Carbon mask deposition process machine and process method

Abstract

This invention discloses a carbon mask deposition apparatus and process method. The apparatus includes: a reaction chamber, the chamber wall of which serves as a lower electrode; a heating plate located within the reaction chamber for holding a substrate, wherein the heating plate serves as an upper electrode; and a controller configured to: introduce a process gas into the interior of the reaction chamber, wherein the process gas includes a hydrocarbon reaction source; and simultaneously apply a first high-frequency voltage and a second low-frequency voltage to the upper electrode or the lower electrode to form a radio frequency electric field with the other electrode, dissociate the hydrocarbon reaction source, and deposit a carbon mask on the substrate via the plasma obtained from the dissociation. This invention can improve the Young's modulus of the deposited carbon mask and reduce the film stress in the absence of amorphous carbon doping, achieving a balance between Young's modulus and film stress. This not only avoids substrate warping but also increases etching selectivity, thereby improving the overall film quality of the carbon mask.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor manufacturing, and in particular to a carbon mask deposition process machine, a carbon mask deposition process method, and a computer readable storage medium. BACKGROUND

[0002] With the continuous rise of data storage demand, the number of layers of three-dimensional flash memory (3D NAND) is increasing, which means that the aspect ratio requirement of the gap structure is increasing. Due to the increase in the number of stacked layers, the requirement for etching selectivity is also higher, so it is necessary to increase the thickness of the hard mask. If the strength of the hard mask is not enough after the thickness is increased, it is easy to cause the gap sidewall to bend and deform, thereby affecting the width of the etching.

[0003] In order to maintain the high conformality of the storage unit pattern transfer, a high Young's modulus, a high etching selectivity, and a high temperature amorphous carbon mask with good etching conformality can be used. However, in the prior art, when the thin film has a high Young's modulus, the stress on the substrate is large, and obvious warping is easy to occur. This will cause problems in the subsequent process, such as abnormal discharge of the subsequent etching machine due to adsorption problems, and the inability to perform subsequent processes due to the inability to adsorb the highly warped product. In view of this, in combination with the limitations of the machine hardware and the process requirements, there is also a certain requirement for the stress of the carbon mask with high Young's modulus. Although the doping of other elements in amorphous carbon material can achieve a certain balance between the Young's modulus and the film stress, but the doping has certain complexity for the removal of the thin film.

[0004] In order to solve the above problems existing in the prior art, there is an urgent need in the art for a carbon mask deposition process technology, which can improve the Young's modulus of the deposited carbon mask and reduce the film stress without doping amorphous carbon, so as to achieve the balance between the Young's modulus and the film stress, thereby not only avoiding the warping of the substrate, but also increasing the etching selectivity, and improving the overall quality of the carbon mask film. SUMMARY

[0005] The following gives a brief summary of one or more aspects to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all contemplated aspects, and is neither intended to identify key or critical elements of all aspects nor to delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description to be given later.

[0006] In order to overcome the above-mentioned defects existing in the prior art, the present application provides a carbon mask deposition process machine, a carbon mask deposition process method and a computer readable storage medium, which can improve the Young's modulus of the deposited carbon mask and reduce the film stress in the case of undoped amorphous carbon, realize the balance of the Young's modulus and the film stress, thereby not only avoiding the warping of the substrate, but also increasing the etching selectivity and improving the film quality of the carbon mask as a whole.

[0007] Specifically, according to the first aspect of the present application, the above-mentioned carbon mask deposition process machine comprises: a reaction cavity, the cavity wall of which serves as a lower electrode; a heating disc located in the reaction cavity and used for containing a substrate, wherein the heating disc serves as an upper electrode; and a controller configured to: introduce a process gas into the inside of the reaction cavity, wherein the process gas comprises a carbon-hydrogen reaction source; and simultaneously apply a first high-frequency voltage and a second low-frequency voltage on the upper electrode or the lower electrode to form a radio frequency electric field between the other electrode to dissociate the carbon-hydrogen reaction source and deposit a carbon mask on the substrate via the plasma obtained by dissociation.

[0008] Further, in some embodiments of the present application, the electrode area of the upper electrode is smaller than the electrode area of the lower electrode, according to the relationship between the warping voltage and the electrode area wherein V1 represents the warping voltage of the upper electrode, V2 represents the warping voltage of the lower electrode, A1 represents the electrode area of the upper electrode, and A2 represents the electrode area of the lower electrode, so that the warping voltage on the heating disc as the upper electrode is greater than the warping voltage on the cavity wall as the lower electrode.

[0009] Further, in some embodiments of the present application, a spraying plate is arranged at the upper part of the reaction cavity, the spraying plate and the cavity wall together serve as the lower electrode, and the lower electrode is grounded when the upper electrode is applied with the first high-frequency voltage and the second low-frequency voltage.

[0010] Further, in some embodiments of the present application, the process machine further comprises: a first radio frequency power source for providing the first high-frequency voltage and a second radio frequency power source for providing the second low-frequency voltage.

[0011] Further, in some embodiments of the present application, the atomic number ratio of carbon atoms to hydrogen atoms in the carbon-hydrogen reaction source is greater than 0.5.

[0012] Further, the carbon mask deposition process according to the second aspect of the present application comprises the following steps: introducing a process gas into the reaction chamber of the carbon mask deposition process apparatus according to the first aspect of the present application, wherein the process gas comprises a hydrocarbon reaction source, the heating plate in the reaction chamber is used as an upper electrode, and the wall of the reaction chamber is used as a lower electrode; and simultaneously applying a first high-frequency voltage and a second low-frequency voltage on the upper electrode or the lower electrode to form a radio frequency electric field between the other electrode, dissociate the hydrocarbon reaction source, and deposit a carbon mask on the substrate via the plasma generated by the dissociation.

[0013] Further, in some embodiments of the present application, before the step of introducing a process gas into the reaction chamber of the carbon mask deposition process apparatus, the method further comprises: preheating a substrate introduced into the reaction chamber at a high temperature to release the stress of the substrate; and applying a third high-frequency voltage with a first power on the upper electrode to electrostatically attract the substrate placed above the heating plate, wherein the first power ranges from 100 to 1500 W.

[0014] Further, in some embodiments of the present application, the step of simultaneously applying a first high-frequency voltage and a second low-frequency voltage on the upper electrode or the lower electrode to form a radio frequency electric field between the other electrode, dissociate the hydrocarbon reaction source, and deposit a carbon mask on the substrate via the plasma generated by the dissociation comprises: introducing the hydrocarbon reaction source, and applying the first high-frequency voltage with a first deposition power or the combination of the first high-frequency voltage and the second low-frequency voltage on the upper electrode or the lower electrode to deposit a carbon film with a first thickness on the surface of the substrate; and in response to the completion of the deposition of the carbon film with the first thickness, simultaneously applying the first high-frequency voltage with a second deposition power and the second low-frequency voltage on the upper electrode or the lower electrode to deposit a main carbon film with a second thickness on the surface of the carbon film with the first thickness, wherein the main carbon film with the second thickness adheres to the substrate via the carbon film with the first thickness, the second thickness is greater than the first thickness, and the second deposition power is greater than or equal to the first deposition power.

[0015] Further, in some embodiments of the present application, after the step of simultaneously applying the first high-frequency voltage with the second deposition power and the second low-frequency voltage on the upper electrode or the lower electrode to deposit a main carbon film with a second thickness on the surface of the carbon film with the first thickness, the method further comprises: gradually reducing the first high-frequency voltage and / or the second low-frequency voltage in the reaction chamber; introducing an inert gas into the reaction chamber to purge the reaction byproducts; and stopping the application of the first high-frequency voltage and the second low-frequency voltage, and transferring the coated substrate for post-processing out of the reaction chamber.

[0016] In addition, the third aspect of the present application also provides a computer readable storage medium having computer instructions stored thereon. The computer instructions, when executed by a processor, implement the above-mentioned process of carbon mask deposition provided by the second aspect of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0017] The above features and advantages of the present application will be better understood through the following detailed description of embodiments of the present application in conjunction with the attached drawings. In the drawings, components are not necessarily drawn to scale and components of similar or identical function or structure can be designated with the same or similar reference numerals.

[0018] Figure 1 A structural diagram of a process tool for carbon mask deposition is shown according to some embodiments of the present application;

[0019] Figure 2 A structural diagram of a process tool for carbon mask deposition is shown according to some embodiments of the present application;

[0020] Figure 3 A flowchart of a process of carbon mask deposition is shown according to some embodiments of the present application;

[0021] Figure 4 A flowchart of a process of carbon mask deposition is shown according to some embodiments of the present application;

[0022] Figure 5 A diagram showing the relationship between stress and Young's modulus of a carbon mask is shown according to some embodiments of the present application; and

[0023] Figure 6 A table of process parameters of carbon masks generated under various reaction sources and radio frequency conditions is shown according to some embodiments of the present application.

[0024] REFERENCE NUMERALS:

[0025] 100 process tool for carbon mask deposition

[0026] 110 reaction cavity

[0027] 111 cavity wall

[0028] 112 shower plate

[0029] 120 heating disc

[0030] 130 radio frequency power supply

[0031] 140 plasma

[0032] A1 electrode area of upper electrode

[0033] The electrode area of ​​the lower electrode in A2;

[0034] The warping voltage of the upper electrode of V1;

[0035] The warping voltage of the lower electrode at V2;

[0036] Steps S310 to S320;

[0037] Steps S311 to S313; and

[0038] Steps S321 to S322. Detailed Implementation

[0039] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Although the description of the present invention is presented in conjunction with preferred embodiments, this does not mean that the features of the invention are limited to these embodiments. On the contrary, the purpose of describing the invention in conjunction with embodiments is to cover other options or modifications that may be derived based on the claims of the present invention. To provide a thorough understanding of the invention, many specific details will be included in the following description. The invention may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of the invention, some specific details will be omitted in the description.

[0040] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0041] Furthermore, the terms "upper," "lower," "left," "right," "top," "bottom," "horizontal," and "vertical" used in the following description should be understood as the orientations shown in the relevant paragraphs and accompanying drawings. These relative terms are for illustrative purposes only and do not imply that the described apparatus must be manufactured or operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0042] It is to be understood that, although terms such as "first", "second", "third", etc. are used herein to describe various components, regions, layers and / or sections, these components, regions, layers and / or sections should not be limited by these terms, and these terms are only used to distinguish different components, regions, layers and / or sections. Therefore, the first components, regions, layers and / or sections discussed below can be referred to as the second components, regions, layers and / or sections without departing from some embodiments of the present application.

[0043] As described above, in order to maintain the high conformality of the storage unit pattern transfer, a high Young's modulus, a high etching selectivity, and a high-temperature amorphous carbon mask with good etching conformality can be used. However, in the prior art, when the thin film has a relatively high Young's modulus, the substrate is subjected to a relatively large stress, and is prone to obvious warping, which can cause problems in subsequent processes, such as abnormal discharge of a subsequent etching machine due to adsorption problems, and inability to perform subsequent processes due to the inability to adsorb the highly warped product. In view of the limitations of the machine hardware and the process requirements, there are certain requirements for the stress of the carbon mask with a high Young's modulus. Although the doping of other elements in the amorphous carbon material can achieve a balance between the Young's modulus and the film stress to a certain extent, the doping complicates the removal of the thin film.

[0044] In order to solve the above problems existing in the prior art, the present application provides a carbon mask deposition process machine, a carbon mask deposition process method, and a computer readable storage medium, which can improve the Young's modulus of the deposited carbon mask and reduce the film stress without doping the amorphous carbon, achieve a balance between the Young's modulus and the film stress, thereby not only avoiding warping of the substrate, but also increasing the etching selectivity and improving the overall film quality of the carbon mask.

[0045] In some non-limiting embodiments, the above-mentioned carbon mask deposition process machine provided by the first aspect of the present application can be used to implement the above-mentioned carbon mask deposition process method provided by the second aspect of the present application.

[0046] Specifically, in some non-limiting embodiments, the above-mentioned computer readable storage medium provided by the third aspect of the present application has computer instructions stored thereon. When the computer instructions are executed by a processor, they can be used to implement the above-mentioned carbon mask deposition process machine provided by the second aspect of the present application.

[0047] The working principle of the carbon mask deposition processing machine will be described below in combination with some embodiments of the carbon mask deposition processing method. Those skilled in the art can understand that the embodiments of the carbon mask deposition processing method are only some non-limiting embodiments provided by the present application, which are intended to clearly show the main concept of the present application and provide some specific solutions for facilitating the public to implement, but not to limit the overall working mode or overall function of the carbon mask deposition processing machine. Similarly, the plasma filtering device is also only a non-limiting embodiment provided by the present application, which does not limit the implementation subject of each step in the carbon mask deposition processing method.

[0048] Please refer to Figure 1 , Figure 1 A structural schematic diagram of a carbon mask deposition processing machine according to some embodiments of the present application is shown.

[0049] As Figure 1 shown, in some embodiments of the present application, the carbon mask deposition processing machine 100 can include a reaction cavity 110, and the cavity wall 111 thereof can serve as a lower electrode. In addition, the upper part of the reaction cavity 110 can be provided with a shower plate 112 for introducing process gas into the reaction cavity 110. Alternatively, the "L-shaped" cavity wall 111 on both sides of the reaction cavity 110 and the shower plate 112 can jointly serve as a lower electrode.

[0050] Continuing as Figure 1 shown, the inside of the reaction cavity 110 can further include a heating disc 120 for holding a substrate, wherein the heating disc 120 can serve as an upper electrode. The carbon mask deposition processing machine 100 further includes a controller (not shown in the figure). The controller can be configured to introduce process gas into the inside of the reaction cavity 110, wherein the process gas can include a hydrocarbon reaction source and an inert gas. Alternatively, the inert gas can be selected from nitrogen, argon, helium, etc. Then, the controller can control the simultaneous application of a first high-frequency voltage and a second low-frequency voltage on the upper electrode or the lower electrode to form a radio frequency electric field between the other electrode, dissociate the hydrocarbon reaction source and the inert gas, and deposit a carbon mask on the substrate via the plasma 140 obtained by dissociation.

[0051] As Figure 1As shown, in some preferred embodiments, the carbon mask deposition process machine 100 can simultaneously cover two frequencies of the RF power source, and therefore the RF power source 130 can further include a first RF power source and a second RF power source, wherein the first RF power source can be used to provide a first high frequency voltage, and the second RF power source can be used to provide a second low frequency voltage. The high frequency electric field provided by the first RF power source can be used to control the density of the plasma 140. Under the high frequency electric field, the process gas is more likely to dissociate to form the plasma 140. The low frequency electric field provided by the second RF power source can be used to control the bombardment energy of the plasma 140. By introducing the low frequency, the bombardment energy of the ions can be increased, thereby improving the film density. In the present embodiment, by combining the first high frequency voltage and the second low frequency voltage, the advantages of the above two frequencies can be simultaneously covered, and different frequencies can be suitable for different process requirements.

[0052] Alternatively, the first RF power source and the second RF power source can be connected to the heating disc 120 through a match box, so that the first RF power source or the first RF power source can be turned on alone to provide the first high frequency voltage or the second low frequency voltage to the heating disc 120, respectively, or the first RF power source and the first RF power source can also be turned on simultaneously to apply the first high frequency voltage and the second low frequency voltage to the heating disc 120 at the same time, thereby performing the carbon mask deposition process method.

[0053] As shown in the above Figure 1 In some embodiments, the electrode area A1 of the upper electrode in the heating disc 120 can be smaller than the electrode area A2 of the lower electrode in the cavity wall 111 and the shower plate 112. Specifically, according to the relationship between the sheet voltage and the electrode area wherein V1 represents the sheet voltage of the upper electrode, V2 represents the sheet voltage of the lower electrode, A1 represents the electrode area of the upper electrode, and A2 represents the electrode area of the lower electrode, it can be concluded that the sheet voltage of the electrode is inversely proportional to the electrode area. Therefore, by setting the electrode area A1 of the upper electrode in the heating disc 120 to be smaller than the electrode area A2 of the lower electrode in the cavity wall 111 and the shower plate 112, the sheet voltage on the heating disc 120 as the upper electrode can be made to be greater than the sheet voltage on the cavity wall 111 and the shower plate 112 as the lower electrode, i.e. A1 < A2, V1 > V2.

[0054] Further, when the upper electrode is connected to the RF power source 130, the upper electrode can be applied with the first high frequency voltage and the second low frequency voltage, and at this time the lower electrode including the shower plate 112 and the cavity wall 111 can be grounded.

[0055] In the above Figure 1In the embodiment shown, the RF is introduced from the bottom of the heating plate 120, i.e. the heating plate 120 is used as the upper electrode, and the shower plate 112 and the chamber wall 111 are used as the lower electrode. Moreover, since the area of the heating plate 120 as the upper electrode is small, i.e. the electrode area A1 of the upper electrode is small, the bucking voltage V1 of the upper electrode on the surface of the heating plate 120 is large. This RF introduction mode can make the utilization of the RF higher, and the probability of partial discharge lower, so that the substrate placed on the surface of the heating plate 120 has a higher sheath potential, thereby generating higher ion energy, and it is easier to form high-density plasma 140, and thus a denser thin film is formed, and the surface flatness of the thin film is also high, the roughness is greatly improved, and the film quality is improved.

[0056] In some embodiments, the carbon-hydrogen reaction source is preferably a main reaction source with a small amount of hydrogen atoms. Alternatively, the atomic ratio of carbon atoms to hydrogen atoms of the carbon-hydrogen reaction source can be preferably greater than 0.5. For example, the carbon-hydrogen reaction source can be selected as acetylene (C2H2). Compared with C3H6, CH4 and other carbon-hydrogen compounds with a large amount of hydrogen atoms, the C2H2 main reaction source with a small amount of hydrogen atoms can increase the etching selectivity of the carbon hard mask. It can be understood that "a small amount of hydrogen" herein is a relative concept rather than an absolute concept. For example, C2H2 is a carbon-hydrogen reaction source with a small amount of hydrogen compared with C3H6 and CH4.

[0057] In addition, alternatively, the electrode area A1 of the upper electrode can also be greater than or equal to the electrode area A2 of the lower electrode. Please refer to Figure 2 , Figure 2 A structure schematic diagram of a process machine for carbon mask deposition according to another embodiment of the present application is shown.

[0058] As Figure 2 shown, in another alternative embodiment, the shower plate 112 can also be selected as the upper electrode, and the RF power source 130 is connected to introduce the RF from the top of the reaction chamber 110. Moreover, the electrode area A1 of the shower plate 112 as the upper electrode is greater than or equal to the electrode area A2 of the heating plate 120 as the lower electrode. According to the relationship between the bucking voltage and the electrode area At this time, the bucking voltage on the heating plate 120 as the lower electrode is less than or equal to the bucking voltage on the shower plate 112 as the upper electrode, i.e. A1≥A2, V1≤V2. In this embodiment, C2H2 is introduced as the carbon-hydrogen reaction source, although the carbon mask can also be deposited on the substrate, but in this RF introduction mode, since the shower plate 112 as the upper electrode does not directly contact the substrate, some RF energy will be lost in the process of reaching the substrate surface after the RF is introduced from the shower plate 112, thereby reducing the utilization of the RF.

[0059] Next, the working principle of the carbon mask deposition process machine 100 will be further described in combination with a carbon mask deposition process method according to another aspect of the present application. Please refer to Figure 3 , Figure 3 A flow chart of a carbon mask deposition process method according to some embodiments of the present application is shown.

[0060] As shown in Figure 3 , in some embodiments of the present application, the carbon mask deposition process method can include the following step S310: introducing a process gas into the interior of the reaction chamber 110 of the carbon mask deposition process machine 10. Optionally, the process gas can include a hydrocarbon reaction source and an inert gas, such as nitrogen, argon, helium, etc. And the heating plate 120 in the reaction chamber 110 can be used as an upper electrode, and the chamber wall 111 of the reaction chamber 110 can be used as a lower electrode.

[0061] Then, step S320 can be performed: simultaneously applying a first high-frequency voltage and a second low-frequency voltage on the upper electrode or the lower electrode to form a radio frequency electric field between the other electrode, dissociate the hydrocarbon reaction source, and deposit a carbon mask on the substrate via the dissociated plasma 140.

[0062] Specifically, the step S320 can be combined with Figure 4 , and understood together, Figure 4 A flow chart of a carbon mask deposition process method according to an embodiment of the present application is shown.

[0063] In some optional embodiments, as shown in Figure 4 , the step S310 can be implemented as steps S311-S313.

[0064] As shown in Figure 4 , first, step S311 can be performed: preheating the substrate sent into the reaction chamber 110 at a high temperature to release the stress of the substrate, thereby avoiding the substrate from being warped due to the deposition process immediately, causing the thin film to grow on the back of the warped substrate, and causing abnormal discharge and other problems. The "substrate" here can not only include a pure silicon wafer, but also an integrated circuit product wafer. Optionally, the preheating temperature can be greater than 660°C, so that the reaction chamber 110 can reach a high-temperature process environment in advance. By preheating the substrate to be processed before the carbon mask deposition process, the process efficiency can also be improved.

[0065] Then, as shown in Figure 4 , optionally, step S312 can be performed: introducing a general gas, i.e. an inert gas, into the reaction chamber 110 until the gas pressure in the reaction chamber 110 reaches a stable state, thereby improving the stability of the subsequent process reaction.

[0066] After that, in combination with Figure 1 andFigure 4 As shown, step S313 can be executed to apply a third high-frequency voltage with a first power to the heating plate 120, which serves as the upper electrode, for electrostatic adsorption of the substrate placed above the heating plate 120. Preferably, the third high-frequency voltage is typically a low-power high-frequency voltage; therefore, the first power can be in the range of 100–1500 W.

[0067] Optionally, in some embodiments, the heating plate 120 may be a unipolar type electrostatic chuck. The substrate can acquire charge from the plasma, and the electrodes generate opposite charges when energized, thereby electrostatically attracting the substrate. Alternatively, in other optional embodiments, the heating plate 120 may also be a bipolar type electrostatic chuck.

[0068] Furthermore, please continue as follows Figure 4 As shown, the above step S320 can be specified as steps S321 to S322.

[0069] like Figure 4 As shown, step S321 can then be performed. After introducing the hydrocarbon reaction source C2H2 into the reaction chamber 110, a first high-frequency voltage of the first deposition power, or a combination of the first high-frequency voltage and the second low-frequency voltage, can be applied to the upper electrode or the lower electrode to deposit a carbon film of the first thickness on the substrate surface.

[0070] Specifically, to increase the adhesion between the subsequently deposited main carbon film and the substrate, a first high-frequency voltage with a first deposition power, or a combination of a first high-frequency voltage and a second low-frequency voltage, can be applied to the heating plate 120, which serves as the upper electrode, to generate a carbon film of a relatively thin first thickness. It is understood that the "first deposition power" here is not a fixed power value, but can be adjusted according to the type of radio frequency voltage selected for depositing the carbon film of the first thickness. For example, the first deposition power of a carbon film of the first thickness deposited using a first high-frequency voltage can be different from the first deposition power of a carbon film of the first thickness deposited using a combination of a first high-frequency voltage and a second low-frequency voltage.

[0071] Continue as Figure 4 As shown, step S322 can then be executed. In response to the completion of the deposition of the carbon film of the first thickness, a first high-frequency voltage and a second low-frequency voltage can be applied simultaneously to the upper electrode or the lower electrode to deposit a main carbon film of the second thickness on the surface of the carbon film of the first thickness.

[0072] Specifically, preferably, to improve the utilization rate of radio frequency and plasma, a first high-frequency voltage and a second low-frequency voltage with a second deposition power can be simultaneously applied to the heating plate 120, which serves as the upper electrode. That is, dual frequencies are simultaneously introduced from the bottom of the reaction chamber 110, thereby generating a second-thickness main carbon film on the surface of the first-thickness carbon film. The second-thickness main carbon film can adhere to the substrate via the first-thickness carbon film. The thickness of the second-thickness main carbon film can be significantly greater than the thickness of the first-thickness carbon film, and the second deposition power can be greater than or equal to the first deposition power. In this embodiment, the introduction of the second low-frequency voltage not only increases the bombardment intensity of ions but also simultaneously reduces the energy of the first high-frequency voltage, avoiding abnormal discharge caused by excessively high high-frequency voltage.

[0073] Subsequently, optionally, in some embodiments, after completing the above step S323, a post-treatment can be performed on the substrate in the reaction chamber 110 where the carbon mask is deposited.

[0074] Specifically, in some embodiments, the radio frequency (RF) can be kept on while the first high-frequency voltage and / or the second low-frequency voltage within the reaction chamber 110 are gradually reduced. During the carbon mask deposition process, the switching on and off of the RF causes drastic changes in the plasma state. If the RF power is immediately switched off after the deposition process, the RF energy needed to maintain plasma equilibrium disappears, and this instantaneous fluctuation in RF power can lead to instability of the process gases (e.g., C2H2 and inert gases) within the chamber. Consequently, incompletely dissociated process gases can easily agglomerate, generating particles. Therefore, by maintaining the RF on for a period after the deposition reaction, it is possible to ensure the plasma gradually and stably dissipates, thereby reducing particle generation and providing conditions for subsequent post-processing steps.

[0075] Next, inert gas can be introduced into the reaction chamber 110 to purge reaction byproducts and clean the chamber. Finally, after the plasma in the reaction chamber 110 gradually and stably disappears, the application of the first high-frequency voltage and the second low-frequency voltage can be stopped, and the coated substrate after the treatment can be transferred out of the reaction chamber 110 for the next process.

[0076] Next, please refer to Figure 5 , Figure 5 A schematic diagram showing the relationship between stress and Young's modulus of a carbon mask provided according to some embodiments of the present invention is shown.

[0077] like Figure 5 As shown, in some embodiments of the present invention, three different test cases are illustrated, wherein, Figure 5 The horizontal axis in the figure represents the absolute value of the film stress, and the vertical axis represents the Young's modulus.

[0078] In the first test example, C3H6 was used as the hydrocarbon reaction source, and only a first high-frequency voltage was introduced into the heating pan 120. At this time, the film stress of the generated carbon mask was approximately in the range of 450–550 MPa, and the Young's modulus was approximately in the range of 60–70 GPa. Based on this, in the second test example, C3H6 was used as the hydrocarbon reaction source, and a first high-frequency voltage combined with a second low-frequency voltage was simultaneously introduced into the heating pan 120. At this time, the film stress of the generated carbon mask was approximately in the range of 200–350 MPa, the film stress was somewhat reduced, and the change in Young's modulus was not significant.

[0079] Furthermore, such as Figure 5 As shown, in the third test example, C2H2, which has a relatively low hydrogen atom content, was used as the hydrocarbon reaction source, and a first high-frequency voltage combined with a second low-frequency voltage was simultaneously introduced into the heating plate 120. In this case, the film stress of the generated carbon mask was significantly reduced, falling within the range of approximately 0–100 MPa, and the Young's modulus could be maintained within the range of approximately 55–80 GPa. According to... Figure 5 The three test cases show that, in this invention, by introducing dual frequencies (a first high-frequency voltage and a second low-frequency voltage) on the second electrode in the heating plate 120, and introducing a hydrocarbon reaction source with a low hydrogen atom content (such as C2H2), it is possible to increase Young's modulus and reduce film stress in the absence of amorphous carbon doping, thereby achieving a balance between Young's modulus and film stress. This not only avoids substrate warping but also increases etching selectivity, thus improving the overall film quality of the carbon mask.

[0080] In addition, you can also refer to Figure 6 , Figure 6 A table showing process parameters for carbon masks generated by various reaction sources and radio frequency conditions according to some embodiments of the present invention is provided.

[0081] like Figure 6 As shown, in some embodiments of the present invention, four different test examples are presented respectively: a first test example using C3H6 as a hydrocarbon reaction source and introducing only a first high-frequency voltage into the heating plate 120; a second test example using C2H2 as a hydrocarbon reaction source and introducing only a first high-frequency voltage into the heating plate 120; a third test example using C3H6 as a hydrocarbon reaction source and introducing a first high-frequency voltage combined with a second low-frequency voltage into the heating plate 120; and a fourth test example using C2H2 as a hydrocarbon reaction source and introducing a first high-frequency voltage combined with a second low-frequency voltage into the heating plate 120.

[0082] like Figure 6 As shown, in these four test cases, the thickness of the generated carbon masks is basically the same. However, in the first and third test cases using C3H6 as the hydrocarbon reaction source, the film stress was still relatively high, at -520 MPa and -200 MPa respectively. Since stress can be positive or negative, with positive values ​​representing tensile stress and negative values ​​representing compressive stress, "-520" and "-200" represent 520 MPa and 200 MPa of compressive stress, respectively. In the second and fourth test cases using C2H2 as the hydrocarbon reaction source, the film stress decreased significantly, reaching 70 MPa of compressive stress and 0 MPa, respectively.

[0083] And, as Figure 6 As shown, in the first to fourth test examples, the hardness of the generated carbon masks was approximately 9 GPa, 8.4 GPa, 8.2 GPa, and 9 GPa, respectively, and the Young's modulus was approximately 76 GPa, 65 GPa, 62.7 GPa, and 73 GPa, respectively. It can be seen that among these four test examples, the carbon mask generated in the fourth test example had the lowest film stress (0 MPa), but the highest film hardness (9 GPa) and Young's modulus (73 GPa), thus achieving a balance between Young's modulus and film stress. This not only prevents substrate warping but also increases etching selectivity, thereby improving the overall film quality of the carbon mask.

[0084] Although the methods described above are illustrated and depicted as a series of actions for the sake of simplicity, it should be understood and appreciated that these methods are not limited by the order of the actions, as some actions may occur in a different order and / or concurrently with other actions from the illustrations and descriptions herein or not illustrated and described herein but which may be understood by those skilled in the art, according to one or more embodiments.

[0085] Those skilled in the art will further appreciate that the steps of the methods or algorithms described in connection with the embodiments disclosed herein can be embodied directly in hardware, in a software module executed by a processor, or in a combination of both. The software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor so that the processor can read and write information to / from the storage medium. In an alternative, the storage medium may be integrated into the processor. The processor and storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In an alternative, the processor and storage medium may reside as discrete components in the user terminal.

[0086] In one or more exemplary embodiments, the described functionality may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software as a computer program product, the functionality may be stored or transmitted as one or more instructions or code on or through a computer-readable medium. A computer-readable medium includes both computer storage media and communication media, encompassing any medium that facilitates the transfer of a computer program from one location to another. A storage medium may be any available medium accessible to a computer. By way of example and not limitation, such a computer-readable medium may include RAM, ROM, EEPROM, CD-ROM or other optical disc storage, disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and is accessible to a computer. Any connection is also legitimately referred to as a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of a medium. As used in this article, disk and disc include compact discs (CDs), laser discs, optical discs, digital multi-purpose discs (DVDs), floppy disks, and Blu-ray discs. Disks typically reproduce data magnetically, while discs reproduce data optically using lasers. Combinations of these should also be included within the scope of computer-readable media.

[0087] In summary, this invention provides a carbon mask deposition equipment, a carbon mask deposition process, and a computer-readable storage medium. These technologies can improve the Young's modulus of the deposited carbon mask and reduce film stress in the absence of amorphous carbon doping, achieving a balance between Young's modulus and film stress. This not only prevents substrate warping but also increases etching selectivity, thereby improving the overall film quality of the carbon mask.

[0088] The prior description of this disclosure is provided to enable any person skilled in the art to make or use this disclosure. Various modifications to this disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not intended to be limited to the examples and designs described herein, but should be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A process equipment for carbon mask deposition, characterized in that, include: The reaction chamber, with its walls serving as the lower electrode; A heating plate, located within the reaction chamber, is used to hold the substrate, wherein the heating plate serves as the upper electrode; and The controller is configured to: introduce a process gas into the interior of the reaction chamber, wherein the process gas includes a hydrocarbon reaction source; and simultaneously apply a first high-frequency voltage and a second low-frequency voltage to the upper electrode or the lower electrode to form a radio frequency electric field between the upper electrode and the other electrode, dissociate the hydrocarbon reaction source, and deposit a carbon mask on the substrate via the plasma obtained from the dissociation.

2. The process equipment as described in claim 1, characterized in that, The electrode area of ​​the upper electrode is smaller than that of the lower electrode, according to the relationship between the warp voltage and the electrode area. Wherein, V1 represents the warp voltage of the upper electrode, V2 represents the warp voltage of the lower electrode, A1 represents the electrode area of ​​the upper electrode, and A2 represents the electrode area of ​​the lower electrode, so that the warp voltage on the heating plate serving as the upper electrode is greater than the warp voltage on the cavity wall serving as the lower electrode.

3. The process equipment as described in claim 2, characterized in that, The upper part of the reaction chamber is provided with a spray plate, and the spray plate and the chamber wall together serve as the lower electrode. When the upper electrode is subjected to the first high-frequency voltage and the second low-frequency voltage, the lower electrode is grounded.

4. The process equipment as described in claim 1, characterized in that, Also includes: A first radio frequency (RF) power supply and a second RF power supply, wherein the first RF power supply is used to provide the first high-frequency voltage and the second RF power supply is used to provide the second low-frequency voltage.

5. The process equipment as described in claim 1, characterized in that, The ratio of carbon atoms to hydrogen atoms in the hydrocarbon reaction source is greater than 0.

5.

6. A process for carbon mask deposition, characterized in that, Includes the following steps: A process gas is introduced into the reaction chamber of the carbon mask deposition process equipment as described in any one of claims 1 to 5, wherein the process gas includes a hydrocarbon reaction source, and the heating plate in the reaction chamber serves as the upper electrode, and the chamber wall of the reaction chamber serves as the lower electrode. as well as A first high-frequency voltage and a second low-frequency voltage are simultaneously applied to the upper electrode or the lower electrode to form a radio frequency electric field between the upper electrode and the lower electrode, thereby dissociating the hydrocarbon reaction source and depositing a carbon mask on the substrate via the plasma obtained from the dissociation.

7. The process method as described in claim 6, characterized in that, Prior to the step of introducing process gas into the reaction chamber of the carbon mask deposition equipment, the method further includes: The substrate, fed into the reaction chamber, is preheated at high temperature to release stress on the substrate; and A third high-frequency voltage with a first power is applied to the upper electrode for electrostatic adsorption of a substrate placed above the heating plate, wherein the first power is in the range of 100 to 1500 W.

8. The process method as described in claim 7, characterized in that, The step of simultaneously applying a first high-frequency voltage and a second low-frequency voltage to the upper electrode or the lower electrode to form a radio frequency electric field with the other electrode, dissociating the hydrocarbon reaction source, and depositing a carbon mask on the substrate via the plasma obtained from the dissociation includes: A hydrocarbon reaction source is introduced, and a first high-frequency voltage of a first deposition power, or a combination of the first high-frequency voltage and the second low-frequency voltage, is applied to the upper electrode or the lower electrode to deposit a carbon film of a first thickness on the substrate surface; and In response to the completion of carbon film deposition of the first thickness, a first high-frequency voltage and a second low-frequency voltage of the second deposition power are simultaneously applied to the upper electrode or the lower electrode to deposit a main carbon film of the second thickness on the surface of the carbon film of the first thickness. The main carbon film of the second thickness is adhered to the substrate via the carbon film of the first thickness, wherein the second thickness is greater than the first thickness and the second deposition power is greater than or equal to the first deposition power.

9. The process method as described in claim 8, characterized in that, After the step of simultaneously applying the first high-frequency voltage and the second low-frequency voltage with a second deposition power to the upper electrode or the lower electrode to deposit a second-thickness main carbon film on the surface of the first-thickness carbon film, the method further includes: Gradually reduce the first high-frequency voltage and / or the second low-frequency voltage within the reaction chamber; An inert gas is introduced into the reaction chamber to purge reaction byproducts; and Stop applying the first high-frequency voltage and the second low-frequency voltage, and then transfer the coated substrate that has undergone the processing out of the reaction chamber.

10. A computer-readable storage medium storing computer instructions thereon, characterized in that, When the computer instructions are executed by the processor, the carbon mask deposition process method as described in any one of claims 6 to 9 is implemented.

Images