Gas spray head and plasma processing device

Abstract

The utility model discloses a gas spray header and a plasma processing device. The gas spray header comprises a spray header main body which comprises a front surface and a back surface which are opposite to each other; the air holes penetrate through the front surface and the back surface of the spray head main body, each air hole comprises a first air hole section and a second air hole section which are communicated with each other, the first air hole section comprises a first end and a second end, the first end is used for outputting process gas, and the second end is connected with the second air hole section; the diameter of the second end of the first air hole section is smaller than that of the second air hole section; the corrosion-resistant coating covers the surface of the inner wall of the first air hole section; wherein the ratio of the length to the diameter of the first air hole section is (2: 1)-(5: 1). The corrosion-resistant coatings in the air holes are high in density, and generation of particulate pollutants can be effectively reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor etching equipment, in particular to a gas shower head and a plasma processing device. Background Art

[0002] In a plasma processing chamber, a gas shower head is often used to inject process gas (including corrosive gas) into the reaction chamber. The process gas forms plasma under the action of a radio frequency power supply, and the plasma deposits or etches the surface of the silicon wafer. In order to protect the gas shower head from being corroded by corrosive gas and plasma, the gas shower head is usually anodized and then a corrosion-resistant coating is prepared on the surface of the gas shower head using physical vapor deposition (PVD) technology. In addition, in order to increase the output flow rate and distribution uniformity of the process gas, the pores of the existing gas shower head usually have a high aspect ratio.

[0003] However, due to the line-of-sight effect, the corrosion-resistant coating deposited by PVD technology on the inner wall of the gas shower head pores, especially in the deep holes, is relatively loose. Under the combined action of corrosive gas scouring and plasma bombardment, the loose corrosion-resistant coating is prone to fall off and form particulate contaminants. The particulate contaminants appearing in the reaction chamber will greatly affect the etching accuracy or cause critical defects, thereby affecting the yield of chip products. Utility Model Content

[0004] The utility model aims to provide a gas shower head and a plasma processing device to improve the corrosion resistance of the gas shower head and reduce particle pollution.

[0005] In order to achieve the above object, the utility model provides a gas shower head, comprising:

[0006] a showerhead body including opposite front and back faces, the front face being configured to contact the plasma environment;

[0007] a plurality of air holes, the air holes passing through the front and back of the shower head body, each of the air holes comprising: a first air hole section and a second air hole section connected to each other, the first air hole section comprising a first end and a second end, the first end being used to output a process gas, the process gas being used to form the plasma environment, the second end being connected to the second air hole section, the diameter of the second end of the first air hole section being smaller than the diameter of the second air hole section; and,

[0008] A corrosion-resistant coating covering the inner wall surface of the first pore section;

[0009] Wherein, the ratio of the length of the first pore section to its diameter is 2:1 to 5:1.

[0010] Optionally, it further includes: a buffer layer, which is located between the corrosion-resistant coating and the shower head body; the buffer layer includes: a yttrium aluminum garnet layer or a micro-arc aluminum oxide layer.

[0011] Optionally, the buffer layer has a thickness of 30 μm-80 μm.

[0012] Optionally, the surface roughness of the buffer layer is 2 μm-3 μm.

[0013] Optionally, a ratio of a diameter of the second pore segment to a diameter of the first end of the first pore segment is 1:1 to 2:1.

[0014] Optionally, the diameter of the first end of the first air hole segment is 0.3 mm-0.7 mm.

[0015] Optionally, the diameter of the first air hole segment is the same from the first end to the second end.

[0016] Optionally, a diameter of the first air hole segment gradually decreases from the first end to the second end.

[0017] Optionally, a first angle is formed between the side wall of the first air hole section and the front surface of the shower head body, and the first angle is in the range of 90 degrees to 100 degrees.

[0018] Optionally, the first pore section and the second pore section are connected via a transition section.

[0019] Optionally, an inner side wall of the transition section and an inner side wall of the second air hole section have a second angle, and an angle range of the second angle is 100 degrees to 160 degrees.

[0020] Optionally, the pore further comprises:

[0021] The Nth pore segment is connected to the N-1th pore segment;

[0022] The Nth air hole segment is arranged close to the back side of the shower head body, and N is an integer greater than or equal to 3.

[0023] Optionally, the diameter of the Nth pore segment is greater than the diameter of the N-1th pore segment.

[0024] Optionally, the corrosion-resistant coating is also located on the front side of the shower head body.

[0025] Optionally, the corrosion-resistant coating comprises at least one of a rare earth metal oxide, a rare earth metal fluoride or a rare earth metal oxyfluoride coating.

[0026] Optionally, the corrosion-resistant coating has a thickness of 5 μm-150 μm and a porosity of less than 0.1%.

[0027] Another aspect of the present invention further provides a plasma processing device, the plasma processing device comprising:

[0028] A reaction chamber, wherein a base is provided at the bottom of the chamber, and the base is used to carry a substrate to be processed;

[0029] As mentioned above, the gas shower head is arranged opposite to the base and is used to transport process gas to the reaction chamber.

[0030] Optionally, the plasma processing device is a capacitively coupled plasma processing device, which further comprises: at least one radio frequency source, the radio frequency source is electrically connected to the gas shower head or the base, and generates a radio frequency electric field between the gas shower head and the base to dissociate the process gas into plasma.

[0031] Optionally, the plasma processing device is a plasma enhanced chemical vapor deposition device, which further comprises: at least one radio frequency source, the radio frequency source is electrically connected to the gas shower head, and generates a radio frequency electric field between the gas shower head and the base to dissociate the process gas into plasma.

[0032] Compared with the prior art, the beneficial effects of the technical solution of the utility model include at least:

[0033] (1) The utility model provides a gas shower head, the gas shower head comprising a shower head body and pores penetrating the front and back of the shower head body, the pores comprising a first pore section and a second pore section connected, wherein the first pore section is close to a plasma environment. By constraining the relationship between the length L1 of the first pore section and the diameter D1 of its first end (L1:D1=2:1-5:1), and the relationship between the diameter D2 of the second pore section at the connection point and the diameter D1' of the second end of the first pore section (D2>D1'), the distribution area of ​​the corrosion-resistant coating on the inner wall of the pore is controlled, so that the corrosion-resistant coating is formed only on the inner wall of the first pore section and the coating is dense, while avoiding the formation of loose corrosion-resistant coating on the inner wall of the second pore section, thereby preventing the loose corrosion-resistant coating from easily falling off during subsequent use and causing wafer contamination.

[0034] (2) The present invention also introduces a buffer layer, which not only alleviates the difference in thermal expansion coefficients between the corrosion-resistant coating and the shower head body, but also the buffer layer can withstand high temperatures above 120°C, thereby solving the problem of cracking and peeling of the corrosion-resistant coating caused by cracking of the traditional hard anodized aluminum layer in a high temperature environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The figure is a schematic diagram of the cross-sectional structure of the air hole of a gas shower head; the "cross-section" refers to the plane perpendicular to the front of the shower head body.

[0036] Figure 2 for Figure 1 Schematic diagram of the deposition of corrosion-resistant coating inside the pores of a gas showerhead.

[0037] Figure 3 A schematic structural diagram of a capacitively coupled plasma device provided in one embodiment of the utility model.

[0038] Figure 4 A schematic cross-sectional structure diagram of a gas shower head provided in one embodiment of the utility model.

[0039] Figure 5 to Figure 6 Schematic diagram of the cross-sectional structure of the pores provided in different embodiments of the utility model,

[0040] a represents the structure before the corrosion-resistant coating is deposited, and b represents the structure after the corrosion-resistant coating is deposited.

[0041] Figure 7 A schematic diagram of the structure of a coating deposited in a pore of a gas shower head provided by an embodiment of the utility model.

[0042] Figure ID:

[0043] Reaction chamber 1; base 2; substrate w; gas shower head 3; RF source 4; shower head body 31; front side 311 of shower head body; back side 312 of shower head body; air hole 32; first air hole section 321; first end 3211 of first air hole section; second end 3212 of first air hole section; second air hole section 322; transition section 323; first cylindrical hole 210 and second cylindrical hole 220; evaporation source 5; corrosion-resistant coating 33, 33'; buffer layer 34. DETAILED DESCRIPTION

[0044] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0045] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0046] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] Figure 1 The figure is a schematic diagram of the structure of the gas holes in a gas shower head, and the gas holes of the gas shower head include: a first cylindrical hole 210 and a second cylindrical hole 220. The first cylindrical hole 210 is used to output process gas. In order to improve the output flow rate and distribution uniformity of the process gas, the gas shower head is provided with the first cylindrical hole 210 having a high aspect ratio feature, that is, the length L1" of the first cylindrical hole 210 is much larger than its diameter D1, and the diameter D2" of the second cylindrical hole 220 is set to be larger than the diameter D1" of the first cylindrical hole 210.

[0048] Figure 2 In order to use PVD technology in Figure 1 Schematic diagram of the corrosion-resistant coating 33' deposited in the pores of the gas shower head. However, due to the line-of-sight effect, PVD technology is only suitable for deposition on the surface of parts and components, and has natural limitations when coating special-shaped structures such as deep holes and grooves, making the corrosion-resistant coating 33' deposited in the pores of the gas shower head relatively loose. After the gas shower head has been used for a period of time, the loose corrosion-resistant coating is easy to peel off to form particle pollutants, causing wafer contamination.

[0049] In addition, the existing corrosion-resistant coating usually adopts Y 2 O 3 (yttrium oxide) coating, however, Y 2 O 3 There is a difference in thermal expansion coefficient between the coating and the shower head body (such as the aluminum substrate). In order to alleviate this problem, the prior art usually performs hard anodizing on the gas shower head to form aluminum oxide before preparing the corrosion-resistant coating. However, the present application found that the hard anodized aluminum layer formed by this method is an amorphous coating, which is not resistant to high temperatures and is prone to cracking when the temperature is higher than 100°C, causing the corrosion-resistant coating on its surface to peel off, losing the protection of the gas shower head and causing particle pollution problems.

[0050] In summary, the corrosion-resistant coating on the inner wall of the existing gas shower head pores is prone to cracking and peeling, which not only reduces the corrosion resistance of the gas shower head, but also the peeled coating will form particulate pollutants, causing wafer contamination, and cannot meet the process application requirements of semiconductor manufacturing.

[0051] In order to solve the above technical problems, the utility model provides a gas shower head, which divides the pores into a connected first pore section and a second pore section, wherein the first pore section is close to the plasma environment. By constraining the relationship between the length L1 of the first pore section and the diameter D1 of its first end (L1:D1=2:1~5:1), and the relationship between the diameter D2 of the second pore section at the connection point and the diameter D1' of the second end of the first pore section (D2>D1'), the distribution area of ​​the corrosion-resistant coating on the inner wall of the pore is controlled, so that the corrosion-resistant coating is only formed on the inner wall of the first pore section and the coating is dense, and the formation of loose corrosion-resistant coating on the inner wall of the second pore section is avoided, so as to prevent the subsequent loose corrosion-resistant coating from falling off and causing wafer contamination. Further, a buffer layer is introduced, which not only alleviates the difference in thermal expansion coefficient between the corrosion-resistant coating and the shower head body, but also the buffer layer can withstand high temperatures above 120°C, solving the problem of cracking and peeling of the corrosion-resistant coating caused by cracking of the traditional hard anodized aluminum layer in a high temperature environment.

[0052] The gas shower head provided by the utility model can be used for a plasma processing device.

[0053] Figure 3 A capacitively coupled plasma device 100 provided in one embodiment of the utility model includes:

[0054] A reaction chamber 1, in which a base 2 is arranged, and the base 2 is used to carry a substrate w to be processed;

[0055] The gas shower head 3 provided by the utility model is arranged opposite to the base 2 and is used to deliver process gas to the reaction chamber 1; and

[0056] At least one RF source 4 is electrically connected to the gas shower head 3 or the susceptor 2 (connected to the susceptor 2 in this embodiment) and is used to generate a RF electric field between the gas shower head 3 and the susceptor 2 to dissociate the process gas into plasma.

[0057] Another embodiment of the utility model further provides a plasma enhanced chemical vapor deposition device comprising:

[0058] A reaction chamber, in which a base is arranged, and the base is used to carry a substrate w to be processed;

[0059] The gas shower head provided by the utility model is arranged opposite to the base and is used to deliver process gas to the reaction 1; and

[0060] At least one radio frequency source is electrically connected to the gas shower head and is used to generate a radio frequency electric field between the gas shower head and the susceptor to dissociate the process gas into plasma.

[0061] It should be understood that the plasma processing device in the present invention can be any type of plasma device including a gas shower head. Figure 3 It is merely exemplary and may include fewer or more constituent elements, or the arrangement of the constituent elements may be the same as or different from that shown in the drawings.

[0062] The gas shower head 3 of the present invention is described in detail below with reference to the accompanying drawings.

[0063] See also Figure 5 and Figure 6 In the description of the present utility model, L1 is the length of the first pore section; L2 is the length of the second pore section; D1 is the diameter of the first end of the first pore section, and D1' is the diameter of the second end of the first pore section. If the diameter of the first pore section is the same from the first end to the second end, the diameter of the first pore section is D1 and equal to D1'. If the diameter of the first pore section gradually decreases from the first end to the second end, D1 is greater than D1'; D2 is the diameter of the second pore section.

[0064] As attached Figure 4 To Attachment Figure 5 As shown, an embodiment of the utility model provides a gas shower head, the gas shower head 3 comprises: a shower head body 31, a plurality of air holes 32 and a corrosion-resistant coating 33 (see Figure 5 ).

[0065] The shower head body 31 includes a front side 311 and a back side 312 opposite to each other, wherein the front side 311 is used to contact with the plasma environment. The shower head body 31 is made of metal material, such as aluminum or aluminum alloy.

[0066] The air hole 32 passes through the front side 311 and the back side 312 of the shower head body. Figure 5 In a, each of the pores 32 includes: a first pore section 321 and a second pore section 322 that are interconnected, the first pore section 321 includes a first end 3211 and a second end 3212, the first end 3211 is used to output process gas, and the second end 3212 is connected to the second pore section 322.

[0067] See also Figure 5 In b, the corrosion-resistant coating 33 covers the inner wall surface of the first pore section 321. In some embodiments, the corrosion-resistant coating 33 is also located on the front surface 311 of the shower head body. As an example, the corrosion-resistant coating 33 includes: any one of rare earth metal oxide, rare earth metal fluoride or rare earth metal oxyfluoride coating, with a thickness of 5μm-150μm and a porosity of less than 0.1%.

[0068] In the present invention, the ratio of the length L1 of the first pore section 321 to its diameter D1 is 2:1 to 5:1. As can be seen from the above, in order to pursue the improvement of gas flow rate, the prior art designs the first pore section to have a high aspect ratio. This design ignores the line-of-sight effect of PVD technology in depositing corrosion-resistant coatings in the pores. However, in order to solve the line-of-sight effect problem, the first pore section cannot be simply designed to have a low aspect ratio, which will lead to many other problems, such as: the depth of corrosion-resistant coating coverage in the pores is less than the depth of plasma splashing into the pores, resulting in poor corrosion resistance of the gas shower head; low gas flow rate, uneven gas distribution, etc. In order to take into account the corrosion-resistant coating performance of the gas shower head and the effective acceleration of the gas flow rate, the present invention has conducted a lot of research and finally found that: the depth of plasma splashing into the pores is related to the pore diameter, and the splashing depth is within 5 times the pore diameter. When the plasma splashes into the pores, the plasma will collide with the side walls of the pores, and the smaller the pore diameter, the higher the collision frequency, the easier it is to cause the plasma to extinguish, and the smaller the probability of the plasma entering the deeper part of the pores. In other words, the corrosion-resistant coating 33 can obtain a good protection effect if the coverage depth in the pore is within 5 times the pore diameter, and the smaller the diameter, the smaller the coverage depth. There is no need to deposit the corrosion-resistant coating deeper in the pores, which cannot better improve the corrosion resistance. At the same time, the corrosion-resistant coating deposited deeper is often loose, which brings about the problem of particle contamination caused by the peeling of the loose coating during subsequent use. In addition, experiments have found that the aspect ratio of the first pore section 321 should be at least greater than 2:1, otherwise it will have an adverse effect on the increase in gas flow rate and the uniformity of gas distribution, and it is difficult to meet the needs of process applications.

[0069] In addition, the utility model also sets the diameter of the second end 3212 of the first pore section to be smaller than the diameter of the second pore section 322, which is used to: (1) increase the output flow rate of the process gas. According to the principle of fluid mechanics, when the process gas flows from the second pore section 322 with a slightly larger diameter into the first pore section 321 with a smaller diameter, the gas flow rate is accelerated, which is further beneficial to improve the uniformity of gas distribution in the reaction chamber and ensure the smooth progress of the process reaction. (2) Avoid the formation of a loose corrosion-resistant coating on the inner wall of the second pore section 322. It can be understood that the coating molecular flow entering the pore 32 will not all be deposited on the inner wall of the first pore section 321, and the undeposited coating molecular flow will continue to enter the second pore section 322. When the undeposited molecular flow enters the second pore segment 322 from the second end 3212 of the first pore segment, due to the increase in the diameter of the second pore segment 322, the inner wall of the second pore segment 322 is kept away from the coating molecular flow by utilizing the poor wraparound property of the PVD coating technology. Therefore, no corrosion-resistant coating will be deposited on the inner wall of the second pore segment 322, thereby solving the problem in the prior art that the loose corrosion-resistant coating at the deep holes is prone to peeling off and causing particle contamination during subsequent use.

[0070] In summary, the utility model not only ensures the effective improvement of gas flow rate, but also controls the distribution area of ​​the corrosion-resistant coating 33 on the inner wall of the pore by constraining the relationship between the length L1 of the first pore section 321 and the diameter D1 of its first end 3211 (L1:D1=2:1~5:1), and the relationship between the diameter D2 of the second pore section 322 and the diameter D1' of the second end 3212 of the first pore section (D2>D1'), so as to form a loose corrosion-resistant coating 33 on the inner wall of the pore, thereby effectively protecting the gas shower head from plasma erosion and avoiding the problem of particle contamination caused by subsequent peeling of the loose corrosion-resistant coating.

[0071] In some embodiments, the diameter of the first air hole section 321 is the same from the first end 3211 to the second end 3212 ( Figure 5 a); In other embodiments, in order to further improve the density of the corrosion-resistant coating 33 and the bonding strength with the inner wall of the first pore section 321, the diameter of the first pore section 321 gradually decreases from the first end 3211 to the second end 3212 ( Figure 6 It can be understood that such a structure will make the direction of the molecular flow of the corrosion-resistant coating to be deposited have a certain angle with the inner wall of the first pore section 321 instead of being parallel. When the molecular flow of the coating enters the pore, it will collide with the inner wall of the first pore section 321 with a higher intensity, and finally form a corrosion-resistant coating 33 with higher density and higher bonding strength, further improving the anti-plasma erosion performance of the gas shower head and reducing the particle pollution problem.

[0072] like Figure 6 As shown, when the diameter of the first air hole section 321 gradually decreases from the first end 3211 to the second end 3212, the side wall of the first air hole section 321 and the front surface 311 of the shower head body have a first angle A, and the range of the first angle A is 90 degrees to 100 degrees. If the first angle A is greater than 100 degrees, it is easy to cause the size of the second end 3212 of the first air hole section to be too small, affecting the output flow rate of the process gas, resulting in too small an output flow rate of the process gas, affecting the normal progress of the reaction process.

[0073] In some embodiments, considering the acceleration requirements of the process gas, in order to further increase the flow rate of the process gas, the pore 32 further includes: an Nth pore segment, which is connected to the N-1th pore segment; wherein the Nth pore segment is arranged close to the back side 312 of the shower head body, and N is an integer greater than or equal to 3. The diameter of the Nth pore segment is greater than the diameter of the N-1th pore segment. It can be understood that according to the principle of fluid mechanics, after the process gas injected from the Nth pore segment flows into the N-1th pore segment, the N-2th pore segment, etc., whose diameters are decreasing step by step, the gas flow rate is continuously accelerated, so that the process gas flow rate output from the first pore segment 321 meets the application requirements. It should be noted that the specific length or diameter of the Nth pore segment, etc., can be designed and defined by those skilled in the art according to actual application requirements and gas flow rate calculation formulas, etc., and the utility model does not make specific restrictions on this, and only makes specific restrictions on D1, L1 and D2 that affect PVD coating.

[0074] In some embodiments, in order to make the connection between the first pore section 321 and the second pore section 322 smoother and reduce the impact on the gas flow rate input from the second pore section 322 to the first pore section 321, the utility model sets a transition section 323 ( Figure 6 b) is connected. Figure 6 As shown, the inner side wall of the transition section 323 and the inner side wall of the second air hole section 322 have a second angle B, and the range of the second angle B is 100 degrees to 160 degrees.

[0075] In some embodiments, the first pore segment 321 and the second pore segment 322 are arranged coaxially, which further ensures the stability of the flow rate of the process gas entering the pores.

[0076] In addition, in order to solve the problem that the conventional hard anodized aluminum layer cracks in a high temperature environment and causes the corrosion-resistant coating to crack and peel off, in some embodiments, Figure 7 As shown, the gas shower head 3 further includes a buffer layer 34 . The buffer layer 34 is located between the corrosion-resistant coating 33 and the shower head body 31 .

[0077] In some embodiments, the buffer layer 34 includes: a yttrium aluminum garnet layer or a micro-arc aluminum oxide layer. Yttrium aluminum garnet (YAG) is a compound composed of yttrium (Y), aluminum (Al) and oxygen (O), and its chemical formula is Y 3 Al 5 O 12, a class of compounds belonging to the garnet structure, has good thermal stability and chemical stability, can not crack at high temperatures of 120℃-200℃, and the thermal expansion coefficient is between the shower head body 31 and the corrosion-resistant coating 33; the micro-arc aluminum oxide layer is an aluminum oxide coating formed by micro-arc oxidation technology. Compared with aluminum oxide formed by ordinary hard anodizing reaction, the voltage and current of the micro-arc oxidation reaction are higher, and the bombardment of the coating material source is stronger, so that the grown micro-arc aluminum oxide layer is a crystalline coating, which can not crack at high temperatures of 120℃-200℃. The buffer layer 34 not only alleviates the difference in thermal expansion coefficient between the corrosion-resistant coating and the shower head body, but also can withstand high temperatures above 120℃, solving the problem of cracking and peeling of the corrosion-resistant coating caused by cracking of the traditional hard anodized aluminum layer in a high temperature environment.

[0078] It should be noted that the yttrium aluminum garnet layer (YAG layer) can be obtained by atomic layer deposition (ALD) technology: select a suitable precursor, alternately form an aluminum oxide layer and a yttrium oxide layer, and the coating interface reacts to form a YAG layer; micro-arc oxidation technology or other methods can also be used to form the YAG layer, which will not be elaborated here.

[0079] In some embodiments, the buffer layer 34 has a thickness of 30 μm-80 μm and a surface roughness of 2 μm-3 μm. The surface roughness helps to form a corrosion-resistant coating 33 with higher bonding strength, lower surface roughness and porosity during subsequent deposition, thereby improving the corrosion resistance of the gas shower head and extending its service life.

[0080] In summary, the gas shower head provided by the utility model controls the distribution area of ​​the corrosion-resistant coating on the inner wall of the pore by constraining the relationship between the length L1 of the first pore section and the diameter D1 of the first end thereof (L1:D1=2:1~5:1), and the relationship between the diameter D2 of the second pore section at the connecting point and the diameter D1' of the second end of the first pore section (D2>D1'), so that the corrosion-resistant coating is formed only on the inner wall of the first pore section and the coating is dense, while avoiding the formation of loose corrosion-resistant coating on the inner wall of the second pore section, thereby preventing the loose corrosion-resistant coating from falling off easily during subsequent use and causing wafer contamination.

[0081] Although the content of the utility model has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the utility model. After reading the above content, various modifications and substitutions of the utility model will be obvious to those skilled in the art. Therefore, the protection scope of the utility model should be limited by the attached claims.

Claims

1. A gas shower head, characterized in that: include: a showerhead body including opposite front and back faces, the front face being configured to contact the plasma environment; a plurality of air holes, the air holes passing through the front and back of the shower head body, each of the air holes comprising: a first air hole section and a second air hole section connected to each other, the first air hole section comprising a first end and a second end, the first end being used to output a process gas, the process gas being used to form the plasma environment, the second end being connected to the second air hole section, the diameter of the second end of the first air hole section being smaller than the diameter of the second air hole section; and, A corrosion-resistant coating covering the inner wall surface of the first pore section; Wherein, the ratio of the length of the first pore section to its diameter is 2:1 to 5:

1.

2. The gas shower head according to claim 1, characterized in that: Also includes: The buffer layer is located between the corrosion-resistant coating and the shower head body; the buffer layer comprises: a yttrium aluminum garnet layer or a micro-arc aluminum oxide layer.

3. The gas shower head according to claim 2, characterized in that: The thickness of the buffer layer is 30 μm-80 μm.

4. The gas shower head according to claim 2, characterized in that: The surface roughness of the buffer layer is 2 μm-3 μm.

5. The gas shower head according to claim 1, wherein: The ratio of the diameter of the second pore segment to the diameter of the first end of the first pore segment is 1:1 to 2:

1.

6. The gas shower head according to claim 1, wherein: The diameter of the first end of the first air hole segment is 0.3 mm-0.7 mm.

7. The gas shower head according to claim 1, wherein: The diameter of the first air hole section is the same from the first end to the second end.

8. The gas shower head according to claim 1, wherein: The diameter of the first air hole section gradually decreases from the first end to the second end.

9. The gas shower head according to claim 8, characterized in that: A first angle is formed between the side wall of the first air hole section and the front surface of the shower head body, and the first angle ranges from 90 degrees to 100 degrees.

10. The gas shower head according to claim 1, wherein: The first pore section and the second pore section are connected via a transition section.

11. The gas shower head according to claim 10, wherein: An inner side wall of the transition section and an inner side wall of the second air hole section have a second angle, and the angle range of the second angle is 100 degrees to 160 degrees.

12. The gas shower head according to claim 1, wherein: The pores also include: The Nth pore segment is connected to the N-1th pore segment; The Nth air hole segment is arranged close to the back side of the shower head body, and N is an integer greater than or equal to 3.

13. The gas shower head according to claim 12, wherein: The diameter of the Nth pore segment is greater than the diameter of the N-1th pore segment.

14. The gas shower head according to any one of claims 1 to 13, characterized in that: The corrosion-resistant coating is also located on the front side of the shower head body.

15. The gas shower head according to claim 1, wherein: The corrosion-resistant coating comprises at least one of a rare earth metal oxide, a rare earth metal fluoride or a rare earth metal oxyfluoride coating.

16. The gas shower head according to claim 1, wherein: The thickness of the corrosion-resistant coating is 5 μm-150 μm, and the porosity is less than 0.1%.

17. A plasma processing device, characterized in that: The plasma processing device comprises: A reaction chamber, wherein a base is provided at the bottom of the chamber, and the base is used to carry a substrate to be processed; The gas shower head according to any one of claims 1 to 16, which is arranged opposite to the base and is used to transport process gas to the reaction chamber.

18. The plasma processing apparatus according to claim 17, wherein: The plasma processing device is a capacitively coupled plasma processing device, which further comprises: at least one radio frequency source, the radio frequency source is electrically connected to the gas shower head or the base, and generates a radio frequency electric field between the gas shower head and the base to dissociate the process gas into plasma.

19. The plasma processing apparatus according to claim 17, wherein: The plasma processing device is a plasma enhanced chemical vapor deposition device, which further comprises: at least one radio frequency source, the radio frequency source is electrically connected to the gas shower head, and generates a radio frequency electric field between the gas shower head and the base to dissociate the process gas into plasma.

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