A method of and apparatus for filling gaps

Abstract

The application discloses a kind of gap filling method and gap filling device.Gap filling method includes the following steps: the wafer surface with gap is passed into PEALD precursor, and first radio frequency energy is provided to wafer surface in the process of passing into PEALD precursor, to generate first PECVD film on wafer surface;Stop passing into PEALD precursor, and second radio frequency energy is provided to wafer surface, to generate PEALD film on the surface of first PECVD film;Again pass into PEALD precursor to wafer surface in the latter section of providing second radio frequency energy, to generate second PECVD film on the surface of PEALD film;And after generating first PECVD film, PEALD film and second PECVD film, again pass into PEALD precursor to wafer surface, and third radio frequency energy is provided to wafer surface simultaneously, to generate mixed film on the surface of second PECVD film.

Description

Technical Field

[0001] This invention relates to the field of semiconductor processing technology, and specifically to a gap-filling method, a gap-filling device, and a computer-readable storage medium. Background Technology

[0002] Traditional atomic layer deposition (ALD) technology, due to its unique conformal growth mechanism, possesses excellent gap-filling capabilities, enabling precise control of film thickness for filling high aspect ratio gaps in chip structures, as well as superior step coverage. However, ALD technology also has a relatively slow growth rate, thus often facing significant cost challenges in gap-filling applications of large-size structures. Traditional plasma-enhanced chemical vapor deposition (PECVD) technology offers advantages such as high deposition rates and low operating costs; however, its gap-filling capability and step coverage are significantly inferior to those of plasma-enhanced atomic layer deposition (PEALD).

[0003] Currently, while some technologies combine ALD (Alternating Deposition) with CVD (Chemical Vapor Deposition) for thin film gap filling to leverage the complementary advantages of both and achieve a balance between gap-filling capability and economic efficiency, existing technologies require additional CVD chemical sources and reactant gases to be introduced into the traditional ALD cycle. This necessitates the addition of separate CVD chemical source and reactant gas delivery systems, as well as chemical source switching devices, increasing the complexity of the control system. Furthermore, the increased chemical source switching operations introduce additional purging and system stabilization times, impacting process throughput.

[0004] To address the aforementioned problems in existing technologies, there is an urgent need in the field for an improved gap-filling technology that can not only enhance the growth rate and step coverage of film gap filling, but also reduce system complexity, improve film purity and particle performance, and eliminate the need for additional purging time and system stabilization time introduced by chemical source switching. This would significantly improve process capacity while balancing the gap-filling capability and economic efficiency of the film. Summary of the Invention

[0005] The following provides a brief overview of one or more aspects to offer a basic understanding of them. This overview is not an exhaustive summary of all conceived aspects, nor is it intended to identify key or decisive elements of all aspects, nor to define 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 descriptions that follow.

[0006] To overcome the aforementioned deficiencies in the prior art, the present invention provides a gap-filling method, a gap-filling device, and a computer-readable storage medium, which can not only improve the growth rate and step coverage of film gap filling, but also reduce system complexity, improve film purity and particle performance, and eliminate the need for additional purging time and system stabilization time introduced by chemical source switching, thereby significantly improving process capacity and balancing film gap-filling capability and economy.

[0007] Specifically, the gap-filling method provided by the first aspect of the present invention includes the following steps: introducing a PEALD precursor into a wafer surface with gaps, and providing a first radio frequency energy to the wafer surface during the introduction of the PEALD precursor to generate a first PECVD film on the wafer surface; stopping the introduction of the PEALD precursor and providing a second radio frequency energy to the wafer surface to generate a PEALD film on the surface of the first PECVD film; introducing the PEALD precursor into the wafer surface again after the second radio frequency energy is provided to generate a second PECVD film on the surface of the PEALD film; and after generating the first PECVD film, the PEALD film, and the second PECVD film, introducing the PEALD precursor into the wafer surface again and simultaneously providing a third radio frequency energy to the wafer surface to generate a hybrid film on the surface of the second PECVD film.

[0008] Furthermore, in some embodiments of the present invention, the PEALD precursor comprises a bissilane, and the mixed film comprises a compound of silicon oxide, silicon nitride, and / or titanium oxide.

[0009] Furthermore, in some embodiments of the present invention, after the first PECVD film is generated and before the second radio frequency energy is provided to the wafer surface, the gap-filling method further includes the step of: introducing a purge gas into the wafer surface to remove excess PEALD precursor from the surface of the first PECVD film.

[0010] Furthermore, in some embodiments of the present invention, after the second PECVD film is generated and before the PEALD precursor is introduced into the wafer surface again and a third radio frequency energy is provided to the wafer surface, the gap-filling method further includes the step of introducing a purge gas into the wafer surface to remove reaction byproducts on the surface of the second PECVD film.

[0011] Furthermore, in some embodiments of the present invention, the purging gas includes at least one of argon, nitrogen, nitrous oxide, and oxygen.

[0012] Furthermore, in some embodiments of the present invention, the start-up speed of the first radio frequency energy is less than 20ms, and the start-up speed of the second radio frequency energy is less than 30ms.

[0013] Furthermore, in some embodiments of the present invention, after generating the hybrid film, the gap-filling method further includes the following steps: chemically and mechanically polishing the hybrid film, the second PECVD film, the PEALD film and the first PECVD film to obtain a wafer that fills the gap.

[0014] Furthermore, the gap-filling device provided according to the second aspect of the present invention includes: a memory; and a processor connected to the memory and configured to implement the gap-filling method provided in the first aspect of the present invention.

[0015] Furthermore, in some embodiments of the present invention, the invention further includes: a process chamber for accommodating a wafer with gaps on its surface for filling the gaps; a precursor source for introducing a PEALD precursor to the wafer surface; a radio frequency power supply for providing radio frequency energy to the wafer surface; a purge gas source for introducing purge gas to the wafer surface; and / or a CMP module for performing chemical mechanical polishing on the wafer surface.

[0016] Furthermore, according to a third aspect of the present invention, a computer-readable storage medium is provided having computer instructions stored thereon. When the computer instructions are executed by a processor, the gap-filling method described above in the first aspect of the present invention is implemented. Attached Figure Description

[0017] The above-described features and advantages of the present invention will be better understood after reading the following detailed description of embodiments of the present disclosure in conjunction with the accompanying drawings. In the drawings, components are not necessarily drawn to scale, and components having similar related characteristics or features may have the same or similar reference numerals.

[0018] Figure 1 This is a schematic diagram of the timing process of the traditional PEALD gap-filling method in the prior art;

[0019] Figure 2 A flowchart of a gap-filling method provided according to some embodiments of the present invention is shown;

[0020] Figure 3 A timing flowchart of a gap-filling method provided according to some embodiments of the present invention is shown; and

[0021] Figure 4 A structural block diagram of a gap-filling device provided according to some embodiments of the present invention is shown.

[0022] Figure label:

[0023] 100. Timing flow diagram of the traditional PEALD gap-filling method;

[0024] Steps S210 to S240;

[0025] Schematic diagram of the timing flow of the 300 gap-filling method;

[0026] 400 Gap Filler;

[0027] 410 Memory; and

[0028] 420 processor. Detailed Implementation

[0029] 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.

[0030] 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.

[0031] 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.

[0032] It is understood that although terms such as "first," "second," and "third" may be used herein to describe various components, regions, layers, and / or parts, these components, regions, layers, and / or parts should not be limited by these terms, and these terms are only used to distinguish different components, regions, layers, and / or parts. Therefore, the first components, regions, layers, and / or parts discussed below may be referred to as second components, regions, layers, and / or parts without departing from some embodiments of the present invention.

[0033] As mentioned above, while there are currently technologies that combine ALD with CVD for thin film gap filling to achieve a complementary advantage and balance gap-filling capacity with economic efficiency, existing technologies require additional CVD chemical sources and reactant gases in the traditional ALD cycle. This necessitates the introduction of additional CVD chemical sources and reactant gas delivery devices, as well as chemical source switching mechanisms, increasing the complexity of the control system. Furthermore, the added chemical source switching operation also introduces additional purging and system stabilization time, impacting process throughput.

[0034] To address the aforementioned problems in the prior art, this invention provides a gap-filling method, a gap-filling device, and a computer-readable storage medium. These methods not only improve the growth rate and step coverage of the film gap-filling process but also reduce system complexity, enhance film purity and particle characteristics, and eliminate the need for additional purging time and system stabilization time introduced by chemical source switching. This significantly increases process productivity while balancing the gap-filling capability and economic efficiency of the film.

[0035] In some non-limiting embodiments, the gap-filling method provided in the first aspect of the present invention can be implemented by the gap-filling device provided in the second aspect of the present invention.

[0036] The working principle of the above-mentioned gap-filling device will be described below with reference to some embodiments of gap-filling methods. Those skilled in the art will understand that these embodiments of gap-filling methods are merely non-limiting implementations provided by the present invention, intended to clearly demonstrate the main concept of the invention and provide specific solutions convenient for public implementation, rather than limiting all operating methods or functions of the gap-filling device. Similarly, the gap-filling device is also only a non-limiting implementation provided by the present invention and does not limit the entities implementing the steps in these gap-filling methods.

[0037] First, please refer to Figure 1 , Figure 1 This is a schematic diagram of the film-forming reaction process of traditional PEALD in existing technology. (Example:) Figure 1 As shown in the timing flow diagram 100 of the traditional PEALD gap-filling method, the gap-filling method may include four steps: step S110: introduce PEALD precursor pulse (Dose); step S120: purge (Dose Purge); step S130: start radio frequency energy (RF on); and step S140: purge (RF Purge).

[0038] In this invention, improvements have been made to steps S110 to S140 described above. For details, please refer to... Figure 2 , Figure 2 A flowchart of a gap-filling method provided according to some embodiments of the present invention is shown.

[0039] like Figure 1 As shown, in some embodiments of the present invention, the gap-filling method may include the following step S210: introducing a PEALD precursor into the wafer surface with gaps, and providing a first radio frequency energy to the wafer surface during the introduction of the PEALD precursor, so as to generate a first PECVD thin film on the wafer surface.

[0040] Step S210 is an improvement over step S110 in the prior art. Please refer to further details. Figure 3 , Figure 3 A timing flow diagram of a gap-filling method provided according to some embodiments of the present invention is shown.

[0041] exist Figure 3In the timing flow diagram 300 of the gap-filling method shown, as indicated by the timing flow line below step S210, in some embodiments, a PEALD precursor is first introduced into the wafer surface with gaps within the reaction chamber. The PEALD precursor may include bissilane (BDEAS), etc. In some optional embodiments, a reaction gas and a purge gas may be introduced into the reaction chamber simultaneously with the introduction of the PEALD precursor. The purge gas can act as a carrier gas, used to carry the PEALD precursor vapor at a certain flow rate. The purge gas may include at least one of argon, nitrogen, nitrous oxide, and oxygen. Optionally, when the purge gas includes nitrides or oxygen, the nitrides or oxygen can be used as the reaction gas. Adding plasma during the PEALD process can achieve the low-temperature preparation of thin films of certain metal oxides and nitrides.

[0042] After the PEALD precursor has been introduced for a period of time, first radio frequency (RF) energy can be provided to the wafer surface, thereby generating the first PECVD thin film on the wafer surface. In terms of process, it is necessary to control the start-up time and timing of the additional first RF energy. Optionally, the start-up speed of the first RF energy can preferably be less than 20ms, thereby controlling the system time accuracy corresponding to this step to below 20ms.

[0043] During the process of providing the first radio frequency (RF) energy to the wafer surface, the PEALD precursor and purge gas can be continuously supplied. After the first RF energy is turned off, purge gas can continue to be supplied to purge the products after the first RF reaction. By combining precise control of the purge gas and pressure, the first RF energy, and the time, high-quality first PECVD films with good uniformity can be produced.

[0044] Furthermore, such as Figure 3 As shown, after the first PECVD film is generated and before the second radio frequency energy is provided to the wafer surface, the gap-filling method provided by the present invention may further include step S211: passing a purge gas into the wafer surface to remove excess PEALD precursor from the surface of the first PECVD film.

[0045] Please continue to return Figure 2 The gap-filling method provided by the present invention may further include steps S220 and S230. Steps S220 and S230 are improvements on step S130 in the prior art.

[0046] Specifically, in some embodiments of the present invention, step S220 is: stopping the introduction of the PEALD precursor and providing second radio frequency energy to the wafer surface to generate a PEALD film on the surface of the first PECVD film. Step S230 is: introducing the PEALD precursor again to the wafer surface after providing the second radio frequency energy to generate a second PECVD film on the surface of the PEALD film.

[0047] exist Figure 3 In the timing flowchart 300 of the gap-filling method shown, as indicated by the timing flow lines below steps S220 and S230, in some embodiments, after the purging operation is completed, the flow of the PEALD precursor can be stopped, and a second radio frequency energy can be continuously supplied to the wafer surface to form a dense PEALD film, such as SiO2, on the surface of the first PECVD film. x Thin film. Further, after the second radio frequency energy is provided, i.e. after the second radio frequency reaction has been performed for a period of time, the same PEALD precursor can be introduced again onto the wafer surface to generate a second PECVD thin film on the PEALD thin film surface.

[0048] In terms of process, when adding an additional PEALD precursor activation step to the traditional PEALD internal loop, the process needs to control the activation time and timing of the additional PEALD precursor. Optionally, the activation speed of the second RF energy can preferably be less than 30ms, so that the system time accuracy corresponding to this step can be controlled to less than 30ms.

[0049] Furthermore, such as Figure 3 As shown, during the process of providing the second radio frequency energy to the wafer surface, the purge gas can be continuously introduced throughout the process. After the second PECVD film is formed and the second radio frequency energy is turned off, the gap-filling method provided by this invention may further include step S231: continuing to introduce purge gas to the wafer surface to remove excess reaction byproducts from the surface of the second PECVD film. By combining precise control of the purge gas and pressure, the second radio frequency energy, and time, a second PECVD film with good uniformity and high quality can be produced.

[0050] The above Figure 3 Steps S210 to S231 can be repeated at least once. Please continue back to... Figure 2 The gap-filling method provided by the present invention may further include step S240: after generating the first PECVD film, the PEALD film and the second PECVD film, the PEALD precursor is introduced into the wafer surface again, and at the same time, a third radio frequency energy is provided to the wafer surface to generate a mixed film on the surface of the second PECVD film.

[0051] exist Figure 3In the timing flow diagram 300 of the gap-filling method shown, as indicated by the timing flow line below step S240, in some embodiments, after the above-mentioned PEALD combined with PECVD mixing process steps S210 to S231 have been cycled at least once, and a first PECVD film, a PEALD film, and a second PECVD film have been generated, the same PEALD precursor as before can be introduced into the wafer surface in the reaction chamber again, along with a purge gas to feed its carrier tape in, while simultaneously providing a third radio frequency energy to the wafer surface, thereby generating a mixed film on the surface of the second PECVD film. The mixed film may include compounds of silicon oxide, silicon nitride, and / or titanium oxide; for example, the mixed film may be SiO2. x Si x N y TiO x Thin films, etc.

[0052] Compared to the traditional PEALD cycle in existing technologies, this process adds an additional PEALD precursor activation step after the cycle is complete. This, combined with third radio frequency (RF) energy, generates a PECVD reaction, thus forming a PEALD & PECVD in-situ thin film. In terms of process, it is necessary to control the activation time and timing of the additional PEALD precursor, as well as the valve opening and closing of the PEALD precursor and the activation timing of the third RF energy. Optionally, the activation speed of the third RF energy can preferably be less than 30ms, thereby controlling the system time accuracy corresponding to this step to below 30ms. By combining precise control of the purge gas and pressure, the third RF energy, and the time, a mixed thin film with good uniformity and high quality can be produced.

[0053] Furthermore, in some preferred embodiments, after generating the hybrid film, the gap-filling method may further include the following steps: chemically mechanically polishing (CMP) the hybrid film, the second PECVD film, the PEALD film and the first PECVD film to obtain a wafer with gaps filled.

[0054] This concludes the introduction of a gap-filling method provided by the first aspect of the present invention. In the above-described gap-filling method, both PECVD and PEALD film growth are based on the same chemical source supply system, i.e., a single chemical source system, achieving mixed film growth through precise time axis control. Therefore, compared to the dual chemical source system in the prior art and its corresponding additional chemical source switching operation, this method reduces system complexity, lowers system error, improves film purity and particle characteristics, and eliminates the additional purging and system stabilization time introduced by chemical source switching, significantly increasing process throughput. Furthermore, in the gap-filling method of the present invention, the respective process parameters can be controlled in the PEALD and PECVD steps to increase process flexibility.

[0055] 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.

[0056] In a second aspect of the invention, a gap-filling device is also provided. Please see [link / reference needed]. Figure 4 , Figure 4 A structural block diagram of a gap-filling device provided according to some embodiments of the present invention is shown.

[0057] like Figure 4 As shown, a memory 410 and a processor 420 may be configured in the gap-filling device 400. The memory 410 may include, but is not limited to, the computer-readable storage medium described in the third aspect of the present invention, on which computer instructions are stored. The processor 420 may be connected to the memory 410 and configured to execute the computer instructions stored in the memory 410 to implement the gap-filling method described in the first aspect of the present invention.

[0058] In summary, the present invention provides a gap-filling method, a gap-filling device, and a computer-readable storage medium, which can not only improve the growth rate and step coverage of thin film gap filling, but also reduce system complexity, improve film purity and particle performance, and eliminate the need for additional purging time and system stabilization time introduced by chemical source switching, thereby significantly improving process capacity and balancing the gap-filling ability and economy of the thin film.

[0059] 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 gap-filling method, characterized in that, Includes the following steps: A PEALD precursor is introduced into the wafer surface with gaps, and a first radio frequency energy is provided to the wafer surface during the introduction of the PEALD precursor to generate a first PECVD thin film on the wafer surface. Stop the flow of the PEALD precursor and provide a second radio frequency energy to the wafer surface to generate a PEALD film on the surface of the first PECVD film; After the second radio frequency energy is provided, the PEALD precursor is introduced again into the wafer surface to form a second PECVD film on the PEALD film surface. as well as After the first PECVD film, the PEALD film and the second PECVD film are generated, the PEALD precursor is introduced into the wafer surface again, and at the same time, a third radio frequency energy is provided to the wafer surface to generate a PECVD reaction, so as to form a PEALD & PECVD in-situ film on the surface of the second PECVD film.

2. The gap-filling method as described in claim 1, characterized in that, The PEALD precursor includes bissilane, and the PEALD & PECVD in-situ thin film includes compounds of silicon oxide, silicon nitride, and / or titanium oxide.

3. The gap-filling method as described in claim 1, characterized in that, After the first PECVD thin film is formed and before the second radio frequency energy is provided to the wafer surface, the gap-filling method further includes the following steps: A purge gas is introduced into the wafer surface to remove excess PEALD precursor from the surface of the first PECVD film.

4. The gap-filling method as described in claim 1, characterized in that, After the second PECVD film is generated, and before the PEALD precursor is introduced back into the wafer surface and a third radio frequency energy is simultaneously provided to the wafer surface, the gap-filling method further includes the following steps: A purge gas is introduced into the wafer surface to remove reaction byproducts from the surface of the second PECVD film.

5. The gap-filling method as described in claim 3 or 4, characterized in that, The purging gas includes at least one of argon, nitrogen, nitrous oxide, and oxygen.

6. The gap-filling method as described in claim 1, characterized in that, The start-up speed of the first radio frequency energy is less than 20ms, and the start-up speed of the second radio frequency energy is less than 30ms.

7. The gap-filling method as described in claim 1, characterized in that, After generating the PEALD & PECVD in-situ thin film, the gap-filling method further includes the following steps: The PEALD & PECVD in-situ thin films, the second PECVD thin film, the PEALD thin film, and the first PECVD thin film are subjected to chemical mechanical polishing to obtain a wafer that fills the gap.

8. A gap-filling device, comprising: Memory; as well as A processor, connected to the memory, and configured to implement the gap-filling method as described in any one of claims 1 to 7.

9. The gap-filling device as described in claim 8, characterized in that, Also includes: A process chamber for accommodating wafers with gaps on their surfaces, in order to fill the gaps in the wafers; A precursor source is used to introduce PEALD precursors onto the wafer surface. Radio frequency power supply, used to provide radio frequency energy to the wafer surface; A purge gas source is used to introduce purge gas onto the surface of the wafer. and / or The CMP module is used to perform chemical mechanical polishing on the wafer surface.

10. A computer-readable storage medium storing computer instructions thereon, characterized in that, When the computer instructions are executed by the processor, the gap-filling method as described in any one of claims 1 to 7 is implemented.

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