

[0022] Example 2:

[0023] Please see Figure 2 A high-voltage power device with ultra-low specific on-resistance characteristics includes a silicon wafer body 1 and a substrate layer 2, wherein the substrate layer 2 is located inside the silicon wafer body 1.

[0024] A drift layer 3 is formed inside the silicon wafer body 1. The drift layer 3 is arc-shaped, and the diameter of the left and right sides of the drift layer 3 is larger than the internal diameter of the drift layer 3. By increasing the diameter of the drift layer 3, it is easier to electroplate the inner wall of the drift layer 3. The drift layer 3 is located at the bottom of the substrate layer 2. The drift layer 3 contains free electrons. The inner wall of the drift layer 3 is electroplated with silicon oxide. An expansion groove 31 is formed at the bottom of the drift layer 3. The expansion groove 31 is arc-shaped and located on the left and right sides of the bottom wall of the drift layer 3. By reasonably designing the position of the expansion groove 31, it is easier to plate the inner wall of the expansion groove 31. The inner wall of the expansion groove 31 is also plated with silicon oxide. A substrate 4 is fixedly installed at the bottom of the drift layer 3. A trench 5 is formed inside the silicon wafer body 1. The trench 5 is located above the drift layer 3. A drain metal layer 6 is fixedly installed at the bottom of the substrate 4. A source metal layer 7 is fixedly installed at the top of the substrate layer 2.

[0025] Working principle: By setting the diameter of the drift layer 3 on both sides to be larger than the diameter of the middle position of the drift layer 3, it is convenient to perform coating treatment on the drift layer 3. At the same time, the expansion groove 31 opened on the drift layer 3 is set near the diameter of the left and right sides of the drift layer 3, which facilitates the effect of silicon oxide coating treatment on the expansion groove 31.

[0026] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-voltage power device with ultra-low specific on-resistance characteristics, comprising a silicon wafer body (1) and a substrate layer (2), the substrate layer (2) being located inside the silicon wafer body (1); the inside of the silicon wafer body (1) is provided with a drift layer (3), the drift layer (3) being located at the bottom of the substrate layer (2), the inside of the drift layer (3) containing free electrons, the inner wall of the drift layer (3) being electroplated with silicon oxide, the bottom of the drift layer (3) being provided with a capacity expansion groove (31), the bottom of the drift layer (3) being fixedly installed with a substrate (4), the inside of the silicon wafer body (1) being provided with a groove (5), the groove (5) being located above the drift layer (3), the bottom of the substrate (4) being fixedly installed with a drain metal layer (6), the top of the substrate layer (2) being fixedly installed with a source metal layer (7). characterized in that The upper and lower sidewalls of the drift layer (3) are parallel, and the capacity expansion groove (31) is provided with a circular arc transition section at the connection part with the drift layer (3).

2. The high voltage power device with super low on-resistance according to claim 1, characterized in that: The drift layer (3) is in the shape of a circular arc.

3. The high voltage power device with super low on-resistance according to claim 1, wherein: The left and right side diameters of the drift layer (3) are greater than the inner diameter of the drift layer (3).

4. The high voltage power device with super low on-resistance according to claim 3, characterized in that: The capacity expansion groove (31) is in the shape of a circular arc and is located at the left and right sides of the bottom wall of the drift layer (3).

5. The high voltage power device with super low on-resistance according to claim 4, characterized in that: ​

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