A melt spraying process for improving the bonding force of a spare part coating of a general semiconductor etching cavity

Abstract

The present application relates to a kind of to improve the bonding force of generic semiconductor etching cavity spare parts coating fusion process, the surface of substrate is sandblasted and roughened;Modification layer spraying is carried out on the surface of substrate, initial bonding layer is sprayed on the surface of substrate, the spraying parameters are controlled to make yttrium zirconium oxide powder reach 100% complete melting state, and the molten droplet is completely spread on the surface of substrate, modification core layer is sprayed on the initial bonding layer, mixed mode of complete melting state particle and semi-melting state particle is simultaneously sprayed, wherein the mass ratio of complete melting state particle is 70%-85%, and the mass ratio of semi-melting state ion is 15%-30%, in the state of not stopping gun, the mass ratio of semi-melting particle is dynamically adjusted to be low, until the mass ratio of semi-melting state particle is 0%, in the third step, the mass ratio of semi-melting state particle is kept to be 0%, and 100% complete melting state particle is sprayed, and yttrium zirconium oxide etching-resistant working layer is prepared.The present application solves the technical problem that surface working layer is easy to peel off in the prior art.

Description

Technical Field

[0001] This invention relates to the field of surface treatment in semiconductor precision manufacturing, and more particularly to a spraying process for improving the adhesion of coatings on semiconductor etching cavity spare parts. Background Technology

[0002] In the manufacturing process of semiconductors such as integrated circuits and panel displays, etching is one of the core processes. The internal components of the etching cavity, such as the inner lining and gas distribution plate, are usually made of aluminum alloy or ceramic as the substrate. In order to protect the substrate from the strong physical bombardment and chemical corrosion of plasma, the surface of these components is usually coated with a corrosion-resistant rare earth ceramic coating by thermal spraying (melting) technology. Currently, one of the best performing materials is yttrium zirconium oxide (rare earth ceramic material).

[0003] However, due to the high melting point of rare earth ceramic materials (typically above 2600℃), when preparing coatings using atmospheric plasma spraying or other spraying techniques, the plasma jet requires extremely high enthalpy and particle velocity. This results in severe thermal shock when the high-temperature, high-speed ceramic ions bombard the substrate. Existing methods of setting metal transition layers or single-component modification layers either cannot resist secondary corrosion caused by plasma penetrating the coating micropores, or there are obvious "process seams" and weak interfaces between the modified layer and the working layer. Under the alternating hot and cold working environment of the etching chamber, interlayer delamination is prone to occur, resulting in particulate contamination. Summary of the Invention

[0004] The purpose of this invention is to provide a spraying process that improves the adhesion of coatings to semiconductor etching cavity spare parts, thereby solving the technical problem of easy peeling of the surface working layer in the prior art.

[0005] The technical solution of the present invention is as follows:

[0006] A spraying process for improving the adhesion of coatings on semiconductor etching cavity spare parts, the first step of which is to sandblast and roughen the surface of the substrate.

[0007] The second step is to spray a modified layer onto the substrate surface.

[0008] 1) Spray an initial adhesive layer onto the substrate surface, controlling the spraying parameters to ensure the yttrium zirconium powder reaches a 100% fully molten state, with the molten droplets completely spreading across the substrate surface.

[0009] 2) A modified core layer is sprayed onto the initial adhesive layer, using a mixed spraying mode of fully molten particles and semi-molten particles simultaneously. The fully molten particles account for 70%~85% of the mass, and the semi-molten particles account for 15%~30% of the mass.

[0010] 3) While maintaining continuous firing, dynamically reduce the mass percentage of semi-molten particles until the mass percentage of semi-molten particles reaches 0%.

[0011] The third step involves maintaining a 0% mass percentage of semi-molten particles and spraying 100% fully molten particles to prepare a yttrium zirconium oxide etching-resistant working layer.

[0012] Furthermore, the substrate is an aluminum alloy substrate.

[0013] Furthermore, in step 3 of the second step, the process of dynamically reducing the mass ratio of semi-molten particles is as follows: the mass ratio of semi-molten particles is adjusted from 30% to 20%, then from 20% to 10%, and then from 10% to 0%. At each ratio of the mass ratio of semi-molten particles, at least one layer needs to be sprayed.

[0014] Furthermore, the simultaneous spraying and dynamic control of fully molten and semi-molten particles are achieved through a single-gun dual-powder-feeding-channel system. This system includes a plasma spray gun, which is equipped with a first powder-feeding port channel and a second powder-feeding port channel. The first powder-feeding port channel delivers yttrium zirconium oxide powder particles with a particle size of 15~25μm to the center region of the plasma spray gun's flame to form fully molten particles. The second powder-feeding port channel delivers yttrium zirconium oxide powder particles with a particle size of 45~65μm to the center region of the plasma spray gun's flame to form semi-molten particles.

[0015] Furthermore, the single-spray gun dual-air supply channel system also includes a first powder feeder and a second powder feeder, which correspond to the first air supply channel and the second powder supply channel, respectively. The mass ratio of yttrium zirconium oxide powder particles in the corresponding air supply channel is adjusted by the rotation speed ratio of each powder feeder.

[0016] Furthermore, the macroscopic porosity of the modified core layer is controlled at 3.0% to 6.0%, and the surface roughness of the modified core layer is 6 to 10 μm.

[0017] Furthermore, during the second and third spraying processes, the back side of the substrate is cooled to keep the substrate temperature below 120°C.

[0018] Furthermore, in the second and third steps, the thickness of a single spray coating is controlled at 5~15μm. The modified layer and the yttrium zirconium oxide etching-resistant working layer are formed by multiple layers of spray gun on the surface of the substrate. The total thickness of the modified layer is 50~100μm, and the total thickness of the yttrium zirconium oxide etching-resistant working layer is 150~250μm.

[0019] The beneficial effects of this application: The core difference between this invention and the prior art lies in the fabrication of the modified layer and the combination of the modified layer and the yttrium zirconium oxide etching-resistant working layer. In the fabrication of the modified layer, this invention abandons the traditional method of spraying yttrium zirconium oxide in a completely molten state. Instead, it adopts a combination of completely molten particles and semi-molten particles. For the completely molten particles, the powder completely transforms into liquid droplets. When impacting the substrate, they spread out extremely flat, like water droplets hitting the ground, forming a flat, disc-like shape. These particles provide high density and strong adhesion. For the semi-molten particles (also known as incompletely molten particles), the particle surface melts, but there are still hard solids in the middle. When impacting the substrate, they cannot spread out completely, but instead bulge like a "fried egg". During the hybrid stacking process, when thousands of particles in these two states intertwine and accumulate, the fully molten droplets envelop and fill the gaps between the semi-molten particles. The resulting modified layer surface is not smooth and flat, but rather exhibits a microscopically undulating, porous, and "burr-like" rough topology. This rough surface provides excellent mechanical anchoring points (interlocking structures) for the particles of the next "fully molten" working layer, thereby significantly improving the interlayer bonding force and preventing the peeling of the yttrium zirconium oxide etching-resistant working layer during use. At the same time, the micro-voids brought by the semi-molten particles can absorb the thermal stress of subsequent high-energy particle bombardment like a sponge. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the single-spray gun dual-air supply channel system in this invention;

[0021] In the figure: 1. Substrate; 2. Coating; 3. Jet; 4. Central region of the flame of the ion spray gun; 5. First powder feeding port channel; 6. Second powder feeding port channel; 7. First annular cooling channel; 8. Plasma gas channel; 9. Plasma spray gun; 10. Water inlet; 11. Water outlet; 12. Second annular cooling channel; 13. Cooling water channel; 14. Tungsten electrode. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, and not all embodiments. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0023] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0024] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0025] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0026] A specific embodiment of a spraying process for improving the adhesion of coatings on semiconductor etching cavity spare parts in this invention is as follows: Figure 1 As shown:

[0027] The first step is to sandblast and roughen the surface of the substrate;

[0028] Specifically, alumina or silicon carbide particles are used to sandblast and roughen the surface of the substrate, so that the surface roughness of the substrate is 5.0μm~7.5μm. The specific process of sandblasting and roughening is existing technology and will not be described in detail here.

[0029] The second step is to spray a modified layer onto the substrate surface.

[0030] 1) Spray an initial adhesive layer onto the substrate surface, controlling the spraying parameters to ensure the yttrium zirconium powder reaches a 100% fully molten state, with the molten droplets completely spreading across the substrate surface.

[0031] 2) A modified core layer is sprayed onto the initial adhesive layer, using a mixed spraying mode of fully molten particles and semi-molten particles simultaneously. The fully molten particles account for 70%~85% of the mass, and the semi-molten particles account for 15%~30% of the mass.

[0032] 3) While maintaining continuous firing, dynamically reduce the mass percentage of semi-molten particles until the mass percentage of semi-molten particles reaches 0%.

[0033] The third step involves maintaining a 0% mass percentage of semi-molten particles and spraying 100% fully molten particles to prepare a yttrium zirconium oxide etching-resistant working layer.

[0034] In the above scheme, the substrate is an aluminum alloy substrate. In this embodiment, semi-molten ions refer to particles that are not fully fused.

[0035] In step 3 of the second step, the process of dynamically reducing the mass percentage of semi-molten particles is as follows: the mass percentage of semi-molten particles is adjusted from 30% to 20%, then from 20% to 10%, and then from 10% to 0%. For each ratio of the semi-molten particle mass percentage, at least one layer needs to be sprayed, with the thickness of each layer controlled between 5 and 15 μm. For example, when the mass percentage of semi-molten particles is adjusted to 30%, one layer is sprayed; when the mass percentage of semi-molten particles is adjusted to 20%, another layer is sprayed; when the mass percentage of semi-molten particles is adjusted to 10%, two more layers are sprayed; and when the mass percentage of semi-molten particles is adjusted to 0%, two more layers are sprayed.

[0036] The simultaneous spraying and dynamic control of fully molten and semi-molten particles are achieved through a single-gun dual-powder-channel system, such as... Figure 1 As shown, the single-gun dual-airflow system includes a plasma gun 9, which is provided with a first powder feeding port channel 5 and a second powder feeding port channel 6. The first and second powder feeding port channels are distributed on opposite sides of the plasma gun 9. The first powder feeding port channel delivers yttrium zirconium oxide powder particles with a particle size of 15~25μm to the flame center region 4 of the plasma gun to form fully molten particles. The second powder feeding port channel delivers yttrium zirconium oxide powder particles with a particle size of 45~65μm to the flame center region 4 of the plasma gun to form semi-molten particles.

[0037] Figure 1 In this document, item 14 represents a tungsten electrode, item 7 represents a first annular cooling channel, item 12 represents a second annular cooling channel, item 13 represents a cooling water channel connecting the first annular cooling channel and the second annular cooling channel, item 10 represents a water inlet, item 11 represents a water outlet, item 8 represents a plasma gas channel, item 3 represents a jet ejected from the plasma spray gun 9, item 2 represents a coating, and item 1 represents a substrate.

[0038] In use, cooling water enters the first annular cooling channel 7 through the inlet 10, flows through the cooling water flow channel 13 to the second annular cooling channel 12, and then flows out through the outlet 11.

[0039] The first and second powder feeding channels deliver the corresponding yttrium zirconium oxide powder into the flame center region 4 of the ion spray gun for melting, and then form a jet 3 that is sprayed onto the surface of the substrate 1.

[0040] In this embodiment, the first powder feeding port channel delivers yttrium zirconium oxide powder particles with a particle size of 15~25μm to the center region of the plasma spray gun to form fully molten particles; the second powder feeding port channel delivers yttrium zirconium oxide powder particles with a particle size of 45~65μm to the center region of the plasma spray gun to form semi-molten particles.

[0041] The single-spray gun dual-airflow channel system also includes a first powder feeder and a second powder feeder, respectively corresponding to the first airflow channel and the second powder inlet channel. The mass ratio of yttrium zirconium oxide powder particles in the corresponding airflow channel is adjusted by the rotational speed ratio of each powder feeder. The working principle of the powder feeder is existing technology and will not be described in detail here.

[0042] In this invention, the macroscopic porosity of the modified core layer is controlled at 3.0% to 6.0%, and the surface roughness of the modified core layer is 6 to 10 μm.

[0043] In the second and third steps, the thickness of a single spray coating is controlled at 5~15μm. The modified layer and the yttrium zirconium oxide etching-resistant working layer are formed by multiple layers of spray gun on the surface of the substrate. The total thickness of the modified layer is 50~100μm, and the total thickness of the yttrium zirconium oxide etching-resistant working layer is 150~250μm.

[0044] During the second and third spraying processes, the back of the substrate is cooled to keep the substrate temperature below 120°C. This can be achieved by attaching a circulating liquid nitrogen cooling fixture to the back of the substrate.

[0045] After the final coating is completed, the spare parts are allowed to cool naturally to room temperature, and then transferred to an annealing furnace. The temperature is increased to 200°C at a rate of 2°C / min and held for 6 hours to release interlayer tensile stress. Finally, the parts are slowly cooled to room temperature at a rate of 0.5°C before being removed from the furnace.

[0046] The core difference between this invention and existing technologies lies in the fabrication of the modified layer and its combination with the yttrium zirconium oxide etching-resistant working layer. In the fabrication of the modified layer, this invention abandons the traditional method of spraying yttrium zirconium oxide in a completely molten state. Instead, it uses a combination of completely molten particles and semi-molten particles. For the completely molten particles, the powder completely transforms into liquid droplets. When impacting the substrate, they spread out extremely flat, like water droplets hitting the ground, forming a flat, disc-like shape. These particles provide high density and strong adhesion. For the semi-molten particles (also known as incompletely molten particles), the particle surface melts, but there are still hard solids in the middle. When impacting the substrate, they cannot spread out completely but instead bulge like a "fried egg". During the hybrid stacking process, when thousands of particles in these two states intertwine and accumulate, the fully molten droplets envelop and fill the gaps between the semi-molten particles. The resulting modified layer surface is not smooth and flat, but rather exhibits a microscopically undulating, porous, and "burr-like" rough topology. This rough surface provides excellent mechanical anchoring points (interlocking structures) for the particles of the next "fully molten" working layer, thereby significantly improving the interlayer bonding force and preventing the peeling of the yttrium zirconium oxide etching-resistant working layer during use. At the same time, the micro-voids brought by the semi-molten particles can absorb the thermal stress of subsequent high-energy particle bombardment like a sponge.

[0047] This invention abandons the traditional "multi-layer, step-by-step" spraying process. By dynamically adjusting the ratio of fully molten to semi-molten particles without stopping the spray gun, a continuous chemical composition and phase gradient is formed between the modified layer and the working layer. The subsequent high-energy working layer particles can slightly melt the ceramic surface of the previous modified layer, achieving epitaxial growth of grains and fusing the two ceramic layers into one. This completely eliminates the traditional physical parting line and weak interlayer interfaces, significantly improving the coating's resistance to shear peeling.

[0048] The 15% to 30% semi-molten particles intentionally introduced into the core area of ​​the modified layer form a uniformly distributed micropore and low elastic modulus region inside the coating. This acts as a "stress buffer pad", which can greatly absorb and relax the residual tensile stress caused by the mismatch of thermal expansion coefficients of aluminum alloy and rare earth ceramics, and can prevent the longitudinal propagation of cracks generated during the hot and cold cycles of plasma etching machine start-up and shutdown.

[0049] With dynamic extreme cooling throughout the entire process, the aluminum alloy substrate is strictly controlled below 120°C, which completely overcomes the risk of substrate overheating and deformation and "uprooting" peeling caused by dual-channel or dual-gun high-energy spraying, ensuring the precision dimensional tolerance of the cavity spare parts.

[0050] The outermost layer remains 100% fully molten to form an ultra-dense layer (porosity <1%), blocking the penetration of corrosive gases. Due to the significantly improved adhesion, the coating is less prone to peeling or flaking under harsh plasma bombardment environments, significantly reducing the defect rate during etching and extending the life of spare parts.

[0051] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. The scope of patent protection of the present invention shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present invention shall also be included within the scope of protection of the present invention.

Claims

1. A spray coating process for improving the adhesion of coatings on semiconductor etching cavity spare parts, characterized in that, The first step is to sandblast and roughen the surface of the substrate; The second step is to spray a modified layer onto the substrate surface. 1) Spray an initial adhesive layer onto the substrate surface, controlling the spraying parameters to ensure the yttrium zirconium powder reaches a 100% fully molten state, with the molten droplets completely spreading across the substrate surface. 2) A modified core layer is sprayed onto the initial adhesive layer, using a mixed spraying mode of fully molten particles and semi-molten particles simultaneously. The fully molten particles account for 70%~85% of the mass, and the semi-molten particles account for 15%~30% of the mass. 3) While maintaining continuous firing, dynamically reduce the mass percentage of semi-molten particles until the mass percentage of semi-molten particles reaches 0%. The third step involves maintaining a 0% mass percentage of semi-molten particles and spraying 100% fully molten particles to prepare a yttrium zirconium oxide etching-resistant working layer.

2. The spraying process for improving the adhesion of coatings on semiconductor etching cavity spare parts according to claim 1, characterized in that, The substrate is an aluminum alloy substrate.

3. The spraying process for improving the adhesion of coatings on semiconductor etching cavity spare parts according to claim 1, characterized in that: In step 3 of the second step, the process of dynamically reducing the mass ratio of semi-molten particles is as follows: the mass ratio of semi-molten particles is adjusted from 30% to 20%, then from 20% to 10%, and then from 10% to 0%. At each ratio of the mass ratio of semi-molten particles, at least one layer needs to be sprayed.

4. The spraying process for improving the adhesion of coatings on semiconductor etching cavity spare parts according to claim 1, characterized in that: The simultaneous spraying and dynamic control of fully molten and semi-molten particles are achieved through a single-gun dual-powder-channel system. This system includes a plasma spray gun, which has a first powder-feeding port and a second powder-feeding port. The first powder-feeding port delivers yttrium zirconium oxide powder particles with a diameter of 15-25 μm to the center region of the plasma spray gun's flame to form fully molten particles. The second powder-feeding port delivers yttrium zirconium oxide powder particles with a diameter of 45-65 μm to the center region of the plasma spray gun's flame to form semi-molten particles.

5. The spraying process for improving the adhesion of coatings on semiconductor etching cavity spare parts according to claim 4, characterized in that: The single-spray gun dual-air supply channel system also includes a first powder feeder and a second powder feeder, which correspond to the first air supply channel and the second powder supply channel, respectively. The mass ratio of yttrium zirconium oxide powder particles in the corresponding air supply channel is adjusted by the rotation speed ratio of each powder feeder.

6. The spraying process for improving the adhesion of coatings on semiconductor etching cavity spare parts according to claim 1, characterized in that: The macroscopic porosity of the modified core layer is controlled at 3.0% to 6.0%, and the surface roughness of the modified core layer is 6 to 10 μm.

7. The spraying process for improving the adhesion of coatings on semiconductor etching cavity spare parts according to claim 1, characterized in that: During the second and third spraying processes, the back of the substrate is cooled to keep the substrate temperature below 120°C.

8. The spraying process for improving the adhesion of coatings on semiconductor etching cavity spare parts according to claim 1, characterized in that: In the second and third steps, the thickness of a single spray coating is controlled at 5~15μm. The modified layer and the yttrium zirconium oxide etching-resistant working layer are formed by multiple layers of spray gun on the surface of the substrate. The total thickness of the modified layer is 50~100μm, and the total thickness of the yttrium zirconium oxide etching-resistant working layer is 150~250μm.

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