Electroplating method for metal wiring of silicon carbide device

Abstract

The invention relates to the technical field of silicon carbide devices, and discloses an electroplating method for metal wiring of a silicon carbide device, which comprises the following steps: preparing a silicon carbide wafer substrate (1) to be subjected to metal wiring; growing a metal seed layer (2) on the surface of the silicon carbide wafer substrate (1); forming a barrier layer (3) on a part of the upper surface of the metal seed layer (2) through photoetching; performing chemical electroplating on the upper surface of the metal seed layer (2) which is not covered by the barrier layer (3) in the step (3) to form a metal electroplated layer (4); and removing the barrier layer (3) and the metal seed layer (2) below the barrier layer (3) by using a chemical corrosion method to complete metal wiring. Metal wiring of the silicon carbide device can be completed at a time, film forming before etching is not needed, the process steps are reduced, and the production cost is reduced; and meanwhile, metal substances (including but not limited to copper) with higher conductivity are adopted, so that the performance of the silicon carbide device can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of silicon carbide devices, and particularly relates to a plating method for metal wiring of silicon carbide devices. Background Art

[0002] Currently, for the metal wiring of silicon carbide devices, physical vapor deposition (PVD) or chemical vapor deposition (CVD) plus physical vapor deposition (PVD) methods are mostly used to form a film, and then metal wiring is formed by etching after the film is formed. The disadvantages of this method are as follows: 1. More equipment is required, and the equipment is expensive, resulting in higher costs; 2. The process is complex, with many intermediate links and is not easy to control; 3. The conductivity of the metal wire is relatively low.

[0003] Currently, a packaging structure and manufacturing method of a silicon carbide MOSFET module with the patent number CN201911090620.8 discloses a wiring method for silicon carbide, and the method is relatively complex and costly. Summary of the Invention

[0004] The present invention aims at the disadvantages in the prior art and provides a plating method for metal wiring of silicon carbide devices.

[0005] In order to solve the above technical problems, the present invention is solved by the following technical solutions:

[0006] A plating method for metal wiring of silicon carbide devices includes the following steps:

[0007] 1) Prepare a silicon carbide wafer substrate to be metal-wired;

[0008] 2) Grow a metal seed layer on the surface of the silicon carbide wafer substrate;

[0009] 3) Form a barrier layer with a specific pattern on a part of the upper surface of the metal seed layer by photolithography;

[0010] 4) Chemically plate the upper surface of the metal seed layer not covered by the barrier layer in step 3) to form a metal plating layer;

[0011] 5) Remove the barrier layer and the metal seed layer located below the barrier layer by chemical etching method, so as to form a metal plating layer with a specific pattern, complete the metal wiring. When removing the metal seed layer, about 2% (not exceeding 5%) of the metal plating layer will be consumed, which will not affect the entire plating layer, thus forming the metal wiring.

[0012] Preferably, in step 2), the metal seed layer is generated by sputtering. Sputtering is a kind of PVD thin film preparation technology. The sputtering environmental temperature is -30 °C to 30 °C, and the gas pressure is 200 mTorr to 800 mTorr.

[0013] Preferably, the thickness of the metal seed layer in step 2) is 20 to 200 nanometers; the metal seed layer is a copper seed layer.

[0014] Preferably, step 3) includes coating a layer of photoresist on the metal seed layer, then performing exposure with a lithography machine, and then developing to form a barrier layer with a specific pattern.

[0015] Preferably, the thickness of the photoresist is 1 to 10 micrometers.

[0016] Preferably, in step 4), the silicon carbide wafer substrate forming the barrier layer is placed in a chemical electroplating solution, and the chemical electroplating solution is an electroplating solution containing metal ions of the metal seed layer.

[0017] Preferably, the temperature of the chemical electroplating solution is 10 degrees Celsius to 50 degrees Celsius, and the electroplating current is 0.5 amperes to 15 amperes.

[0018] Preferably, the chemical electroplating solution is a copper ion electroplating solution.

[0019] Preferably, the thickness of the metal electroplating layer is 1 to 10 micrometers.

[0020] Since the present invention adopts the above technical solutions, it has remarkable technical effects: This application can complete the metal wiring of silicon carbide devices at one time, without the need for film formation first and then etching, reducing the process steps and lowering the production cost; at the same time, using metal substances with higher conductivity (including copper, but not limited to copper) is beneficial to improving the performance of silicon carbide devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic structural diagram of step 1) of the present invention.

[0022] Figure 2 is a schematic structural diagram of step 2) of the present invention.

[0023] Figure 3 is a schematic structural diagram of step 3) of the present invention.

[0024] Figure 4 is a schematic structural diagram of step 4) of the present invention.

[0025] Figure 5 is a schematic structural diagram of step 5) of the present invention.

[0026] The names of the parts referred to by the numerical labels in the drawings are as follows: 1 - silicon carbide wafer substrate, 2 - metal seed layer, 3 - barrier layer, 4 - metal electroplating layer. DETAILED DESCRIPTION OF THE INVENTION

[0027] The present invention will be further described in detail below in conjunction with the drawings and embodiments.

[0028] Example 1

[0029] An electroplating method for metal wiring of a silicon carbide device, as shown in the figure, includes the following steps:

[0030] 1) Prepare a silicon carbide wafer substrate 1 to be metal-wired;

[0031] 2) Grow a metal seed layer 2 on the surface of the silicon carbide wafer substrate 1;

[0032] 3) Form a barrier layer 3 with a specific pattern on a part of the upper surface of the metal seed layer 2 by photolithography. The barrier layer 3 is a photoresist;

[0033] 4) Chemically electroplate the upper surface of the metal seed layer 2 not covered by the barrier layer 3 in step 3) to form a metal electroplating layer 4;

[0034] 5) Remove the barrier layer 3 and the metal seed layer 2 located below the barrier layer 3 by chemical etching method, so as to form a metal electroplating layer 4 with a specific pattern, complete the metal wiring. When removing the metal seed layer 2, about 2% (not exceeding 5%) of the metal electroplating layer 4 will be consumed, which will not affect the entire electroplating layer, thus forming the metal wiring.

[0035] Example 2

[0036] Same as Example 1, except that in step 2), the metal seed layer 2 is generated by sputtering. Sputtering is a kind of PVD thin film preparation technology. The ambient temperature of sputtering is 10 degrees Celsius and the air pressure is 500 mTorr.

[0037] The thickness of the metal seed layer 2 in step 2) is 100 nanometers; the metal seed layer 2 is a copper seed layer.

[0038] Example 3

[0039] Same as Example 1, except that step 3) includes coating a layer of photoresist on the metal seed layer 2 first, then exposing it with a lithography machine, and then developing it to form a barrier layer 3 with a specific pattern.

[0040] The thickness of the photoresist is 5 microns.

[0041] Example 4

[0042] Same as Example 1, except that in step 4), the silicon carbide wafer substrate 1 on which the barrier layer 3 is formed is put into a chemical electroplating solution. The chemical electroplating solution is an electroplating solution containing metal ions of the metal seed layer 2.

[0043] The temperature of the chemical electroplating solution is 30 degrees Celsius and the electroplating current is 8 amperes.

[0044] The chemical electroplating solution is a copper ion electroplating solution.

[0045] The thickness of the metal plating layer 4 is 5 microns.

[0046] In summary, the above are only the preferred embodiments of the present invention, and all equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope covered by the patent of the present invention.

Claims

1. An electroplating method for metal wiring of a silicon carbide device, characterized in that: It includes the following steps: 1) Prepare a silicon carbide wafer substrate (1) to be metal-wired; 2) Grow a metal seed layer (2) on the surface of the silicon carbide wafer substrate (1); 3) Form a barrier layer (3) by lithography on a part of the upper surface of the metal seed layer (2); 4) Electroplate the upper surface of the metal seed layer (2) not covered by the barrier layer (3) in step 3) chemically to form a metal electroplated layer (4); 5) Remove the barrier layer (3) and the metal seed layer (2) under the barrier layer (3) by chemical etching method, so as to form a metal electroplated layer (4) with a specific pattern and complete the metal wiring.

2. The electroplating method for metal wiring of a silicon carbide device according to claim 1, wherein: In step 2), the metal seed layer (2) is generated by sputtering, the ambient temperature of sputtering is -30 °C to 30 °C, and the air pressure is 200 mTorr to 800 mTorr.

3. The electroplating method for metal wiring of a silicon carbide device according to claim 1, characterized in that: In step 2), the thickness of the metal seed layer (2) is 20 to 200 nanometers; the metal seed layer (2) is a copper seed layer.

4. A plating method for metal wiring of a silicon carbide device according to claim 1, characterized in that: Step 3) includes coating a layer of photoresist on the metal seed layer (2) first, then exposing it with a lithography machine, and then developing it to form a barrier layer (3) with a specific pattern.

5. The electroplating method for metal wiring of a silicon carbide device according to claim 4, characterized in that: The thickness of the photoresist is 1 to 10 micrometers.

6. A plating method for metal wiring of a silicon carbide device according to claim 1, characterized in that: In step 4), the silicon carbide wafer substrate (1) on which the barrier layer (3) is formed is put into a chemical electroplating solution, and the chemical electroplating solution is an electroplating solution containing metal ions of the metal seed layer (2).

7. A plating method for metal wiring of a silicon carbide device according to claim 6, characterized in that: The temperature of the chemical electroplating solution is 10 °C to 50 °C, and the electroplating current is 0.5 ampere to 15 amperes.

8. A plating method for metal wiring of a silicon carbide device according to claim 6, characterized in that: The chemical electroplating solution is a copper ion electroplating solution.

9. A plating method for metal wiring of a silicon carbide device according to claim 6, characterized in that: The thickness of the metal electroplated layer (4) is 1 to 10 micrometers.

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