Etching method of a substrate and semiconductor process apparatus

Abstract

The application discloses an etching method of a substrate and a semiconductor processing device, and belongs to the technical field of semiconductor processing. The method comprises the following steps: providing a structure to be etched, wherein the structure to be etched comprises a substrate, a transfer layer and a patterned mandrel layer formed on the substrate in sequence; forming a sidewall on both sides of each mandrel of the patterned mandrel layer; removing the patterned mandrel layer; etching the transfer layer to obtain a transfer pattern by taking the sidewall as a mask; etching the substrate by taking the transfer pattern as a mask; when the actual width of the mandrel is greater than a first predetermined width, the actual width of the sidewall is less than a second predetermined width, and the width of one end of the transfer pattern close to the substrate is greater than the width of the other end close to the sidewall; or when the actual width of the mandrel is less than the first predetermined width, the actual width of the sidewall is greater than the second predetermined width, and the width of one end of the transfer pattern close to the substrate is less than the width of the other end close to the sidewall.

Description

Technical Field

[0001] This application belongs to the field of semiconductor processing technology, specifically relating to a substrate etching method and semiconductor process equipment. Background Technology

[0002] In semiconductor manufacturing, multiple exposure technology is used to achieve smaller feature size patterns. However, during the multiple exposure process, as processes such as exposure, deposition, and etching are carried out, the spacing between patterns may change, resulting in inconsistent width dimensions of the final patterns.

[0003] like Figure 1 As shown, etching the patterned photoresist layer 3 can transfer the pattern to the core layer 2. During this process, the pattern width of the core layer 2 may differ from the predetermined width due to certain factors. Taking the pattern width of the core layer 2 being larger than the predetermined width as an example, if a deposition layer 4 with preset parameters is still formed on the core layer 2, the spacing between the sidewalls sandwiched between two adjacent patterns in the core layer 2 will be relatively small. After removing the core layer 2 and etching the substrate 1 using the sidewalls as a mask to transfer the pattern to the substrate 1, the first width period L1 and the second width period L2 of two adjacent patterns formed on the substrate 1 will be different. This will have a serious impact on the electrical properties and yield of the chip device. Summary of the Invention

[0004] The purpose of this application is to provide a substrate etching method and semiconductor process equipment to solve the problem that in current etching methods, if the pattern width of the core layer differs from the predetermined width, the period widths between the patterns formed on the substrate will be different, which will seriously affect the electrical properties and yield of the chip device.

[0005] In a first aspect, embodiments of this application disclose a substrate etching method, comprising:

[0006] A structure to be etched is provided, the structure to be etched comprising a substrate and a transfer layer and a patterned mandrel layer sequentially formed on the substrate;

[0007] Sidewalls are formed on both sides of each mandrel in the patterned mandrel layer;

[0008] Remove the patterned mandrel layer;

[0009] Using the sidewall as a mask, the transfer layer is etched to obtain the transfer pattern;

[0010] The substrate is etched using the transfer pattern as a mask;

[0011] Wherein, when the actual width of the mandrel is greater than a first predetermined width, the actual width of the sidewall is made less than a second predetermined width, and the width of the end of the transfer pattern near the substrate is made greater than the width of the end near the sidewall; or,

[0012] When the actual width of the mandrel is less than the first predetermined width, the actual width of the sidewall is made greater than the second predetermined width, and the width of the end of the transfer pattern near the substrate is made less than the width of the end near the sidewall.

[0013] Secondly, embodiments of this application disclose a semiconductor process apparatus, which includes a processor, a memory, and a program or instructions stored in the memory and executable on the processor. When the program or instructions are executed by the processor, they implement the steps of the etching method described above.

[0014] This application discloses a substrate etching method, which sequentially forms a transfer layer and a patterned core layer on the substrate. Sidewalls are formed on both sides of each core in the patterned core layer. After removing the patterned core layer, the size of the mask pattern is reduced and the number of mask patterns is doubled. Then, during the etching of the transfer layer using the sidewalls as masks, transfer patterns with twice the number of patterns compared to the patterned core layer can be formed on the transfer layer. Subsequently, during the etching of the substrate using the transfer patterns of the transfer layer as masks, the transfer patterns can be further transferred to the substrate, thereby reducing the critical size of the patterns formed on the substrate.

[0015] In the etching method of this application, if there is a difference between the actual width of the mandrel of the patterned mandrel layer and its predetermined width, i.e., the first predetermined width, the uniformity of the period width of the pattern formed on the substrate can be improved by adjusting the actual widths of the two ends of the transfer pattern in the transfer layer.

[0016] In more detail, when the actual width of the mandrel in the patterned mandrel layer is greater than the first predetermined width, by making the actual width of the sidewalls smaller than their initial design size, i.e., the second predetermined width, the spacing between two sidewalls located between adjacent mandrels can be appropriately increased, thereby improving the width dimension between any two adjacent sidewalls. At the same time, by controlling the actual width of the end of the transfer pattern near the substrate in the transfer layer to be greater than the actual width of the end of the transfer pattern near the sidewall, the width dimension of the pattern formed on the substrate can be increased when the transfer layer is used as a mask to etch the substrate, thereby ensuring that the uniformity of the width dimension and the period width of the pattern on the substrate meets the requirements.

[0017] Alternatively, if the actual width of the mandrel is less than the first predetermined width, the actual width of the sidewall can be controlled to be greater than the second predetermined width, and the actual width of the end of the transfer pattern near the substrate in the transfer layer can be controlled to be less than the actual width of the end of the transfer pattern near the sidewall, so that the uniformity of the width dimension and period width of the pattern on the substrate can also meet the requirements. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0019] Figure 1 This is a schematic diagram of the substrate etching process in current technology;

[0020] Figure 2 A schematic diagram of the substrate etching process disclosed in this application embodiment;

[0021] Figure 3 Another schematic diagram of the substrate etching process disclosed in the embodiments of this application;

[0022] Figure 4 This is a flowchart of the substrate etching method disclosed in the embodiments of this application.

[0023] Figure label:

[0024] 1-Substrate, 2-Core layer, 3-Photoresist layer, 4-Deposited layer, L1-First width period, L2-Second width period

[0025] 100 - Substrate, 200 - Core layer, 300 - Photoresist layer, 400 - Deposited layer, 510 - First transfer layer, 520 - Second transfer layer, L3 - First width period, L4 - Second width period. Detailed Implementation

[0026] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0027] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0028] This application discloses a substrate etching method. Using this etching method, when the actual width of the pattern on the core layer differs significantly from the predetermined width due to certain reasons, the actual width of the pattern on the transfer layer can be controlled by controlling parameters such as the thickness parameters of the sidewalls and the etching conditions of the sidewalls. This results in better uniformity of the width and period width of the pattern formed on the substrate.

[0029] In detail, such as Figure 4 As shown, the substrate etching method disclosed in this application includes:

[0030] S1. Provide a structure to be etched, the structure to be etched includes a substrate and a transfer layer and a patterned mandrel layer sequentially formed on the substrate;

[0031] S2. Sidewalls are formed on both sides of each mandrel in the patterned mandrel layer;

[0032] S3. Remove the patterned core layer;

[0033] S4. Using the sidewalls as a mask, etch the transfer layer to obtain the transfer pattern;

[0034] S5. Using the transfer pattern as a mask, etch the substrate.

[0035] Specifically, the material of the transfer layer can be selected according to the material of the sidewalls to ensure that the sidewalls can act as a mask for the transfer layer during the etching process, and the pattern of the sidewalls can be transferred to the transfer layer, thus giving the transfer layer a transfer pattern. Of course, the materials and thicknesses of the core layer, transfer layer, and sidewalls can be flexibly selected according to the actual situation.

[0036] In one specific embodiment of this application, the core layer can be formed using amorphous silicon, and the sidewalls can be formed using silicon nitride. In this case, the transfer layer can be formed solely using silicon oxide, ensuring that the sidewalls can serve as a mask for the transfer layer, allowing the pattern of the sidewalls to be transferred to the transfer layer during etching. In other embodiments of this application, the transfer layer is made of at least one of silicon nitride, silicon oxide, silicon oxynitride, titanium dioxide, and aluminum oxide.

[0037] More specifically, a transfer layer and a core layer can be sequentially formed on a substrate using processes such as vapor deposition. After the core layer is patterned, sidewalls are formed on both sides of each core in the core layer. Specifically, the sidewalls can be formed by partially etching the deposition layer 400. That is, after forming the patterned core layer, a deposition process can be used to form a deposition layer 400 above the patterned core layer and the transfer layer. Then, by etching, the portion of the deposition layer covering the top of the patterned core layer and the top of the transfer layer can be removed, leaving the portion of the deposition layer deposited on the opposite sides of each core in the patterned core layer. This portion is the sidewall.

[0038] More specifically, step S1 above may include:

[0039] S11, Provide substrate;

[0040] S12. A transfer layer, a core layer, and a photoresist layer are sequentially formed on the substrate;

[0041] S13, patterned photoresist layer;

[0042] S14. Using the photoresist layer as a mask, the core layer is etched to form a patterned core layer;

[0043] S15. Measure the actual width of the mandrel in the patterned mandrel layer.

[0044] That is, after the transfer layer and the core layer 200 are formed sequentially using processes such as deposition, a photoresist layer 300 can be formed on the side of the core layer 200 away from the transfer layer. Specifically, the photoresist layer 300 can be formed by spin coating or similar methods. Subsequently, the photoresist layer can be patterned by exposure and development, thereby forming a patterned photoresist layer. Then, the patterned photoresist layer can be used as a mask to etch the core layer, so that the pattern of the photoresist layer is transferred onto the core layer, thereby forming a patterned core layer.

[0045] As described above, during the formation of the patterned mandrel layer, the width of the patterned mandrel layer may differ from the predetermined width for various reasons. Therefore, in the etching method disclosed in this application embodiment, after the patterned mandrel layer is formed, it is necessary to measure the actual width of the mandrel in the patterned mandrel layer to determine whether the actual width of the mandrel in the patterned mandrel layer meets the predetermined width.

[0046] Specifically, a scanning electron microscope can be used to measure the actual width of the mandrel in the patterned mandrel layer. In this case, the measurement cost can be reduced as much as possible while ensuring relatively high measurement accuracy of the actual width of the mandrel in the patterned mandrel layer.

[0047] After measuring the actual width of the mandrel in the patterned mandrel layer, if the actual width of the mandrel meets the first predetermined width, the deposition layer can still be formed according to the preset parameters, and the process formula can be controlled according to the preset parameters to use the sidewalls as a mask to etch the transfer layer, and finally form a pattern that meets the requirements on the substrate.

[0048] If the actual width of the mandrel does not meet the first predetermined width, the process formula can be controlled according to the specific situation of the actual width of the mandrel, and the deposition thickness of the sidewall can be changed. At the same time, the etching of the transfer layer can be changed accordingly, so that the required pattern can still be formed on the substrate. That is, the pattern width of the substrate is equal or basically equal, and the density is the same or basically the same, thereby ensuring that the uniformity of the pattern on the substrate meets the requirements.

[0049] In detail, if the actual width of the mandrel in the patterned mandrel layer is greater than the first predetermined width, and sidewalls are still formed on both sides of the mandrel according to preset parameters, the spacing between the two sidewalls between two adjacent mandrels will be less than the spacing between the two sidewalls on opposite sides of the same mandrel. In this case, if the transfer layer is directly etched using the aforementioned sidewalls as a mask, the period width of two adjacent patterns on the substrate will be different.

[0050] Therefore, in the etching method disclosed in the embodiments of this application, in view of the above situation, as follows: Figure 2 As shown, by changing the process formulation, the actual width of the sidewalls can be controlled to be less than the second predetermined width. That is, compared to the first predetermined width of the mandrel, if the actual width of the mandrel in the patterned mandrel layer is larger, the actual width of the sidewalls formed on opposite sides of the mandrel can be smaller than its second predetermined width. This can compensate for the situation where the remaining width between two adjacent mandrels is relatively small due to the larger width of the mandrel.

[0051] Meanwhile, since the width of the sidewall formed in the above process is less than the second predetermined width, in order to ensure that the transfer layer is etched using the sidewall as a mask and the substrate is etched using the transfer layer as a mask, so that the width of the pattern finally formed on the substrate can still be comparable to the predetermined width, in this embodiment of the application, the actual width of the end of the transfer pattern near the substrate formed on the transfer layer is also controlled to be greater than the width of the end of the transfer pattern near the sidewall.

[0052] More specifically, the actual width of the transfer pattern near the substrate in the transfer layer can be less than or equal to the second predetermined width. Thus, during the etching process of the substrate using the transfer layer as a mask, the width of the pattern formed on the substrate can be equivalent to the second predetermined width, i.e. the original width design size of the sidewall. Furthermore, the third width period L3 between two adjacent patterns in the pattern formed on the substrate 100 is equal to the fourth width period L4 between two other adjacent patterns, thereby ensuring that the uniformity of the pattern on the substrate 100 meets the requirements.

[0053] In some other embodiments, if the actual width of the mandrel in the patterned mandrel layer is less than the first predetermined width, and sidewalls are still formed on both sides of the mandrel according to preset parameters, the spacing between the two sidewalls between two adjacent mandrels will be greater than the spacing between the two sidewalls on opposite sides of the same mandrel. In this case, if the sidewalls are used directly as masks, the period widths of two adjacent patterns on the substrate will also differ.

[0054] Therefore, in the etching method disclosed in the embodiments of this application, in view of the above situation, as follows: Figure 3 As shown, the process formula can also be changed accordingly to control the actual width of the sidewalls to be greater than the second predetermined width. That is, compared with the first predetermined width of the mandrel, if the actual width of the mandrel in the patterned mandrel layer is smaller, the width of the sidewalls formed on opposite sides of the mandrel is larger than its second predetermined width. This can compensate for the situation where the remaining width between two adjacent mandrels is relatively large due to the smaller width of the mandrel.

[0055] Meanwhile, since the width of the sidewall formed in the above process is greater than the second predetermined width, in order to ensure that the width of the pattern finally formed on the substrate can still be comparable to the predetermined width when the sidewall is used as a mask, in this embodiment of the application, the actual width of the end of the transfer pattern near the substrate in the transfer layer is also controlled to be less than the actual width of the end of the transfer pattern away from the sidewall.

[0056] More specifically, the actual width of the transfer pattern near the substrate in the transfer layer can be greater than or equal to the second predetermined width. Thus, during the etching process of the substrate using the transfer layer as a mask, the width of the pattern formed on the substrate can be comparable to the second predetermined width, i.e., the original width design size of the sidewall. Furthermore, the third width period L3 between two adjacent patterns in the pattern formed on the substrate 100 is equal to the fourth width period L4 between two other adjacent patterns, thereby ensuring that the uniformity of the pattern on the substrate 100 meets the requirements.

[0057] This application discloses a substrate etching method, which sequentially forms a transfer layer and a patterned core layer on the substrate. Sidewalls are formed on both sides of each core in the patterned core layer. After removing the patterned core layer, the size of the mask pattern is reduced and the number of mask patterns is doubled. Then, during the etching of the transfer layer using the sidewalls as masks, transfer patterns with twice the number of patterns compared to the patterned core layer can be formed on the transfer layer. Subsequently, during the etching of the substrate using the transfer patterns of the transfer layer as masks, the transfer patterns can be further transferred to the substrate, thereby reducing the critical size of the patterns formed on the substrate.

[0058] In the etching method of this application, if there is a difference between the actual width of the mandrel of the patterned mandrel layer and its predetermined width, i.e., the first predetermined width, the uniformity of the period width of the pattern formed on the substrate can be improved by adjusting the actual widths of the two ends of the transfer pattern in the transfer layer.

[0059] In more detail, when the actual width of the mandrel in the patterned mandrel layer is greater than the first predetermined width, by making the actual width of the sidewalls smaller than their initial design size, i.e., the second predetermined width, the spacing between two sidewalls located between adjacent mandrels can be appropriately increased, thereby improving the width dimension between any two adjacent sidewalls. At the same time, by controlling the actual width of the end of the transfer pattern near the substrate in the transfer layer to be greater than the actual width of the end of the transfer pattern near the sidewall, the width dimension of the pattern formed on the substrate can be increased when the transfer layer is used as a mask to etch the substrate, thereby ensuring that the uniformity of the width dimension and the period width of the pattern on the substrate meets the requirements.

[0060] In some other embodiments, if the actual width of the mandrel is less than the first predetermined width, the actual width of the sidewall can be controlled to be greater than the second predetermined width, and the actual width of the end of the transfer pattern near the substrate in the transfer layer can be controlled to be less than the actual width of the end of the transfer pattern near the sidewall, so that the uniformity of the width dimension and the period width of the pattern on the substrate can also meet the requirements.

[0061] As described above, the transfer layer can be formed using a single material. To reduce the difficulty of controlling the actual width of the transfer layer near the substrate, in another embodiment of this application, the transfer layer can include a first transfer layer 510 and a second transfer layer 520. In this case, step S12 includes:

[0062] A first transfer layer, a second transfer layer, a core layer, and a photoresist layer are sequentially formed on the substrate.

[0063] That is, the second transfer layer is located on the side of the first transfer layer away from the substrate. Of course, during the design process, it is necessary to ensure that the etching rates of the first and second transfer layers are different under the same etching conditions, thereby reducing the difficulty of controlling the etching process. Optionally, the first transfer layer 510 and the second transfer layer 520 are made of different materials so that during the etching process of the second and first transfer layers...

[0064] By controlling parameters such as the type of etching gas, the etching parameters of the first transfer layer, which is closer to the substrate, can be changed relatively easily.

[0065] More specifically, in one embodiment of this application, one of the first transfer layer and the second transfer layer is silicon nitride, and the other is silicon oxide. These two materials have relatively higher chemical stability and can form a better interface with the core layer and the substrate, thereby improving the etching effect. Furthermore, when the first and second transfer layers use the aforementioned materials, the selection of etching gases is also easier. Specifically, fluorine gas and its compounds etch silicon oxide faster than silicon nitride, while chlorine gas and its compounds etch silicon nitride faster than silicon oxide. Therefore, precise etching of the first and second transfer layers can be achieved by correspondingly combining different etching gases.

[0066] When the transfer layer includes a first transfer layer and a second transfer layer, step S4 above may specifically include:

[0067] Using the sidewalls as a mask, the pattern of the sidewalls is transferred to the second transfer layer to form the second transfer pattern;

[0068] Using the second transfer pattern as a mask, the first transfer layer is etched to form the first transfer pattern;

[0069] As described above, the second transfer layer is located on the side of the first transfer layer facing away from the substrate. Therefore, during the etching process, the sidewalls are used as masks to first etch the second transfer layer to transfer the pattern of the sidewalls to the second transfer layer, thereby patterning the second transfer layer. Then, the patterned second transfer layer is used as a mask to etch the first transfer layer to further transfer the pattern of the second transfer layer to the first transfer layer, forming a patterned first transfer layer. It should be noted that the pattern formed on the second transfer layer is specifically the second transfer pattern, and the pattern formed on the first transfer layer is the first transfer pattern. The first and second transfer layers constitute the entire transfer layer, and the first and second transfer patterns constitute the entire transfer pattern. In addition, during the etching process of the first transfer layer, some sidewalls may remain.

[0070] Of course, if the actual width of the mandrel in the mandrel layer does not meet the first predetermined width, in order to ensure that the width and density of the pattern formed on the substrate can meet the preset requirements when the first transfer layer is used as a mask and the substrate is etched, the first transfer pattern on the first transfer layer can be controlled when the transfer layer includes the first transfer layer and the second transfer layer.

[0071] Specifically, when the actual width of the mandrel is greater than the first predetermined width, the width of the first transfer pattern is made greater than the width of the second transfer pattern; when the actual width of the mandrel is less than the first predetermined width, the width of the first transfer pattern is made less than the width of the second transfer pattern.

[0072] When the above technical solution is adopted, when the actual width of the mandrel is greater than the first predetermined width, it can be ensured that the width of the end of the transfer pattern near the substrate in the overall structure of the entire transfer layer is greater than the width of the end near the sidewall; correspondingly, when the actual width of the mandrel is less than the first predetermined width, it can be ensured that the width of the end of the transfer pattern near the substrate in the overall structure of the entire transfer layer is less than the width of the end near the sidewall.

[0073] Based on the above embodiments of this application, in the process of controlling the width of the first transfer pattern, the widths at different height positions in the first transfer pattern can be made equal or substantially equal. In order to further reduce the difficulty of controlling the structural parameters of the first transfer pattern, in another embodiment of this application, in the process of etching the first transfer layer, the width of the end of the first transfer pattern near the substrate can be controlled by controlling the slope angle of the first transfer pattern.

[0074] In this embodiment, the width of the end of the first transfer pattern closest to the substrate differs from the width of the end closest to the sidewall (or the second transfer layer), and the sidewall of the first transfer pattern is generally inclined, i.e., the first transfer pattern has a preset sidewall inclination angle (i.e., slope angle). By adopting the technical solution of this application, controlling the width of the end of the first transfer pattern closest to the substrate is relatively easy. Furthermore, during the etching process, the etching parameters of the first transfer layer can be flexibly controlled according to the actual etching condition of the first transfer layer by adjusting parameters such as the process formulation in real time. This results in higher precision in the width of the end of the first transfer layer closest to the substrate, thereby further improving the etching uniformity of the substrate.

[0075] As described above, the sidewall width and the etching rate of the transfer layer can be controlled by adjusting the process formulation. Specifically, in this embodiment, the actual width of the sidewall can be made different from the second predetermined width by changing the process formulation, and the width of the transfer pattern near the substrate can be made different from the width near the sidewall. More specifically, the process formulation may include parameters such as process time and the flow rate and pressure of the process gas. These parameters can directly change the width of the formed sidewall. Furthermore, different types of process gas can also directly change the etching rate of the transfer layer. More specifically, in this embodiment, the width of the sidewall and the etching speed of the transfer layer can also be controlled by changing other parameters such as RF power. Of course, the specific values ​​of the controlled process formulation will also need to be different when the actual width of the patterned mandrel layer differs from the first predetermined width.

[0076] Based on the above, in the embodiments of this application, the process formulation may include at least one of the following: radio frequency power, process time, flow rate and pressure of process gas, and type of process gas.

[0077] As described above, the etching rate of the transfer layer can be adjusted by modifying the process formulation. Since the required adjustment precision for the etching rate of the transfer layer is relatively high, the etching method disclosed in this application can make the chamber pressure during sidewall etching relatively low. That is, the sidewall is etched under relatively low pressure, and the sidewall is used as a mask to etch the transfer layer. This can make the etching rate relatively small, thereby improving the etching uniformity. This is beneficial for more precise control of the etching degree of the transfer layer, and ultimately achieves the goal of improving the etching precision of the pattern on the substrate and the uniformity of the period width between patterns.

[0078] More precisely, under the first chamber pressure, the transfer layer is etched using the sidewalls as a mask, and under the second chamber pressure, the substrate is etched using the transfer pattern as a mask. The first chamber pressure is lower than the second chamber pressure to ensure that the chamber pressure is relatively low when etching the sidewalls, thereby improving the etching uniformity of the substrate.

[0079] In the substrate etching method disclosed in the embodiments of this application, as described above, if the actual width of the mandrel of the patterned mandrel layer is different from the first predetermined width, the width of the sidewall can be adjusted, and the width of the transfer pattern in the transfer layer near the substrate and near the sidewall can be controlled, so that the width of the pattern formed on the substrate meets the predetermined width, and the uniformity of the periodic width between the patterns on the substrate meets the preset requirements.

[0080] Furthermore, in order to determine whether the above adjustment process can have a beneficial effect on the uniformity of the pattern on the substrate, in this embodiment of the application, after step S5, the following may be included:

[0081] The actual width of the pattern in the substrate can be measured. Specifically, a scanning electron microscope can be used to measure the actual width of the pattern in the etched substrate.

[0082] Subsequent etching methods for the substrate include:

[0083] When the difference between the actual width and the standard width meets the first preset difference, a first standard dataset is formed. The first standard dataset includes the actual width of the corresponding mandrel and the actual process formula for the etching process of the sidewall.

[0084] In the next etching of the structure to be etched, if the difference between the width of the mandrel in the patterned mandrel layer and the actual width meets the second preset difference, then the control process formula is the actual process formula.

[0085] That is, in this embodiment of the application, the etching process can be verified when there is a deviation between the actual width of the mandrel of the patterned mandrel layer and the first predetermined width. If the actual width and uniformity of the pattern on the etched substrate meet the requirements after using the corresponding process formula, the adjustment of the above process formula is considered to be effective. Therefore, the process formula and the actual width of the mandrel of the patterned mandrel layer can be recorded as standard data in the subsequent etching process. So when etching the same structure again, if the difference between the width of the mandrel of the patterned mandrel layer and the actual width of the first data meets the second preset difference, the process formula corresponding to the actual width can be directly called. This can basically ensure that the width of the pattern formed on the new substrate meets the requirements, and the uniformity of the width period between the patterns also meets the requirements.

[0086] Of course, if there is a difference between the actual width of the mandrel in the patterned mandrel layer and the first predetermined width, and the actual width and uniformity of the pattern on the etched substrate still do not meet the requirements after the corresponding adjustment of the process formula, then the adjustment of the above process formula is considered to be invalid or partially invalid. In this case, when etching the same structure to be etched next time, even if the difference between the width of the mandrel in the patterned mandrel layer and the actual width meets the second preset difference, the same process formula as the actual process formula corresponding to the aforementioned actual width in the first standard dataset will no longer be used. Instead, the process formula corresponding to the actual width of the mandrel in the patterned mandrel layer needs to be adjusted based on the previous etching result to further optimize the etching effect and ensure that when etching the same structure to be etched next time, if the difference between the width of the mandrel in the patterned mandrel layer and the actual width meets the second preset difference, the width and uniformity of the pattern formed on the substrate will meet the requirements.

[0087] In other words, if the difference between the actual width and the standard width of the substrate pattern does not meet the first preset difference, and the same structure is to be etched next, and the difference between the width of the patterned mandrel layer and the actual width in the first standard dataset meets the second preset difference, then the process formula is adjusted accordingly based on the deviation direction of the aforementioned difference and the actual process formula in the first standard dataset corresponding to the actual width of the mandrel. Generally speaking, if the actual width of the mandrel is not equal to the first preset width, and if adjusting the parameters in the process formula in a positive direction can reduce the width uniformity and periodicity of the substrate pattern, then if the difference between the actual width and the standard width of the substrate pattern still does not meet the first preset difference, the corresponding parameters in the process formula can be further adjusted in a positive direction. Conversely, if further adjusting the corresponding parameters in the process formula increases the width uniformity and periodicity of the substrate pattern, the corresponding parameters in the process formula can be adjusted in a negative direction until the width uniformity and periodicity of the substrate pattern further decrease.

[0088] This application also provides a semiconductor process apparatus, including a processor, a memory, and a program or instructions stored in the memory and executable on the processor. When the program or instructions are executed by the processor, they implement the various processes of the above-described etching method embodiments and achieve the same technical effects. To avoid repetition, they will not be described again here.

[0089] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0090] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A method for etching a substrate, characterized in that, include: A structure to be etched is provided, the structure to be etched comprising a substrate and a transfer layer and a patterned mandrel layer sequentially formed on the substrate; Sidewalls are formed on both sides of each mandrel in the patterned mandrel layer; Remove the patterned mandrel layer; Using the sidewall as a mask, the transfer layer is etched to obtain the transfer pattern; The substrate is etched using the transfer pattern as a mask; Specifically, after forming the patterned mandrel layer, the actual width of the mandrel in the patterned mandrel layer is measured. If the actual width of the mandrel is greater than a first predetermined width, the actual width of the sidewall is made less than a second predetermined width. Furthermore, the width of the end of the transfer pattern closest to the substrate is made greater than the width of the end closest to the sidewall, to prevent the spacing between two sidewalls located between two adjacent mandrels from being less than the spacing between two sidewalls located on opposite sides of the same mandrel; or... After the patterned mandrel layer is formed, the actual width of the mandrel in the patterned mandrel layer is measured. When the actual width of the mandrel is less than the first predetermined width, the actual width of the sidewall is made greater than the second predetermined width, and the width of the end of the transfer pattern near the substrate is made less than the width of the end near the sidewall, so as to prevent the spacing between the two sidewalls located between two adjacent mandrels from being greater than the spacing between the two sidewalls located on opposite sides of the same mandrel.

2. The substrate etching method according to claim 1, characterized in that, The transfer layer is made of at least one of silicon nitride, silicon oxide, silicon oxynitride, titanium dioxide, and aluminum oxide.

3. The substrate etching method according to claim 1, characterized in that, The transfer layer includes a first transfer layer and a second transfer layer, the second transfer layer being located on the side of the first transfer layer away from the substrate, and the first transfer layer and the second transfer layer being made of different materials.

4. The substrate etching method according to claim 3, characterized in that, The step of etching the transfer layer using the sidewall as a mask to obtain the transfer pattern includes: Using the sidewall as a mask, the pattern of the sidewall is transferred to the second transfer layer to form a second transfer pattern; Using the second transfer pattern as a mask, the first transfer layer is etched to form a first transfer pattern; wherein, when the actual width of the mandrel is greater than a first predetermined width, the width of the first transfer pattern is made greater than the width of the second transfer pattern; or, when the actual width of the mandrel is less than the first predetermined width, the width of the first transfer pattern is made less than the width of the second transfer pattern.

5. The substrate etching method according to claim 4, characterized in that, During the etching process of the first transfer layer, the width of the end of the first transfer pattern closest to the substrate is controlled by controlling the slope angle of the first transfer pattern.

6. The substrate etching method according to claim 1, characterized in that, By changing the process formulation, the actual width of the sidewall is made different from the second predetermined width, and the width of the transfer pattern at the end near the substrate is made different from the width at the end near the sidewall, wherein the process formulation includes at least one of radio frequency power, process time, process gas flow rate and pressure, and type of process gas.

7. The substrate etching method according to claim 1, characterized in that, The transfer layer is etched under a first chamber pressure, and the substrate is etched under a second chamber pressure, wherein the first chamber pressure is less than the second chamber pressure.

8. The substrate etching method according to claim 1, characterized in that, After etching the substrate using the transfer pattern as a mask, the process further includes: Measure the actual width of the pattern in the substrate; When the difference between the actual width and the standard width meets the first preset difference, a first standard dataset is formed. The first standard dataset includes the actual width of the corresponding mandrel and the actual process formula for the etching process of the sidewall. In the next etching of the structure to be etched, if the difference between the width of the mandrel in the patterned mandrel layer and the actual width satisfies a second preset difference, then the control process formula is the actual process formula.

9. The substrate etching method according to claim 8, characterized in that, If the difference between the actual width and the standard width does not meet the first preset difference, and the structure to be etched is etched in the next time, if the difference between the width of the mandrel of the patterned mandrel layer and the actual width meets the second preset difference, then the process formula is adjusted accordingly based on the deviation direction of the difference and the actual process formula.

10. A semiconductor process apparatus, characterized in that, It includes a processor, a memory, and a program or instructions stored in the memory and executable on the processor, wherein the program or instructions, when executed by the processor, implement the steps of the etching method as described in any one of claims 1 to 9.

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