Process method for prolonging service life of coating

Abstract

The invention relates to a process method for prolonging the service life of a coating. The process method comprises the following steps: S1, carrying out heat treatment on a graphite substrate; s2, growing 1 / 10-1 / 2 of a coating with required thickness on the surface of the graphite substrate at the growth temperature, cooling to 1 / 3-2 / 3 of the growth temperature, and stabilizing for 10-30 minutes; s3, growing 1 / 10-1 / 2 of the coating with the required thickness on the existing coating at the growth temperature, cooling to 1 / 3-2 / 3 of the growth temperature, and stabilizing for 10-30 minutes; and S4, repeating the step S3 until the coating with the required thickness grows on the graphite substrate. According to the technological method, by means of layered growth and layer-by-layer annealing, the stress in the coating growth process is reduced, meanwhile, the crystal size is changed, the size stress is reduced, and finally the service life of the coating is prolonged.

Description

Technical Field

[0001] This invention relates to the field of semiconductor growth, and in particular to a process method for improving coating life. Background Technology

[0002] In the manufacturing process of third-generation semiconductors, graphite coatings play a wide and crucial role in the semiconductor field, primarily due to their excellent thermal conductivity, electrical conductivity, chemical stability, and mechanical properties. The main application scenarios and advantages of graphite coatings are as follows: 1. Key components in high-temperature processes; 2. Plasma etching; 3. Ion implantation; 4. Semiconductor packaging and thermal management; 5. Lithography; 6. Other applications.

[0003] In the prior art, graphite coatings suffer from low service life and are prone to damage due to factors such as thermal imbalance and stress imbalance between the graphite substrate and the coating. Therefore, this invention provides a preparation method to improve the coating process life and solve the above problems. Summary of the Invention

[0004] The purpose of this invention is to provide a process method for improving coating life, which has the characteristics of increasing coating service life and has good applicability.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A process for improving coating life includes: S1, heat-treating a graphite substrate;

[0007] S2, at the growth temperature, a coating of 1 / 10 to 1 / 2 the required thickness is grown on the surface of the graphite substrate, and the temperature is lowered to 1 / 3 to 2 / 3 of the growth temperature and stabilized for 10 to 30 minutes;

[0008] S3, at the growth temperature, a coating of 1 / 10 to 1 / 2 the required thickness is grown on the existing coating, and the temperature is lowered to 1 / 3 to 2 / 3 of the growth temperature and stabilized for 10 to 30 minutes;

[0009] S4. Repeat step S3 until a coating of the desired thickness is grown on the graphite substrate.

[0010] Preferably, in steps S2 and S3, the thickness of the coating is controlled by controlling the growth time.

[0011] Preferably, in step S1, the graphite substrate has a coefficient of thermal expansion of 5 to 8 × 10⁻⁶ / K, a density of 1.7 to 1.9 g / cm³, and a total ash content of less than 10 ppm.

[0012] Preferably, in steps S2 and S3, after cooling to 1 / 3 to 2 / 3 of the growth temperature, the graphite substrate and the coating are annealed and then stabilized for 10 to 30 minutes.

[0013] Preferably, in step S1, the heat treatment process parameters are as follows: the graphite substrate is heat-treated at 1300°C in a hydrogen atmosphere for 10 to 30 minutes.

[0014] Preferably, the coating is a silicon carbide coating;

[0015] In step S2, the growth temperature is 1200℃, a first silicon carbide coating of 35μm is grown on the graphite substrate, and then annealed at 800℃ for 10-20 minutes and stabilized for 10-30 minutes.

[0016] Preferably, in step S3, the growth temperature is 1200℃, a second silicon carbide coating of 35μm is grown on the first silicon carbide coating, and then annealed at 800℃ for 10-20 minutes and stabilized for 10-30 minutes.

[0017] Preferably, in step S4, the growth temperature is 1200℃, a third silicon carbide coating of 30 μm is grown on the second silicon carbide coating, and then annealed at 800℃ for 10 min to 20 min and stabilized for 10 min to 30 min to obtain the silicon carbide coating.

[0018] Preferably, the coating is one of tantalum carbide, silicon carbide, and silicon nitride.

[0019] Preferably, in steps S2 and S3, the cooling method is natural cooling in a vacuum environment or natural cooling in an argon environment.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] The above-mentioned technical solution provides a process method for improving coating life, comprising four steps: Step S1 is to heat-treat a graphite substrate; Step S2 is to grow a coating of 1 / 10 to 1 / 2 the required thickness on the surface of the graphite substrate at the growth temperature, and then cool down to 1 / 3 to 2 / 3 of the growth temperature and stabilize for 10 to 30 minutes; Step S3 is to grow another coating of 1 / 10 to 1 / 2 the required thickness on the existing coating at the growth temperature, and then cool down to 1 / 3 to 2 / 3 of the growth temperature and stabilize for 10 to 30 minutes; Step S4 is to repeat Step S3 until a coating of the required thickness is grown on the graphite substrate. The above process method reduces the stress during the coating growth process by layer-by-layer growth and annealing, while changing the crystal size to reduce dimensional stress, ultimately increasing the service life of the coating. Attached Figure Description

[0022] Figure 1 A schematic flowchart of a process for improving coating life provided in an embodiment of the present invention;

[0023] Figure 2 SEM image of a graphite substrate for a process method to improve coating life provided in an embodiment of the present invention.

[0024] 1. Graphite substrate; 2. Coating; 21. First silicon carbide coating; 22. Second silicon carbide coating; 23. Third silicon carbide coating. Detailed Implementation

[0025] The present invention will now be described in more detail with reference to the accompanying drawings. It should be noted that the following description of the present invention with reference to the accompanying drawings is merely illustrative and not restrictive. Various different embodiments can be combined with each other to form other embodiments not shown in the following description.

[0026] This invention discloses a process method for improving coating life, characterized by comprising the following steps:

[0027] S1, heat treatment is performed on the graphite substrate 1;

[0028] S2, at the growth temperature, a coating 2 of 1 / 10 to 1 / 2 the required thickness is grown on the surface of the graphite substrate 1, and the temperature is lowered to 1 / 3 to 2 / 3 of the growth temperature and stabilized for 10 to 30 minutes;

[0029] S3, at the growth temperature, re-grow a coating 2 of 1 / 10 to 1 / 2 the required thickness on the existing coating 2, and then cool down to 1 / 3 to 2 / 3 of the growth temperature and stabilize for 10 to 30 minutes;

[0030] S4. Repeat step S3 until a coating 2 of the desired thickness is grown on the graphite substrate 1.

[0031] It should be noted that different coatings 2 have different growth environments, so the corresponding growth environment and number of layers can be adjusted for different coatings 2.

[0032] In steps S2 and S3, this embodiment controls the thickness of the coating 2 by controlling the growth time. This allows the growth time to be changed without changing other environmental parameters, thereby reducing or even avoiding changes in the coating 2 during the growth process.

[0033] The graphite substrate has a coefficient of thermal expansion of 5 to 8 × 10⁻⁶ / K, a density of 1.7 to 1.9 g / cm³, and a total ash content of less than 10 ppm.

[0034] In steps S2 and S3, after cooling to 1 / 3 to 2 / 3 of the growth temperature, the graphite substrate 1 and coating 2 are annealed and then stabilized for 10 to 30 minutes.

[0035] In step S1, the heat treatment process parameters are as follows: the graphite substrate 1 is heat-treated at 1300°C in a hydrogen atmosphere for 10 to 30 minutes.

[0036] This embodiment uses a silicon carbide coating as an example to illustrate the following:

[0037] Step S1: Heat-treat the graphite substrate 1.

[0038] In step S2, the growth temperature is 1200℃, a first silicon carbide coating 21 of 35 μm is grown on the graphite substrate 1, and then annealed at 800℃ for 10 min to 20 min and stabilized for 10 min to 30 min.

[0039] In step S3, the growth temperature is 1200℃, a second silicon carbide coating 22 of 35 μm is grown on the first silicon carbide coating 21, and then annealed at 800℃ for 10 min to 20 min and stabilized for 10 min to 30 min.

[0040] In step S4, the growth temperature is 1200℃, a third silicon carbide coating 23 of 30 μm is grown on the second silicon carbide coating 22, and then annealed at 800℃ for 10 min to 20 min and stabilized for 10 min to 30 min to obtain the silicon carbide coating.

[0041] Coating 2 can be one of tantalum carbide, silicon carbide, or silicon nitride.

[0042] In steps S2 and S3, the cooling method is either natural cooling in a vacuum environment or natural cooling in an argon environment.

[0043] In addition, the annealing temperature and annealing time in step S3 are lower than those in step S2, and the annealing temperature and annealing time in step S4 are lower than those in step S3, thereby further improving the service life of coating 2.

[0044] Example 1

[0045] A silicon carbide coating was grown on a graphite substrate 1. First, the graphite substrate 1 was heat-treated at 1300℃ for 30 min in a hydrogen atmosphere. The growth temperature was 1200℃. First, a 35 μm first silicon carbide coating 21 was grown on the graphite substrate 1, and then annealed at 800℃ for 20 min and stabilized for 30 min. The growth temperature was 1200℃. Then, a 35 μm second silicon carbide coating 22 was grown on the first silicon carbide coating 21, and then annealed at 800℃ for 20 min and stabilized for 30 min. The growth temperature was 1200℃. Finally, a 30 μm third silicon carbide coating 23 was grown on the second silicon carbide coating 22, and then annealed at 800℃ for 20 min and stabilized for 30 min to obtain a 100 μm silicon carbide coating.

[0046] Based on data from multiple experiments, the average lifespan of the silicon carbide coating is 135,780 hours.

[0047] Example 2

[0048] A tantalum carbide coating was grown on a graphite substrate 1. First, the graphite substrate 1 was heat-treated at 1300℃ for 20 min in a hydrogen atmosphere. A 10 μm first tantalum carbide coating was grown on the graphite substrate 1, annealed at 850℃ for 15 min, and stabilized for 20 min at the same temperature. Then, a 10 μm second tantalum carbide coating was grown on the first tantalum carbide coating, annealed at 850℃ for 15 min, and stabilized for 20 min at the same temperature. Finally, a 10 μm third tantalum carbide coating was grown on the second tantalum carbide coating, annealed at 850℃ for 15 min, and stabilized for 20 min at the same temperature, resulting in a 30 μm tantalum carbide coating.

[0049] Based on data from multiple experiments, the average service life of tantalum carbide coating is 151,548 hours.

[0050] Example 3

[0051] A silicon nitride coating was grown on a graphite substrate 1. First, the graphite substrate 1 was heat-treated at 1300℃ for 10 min in a hydrogen atmosphere. The growth temperature was 850℃. A 3 μm first silicon nitride coating 21 was grown on the graphite substrate 1 and annealed at 500℃ for 10 min, then stabilized for 10 min. Next, a 3 μm second silicon nitride coating was grown on the first silicon nitride coating and annealed at 500℃ for 10 min, then stabilized for 10 min. Then, a 2 μm third silicon nitride coating was grown on the second silicon nitride coating and annealed at 500℃ for 10 min, then stabilized for 10 min. Finally, a 2 μm fourth silicon nitride coating was grown on the third silicon nitride coating and annealed at 500℃ for 10 min, then stabilized for 10 min, resulting in a 10 μm silicon nitride coating.

[0052] Based on data from multiple experiments, the average lifespan of the silicon nitride coating is 129,648 hours.

[0053] Example 4

[0054] A silicon carbide coating was grown on a graphite substrate 1. First, the graphite substrate 1 was heat-treated at 1300℃ for 30 min in a hydrogen atmosphere. The growth temperature was 1200℃. First, a 35 μm first silicon carbide coating 21 was grown on the graphite substrate 1, and then annealed at 800℃ for 20 min and stabilized for 10-30 min at a growth temperature of 1200℃. Then, a 35 μm second silicon carbide coating 22 was grown on the first silicon carbide coating 21, and then annealed at 750℃ for 18 min and stabilized for 30 min at a growth temperature of 1200℃. Finally, a 30 μm third silicon carbide coating 23 was grown on the second silicon carbide coating 22, and then annealed at 700℃ for 16 min and stabilized for 30 min to obtain a 100 μm silicon carbide coating.

[0055] Based on data from multiple experiments, the average service life of the silicon carbide coating is 137,930 hours. Compared to Example 1, the service life of the silicon carbide coating can be further improved by changing the annealing temperatures in steps S3 and S4.

[0056] Comparative Example 1

[0057] A silicon carbide coating was grown on a graphite substrate 1. First, the graphite substrate 1 was heat-treated at 1300℃ for 30 min in a hydrogen atmosphere. The growth temperature was 1200℃, and a 100 μm silicon carbide coating was directly grown on the graphite substrate 1. Then, the coating was annealed at 800℃ for 20 min and stabilized for 30 min to obtain the silicon carbide coating.

[0058] Based on data from multiple experiments, the average service life of silicon carbide coatings is 98,540 hours.

[0059] Comparative Example 2

[0060] A silicon carbide coating was grown on a graphite substrate 1. First, the graphite substrate 1 was heat-treated at 1300℃ for 30 min in a hydrogen atmosphere. The growth temperature was 1200℃. First, a 90 μm first silicon carbide coating 21 was grown on the graphite substrate 1, and then annealed at 800℃ for 20 min and stabilized for 30 min. The growth temperature was 1200℃. Then, a 5 μm second silicon carbide coating 22 was grown on the first silicon carbide coating 21, and then annealed at 800℃ for 20 min and stabilized for 30 min. The growth temperature was 1200℃. Finally, a 5 μm third silicon carbide coating 23 was grown on the second silicon carbide coating 22, and then annealed at 800℃ for 20 min and stabilized for 30 min to obtain a 100 μm silicon carbide coating.

[0061] Based on data from multiple experiments, the average lifespan of the silicon carbide coating is 107,534 hours.

[0062] Comparative Example 3

[0063] A tantalum carbide coating was grown on a graphite substrate 1. First, the graphite substrate 1 was heat-treated at 1300℃ for 20 min in a hydrogen atmosphere. The growth temperature was 1300℃. First, a 10 μm first tantalum carbide coating was grown on the graphite substrate 1, then annealed at 900℃ for 30 min and stabilized for 20 min at 1300℃. Next, a 10 μm second tantalum carbide coating was grown on the first tantalum carbide coating, annealed at 900℃ for 30 min and stabilized for 20 min at 1300℃. Finally, a 10 μm third tantalum carbide coating was grown on the second tantalum carbide coating, annealed at 900℃ for 30 min and stabilized for 20 min, resulting in a 30 μm tantalum carbide coating.

[0064] Based on data from multiple experiments, the average service life of tantalum carbide coating is 114,965 hours.

[0065] The above embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and replacements made by technicians in this field on the basis of the present invention fall within the scope of protection required by the present invention.

Claims

1. A process for improving coating life, characterized in that, Includes the following steps: S1, heat treatment is performed on the graphite substrate (1); S2, at the growth temperature, a coating (2) of 1 / 10 to 1 / 2 the required thickness is grown on the surface of the graphite substrate (1), and the temperature is lowered to 1 / 3 to 2 / 3 of the growth temperature and stabilized for 10 to 30 minutes; S3, at the growth temperature, a coating (2) of 1 / 10 to 1 / 2 the required thickness is grown on the existing coating (2), and the temperature is lowered to 1 / 3 to 2 / 3 of the growth temperature and stabilized for 10 to 30 minutes; S4. Repeat step S3 until a coating (2) of the desired thickness is grown on the graphite substrate (1).

2. The process method for improving coating life as described in claim 1, characterized in that, In steps S2 and S3, the thickness of the coating (2) is controlled by controlling the growth time.

3. The process method for improving coating life as described in claim 1, characterized in that, In step S1, the graphite substrate has a coefficient of thermal expansion of 5 to 8 × 10⁻⁶ / K, a density of 1.7 to 1.9 g / cm³, and a total ash content of less than 10 ppm.

4. The process method for improving coating life as described in claim 1, characterized in that, In steps S2 and S3, after cooling to 1 / 3 to 2 / 3 of the growth temperature, the graphite substrate (1) and the coating (2) are annealed and then stabilized for 10 to 30 minutes.

5. The process method for improving coating life as described in claim 1, characterized in that, In step S1, the heat treatment process parameters are as follows: the graphite substrate (1) is heat-treated at 1300°C in a hydrogen atmosphere for 10 to 30 minutes.

6. The process method for improving coating life as described in claim 1, characterized in that, The coating (2) is a silicon carbide coating; In step S2, the growth temperature is 1200℃, a first silicon carbide coating (21) of 35 μm is grown on the graphite substrate (1), and annealed at 800℃ for 10 min to 20 min and stabilized for 10 min to 30 min.

7. The process method for improving coating life as described in claim 6, characterized in that, In step S3, the growth temperature is 1200℃, a second silicon carbide coating (22) of 35 μm is grown on the first silicon carbide coating (21), and annealed at 800℃ for 10 min to 20 min, and stabilized for 10 min to 30 min.

8. The process method for improving coating life as described in claim 7, characterized in that, In step S4, the growth temperature is 1200℃, a third silicon carbide coating (23) of 30 μm is grown on the second silicon carbide coating (22), and annealed at 800℃ for 10 min to 20 min, and stabilized for 10 min to 30 min to obtain the silicon carbide coating.

9. The process method for improving coating life as described in claim 1, characterized in that, The coating is one of tantalum carbide, silicon carbide, and silicon nitride.

10. The process method for improving coating life as described in claim 1, characterized in that, In steps S2 and S3, the cooling method is either natural cooling in a vacuum environment or natural cooling in an argon environment.

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