A substrate etching method, storage medium and electronic device thereof

Abstract

The present invention discloses a substrate etching method and a storage medium and electronic device thereof, wherein the substrate etching method comprises: a processing cycle repeatedly executed, wherein the processing cycle comprises an etching stage and a deposition stage; in the etching stage, an etching gas is introduced into a cavity, and a source radio frequency voltage is provided into the cavity through a source radio frequency power supply to generate plasma to etch the substrate to form a recessed structure; in the deposition stage, a deposition gas and an opening gas are introduced into the cavity, and a source radio frequency voltage and a bias voltage are provided into the cavity respectively through a source radio frequency power supply and a bias power supply, wherein the deposition gas generates plasma under the action of the source radio frequency power supply and deposits a protective layer on the side wall and bottom wall of the recessed structure, and the plasma generated by the opening gas is used to eliminate the protective layer on the bottom wall of the recessed structure under the action of the bias power supply. The advantages are: in the deposition stage, the method only deposits a protective layer on the side wall of the recessed structure, thus saving process steps and helping to improve production efficiency.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a substrate etching method, a storage medium and an electronic device thereof. Background Art

[0002] With the vigorous development of semiconductor technology, the requirements for the integration and performance of semiconductor devices are constantly increasing. Size reduction is one of the driving forces for the development of integrated circuits. By reducing the size, cost-effectiveness and device performance can be improved simultaneously, but this also greatly increases the difficulty of three-dimensional circuit integration, bringing great challenges in both process and equipment.

[0003] As a key component of three-dimensional integration technology, TSV (Through Silicon Via) silicon via etching technology allows vertical interconnection between silicon chips, greatly improving the density and performance of integrated circuits. However, to achieve high-efficiency and high-precision silicon via manufacturing, the etching process is a crucial link. Among the traditional silicon via etching processes, the Bosch Process is widely used because it can achieve isotropic etching on harder silicon materials. The Bosch process can effectively remove silicon materials, and it uses deposition gas to form a protective layer on the silicon sidewall to prevent unnecessary etching. This process has achieved high aspect ratio etching of silicon materials to a certain extent, but it also has some limitations. For example, the operation steps of the Bosch process are relatively cumbersome. In practical applications, especially in large-scale production, the complicated and cumbersome process will greatly increase the difficulty and complexity of the process, thereby increasing the risk of production, and easily leading to an increase in production costs and a decrease in production efficiency. Therefore, it is necessary to improve the existing technology.

[0004] It should be understood that the above statements merely provide background technology related to the present invention and do not necessarily constitute prior art. Summary of the invention

[0005] Based on the aforementioned technical problems, the object of the present invention is to provide a substrate etching method, a storage medium and an electronic device thereof. The etching method introduces deposition gas and opening gas during the deposition stage, so that the plasma generated by the dissociation of the opening gas bombards the bottom of the recessed structure under the action of a bias voltage to remove the protective layer at the bottom of the recessed structure, thereby depositing the protective layer only on the side wall of the recessed structure during the deposition stage. This method does not require an additional cleaning step, can effectively reduce the process step length, and improve output. At the same time, it also reduces damage to the side wall of the recessed structure, which helps to ensure the quality of the finished product.

[0006] In order to achieve the above object, the present invention is implemented by the following technical solutions:

[0007] A substrate etching method, comprising:

[0008] A process cycle is repeatedly performed multiple times, wherein the process cycle includes an etching phase and a deposition phase;

[0009] In the etching stage, an etching gas is introduced into the cavity, and a source RF power supply provides a source RF voltage into the cavity to generate plasma to etch the substrate to form a recessed structure;

[0010] In the deposition stage, deposition gas and opening gas are introduced into the cavity, and source RF voltage and bias voltage are respectively provided into the cavity through the source RF power supply and a bias power supply. The deposition gas generates plasma under the action of the source RF power supply and deposits a protective layer on the side wall and bottom wall of the recessed structure. The plasma generated by the opening gas is used to eliminate the protective layer on the bottom wall of the recessed structure under the action of the bias power supply.

[0011] Optionally, the etching gas contains at least one of SF6, Cl2 or HBr.

[0012] Optionally, the opening gas contains Ar.

[0013] Optionally, the deposition gas contains at least one of C4F8, C4F6, CHF3, CH2F2, CH3F, C5F8 or COS.

[0014] Optionally, the frequency of the source RF voltage is greater than 10 MHz.

[0015] Optionally, in the etching stage and the deposition stage, the source RF voltage applied by the source RF power supply is the same or different.

[0016] Optionally, the bias power supply is a bias RF power supply, which is used to provide a bias RF voltage into the cavity.

[0017] Optionally, the frequency of the bias RF voltage is less than 2 MHz.

[0018] Optionally, in a single deposition phase, the operating duty cycle of the bias RF power supply ranges from 10% to 90%.

[0019] Optionally, the bias power supply is a DC pulse power supply, which is used to provide a bias pulse voltage into the cavity.

[0020] Optionally, the frequency of the bias pulse voltage is less than 1 MHz.

[0021] Optionally, in a single deposition stage, the operating duty cycle of the DC pulse power supply ranges from 1% to 99%.

[0022] Optionally, in a single processing cycle, a ratio of the duration of the deposition phase to the duration of the etching phase is in a range of 1:0.5 to 1:10.

[0023] Optionally, during the etching stage, the bias power supply provides a bias voltage into the chamber to accelerate the plasma generated by the etching gas.

[0024] Optionally, a storage medium includes:

[0025] Computer programs;

[0026] Wherein, when the computer program is executed by the processor, the steps of the aforementioned substrate etching method are implemented.

[0027] An electronic device, comprising:

[0028] processor;

[0029] A memory, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the steps of the aforementioned substrate etching method are implemented.

[0030] Optionally, the electronic device is a controller.

[0031] Compared with the prior art, the present invention has the following advantages:

[0032] In a substrate etching method and storage medium and electronic device of the present invention, the etching method simultaneously introduces deposition gas and opening gas in the deposition stage, dissociates the deposition gas to deposit a protective layer inside the recessed structure, and dissociates and biases the opening gas to remove the protective layer component at the bottom of the recessed structure, thereby depositing the protective layer only on the side wall of the recessed structure in the deposition stage, which helps to improve the quality of the finished product, and also facilitates the subsequent etching to advance in the depth direction, which is conducive to achieving high aspect ratio etching of the substrate. The method does not require an additional separate cleaning step, saves process steps, helps to improve the overall process efficiency, and thus improves production efficiency.

[0033] Furthermore, in the etching method of the present invention, a bias pulse voltage is provided by a DC pulse power supply, which can provide a higher bias voltage in a short time, so that the plasma formed by the dissociation of the opening gas can quickly reach the required high-energy state to bombard the bottom of the recessed structure, which helps to improve the energy utilization efficiency; on the other hand, the DC pulse power supply can provide a higher bias pulse voltage, so that the plasma formed by the dissociation of the opening gas has a higher energy to bombard the bottom of the recessed structure, that is, it can make the plasma formed by the dissociation of the opening gas have a higher ion bombardment energy, which helps to achieve high aspect ratio etching under smaller line width conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A schematic diagram showing a comparison between an etching method of the present invention and an existing Bosch process;

[0035] Figure 2 A schematic diagram of a control sequence of an existing Bosch process;

[0036] Figure 3 A schematic diagram of a control timing of an etching method of the present invention;

[0037] Figure 4 A waveform diagram of a bias radio frequency voltage provided by a bias radio frequency power supply of the present invention;

[0038] Figure 5 The figure is a waveform diagram of a bias pulse voltage provided by a DC pulse power supply of the present invention. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] It should be noted that, in this article, the terms "include", "comprises", "has" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "includes..." or "comprising..." do not exclude the existence of other elements in the process, method, article or terminal device including the elements.

[0041] It should be noted that the drawings are all in very simplified form and use inaccurate ratios, and are only used to conveniently and clearly assist in explaining the embodiments of the present invention.

[0042] As mentioned above, deep silicon hole etching is crucial to the density and performance of integrated circuits. Currently, deep silicon etching is mainly achieved through the Bosch process. Figure 1 The left example and Figure 2As shown in the figure, the Bosch process includes an etching step (Etch Step, referred to as ES phase), a deposition step (Deposition Step, referred to as DS phase) and a cleaning step (Clean Step, referred to as CS phase). In the actual process, a mask layer 120 is provided above the substrate 110 . In the etching step, the source RF power supply provides a source RF voltage into the cavity to dissociate the etching gas, and then etches the substrate 110, i.e., the silicon wafer, to form a recessed structure 111; in the deposition step, the source RF voltage provided by the source RF power supply is used to dissociate the deposition gas, and then isotropically deposits a protective layer 130 on the inner wall of the recessed structure 111, and the protective layer 130 can prevent the etching gas from further etching at this position; in the cleaning step, the source RF voltage provided by the source RF power supply and the RF bias provided by the bias RF power supply are used to dissociate the etching gas and guide it to perform anisotropic etching in the recessed structure 111, so as to remove the protective layer 130 at the bottom of the recessed structure 111 in the vertical direction of the opening position, i.e., so that the etching can continue to be promoted in the vertical direction of the opening position. It can be understood that in actual applications, at the beginning of the process, any one of the etching step, the deposition step, or the cleaning step can be selected to be performed first, so that the process is based on the cycle of the etching step, the deposition step, and the cleaning step, so that the etching process is mainly performed along the depth direction. However, as integrated circuits develop towards smaller feature sizes, the above-mentioned complex process steps bring more unstable factors to actual production, which can easily affect actual production efficiency. At the same time, due to some ion scattering in the cleaning step, the protective layer 130 on the side wall of the recessed structure 111 may be damaged. As the etching progresses, the side wall of the recessed structure 111 may be damaged, thereby affecting the quality of the finished product.

[0043] Based on the above, the present invention proposes an etching method for substrate 210, such as Figure 1 The example on the right and Figure 3 As shown in the figure, the method introduces deposition gas and opening gas in the deposition stage, dissociates the deposition gas to deposit the protective layer 230 inside the recessed structure 211, and dissociates and biases the opening gas to remove the protective layer 230 component in the vertical direction of the opening position of the recessed structure 211, that is, at the bottom, so that the protective layer 230 is only generated on the sidewall of the recessed structure 211 in the deposition stage, and the anisotropic deposition effect of the deposition gas is achieved, so that the subsequent etching is advanced along the depth direction, and it also helps to improve the quality of the finished product. The method does not require an additional separate cleaning step, saves process steps, helps to improve the overall process efficiency, and thus improves production efficiency.

[0044] Specifically, the etching method of the substrate 210 of the present invention includes a processing cycle that is repeatedly executed multiple times, in which a mask layer 220 is provided above the substrate 210, and the processing cycle includes an etching stage (referred to as the ES stage) and a deposition stage (referred to as the DS stage); wherein, in the etching stage, an etching gas is introduced into the cavity, and a source RF voltage is provided into the cavity by a source RF power supply to generate plasma to etch the substrate 210 to form a recessed structure 211; in the deposition stage, a deposition gas and an opening gas are introduced into the cavity, and a source RF voltage and a bias voltage are provided into the cavity respectively by the source RF power supply and a bias power supply, the deposition gas generates plasma under the action of the source RF power supply and simultaneously deposits a protective layer 230 on the side wall and the bottom wall of the recessed structure 211, and the plasma generated by the opening gas is used to eliminate the protective layer 230 on the bottom wall of the recessed structure 211 under the action of the bias power supply.

[0045] As can be seen from the above, in the deposition stage of the present invention, the opening gas and the deposition gas are introduced at the same time. The deposition gas generates plasma under the action of the source RF voltage and then deposits the protective layer 230 in the recessed structure 211. At the same time, the opening gas is converted into plasma under the action of the source RF voltage and obtains higher energy under the action of the bias voltage to be converted into high-energy particles to bombard the bottom wall of the recessed structure 211, so as to bombard away the plasma components of the deposition gas diffused to the bottom wall of the recessed structure 211 (at this time, the bottom wall of the recessed structure 211 has not yet formed a high-density protective layer 230), so as to achieve real-time removal of the components of the protective layer 230 on the bottom wall of the recessed structure 211, so that in the deposition stage, the protective layer 230 is only generated on the side wall of the recessed structure 211, and there is no protective layer 230 in the vertical direction of the opening, that is, the bottom wall, so as to protect the side wall of the recessed structure 211 from being etched in the subsequent etching process, which helps to ensure high-selective etching of the substrate. The method does not need to perform an additional cleaning step to remove the protective layer 230 on the bottom wall of the recessed structure 211, which can effectively reduce the process step length and improve the output. At the same time, the method does not need an additional cleaning step, which can avoid the damage to the protective layer 230 on the side wall of the recessed structure 211 in the traditional cleaning step, thereby avoiding damage to the side wall of the recessed structure 211, which helps to ensure the quality of the finished product and also helps to achieve a higher etching depth-to-width ratio. On the other hand, in the traditional cleaning step, it is usually necessary to use SF6 gas, which is more polluted. The opening gas used in the present invention is argon gas, and SF6 gas only needs to be introduced in the etching step, which can effectively reduce the use of SF6 and is more environmentally friendly. The implementation of this technical solution has promoted the green production and sustainable development of enterprises. By optimizing the process steps, reducing energy consumption and the use of polluting gases, enterprises can better respond to the global call for environmental protection and sustainable development, establish a green, environmentally friendly, and low-carbon corporate image, and make positive contributions to the sustainable development of society.

[0046] Based on the above, in the process, the etching stage and the deposition stage are performed alternately, the bottom of the recessed structure 211 is etched in the etching stage, and the protective layer 230 is deposited on the side wall of the recessed structure 211 in the deposition stage to prevent the etching gas from etching the side wall of the recessed structure 211, thereby promoting the etching along the depth direction, and also helping to ensure the quality of the finished product. Optionally, in a single processing cycle, the ratio of the time length of the deposition stage to the time length of the etching stage is in the range of 1:0.5~1:10. For example, in one embodiment, the time length of the etching stage is between 5s~10s, and the time length of the deposition stage is between 5s~10s. It should be noted that the present invention does not limit the time length of the etching stage and the deposition stage, and in practical applications, it can be set according to actual needs. In practical applications, the time length of the etching stage and the deposition stage is related to the component characteristics of the etching gas, the deposition gas and the opening gas, and is also related to factors such as the etching target.

[0047] Since silicon has many properties suitable for being a substrate for microelectronics and semiconductor devices, such as good semiconductor performance, mature processing technology, and compatibility with existing manufacturing processes, in this embodiment, the substrate 210 is made of silicon material. Of course, the preparation material of the substrate 210 is not limited to silicon, and it can also be prepared with other materials according to specific application requirements and manufacturing processes to meet different performance requirements and cost-effectiveness.

[0048] Optionally, the etching gas includes at least one of SF6, Cl2 or HBr. It is understood that the component types of the etching gas are not limited to the above. According to actual process requirements and equipment conditions, the etching gas may also include other material gases as long as the etching of the substrate 210 can be achieved. The present invention is not limited to this. For example, in another embodiment, the etching gas is another fluorine-based gas.

[0049] Optionally, the opening gas contains Ar. During the deposition stage, Ar can reach an ideal high-energy state under the action of the source RF voltage and the bias voltage to bombard the bottom of the recessed structure 211, thereby blasting the deposition gas components on the bottom wall of the recessed structure 211 out of the recessed structure 211, so as to remove the protective layer 230 components on the bottom wall of the recessed structure 211 in real time. At the same time, the high-energy state particles will not affect the reaction of the plasma generated by the dissociation of the deposition gas to generate the protective layer. It can be understood that the types of the opening gas are not limited to the above, and the present invention does not limit the types, as long as the corresponding functions can be achieved. For example, in another embodiment, the opening gas is other inert gases, which are combined with the deposition gas, and under the action of the source RF voltage and the RF bias voltage, the protective layer 230 is only deposited on the side wall of the recessed structure 211 during the deposition stage. It should be noted that not all inert gases can be used as opening gases. The opening gas needs to reach a sufficiently high energy state under the action of the source RF voltage and the bias voltage to bombard the bottom of the recessed structure 211 in order to blast away the protective layer 230 at the bottom of the recessed structure 211. For example, compared to He, Ar has a larger atomic mass. After absorbing the same energy, Ar has higher kinetic energy and momentum, so that it can enter the bottom of the recessed structure 211 and generate a greater impact force / impact force. Therefore, compared to He, Ar is more suitable as an opening gas. On the other hand, compared to Ar, the etching effect of SF6, which is commonly used as an etching gas, is too strong, and it is difficult to achieve the effect of using Ar and deposition gas in combination in this application when it is used in combination with deposition gas.

[0050] Optionally, the deposition gas includes at least one of C4F8, C4F6, CHF3, CH2F2, CH3F, C5F8 or COS. In the present embodiment, the deposition gas includes C4F8. During the deposition phase, C4F8 dissociates under the action of the source RF voltage to generate plasma, thereby forming a layer of carbon fluoride polymer on the side wall of the recessed structure 211. The carbon fluoride polymer can prevent the reaction between fluoride ions and silicon, thereby protecting the side wall from being corroded. It is understandable that the types of the deposition gas are not limited to the above, and the present invention does not limit the types thereof, as long as the protective layer 230 can be formed on the recessed structure 211 under the action of the source RF voltage to protect the side wall, for example, it can also be other low carbon-fluorine ratio gases. As can be seen from the foregoing, during the deposition stage of the present invention, while the protective layer 230 is deposited on the side wall of the recessed structure 211, the protective layer 230 at the bottom of the recessed structure 211 is removed in real time with the help of the opening gas, so that the protective layer 230 is only formed on the side wall of the recessed structure 211 during the deposition stage. In actual applications, suitable deposition gas and opening gas types can be selected for use in combination.

[0051] In the processing cycle of the present invention, the source RF power supply is in a normally open state, and a high-frequency RF voltage, i.e., a source RF voltage, is provided to the cavity through the source RF power supply to generate plasma. Optionally, the frequency of the source RF voltage is greater than 10 MHz. In the etching stage, the etching gas dissociates under the action of the source RF voltage to generate plasma, thereby realizing the etching of the recessed structure 211; in the deposition stage, the deposition gas dissociates under the action of the source RF voltage to form plasma, thereby simultaneously generating a protective layer 230 on the inner wall and the bottom wall of the recessed structure 211. Optionally, in the etching stage and the deposition stage, the source RF voltage applied by the source RF power supply is the same. Usually, the time length of the etching stage and the deposition stage in a single processing cycle will be very short. This method can avoid the frequent switching operation of the source RF power supply when switching between the various stages, which is helpful for the maintenance of the equipment and thus ensures its service life. At the same time, this method also avoids the response time required for switching back and forth, which helps to save time while improving the control accuracy of the process. Of course, the data range of the source RF voltage is not limited to the above. In other embodiments, it can also be other ranges, and the present invention is not limited to this. Similarly, the source RF voltages in the etching stage and the deposition stage may also be different, and in practical applications, they may be set according to actual needs and equipment conditions. For example, in one embodiment, the single-step lengths of the etching stage and the deposition stage are both greater than 1 s, and different source RF voltages may be used in the etching stage and the deposition stage, respectively.

[0052] In the deposition stage, the bias power supply can be in a normally open state, and a bias voltage is provided to the cavity through the bias power supply, so as to provide energy for the plasma generated by the dissociation of the opening gas, so as to promote it to absorb energy and convert it into a high-energy state and obtain better migration and diffusion capabilities, so as to bombard the bottom of the recessed structure 211, thereby changing the distribution of the protective layer 230 in the recessed structure 211. Optionally, in the etching stage, the bias power supply is in a closed state, and of course it can also be set to an extremely low power state to avoid frequent switching of the bias power supply during the deposition stage and the etching stage. Damage to the equipment caused by the frequent switching of the bias power supply. Of course, in the actual process, a corresponding bias voltage can also be applied to the cavity in the etching stage according to actual needs to optimize the etching effect on the recessed structure 211. Optionally, in the etching stage, the bias power supply provides a bias voltage to the cavity to accelerate the plasma generated by the etching gas, thereby accelerating it to bombard the inside of the recessed structure 211.

[0053] Optionally, the bias power supply is a bias RF power supply, which is used to provide a bias RF voltage into the cavity. Figure 4As shown, in one embodiment, the bias RF voltage provided by the bias RF power supply is in the shape of a sine wave. Under the action of the bias RF voltage, the plasma formed by the dissociation of the opening gas is accelerated by the electric field formed by the bias RF voltage and bombarded to the bottom of the recessed structure 211, thereby bombarding the deposition gas component and the protective layer 230 at the bottom of the recessed structure 211 out of the recessed structure 211 to remove the protective layer 230 at the bottom of the recessed structure 211, so that the protective layer 230 is only deposited on the side wall of the recessed structure 211 during the deposition stage, ensuring that the etching continues to advance in the depth direction. Optionally, the frequency of the bias RF voltage is less than 2MHz. On the other hand, optionally, in a single deposition stage, the operating duty cycle of the bias RF power supply ranges from 10% to 90%. Of course, the frequency of the bias RF voltage and the operating duty cycle of the bias RF power supply can also be other numerical ranges, as long as their corresponding functions can be achieved, and the present invention does not limit this. Similarly, the present invention does not limit the peak value range of the bias RF voltage, and in practical applications it can be set according to actual needs and equipment conditions.

[0054] It is understandable that the bias power supply is not limited to the above-mentioned bias RF power supply, and it can also be other types of power supplies, and the present invention is not limited to this, as long as it can achieve its corresponding functions. Optionally, the bias power supply can also be a DC pulse power supply, which is used to provide a bias pulse voltage to the cavity. For example, Figure 5 As shown, it is the waveform of the bias pulse voltage provided by the DC pulse power supply in one embodiment. Under the action of the bias pulse voltage, the opening gas can quickly absorb energy and convert it into a high-energy plasma to bombard the bottom of the recessed structure 211, so as to remove the protective layer 230 at the bottom of the recessed structure 211 and ensure that the etching advances along the depth direction. In addition to the advantages of the biased RF power supply, the DC pulse power supply also has the characteristics of a rapid rising edge, that is, a short response time and a fast response speed. It can provide a higher bias voltage in a short time, that is, quickly provide a higher energy, so that the plasma dissociated from the opening gas can quickly reach the required high-energy state, and the energy utilization efficiency is high. On the other hand, compared with the biased RF power supply, the DC pulse power supply can provide a higher bias voltage, that is, it can provide higher energy for the plasma dissociated from the opening gas to convert it into a high-energy state to bombard the bottom of the recessed structure 211. It can be understood that the higher the bias pulse voltage provided by the DC pulse power supply, the higher the energy of the plasma dissociated from the opening gas after absorbing energy and bombarding the bottom of the recessed structure 211. This method can meet the requirements of increasingly smaller etching line widths and increasingly higher etching aspect ratios, that is, it is particularly suitable for high aspect ratio silicon etching.

[0055] Furthermore, in practical applications, the bias pulse voltage provided by the DC pulse power supply can be set to a positive voltage or zero voltage, that is, the bias pulse voltage does not exist in a situation where it is less than zero, and a reverse electric field will not be constructed, thereby avoiding reverse acceleration (deceleration or reverse movement) of ions, and helping to ensure the consistency of the motion of high-energy state particles converted from the plasma dissociated from the opening gas, and avoiding situations such as ion scattering, thereby avoiding damage to the silicon sidewalls and the protective layer 230 on the sidewalls, helping to ensure that etching advances in the depth direction, and at the same time ensuring the quality of the finished product. This method is particularly suitable for long-term high aspect ratio silicon etching processes. Furthermore, when the voltage value of the bias pulse voltage in the deposition stage is the same, the high-energy state reached by the plasma dissociated from the opening gas after absorbing energy is also the same, which helps to improve the uniformity of the cleaning effect of the protective layer 230 at various locations at the bottom of the recessed structure 211, thereby ensuring the control accuracy of the deposition stage.

[0056] Optionally, the frequency of the bias pulse voltage is less than 1 MHz. Of course, the frequency of the bias pulse voltage can also be in other numerical ranges, as long as the corresponding functions can be achieved, and the present invention does not limit this. Similarly, the present invention does not limit the voltage value range of the bias pulse voltage, and it can be set according to actual needs and equipment conditions in practical applications. It can be understood that, when other conditions remain unchanged, the larger the voltage value of the bias pulse voltage, the higher the energy of the plasma dissociated from the opening gas to bombard the bottom of the recessed structure 211, and the greater the impact force on the bottom of the recessed structure 211.

[0057] On the other hand, optionally, in a single deposition stage, the operating duty cycle of the DC pulse power supply ranges from 1% to 99%. It is understandable that, under the condition that other conditions remain unchanged, in a single deposition stage, the higher the operating duty cycle of the DC pulse power supply, the stronger the cleaning effect on the protective layer 230 at the bottom of the recessed structure 211. Of course, the operating duty cycle of the DC pulse power supply is not suitable for being too high for a long time, so as not to affect the deposition process of the deposition gas. In practical applications, the operating duty cycle of the DC pulse power supply can be set according to factors such as the component ratio of the deposition gas and the opening gas and the difficulty of deposition of the deposition gas to meet the corresponding needs. It is understandable that in the present invention, there is no restriction on the component ratio of the deposition gas and the opening gas introduced in the deposition stage, and it can be set according to the characteristics of each gas and actual needs.

[0058] Based on the same inventive concept, the present invention further provides a storage medium, the storage medium comprising: a computer program; wherein the computer program, when executed by a processor, implements the steps of the etching method of the substrate 210 of the present invention. Based on the above, the etching method of the substrate 210 of the present invention can be implemented by a computer program.

[0059] Furthermore, based on the same inventive concept, the present invention also provides an electronic device, comprising: a processor; a memory, wherein a computer program is stored on the memory, and when the computer program is executed by the processor, the steps of the etching method of the substrate 210 of the present invention are implemented.

[0060] Optionally, the electronic device is a controller. Of course, in practical applications, the electronic device is not limited to being a controller, and it can also be presented in other forms, which is not limited by the present invention.

[0061] In summary, in an etching method of a substrate 210 of the present invention, a storage medium and an electronic device thereof, the etching method introduces a deposition gas and an opening gas in the deposition stage, dissociates the deposition gas to deposit a protective layer 230 inside the recessed structure 211, and dissociates and biases the opening gas to remove the protective layer 230 component at the bottom of the recessed structure 211, and then deposits the protective layer 230 only on the sidewall of the recessed structure 211 in the deposition stage, which helps to improve the quality of the finished product, and also facilitates the subsequent etching to advance in the depth direction, which helps to achieve high aspect ratio etching of the substrate 210. The method does not require an additional separate cleaning step, saves process steps, helps to improve the overall process efficiency, and thus improves production efficiency.

[0062] Furthermore, in the etching method of the present invention, a bias pulse voltage is provided by a DC pulse power supply, which can provide a higher bias voltage in a short time, so that the plasma formed by the dissociation of the opening gas can quickly reach the required high-energy state and bombard the bottom of the recessed structure 211, which helps to improve the energy utilization efficiency; on the other hand, the DC pulse power supply can provide a higher bias pulse voltage, so that the plasma formed by the dissociation of the opening gas has a higher energy and bombards the bottom of the recessed structure 211, that is, it can make the plasma formed by the dissociation of the opening gas have a higher ion bombardment energy, which helps to achieve high aspect ratio etching under smaller line width conditions.

[0063] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. A substrate etching method, characterized in that: Include: A process cycle is repeatedly performed multiple times, wherein the process cycle includes an etching phase and a deposition phase; In the etching stage, an etching gas is introduced into the cavity, and a source RF power supply provides a source RF voltage into the cavity to generate plasma to etch the substrate to form a recessed structure; During the deposition stage, deposition gas and opening gas are introduced into the cavity at the same time, and source RF voltage and bias voltage are respectively provided to the cavity through the source RF power supply and a bias power supply. The deposition gas generates plasma under the action of the source RF power supply and deposits a protective layer in the recessed structure. At the same time, the plasma generated by the opening gas is bombarded toward the bottom wall of the recessed structure under the action of the bias power supply to bombard away the plasma components of the deposition gas diffused to the bottom wall of the recessed structure, thereby achieving real-time removal of the protective layer components on the bottom wall of the recessed structure.

2. The method for etching a substrate according to claim 1, wherein: The etching gas contains at least one of SF6, Cl2 or HBr.

3. The method for etching a substrate according to claim 1, wherein: The opening gas includes Ar.

4. The method for etching a substrate according to claim 1, wherein: The deposition gas includes at least one of C4F8, C4F6, CHF3, CH2F2, CH3F, C5F8 or COS.

5. The substrate etching method according to claim 1, characterized in that: The frequency of the source radio frequency voltage is greater than 10 MHz.

6. The method for etching a substrate according to claim 1, wherein: In the etching stage and the deposition stage, the source RF voltage applied by the source RF power supply is the same or different.

7. The method for etching a substrate according to claim 1, wherein: The bias power supply is a bias radio frequency power supply, which is used to provide a bias radio frequency voltage into the cavity.

8. The substrate etching method according to claim 7, characterized in that: The frequency of the bias RF voltage is less than 2 MHz.

9. The method for etching a substrate according to claim 7, wherein: In a single deposition phase, the operating duty cycle of the bias RF power source ranges from 10% to 90%.

10. The substrate etching method according to claim 1, characterized in that: The bias power supply is a direct current pulse power supply, which is used to provide a bias pulse voltage into the cavity.

11. The substrate etching method according to claim 10, characterized in that: The frequency of the bias pulse voltage is less than 1 MHz.

12. The method for etching a substrate according to claim 10, wherein: In a single deposition stage, the operating duty cycle of the DC pulse power supply ranges from 1% to 99%.

13. The substrate etching method according to claim 1, characterized in that: In a single processing cycle, the ratio of the duration of the deposition phase to the duration of the etching phase is in the range of 1:0.5 to 1:

10.

14. The substrate etching method according to claim 1, characterized in that: In the etching stage, the bias power supply provides a bias voltage into the chamber to accelerate the plasma generated by the etching gas.

15. A storage medium, characterized in that: The storage medium includes: Computer programs; Wherein, when the computer program is executed by the processor, the steps of the substrate etching method as described in any one of claims 1 to 14 are implemented.

16. An electronic device, characterized in that: The electronic device comprises: processor; A memory, wherein a computer program is stored on the memory, and when the computer program is executed by the processor, the steps of the substrate etching method according to any one of claims 1 to 14 are implemented.

17. The electronic device according to claim 16, characterized in that: The electronic device is a controller.

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