Plasma generator and plasma degumming equipment

Abstract

The present disclosure relates to the field of plasma dry degumming technology, and provides a plasma generator and a plasma degumming device. The plasma generator includes: a generating chamber; a plasma component, which forms an electromagnetic field that plasmatizes gas into plasma; wherein the generating chamber includes: a first chamber wall layer and a second chamber wall layer arranged from the inside to the outside; the first chamber wall layer is implemented as a ceramic layer composed of ceramic parts spliced ​​or ceramic coated with plasma corrosion-resistant ceramics; when the first chamber wall layer is composed of ceramic parts spliced, the thickness is 1mm~10mm; when the ceramic layer is composed of ceramic coating, the thickness is between 1um~1mm; the second chamber wall layer is a quartz layer; the thickness of the second chamber wall layer is 2mm~10mm. By setting the inner and outer chamber walls, it is difficult for free radicals to corrode the inner ceramic layer, which can effectively protect the quartz layer. In addition, the outer quartz wall ensures the high radio frequency power of the degumming reaction. This ensures the stability of the inner wall of the plasma reaction chamber, reduces the particle pollution source, and ensures the quality and rate of the wafer degumming reaction.

Description

Technical Field

[0001] The present disclosure relates to the technical field of plasma dry degumming, and in particular to a plasma generator and a plasma degumming device. Background Art

[0002] In the semiconductor processing process, after etching or ion implantation, photoresist is no longer needed as a protective layer, so the photoresist can be removed from the surface of the silicon wafer. This step is called stripping. In the integrated circuit process, the stripping methods include wet stripping and dry stripping.

[0003] Dry stripping is also called plasma stripping. Plasma stripping uses high-energy plasma to treat the surface of photoresist. It removes the photoresist thoroughly and quickly without the introduction of chemical substances, reducing corrosion and damage to wafer materials. Compared with wet stripping, it has the advantages of high efficiency, uniformity, and no damage. Plasma stripping usually includes two types: ordinary photoresist removal and photoresist removal after high-dose particle injection (HDI) process.

[0004] In the ordinary photoresist removal process, O2 and N2 are dissociated by radio frequency or microwave to produce plasma. The plasma contains active free radicals (such as O·), ions, central atoms and molecules, electrons, etc. Under high temperature conditions (such as 400°C), O· reacts chemically with the photoresist to form products such as CO2 / CO / H2O, completing the photoresist removal process.

[0005] During the photoresist removal process after the high-dose particle injection process, the surface of the photoresist after high-dose implantation will be modified to form a hard shell. The hard shell will block the volatilization and escape of the unmodified photoresist at the bottom layer, resulting in a photoresist "explosion" phenomenon and wafer contamination. In this case, the photoresist cannot be removed directly at high temperature, and the hard shell needs to be treated. The common treatment method is to use a mixture of H2 and N2 under low temperature conditions (such as <100°C) to generate active free radicals H·, which react chemically with the photoresist hard shell to form CH fragments / H2O and other products to complete the photoresist hard shell layer removal process. The speed of this treatment process strictly depends on the reaction temperature and H· density, so on the basis of no photoresist "explosion", the higher the H2 ratio, the faster the reaction speed.

[0006] The wall of the plasma reaction chamber of the traditional degumming machine is made of quartz. The advantage of quartz is that it has poor thermal conductivity. Under high-power bombardment, the temperature gradient of the wall itself is small, thermal stress is easily released, and it is not easy to have cracking problems caused by thermal stress. Experiments show that the quartz wall can withstand RF power bombardment of more than 5000W. However, the quartz wall has a very large defect in the H2 and N2 mixed gas plasma environment. The component SiO2 of quartz is easy to react chemically with H2, and small-scale H· is also easy to react with SiO2, destroying the surface roughness of the quartz wall. Especially in high-end processes below 14nm, the demand for H2 ratio for photoresist removal after high-dose implantation reaches more than 20%. After high-H2 plasma treatment, the quartz wall is more likely to be damaged by pits and become rough. As a result, on the one hand, the quartz wall will easily peel off fragments at high temperature, causing wafer defects. On the other hand, the polymer fragments produced by the photoresist removal reaction are easily adsorbed on the rough quartz wall, forming a source of particle pollution. Summary of the invention

[0007] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a plasma generator and a plasma degumming device to solve the problems in the related art.

[0008] The first aspect of the present disclosure provides a plasma generator, comprising: a generating chamber, having an air inlet and an air outlet for gas to enter; a plasma component, arranged outside the generating chamber, forming an electromagnetic field for plasmatizing the gas into plasma; the air outlet is used for the plasma to escape; wherein the chamber wall of the generating chamber comprises: a first chamber wall layer and a second chamber wall layer arranged from the inside to the outside; the first chamber wall layer is implemented as a ceramic layer composed of ceramic parts resistant to plasma corrosion spliced ​​or ceramic coating; when the first chamber wall layer is composed of ceramic parts spliced, the thickness is 1mm~10mm; when the first chamber wall layer is composed of ceramic coating, the thickness is between 1um~1mm; and, the second chamber wall layer is implemented as a quartz layer; the thickness of the second chamber wall layer is 2mm~10mm.

[0009] In an embodiment of the first aspect, the first cavity wall layer is formed by splicing a plurality of ceramic pieces, and anti-crack gaps are formed between the plurality of ceramic pieces.

[0010] In an embodiment of the first aspect, adjacent ceramic parts among the plurality of ceramic parts form a snap-fitting structure along the axial and / or circumferential direction of the generating chamber to limit the relative movement between the adjacent ceramic parts in the axial and / or circumferential direction.

[0011] In an embodiment of the first aspect, the anti-crack gap is filled with a plasma-corrosion-resistant elastomer.

[0012] In an embodiment of the first aspect, the elastomer is embodied as a fluoroelastomer or an elastomer containing polydimethylsiloxane.

[0013] In an embodiment of the first aspect, the ceramic layer is implemented as a material containing one or a mixed material of aluminum oxide, aluminum nitride, yttrium oxide, zirconium oxide, and yttrium aluminum garnet crystals.

[0014] In an embodiment of the first aspect, the plasma generator further includes: a third cavity wall layer, adjacent to the first cavity wall layer, and implemented as a ceramic layer composed of plasma corrosion-resistant ceramic parts spliced ​​or ceramic coating; wherein the plasma corrosion resistance of the third cavity wall layer is higher than that of the first cavity wall layer.

[0015] In an embodiment of the first aspect, the third cavity wall layer is located on an inner side of the first cavity wall layer.

[0016] In an embodiment of the first aspect, the first cavity wall layer is implemented as a mixed material containing one or more of aluminum oxide, aluminum nitride and zirconium oxide; the third cavity wall layer is implemented as a material containing yttrium oxide or yttrium aluminum garnet crystals; and the ceramic layer is implemented as a material containing zirconium oxide or yttrium aluminum garnet crystals.

[0017] In an embodiment of the first aspect, the gas outlet is provided with an ion filtering grid that can only pass free radicals.

[0018] In an embodiment of the first aspect, an edge portion of the ion filtering grid close to a cavity wall of the generating cavity is implemented as a closed portion to form a barrier against particles falling from the cavity wall.

[0019] In an embodiment of the first aspect, the innermost cavity wall layer of the generating cavity is implemented as a light-transmissive ceramic material to allow detection light entering the generating cavity through an optical detector to be transmitted to observe the surface condition of the outer cavity wall layer.

[0020] A second aspect of the present disclosure provides a plasma degumming device, comprising: a plasma generator as described in any one of the first aspects; a reaction chamber, comprising: an injection port connected to the gas outlet; a carrier, arranged below the injection port, for loading a semiconductor having a glue layer to be removed; wherein the plasma is used to corrode the glue layer to be removed.

[0021] As described above, the present disclosure relates to the field of plasma dry degumming technology, and provides a plasma generator and a plasma degumming device. The plasma generator includes: a generating chamber; a plasma component, which forms an electromagnetic field that plasmatizes gas into plasma; wherein the generating chamber includes: a first chamber wall layer and a second chamber wall layer arranged from the inside to the outside; the first chamber wall layer is implemented as a ceramic layer composed of ceramic parts spliced ​​or ceramic coated with plasma corrosion-resistant ceramics; when the first chamber wall layer is composed of ceramic parts spliced, the thickness is 1mm~10mm; when the ceramic layer is composed of ceramic coating, the thickness is between 1um~1mm; the second chamber wall layer is a quartz layer; the thickness of the second chamber wall layer is 2mm~10mm. By setting the inner and outer chamber walls, it is difficult for free radicals to corrode the inner ceramic layer, which can effectively protect the quartz layer. In addition, the outer quartz wall ensures the high radio frequency power of the degumming reaction. This ensures the stability of the inner wall of the plasma reaction chamber, reduces the source of particle pollution, and ensures the quality and rate of the wafer degumming reaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic cross-sectional structure diagram of a plasma generator in one embodiment of the present disclosure is shown.

[0023] Figure 2 A schematic diagram showing the application of a plasma component in another embodiment of the present disclosure.

[0024] Figure 3 A schematic diagram showing the structure of the first cavity wall layer in some embodiments of the present disclosure.

[0025] Figure 4 A schematic structural diagram of the first cavity wall layer in another embodiment of the present disclosure is shown.

[0026] Figure 5 A schematic diagram showing the structure of the snap-fitting between ceramic parts in one embodiment of the present disclosure.

[0027] Figure 6 A schematic diagram showing the structure of the snap-fitting between ceramic parts in another embodiment of the present disclosure.

[0028] Figure 7 A schematic structural diagram of the first cavity wall layer in yet another embodiment of the present disclosure is shown.

[0029] Figure 8 A schematic structural diagram of the first cavity wall layer in yet another embodiment of the present disclosure is shown.

[0030] Fig. 9 A schematic diagram of the structure of filling anti-crack gaps between ceramic parts in one embodiment of the present disclosure is shown.

[0031] Fig.10 A schematic cross-sectional structure diagram of a plasma generator in another embodiment of the present disclosure is shown.

[0032] Fig.11 A schematic diagram showing optical detection of the cavity wall in an embodiment of the present disclosure.

[0033] Fig.12 A schematic diagram showing optical detection of the cavity wall in another embodiment of the present disclosure.

[0034] Fig.13 A schematic diagram showing optical detection of the cavity wall in yet another embodiment of the present disclosure.

[0035] Fig.14 A schematic diagram showing the structure of an optical detection system in one embodiment of the present disclosure is shown.

[0036] Fig.15 A schematic structural diagram of a plasma degumming device in one embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0037] The following is an explanation of the embodiments of the present disclosure by specific examples, and those skilled in the art can easily understand other advantages and effects of the present disclosure from the information disclosed by the present disclosure. The present disclosure can also be implemented or applied through other different specific embodiments, and the details in the present disclosure can also be modified or changed in various ways according to different viewpoints and application modules without departing from the spirit of the present disclosure. It should be noted that the embodiments in the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0038] The following is a detailed description of the embodiments of the present disclosure with reference to the accompanying drawings so that those skilled in the art can easily implement the present disclosure. The present disclosure can be embodied in many different forms and is not limited to the embodiments described herein.

[0039] In the representations of the present disclosure, the reference terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" and the like mean that the specific features, structures, materials or characteristics represented in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. Moreover, the specific features, structures, materials or characteristics represented may be combined in any one or a group of embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples represented in the present disclosure and the features of different embodiments or examples, unless they are mutually contradictory.

[0040] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the representation of the present disclosure, "a group" means two or more, unless otherwise clearly and specifically defined.

[0041] In order to clearly describe the present disclosure, components not related to the description are omitted, and the same reference numerals are given to the same or similar components throughout the specification.

[0042] Throughout the specification, when a device is said to be "connected" to another device, this includes not only the case of "direct connection" but also the case of "indirect connection" by placing other elements therebetween. In addition, when a device is said to "include" a certain component, unless otherwise stated, it does not exclude other components, but means that other components may be included.

[0043] Although the terms first, second, etc. are used to represent various elements in this article in some examples, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, the first interface and the second interface, etc. are represented. Moreover, as used in this article, the singular forms "one", "one" and "the" are intended to also include plural forms, unless there is an opposite indication in the context. It should be further understood that the terms "containing", "including" indicate the presence of the described features, steps, operations, elements, modules, projects, types, and / or groups, but do not exclude the existence, occurrence or addition of one or a group of other features, steps, operations, elements, modules, projects, types, and / or groups. The terms "or" and "and / or" used herein are interpreted as inclusive, or mean any one or any combination. Therefore, "A, B or C" or "A, B and / or C" means "any of the following: A; B; C; A and B; A and C; B and C; A, B and C". Only when the combination of elements, functions, steps or operations is inherently mutually exclusive in some way, will there be an exception to this definition.

[0044] The technical terms used herein are only used to refer to specific embodiments and are not intended to limit the present disclosure. The singular form used herein also includes the plural form unless the sentence clearly indicates the contrary meaning. The meaning of "including" used in the specification is to specify specific characteristics, regions, integers, steps, operations, elements and / or components, and does not exclude the existence or addition of other characteristics, regions, integers, steps, operations, elements and / or components.

[0045] Although not defined differently, all terms, including technical and scientific terms used herein, have the same meaning as those generally understood by those skilled in the art to which the present disclosure belongs. Terms defined in commonly used dictionaries are additionally interpreted as having meanings consistent with relevant technical literature and the message of the present disclosure, and shall not be overly interpreted as ideal or very formal meanings unless defined.

[0046] In the integrated circuit processing technology, it is necessary to remove the photoresist that is no longer needed. The stripping methods include wet stripping and dry stripping. Dry stripping is plasma stripping, which usually includes two types: ordinary photoresist removal and photoresist removal after high-dose implantation.

[0047] In the ordinary photoresist removal process, O2 and N2 are dissociated by radio frequency or microwave to produce plasma. The plasma contains active free radicals (such as O·), ions, central atoms and molecules, electrons, etc. Under high temperature conditions (such as 400°C), O· reacts chemically with the photoresist to form products such as CO2 / CO / H2O, completing the photoresist removal process.

[0048] During the photoresist removal process after high-dose implantation, the surface of the photoresist after high-dose implantation will be modified to form a hard shell. The hard shell will block the volatilization and escape of the unmodified photoresist at the bottom layer, resulting in a photoresist "explosion" phenomenon and wafer contamination. In this case, the photoresist cannot be removed directly at high temperature, and the hard shell needs to be treated. The common treatment method is to use a mixture of H2 and N2 under low temperature conditions (such as <100°C) to generate active free radicals H·, which react chemically with the photoresist hard shell to form CH fragments / H2O and other products to complete the photoresist hard shell layer removal process. The speed of this treatment process strictly depends on the reaction temperature and H· density, so on the basis of no photoresist "explosion", the higher the H2 ratio, the faster the reaction speed.

[0049] However, the wall of the plasma reaction chamber of the traditional degumming machine is made of quartz. The advantage of quartz is that it has poor thermal conductivity. Under high-power bombardment, the temperature gradient of the wall itself is small, and the thermal stress is easily released, and it is not easy to cause cracking due to thermal stress. The quartz generator can withstand RF power bombardment of more than 5000W. However, quartz is composed of SiO2, which is easily corroded by free radicals such as H· in plasma (such as H2 and N2 mixed gas plasma). The reaction formula is SiO2+H2→SiH x+H2O↑, small-scale H· easily reacts with SiO2, destroying the surface roughness of the quartz wall. Especially for high-end processes below 14nm, the demand for high H2 ratios in high-dose implantation strip (HDIS) and PRStripping reaches more than 20%. After high H2 plasma treatment, the quartz wall is more likely to have a bumpy morphology. There are two unfavorable results of poor roughness: First, the rough inner wall of quartz is easy to peel off fragments at high temperatures, invading and forming wafer defects. In addition, the polymer fragments produced by the PR reaction are easily adsorbed on the inner wall of quartz, forming a source of particle pollution.

[0050] For degumming machines that require high hydrogen ratio plasma, if ceramics are used to completely replace quartz as the material of the plasma generator. Although H· is difficult to react with ceramics, corrosion problems can be avoided; however, the thermal conductivity of ceramics is weaker than that of quartz, so there is a large temperature gradient under high power, causing ceramic cracking problems. Experiments show that under the same physical size, the RF power that a ceramic generator can withstand is less than 3000W, which greatly limits the rate of HDIS PR degumming.

[0051] In view of this, a plasma generator is provided in an embodiment of the present disclosure, which retains the advantages of the quartz cavity wall of the generator through a cavity wall structure with a composite outer and inner layer of quartz and ceramic, and utilizes the ceramic layer to form anti-plasma corrosion protection for the quartz cavity wall.

[0052] like Figure 1 As shown, a schematic cross-sectional structure diagram of a plasma generator in one embodiment of the present disclosure is shown.

[0053] exist Figure 1 In the embodiment, the plasma generator 110 includes a generating chamber 111 and a plasma component 112 .

[0054] The generating chamber 111 includes an air inlet 1111 and an air outlet 1112, wherein the air inlet 1111 is used for gas input. The gas may include reaction gases used for etching and degumming, such as oxygen, hydrogen, fluorine-based gases, etc., and may also include gases with good inertness used to fill the chamber, such as nitrogen, argon, etc. The reaction gas is formed into plasma by the electromagnetic field in the generating chamber 111. Plasma, also known as plasma, is an ionized gaseous substance composed of positive and negative ions generated by the ionization of atoms and atomic groups after some electrons are deprived. The air outlet 1112 is used to discharge the generated plasma.

[0055] In some embodiments, an air inlet 1111 is provided at the top of the shell of the generating chamber 111, and an air outlet 1112 is provided at the bottom. Then, after the gas entering the air inlet 1111 is plasmatized to form plasma, it moves to the air outlet 1112 at the bottom under the action of gravity and escapes. In other embodiments, the position and / or number of the air inlet 1111 may be changed, for example, the air inlet 1111 is provided at the side of the shell of the generating chamber 111, or the air inlet 1111 is provided at the top and the side of the generating chamber 111. Different types of gases can be introduced into different air inlets 1111, such as reaction gas or protective gas.

[0056] In some embodiments, the generating chamber 111 is formed around a central axis. For the convenience of description in this specification, the extension direction of the central axis can be defined as the axial direction, and the direction around the central axis can be defined as the circumferential direction. In some embodiments, the shape of the generating chamber 111 can be cylindrical as shown in the figure. Alternatively, in other embodiments, the shape of the generating chamber 111 can also be a "bell-shaped" with an increasing cross-sectional area from top to bottom, thereby increasing the area of ​​the gas outlet 1112, which is conducive to increasing the amount of gas escaping.

[0057] The plasma component 112 is disposed outside the generating chamber 111 to form an electromagnetic field for plasma-forming the gas. In some embodiments, the plasma component 112 may be implemented as an induction coil, which is connected to a radio frequency source to be applied with a radio frequency voltage to form an electromagnetic field for plasma-forming the gas. Figure 1 In the embodiment of the present invention, the induction coil is exemplified as a spirally extending coil wound outside the generating chamber 111. Alternatively, in other embodiments, for example Figure 2 As shown, the plasma component 112 may also be exemplified as a planar spiral induction coil located outside the generating chamber 111 .

[0058] The cavity wall of the generating chamber 111 includes a first cavity wall layer 1113 and a second cavity wall layer 1114 arranged from the inside to the outside. The first cavity wall layer 1113 is implemented as a ceramic layer constructed of a ceramic material resistant to plasma corrosion. The second cavity wall layer 1114 is implemented as a quartz layer. The ceramic layer can be a split structure or a coating structure, and the second cavity wall layer 1114 can be an integral structure. As the shape of the generating chamber 111 is different (such as a cylindrical shape or a bell shape), the shapes of the second cavity wall layer 1114 and the first cavity wall layer 1113 change adaptively (such as a cylindrical shape or a bell shape). In some embodiments, the plasma corrosion-resistant ceramic material can be implemented as a material containing aluminum oxide (Al2O3), aluminum nitride (AlN), yttrium oxide (Y2O3), zirconium oxide (ZrO2), yttrium aluminum garnet crystal (Y3Al5O 12, referred to as YAG) or a mixed material of multiple types.

[0059] like Figure 3 , which is a schematic diagram showing the structure of the first cavity wall layer in some embodiments of the present disclosure.

[0060] The first cavity wall layer 1113 can be composed of ceramic pieces 11131 spliced ​​together, and anti-crack gaps 1116 can be reserved between adjacent ceramic pieces 11131 to avoid the cracking caused by the stress of high-temperature deformation of the ceramic pieces 11131. The ceramic pieces 11131 can be arranged in an axial and circumferential array along the generating chamber 111, such as circumferential annular arrangement and axial multi-level arrangement. The figure only shows the arrangement structure of the ceramic pieces 11131 of part of the first cavity wall layer 1113. Further optionally, the ceramic piece 11131 can be a sheet-like or block-like structure. Among them, each ceramic piece 11131 can have a certain curvature to suit the cavity wall shape of the cylindrical or bell-shaped generating chamber 111. It can be understood that for the cylindrical generating chamber 111, the circumferential width (i.e., the width extending circumferentially along the generating chamber 111) of the ceramic pieces 11131 located at different axial positions of the generating chamber 111 can be the same. For the bell-shaped generating chamber 111, the cross-sectional area increases from the top to the bottom, so the width of the ceramic member 11131 varies with the axial position. The closer to the bottom of the generating chamber 111, the greater the width of the ceramic member 11131.

[0061] In some embodiments, the ceramic member 11131 can be fixed to the quartz layer by welding or the like.

[0062] like Figure 4 , which is a schematic diagram showing the structure of the first cavity wall layer in another embodiment of the present disclosure.

[0063] It is understandable that the circumferential width of the ceramic member 11131 can be changed as required, for example Figure 4 The circumferential width of each ceramic piece 11131 shown in Figure 3 The circumferential width of the ceramic part 11131. Therefore, Figure 4 In the embodiment, only a smaller number of ceramic pieces 11131 are needed to complete the construction of the circumferential ceramic layer, but due to the increase in the length of each ceramic piece 11131, the crack resistance is weaker than Figure 3 Structure in the embodiment.

[0064] In order to facilitate the mutual positioning between the ceramic parts 11131, in some embodiments, adjacent ceramic parts 11131 among the plurality of ceramic parts 11131 form a snap-fit ​​structure along the axial and / or circumferential direction of the generating chamber 111, so as to form an axial and / or circumferential relative movement restriction between adjacent ceramic parts 11131. Thus, through the snap-fit ​​between the ceramic parts 11131, it is easy to align and place the ceramic parts 11131 during installation, and a certain limit support function is provided for loose ceramic parts 11131 to prevent them from falling.

[0065] like Figure 5 As shown, a schematic diagram of the structure of the snap-fitting between ceramic parts in one embodiment of the present disclosure is shown.

[0066] exist Figure 5 In the figure, multiple ceramic parts 11131 are shown to be clamped together from top to bottom, and each ceramic part 11131 forms a concave-convex structure corresponding to the end of the adjacent ceramic part 11131, and the concave-convex structure exemplarily includes adjacent convex parts 111311 and concave parts 111312, and the convex part 111311 is used to engage with the concave part 111312 of the adjacent ceramic part 11131, and the concave part 111312 is used to engage with the convex part 111311 of the adjacent ceramic part 11131. Thus, through the clamping fit, the multiple ceramic parts 11131 in the figure can be limited to a certain extent in at least one horizontal direction. For example, the first, second, and third ceramic parts 11131 from top to bottom are restricted from moving to the left. The second and third ceramic parts 11131 from top to bottom are restricted from moving to the left and right. The fourth ceramic part 11131 from top to bottom is restricted from moving to the right.

[0067] It should be noted that the second and third ceramic pieces 11131 in the middle are formed with concave-convex structures at both ends. Figure 5 In the figure, the two end protrusions 111311 are on different sides, but in other embodiments, the two end protrusions 111311 can also be on the same side. Accordingly, the ceramic piece 11131 can be limited in only one direction of movement, left or right.

[0068] like Figure 6 As shown, it shows a schematic structural diagram of the snap-fitting between ceramic parts in another embodiment of the present disclosure.

[0069] exist Figure 6In the embodiment, the concave-convex structure at the end of the ceramic piece 11131 can be changed, including at least one snap-in unit, the snap-in unit is implemented as a concave portion 111312 sandwiched by the convex portions on the left and right sides, and a convex portion 111311 sandwiched by the concave portions 111312 on the left and right sides. Thus, after the snap-in is formed by the concave-convex structure in this embodiment, each ceramic piece 11131 is limited in the left and right directions. Optionally, the concave-convex structure can include a plurality of the snap-in units arranged in an array, which is not limited to the figure.

[0070] Optionally, the concave-convex structure may also include a plurality of the snap-in units arranged side by side, and the concave-convex structure may appear as a plurality of concave portions 111312 and convex portions 111311 alternately arranged along a straight line, so the implementation of the concave-convex structure is not limited to that shown in the figure.

[0071] It is understandable that although Figure 5 , Figure 6 What is shown in the figure is that the ceramic part 11131 is snap-fitted in the axial direction of the generating chamber 111, but the adjacent ceramic parts 11131 in the circumferential direction of the generating chamber 111 can also be snap-fitted through a similar structure.

[0072] like Figure 7 , which is a schematic structural diagram of the first cavity wall layer in another embodiment of the present disclosure.

[0073] Figure 7 For Figure 3 On the basis of the above, a structure is added in which the ceramic parts 11131 are clamped and matched along the axial direction (up and down direction in the figure) and the circumferential direction of the generating chamber 111. Specifically, the ceramic parts 11131 are provided with concave and convex structures at the side ends and the bottom ends (or the top ends) corresponding to the circumferential direction, so as to clamp and match in the axial direction and the circumferential direction. Figure 7 The first cavity wall layer 1113 structure of the part.

[0074] like Figure 8 As shown, a schematic structural diagram of the first cavity wall layer in another embodiment of the present disclosure is shown.

[0075] Figure 8 For Figure 4 On the basis of the above, a structure is added in which the ceramic parts 11131 are clamped and matched along the axial and circumferential directions of the generating chamber 111. Specifically, the ceramic parts 11131 are provided with concave and convex structures at the side ends and bottom ends (or top ends) corresponding to the circumferential directions, so as to clamp and match in the axial and axial directions. Figure 8 Then, since the number of ceramic pieces 11131 is reduced, the number of concave-convex structures is also reduced accordingly, which can simplify the structure, but the crack resistance is poor. Figure 7 The embodiment is stronger than Figure 8 Embodiment. Therefore, Figure 3 / Figure 7 Examples and Figure 4 / Figure 8 In practical applications, a trade-off between crack resistance and structural positioning can be made.

[0076] In some embodiments, the ceramic layer can be formed by coating the ceramic material on the wall of the quartz layer, and the coating method can be spray coating (Spray Coating) or physical vapor deposition (Physical Vapor Deposition, PVD). Similarly, it can play a role in preventing plasma from corroding quartz. The method of coating the ceramic material to form the ceramic layer is convenient and efficient. In addition, the oxide layer formed by coating is generally not dense enough, has a certain ductility, and will not crack under high temperature conditions. The generating chamber 111 is generally cylindrical or bell-shaped, and the second chamber wall layer 1114 of the quartz material on the outside can provide support for the first chamber wall of the ceramic material on the inside. In some examples, the two chamber walls can be closely fitted to prevent gas from entering the gap between the chamber walls and causing the accumulation of reaction products. In other examples, a vacuum gap can also be left between the two chamber walls. However, the thickness of the ceramic layer formed by coating will be thinner than that of the ceramic part 11131 directly sintered, and the stress is relatively small and not easy to crack, but the corrosion resistance will be weaker than that of the ceramic layer formed by splicing the ceramic parts 11131.

[0077] In some embodiments, a suitable thickness range of the first cavity wall layer 1113 and the second cavity wall layer 1114 can be given. When the first cavity wall layer 1113 is composed of ceramic pieces 11131 spliced ​​together, the thickness can be 1mm~10mm. When the first cavity wall layer 1113 is composed of ceramic coating, the thickness is between 1um~1mm, preferably, the coating thickness can be less than 200um, and it is less prone to cracking. And the thickness of the second cavity wall layer 1114 can be 2mm~10mm.

[0078] In order to eliminate the hard crust produced by photoresist after high-dose particle implantation or high-density plasma dry etching, in addition to adding hydrogen to remove the hard crust (through H· reacting with C in the hard crust), fluorine-containing gas (such as CF4, C2F6) is also added to oxygen in the stripping process. Specifically, the fluorine free radical F· released by the fluorine-containing gas after plasma has a strong oxidizing property, which can quickly attack the carbon chain in the photoresist and react with carbon atoms to form volatile carbon fluoride compounds (such as CF4 and C2F6). It can also react with hydrogen around the carbon atoms of the photoresist to form hydrogen fluoride (HF), thereby promoting the combination of oxygen and carbon atoms.

[0079] Therefore, in some embodiments, when selecting the material of the ceramic layer, in addition to considering the corrosion resistance to hydrogen in the plasma, the corrosion resistance to fluorine in the plasma may also be considered. As previously mentioned, the ceramic layer is implemented as a ceramic material of a metal oxide, such as a material containing aluminum oxide, aluminum nitride, yttrium oxide, zirconium oxide, and yttrium aluminum garnet crystals or a mixed material of multiple materials. The fluorine corrosion resistance of aluminum oxide and aluminum nitride may not be as good as that of yttrium oxide, zirconium oxide, and yttrium aluminum garnet crystals, so in actual applications, the material of the ceramic layer can be selected according to the gas type of the degumming process.

[0080] In the embodiment of forming a ceramic layer by splicing ceramic pieces 11131, anti-crack gaps 1116 are provided between the ceramic pieces 11131. In order to prevent hydrogen, fluorine, etc. from entering the anti-crack gaps 1116 and corroding the quartz layer, and to take into account the preservation of the anti-crack gaps 1116 and avoid the cracking of the ceramic, in some embodiments, such as Fig. 9 As shown, the anti-crack gap 1116 may be filled with an elastic body 1117 that is resistant to plasma corrosion. Therefore, when the ceramic part 11131 is heated and expanded, the anti-crack gap 1116 is reduced and the elastic body 1117 can be squeezed and deformed accordingly without causing the ceramic part 11131 to break. At the same time, the elastic body 1117 can resist plasma corrosion and protect the outer quartz layer from corrosion.

[0081] In some embodiments, the plasma corrosion-resistant elastomer 1117 can be implemented as a fluorine-containing elastomer 1117 (such as fluorine rubber FKM, perfluoroether rubber FFKM, etc.) or an elastomer 1117 containing polydimethylsiloxane (PDMS), so that it can resist corrosion from fluorine, hydrogen, etc., and also has excellent anti-etching performance and thermal conductivity. Specifically, FKM is a fluorine-containing polymer with excellent chemical stability and high temperature resistance, and exhibits good anti-etching performance when facing plasma. PDMS has good elasticity and high temperature resistance. It can remain stable at high temperatures and has a certain resistance to plasma treatment.

[0082] like Fig.10 As shown, a cross-sectional structural schematic diagram of a plasma generator in another embodiment of the present disclosure is shown.

[0083] exist Fig.10In the figure, it is shown that the generating chamber 111 includes a third chamber wall layer 1115 in addition to the first chamber wall layer 1113 and the second chamber wall layer 1114. The third chamber wall layer 1115 is adjacent to the first chamber wall layer 1113 and is implemented as a ceramic layer composed of ceramic parts spliced ​​or ceramic coated with plasma corrosion resistant ceramic parts. As an example, the third chamber wall layer 1115 is located on the inner side of the first chamber wall layer 1113. The splicing structure or ceramic coating structure of the third chamber wall layer 1115 can refer to the exemplary structure of the first chamber wall layer 1113 provided in the previous embodiment, and will not be repeated here. It can be understood that when the third chamber wall layer 1115 is a structure of ceramic parts splicing, the gaps between the ceramic parts can also be filled with the plasma corrosion resistant elastomer 1117.

[0084] The third cavity wall layer 1115 may also be a ceramic material of metal oxide. The third cavity wall layer 1115 has a higher plasma corrosion resistance than the first cavity wall layer 1113. For example, the first cavity wall layer 1113 is implemented as a material containing one or a mixed material of aluminum oxide, aluminum nitride, zirconium oxide, etc., and the third cavity wall layer 1115 is implemented as a material containing yttrium oxide or yttrium aluminum garnet crystals.

[0085] The third cavity wall layer 1115 located on the inner side has high plasma corrosion resistance, but the cost is relatively high. In actual use, the generating cavity 111 can be used for scenes with high plasma corrosion resistance requirements, such as plasma degumming scenes commonly used for adding hydrogen and fluorine-containing compounds, so that the generating cavity 111 has good process compatibility, and the third cavity wall layer 1115 with good corrosion resistance will preferentially resist the corrosion of different types of plasma. After a period of time, if the third cavity wall layer 1115 is worn away, the first cavity wall layer 1113 will be exposed, and the generating cavity 111 can be used for scenes with low plasma corrosion resistance requirements, such as ordinary degumming, degumming scenes after high-dose particle injection with hydrogen added, etc., so that the service life of the generating cavity 111 can be extended and the cost can be reduced. At the same time, even if the third cavity wall layer 1115 is worn away, the protection of the quartz layer by the first cavity wall layer 1113 still exists, which has good reliability. In addition, through the design of multiple ceramic layers, the thickness of the third cavity wall layer 1115 with higher cost can be reduced, effectively reducing the cost.

[0086] In some embodiments, the ceramic material of some of the cavity wall layers is a light-transmitting material, for example, yttrium aluminum garnet crystals are transparent materials, and yttrium oxide is opaque in the visible light region, but has a certain light transmittance in the ultraviolet light and infrared light regions. Therefore, the optical detector 200 can emit a detection light into the generating cavity 111 to transmit a light-transmitting cavity wall layer to observe the surface condition of the cavity wall layer outside it. The optical detector 200 can select different light sources according to the different light transmittance of the ceramic material. For example, visible light, laser and other detection lights are used for yttrium aluminum garnet crystals, and ultraviolet, infrared and other detection lights are used for yttrium oxide. In some embodiments, the optical detector 200 can be implemented as, for example, a camera, a depth camera, an infrared camera, a visible light / infrared / laser optical transceiver sensor, and the like.

[0087] like Fig.11 , which is a schematic diagram showing optical detection of the cavity wall in one embodiment of the present disclosure.

[0088] exist Fig.11 In the embodiment, the optical detector 200 may include an optical probe 210, which may be directly inserted into the generating cavity 111 and emit detection light toward the cavity wall. The optical probe 210 may be rotated to detect the surface condition of the entire cavity wall, such as the roughness of the cavity wall.

[0089] Optionally, Fig.11 2 shows the structure of the first cavity wall layer 1113 and the second cavity wall layer 1114. The first cavity wall layer 1113 is made of a light-transmitting material, such as YAG. The light emitter in the optical probe 210 emits a detection light, which passes through the first cavity wall layer 1113 to the second cavity wall layer 1114, and is reflected back to be received by the light receiver in the optical probe 210 and converted into an electrical signal to obtain the surface depth data of the second cavity wall layer 1114.

[0090] For example, the optical probe 210 is an imaging probe, which can detect the surface of the second cavity wall layer 1114 through the first cavity wall layer 1113 to form a depth image, thereby determining the roughness of the surface of the second cavity wall layer 1114. The surface of the second cavity wall layer 1114, i.e., the quartz layer, should theoretically not be damaged and rough and potholed. If the second cavity wall layer 1114 surface is found to have an increased roughness change according to the imaging, it can be determined that there may be reaction byproducts leaking between the first cavity wall layer 1113 and the second cavity wall layer 1114, or there may be defects in the protection of the first cavity wall layer 1113, resulting in damage to the second cavity wall layer 1114, and other adverse problems, so that relevant personnel can be warned in time.

[0091] Alternatively, the optical detector 200 may be implemented to include a point light source, a line light source, etc., and may implement a light interference method, that is, the thickness of the first cavity wall layer 1113 may be detected according to the number of interference fringes of signal interference between the first reflected light on the surface of the first cavity wall layer 1113 and the second reflected light on the bottom surface. Specifically, when the optical path difference between the first reflected light and the second reflected light is a non-integer multiple of the wavelength of the detection light, the interference fringes are displayed as dark fringes, that is, light intensity valley values; when the optical path difference between the first reflected light and the second reflected light is an integer multiple of the wavelength of the detection light, the interference fringes are displayed as bright fringes, that is, light intensity peak values. The optical detector 200 obtains the light intensity spectral distribution according to the interference fringes, and may further perform waveform analysis to calculate the thickness of the first cavity wall layer 1113 by the peak-trough method (PV) and the like.

[0092] like Fig.12 As shown, it is a schematic diagram showing the detection of the inner wall of the cavity in another embodiment of the present disclosure.

[0093] Fig.12 The structure shown in the figure is that the cavity wall of the generating cavity 111 includes a first cavity wall layer 1113, a second cavity wall layer 1114 and a third cavity wall layer 1115. The third cavity wall layer 1115 is made of a light-transmitting material, such as YAG. The light emitter in the optical probe 210 emits a detection light, which passes through the third cavity wall layer 1115 to the first cavity wall layer 1113, and is reflected back to be received by the light receiver in the optical probe 210 and converted into an electrical signal to obtain the surface depth data of the first cavity wall layer 1113.

[0094] For example, the optical probe 210 is a probe that can perform light transmission / reception, and can detect data on the surface of the first cavity wall layer 1113 through the third cavity wall layer 1115, and the processing circuit of the optical probe can form an image as a depth image, thereby determining the roughness of the surface of the first cavity wall layer 1113. The surface of the first cavity wall layer 1113, i.e., the ceramic layer, should theoretically not be damaged and rough and potholed. If the imaging shows that the surface of the first cavity wall layer 1113 has an increased roughness change, it can be determined that there may be reaction byproducts leaking between the third cavity wall layer 1115 and the first cavity wall layer 1113, or there may be defects in the protection of the third cavity wall layer 1115, resulting in damage to the first cavity wall layer 1113, and other adverse problems, so that relevant personnel can be warned in time.

[0095] Alternatively, by implementing a light interference method with the optical detector 200, the thickness of the third cavity wall layer 1115 can be detected based on the number of interference fringes of signal interference between the first reflected light on the surface of the third cavity wall layer 1115 and the second reflected light on the bottom.

[0096] In other embodiments, the third cavity wall layer 1115 and the first cavity wall layer 1113 may also be made of light-transmitting materials, so that the detection light can directly detect the surface condition of the second cavity wall layer 1114 .

[0097] Fig.13 A schematic diagram showing optical detection of the cavity wall in yet another embodiment of the present disclosure.

[0098] The reflector 230 can be extended into the generating chamber 111, and the reflector 230 is at a preset angle relative to the axis of the generating chamber 111, such as 45°. Then the optical probe 210 of the optical detector 200 does not need to be extended into the generating chamber 111, but is arranged toward the reflector 230. For example, light is emitted from the air inlet 1111 or the light entrance position next to the air inlet 1111 to the reflector. Optionally, the light emitting direction of the optical probe 210 can be parallel to the axis direction of the generating chamber 111. The reflector 230 can be rotatably arranged around the axis of the generating chamber 111, so that the detection light can circumferentially detect the wall of the generating chamber 111.

[0099] like Fig.14 , which shows a schematic diagram of the structure of an optical detection system in an embodiment of the present disclosure. The optical detection system includes an optical detector 200 having an optical probe 210, a processing circuit 220, a driving device 300 connected to and driving the optical probe 210 (or a reflector) to move in and out of the generating chamber 111, and a controller 400 for controlling the movement of the driving device 300.

[0100] The controller 400 is connected to the drive device 300 and the optical detector 200 in communication to instruct their actions. As an example, the drive device 300 may include a mechanical arm, a manipulator, a robot, etc. including a motor. The controller 400 sends an instruction to move to a preset position to the drive device 300. The drive device 300 parses the instruction into a parameter for driving the motor to move, and controls the motor movement accordingly, so that the optical probe 210 (or reflector) moves to the position. In addition, the controller 400 can also send setting parameters or instructions to the optical detector 200, so that the optical detector 200 performs the detection action according to the setting parameters or instructions. For example, one or more combinations of the detection frequency, the number of detections, the light parameters, etc. are set.

[0101] For example Figure 1 As shown, the gas outlet 1112 of the generating chamber 111 can be connected to the reaction chamber 120 of the wafer, and the gas outlet 1112 can be provided with an ion filter grid 113. The ion filter grid 113 can be configured to allow only free radicals to pass through, so that ions and electrons are filtered out, and free radicals such as H·, N·, and F· pass through the grid holes and diffuse to the wafer surface to perform a degumming reaction.

[0102] In order to prevent particle contamination caused by friction between adjacent ceramic parts 11131, optionally, the edge portion of the ion filtering grid 113 close to the cavity wall of the generating chamber 111 is implemented as a closed portion 1131 (which can be a ring-shaped ring). "Closed" means that there is no grid hole to form a support and barrier for particles falling from the adjacent innermost cavity wall layer (such as the first cavity wall layer 1113 or the third cavity wall layer 1115, etc.), so as to prevent the falling particles from passing through the ion filtering grid 113 and causing contamination of the wafers in the reaction chamber 120.

[0103] like Fig.15 As shown, a schematic diagram of the structure of a plasma degumming device in an embodiment of the present disclosure is shown.

[0104] The plasma stripping equipment 100 includes the plasma generator 110 and a reaction chamber 120 .

[0105] The reaction chamber 120 includes an injection port 121, and the injection port 121 is connected to the gas outlet 1112 of the generating chamber 111. As an example, the generating chamber 111 may be located above the reaction chamber 120, the gas outlet 1112 is located at the bottom of the generating chamber 111, and the injection port 121 is located at the top of the reaction chamber 120 and connected to the gas outlet 1112. A carrier 130 for carrying the semiconductor 500 (such as a wafer) whose adhesive layer is to be removed, such as a hot stage or an electrostatic chuck, may also be provided in the reaction chamber 120. The carrier 130 is located below the injection port 121, and its upper surface is used to carry the semiconductor 500.

[0106] Exemplarily, a plasma component 112, such as an induction coil, is spirally wound outside the generating chamber 111. Under the action of the radio frequency source, an electromagnetic field is formed on the generating chamber 111. After the gas enters the generating chamber 111 through the air inlet 1111, it is plasmatized into plasma by the electromagnetic field of the plasma component 112, enters the reaction chamber 120 from the air outlet 1112 and the injection port 121, and falls on the surface of the semiconductor 500 to corrode the adhesive layer to be removed, completing the degumming process. The degumming reaction product is entrained by the air flow and discharged from the exhaust port 122 of the reaction chamber 120.

[0107] The generating chamber 111 with a composite chamber wall of a ceramic layer and a quartz layer can withstand high RF power (such as 5000W) and resist plasma corrosion, so as to avoid particles formed by plasma corrosion entering the reaction chamber 120 and causing wafer defects. In some embodiments, the ceramic layer can use multiple ceramic pieces 11131 or a thin ceramic layer sprayed to avoid the problem of cracking of a whole ceramic plate under high temperature stress. Using quartz as the outer wall material of the generating chamber 111 can ensure the rate of photoresist removal and good sealing effect.

[0108] In summary, the present disclosure relates to the field of plasma dry degumming technology, and provides a plasma generator and a plasma degumming device. The plasma generator includes: a generating chamber; a plasma component, which forms an electromagnetic field that plasmatizes gas into plasma; wherein the generating chamber includes: a first chamber wall layer and a second chamber wall layer arranged from the inside to the outside; the first chamber wall layer is implemented as a ceramic layer composed of ceramic parts spliced ​​or ceramic coating resistant to plasma corrosion; when the first chamber wall layer is composed of ceramic parts spliced, the thickness is 1mm~10mm; when the ceramic layer is composed of ceramic coating, the thickness is between 1um~1mm; the second chamber wall layer is a quartz layer; the thickness of the second chamber wall layer is 2mm~10mm. By setting the inner and outer chamber walls, it is difficult for free radicals to corrode the inner ceramic layer, which can effectively protect the quartz layer. In addition, the outer quartz wall ensures the high radio frequency power of the degumming reaction. This ensures the stability of the inner wall of the plasma reaction chamber, reduces the source of particle pollution, and ensures the quality and rate of the wafer degumming reaction.

[0109] The above embodiments are merely illustrative of the principles and effects of the present disclosure, and are not intended to limit the present disclosure. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present disclosure. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed in the present disclosure shall still be covered by the protection scope of the present disclosure.

Claims

1. A plasma generator, characterized in that include: A generating chamber having an air inlet for gas to enter and an air outlet; A plasma component is arranged outside the generating chamber and forms an electromagnetic field for plasma-forming the gas; The gas outlet is used for allowing the plasma to escape; Wherein, the cavity wall of the generating cavity includes: a first cavity wall layer and a second cavity wall layer arranged from the inside to the outside; the first cavity wall layer is implemented as a ceramic layer composed of splicing or ceramic coating of ceramic parts resistant to plasma corrosion; when the first cavity wall layer is composed of splicing of ceramic parts, the thickness is 1mm~10mm; when the first cavity wall layer is composed of ceramic coating, the thickness is between 1um~1mm; and, the second cavity wall layer is implemented as a quartz layer; the thickness of the second cavity wall layer is 2mm~10mm; the cavity wall of the generating cavity also includes: a third cavity wall layer, adjacent to the first cavity wall layer, implemented as a ceramic layer composed of splicing or ceramic coating of ceramic parts resistant to plasma corrosion; wherein, the plasma corrosion resistance of the third cavity wall layer is higher than that of the first cavity wall layer.

2. The plasma generator according to claim 1, characterized in that: The first cavity wall layer is formed by splicing a plurality of ceramic pieces, and anti-crack gaps are formed between the plurality of ceramic pieces.

3. The plasma generator according to claim 2, characterized in that: Adjacent ceramic pieces among the plurality of ceramic pieces form a snap-fitting structure along the axial direction and / or circumferential direction of the generating chamber to limit the relative movement between the adjacent ceramic pieces in the axial direction and / or circumferential direction.

4. The plasma generator according to claim 2, characterized in that: The anti-crack gap is filled with an elastomer resistant to plasma corrosion.

5. The plasma generator according to claim 4, characterized in that The elastomer is implemented as a fluoroelastomer or an elastomer containing polydimethylsiloxane.

6. The plasma generator according to claim 1, characterized in that The ceramic layer is implemented as a material containing one or a mixed material of aluminum oxide, aluminum nitride, yttrium oxide, zirconium oxide, and yttrium aluminum garnet crystals.

7. The plasma generator according to claim 1, characterized in that The third cavity wall layer is located on the inner side of the first cavity wall layer.

8. The plasma generator according to claim 1 or 7, characterized in that: The first cavity wall layer is implemented as a mixed material containing one or more of aluminum oxide, aluminum nitride and zirconium oxide; the third cavity wall layer is implemented as a material containing yttrium oxide or yttrium aluminum garnet crystals; the ceramic layer is implemented as a material containing zirconium oxide or yttrium aluminum garnet crystals.

9. The plasma generator according to claim 1, characterized in that: The gas outlet is provided with an ion filtering grid that can only pass free radicals.

10. The plasma generator according to claim 9, characterized in that The edge portion of the ion filtering grid close to the cavity wall of the generating cavity is implemented as a closed portion to form a barrier for particles falling from the cavity wall.

11. The plasma generator according to claim 1, characterized in that: The innermost cavity wall layer of the generating cavity is implemented as a light-transmissive ceramic material, so as to allow the detection light entering the generating cavity by an optical detector to pass through and observe the surface condition of the outer cavity wall layer.

12. A plasma degumming device, characterized in that: include: The plasma generator according to any one of claims 1 to 11; The reaction chamber comprises: an injection port, connected to the gas outlet; The carrier is arranged below the injection port and is used to load the semiconductor with the glue layer to be removed; wherein the plasma is used to corrode the glue layer to be removed.

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