A method for producing silicon-nitrogen polymer

Abstract

The present invention provides a method for generating a silicon-nitrogen polymer, wherein the silicon-nitrogen polymer is used for further curing to prepare a silicon dioxide film. The method comprises: dissociating ammonia gas in an environment where oxygen is introduced to obtain a nitrogen source gas; and depositing the nitrogen source gas and silicon source gas to obtain the silicon-nitrogen polymer, wherein the flow ratio of the silicon source gas to the nitrogen source gas is in the range of 0.3 to 0.9.

Description

Technical Field

[0001] The invention relates to thin film preparation in semiconductor technology, and in particular to a method for generating a silicon nitrogen polymer in the preparation of silicon dioxide thin film. Background Art

[0002] CVD (chemical vapor deposition) refers to the deposition of thin films by chemical reactions of multiple gaseous reactants at different partial pressures at a certain temperature and pressure. In traditional CVD processes, deposited thin films are generally compounds such as oxides, nitrides, carbides, or polysilicon. The epitaxial technology used for thin film growth in specific fields is also considered a type of CVD in a broad sense. CVD can be divided into atmospheric pressure CVD (APCVD), fluid CVD (FCVD), low pressure CVD (LPCVD), plasma enhanced CVD (PECVD), sub-atmospheric pressure CVD (SACVD), high density plasma CVD (HDP-CVD), fluid CVD (FCVD), atomic layer deposition (ALD), etc. according to different reaction conditions, such as pressure, temperature, reaction source, etc.

[0003] Among them, the fluid chemical vapor deposition (FCVD, Flowable CVD) process requires the use of remote plasma equipment to first dissociate ammonia into ammonia free radicals. However, ammonia free radicals are easy to recombine into ammonia. Practical research has found that introducing some oxygen during the deposition process can increase the deposition rate.

[0004] In addition, during the deposition process, due to calibration issues with the mass flow controller (MFC), the flow rate of the silicon source gas will be much lower than normal, resulting in a white film on the wafer during the deposition process.

[0005] In order to overcome the above-mentioned defects of the prior art, the art is in urgent need of a method for generating silicon-nitrogen polymers for preparing silicon dioxide films, by increasing the oxygen input during the dissociation of ammonia and adjusting the ratio of silicon source gas to nitrogen source gas to improve the quality of the prepared silicon dioxide films and enhance the FCVD process level. Summary of the invention

[0006] A brief summary of one or more aspects is given below to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all conceived aspects, and is neither intended to identify the key or critical elements of all aspects nor to define the scope of any or all aspects. Its only purpose is to give some concepts of one or more aspects in a simplified form as a prelude to a more detailed description that will be given later.

[0007] In order to overcome the above-mentioned defects of the prior art, the present invention provides a method for generating a silicon-nitrogen polymer, which is used for further curing to prepare a silicon dioxide film. The generation method comprises: dissociating ammonia in an environment where oxygen is introduced to obtain a nitrogen source gas; and using the nitrogen source gas and silicon source gas to deposit the silicon-nitrogen polymer, wherein the flow ratio of the silicon source gas to the nitrogen source gas is in the range of 0.3 to 0.9.

[0008] In one embodiment, preferably, in the method for producing a silicon-nitrogen polymer provided by the present invention, the silicon-nitrogen polymer is a long-chain silicon-nitrogen polymer.

[0009] In one embodiment, preferably, in the method for generating silicon nitrogen polymer provided by the present invention, dissociating ammonia in an environment of introducing oxygen to obtain nitrogen source gas may include: controlling the flow rate range of the introduced oxygen to be 40 to 70 sccm.

[0010] In one embodiment, preferably, in the method for producing silicon-nitrogen polymer provided by the present invention, the flow ratio of the silicon source gas to the nitrogen source gas is in the range of 0.5 to 0.85.

[0011] In one embodiment, preferably, in the method for generating silicon-nitrogen polymer provided by the present invention, the flow rate of the silicon source gas may range from 200 to 300 sccm, and the flow rate of the nitrogen source gas may range from 300 to 500 sccm.

[0012] In one embodiment, preferably, in the method for generating a silicon-nitrogen polymer provided by the present invention, the silicon source gas includes TSA gas, and the nitrogen source gas includes ammonia gas.

[0013] In one embodiment, preferably, in the method for generating the silicon-nitrogen polymer provided by the present invention, the silicon-nitrogen polymer is obtained by depositing the nitrogen source gas and the silicon source gas, comprising: during the deposition process, controlling the distance between the heating disk and the shower plate to be in the range of 55 to 75 cm.

[0014] In one embodiment, preferably, in the method for generating silicon-nitrogen polymer provided by the present invention, the silicon-nitrogen polymer is obtained by depositing the nitrogen source gas and the silicon source gas, and further comprises: during the deposition process, controlling the distance between the heating disk and the shower plate to be in the range of 60 to 70 cm. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above features and advantages of the present invention can be better understood after reading the detailed description of the embodiments of the present disclosure in conjunction with the following drawings. In the drawings, the components are not necessarily drawn to scale, and components with similar related properties or features may have the same or similar reference numerals.

[0016] Figure 1is a schematic diagram of a method flow of a method for producing a silicon-nitrogen polymer according to an embodiment of the present invention;

[0017] Figure 2A is a schematic structural diagram of a remote plasma source device for dissociating ammonia according to an embodiment of the present invention;

[0018] Figure 2B is a chemical molecular structure formula of a silicon source gas TSA for generating silicon nitrogen polymer according to an embodiment of the present invention;

[0019] Figure 3 is a schematic diagram of the relative positions of a heating disk and a shower plate in a deposition chamber according to an embodiment of the present invention;

[0020] Figure 4A is a schematic diagram of the position of the edge area of ​​a wafer for a deposition process according to an embodiment of the present invention;

[0021] Figure 4B is a schematic diagram of the position of a wafer annular region for performing a deposition process according to an embodiment of the present invention; and

[0022] Figure 4C FIG. 4 is a schematic diagram showing the position of the center area of ​​a wafer during a deposition process according to an embodiment of the present invention.

[0023] For the sake of clarity, a brief description of the reference numerals is given below:

[0024] 201 Gas pipeline

[0025] 200RPS Device

[0026] 301 spray plate

[0027] 302 heating plate

[0028] 401 Wafer edge area

[0029] 402 Wafer Ring Area

[0030] 403 wafer center area DETAILED DESCRIPTION

[0031] The following specific embodiments illustrate the implementation of the present invention, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this invention are limited to this implementation. On the contrary, the purpose of introducing the invention in conjunction with the implementation is to cover other options or modifications that may be extended based on the claims of the present invention. In order to provide a deep understanding of the present invention, the following description will include many specific details. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present invention, some specific details will be omitted in the description.

[0032] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] In addition, the terms "upper", "lower", "left", "right", "top", "bottom", "horizontal" and "vertical" used in the following description should be understood as the directions shown in the paragraph and the related drawings. Such relative terms are only used for the convenience of description and do not mean that the device described therein must be manufactured or operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0034] It is understood that although the terms "first", "second", "third", etc. 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 component, region, layer and / or part discussed below may be referred to as a second component, region, layer and / or part without departing from some embodiments of the present invention.

[0035] CVD (chemical vapor deposition) refers to the deposition of thin films by chemical reactions of multiple gaseous reactants at different partial pressures at a certain temperature and pressure. In traditional CVD processes, deposited thin films are generally compounds such as oxides, nitrides, carbides, or polysilicon. The epitaxial technology used for thin film growth in specific fields is also considered a type of CVD in a broad sense. CVD can be divided into atmospheric pressure CVD (APCVD), fluid CVD (FCVD), low pressure CVD (LPCVD), plasma enhanced CVD (PECVD), sub-atmospheric pressure CVD (SACVD), high density plasma CVD (HDP-CVD), fluid CVD (FCVD), atomic layer deposition (ALD), etc. according to different reaction conditions, such as pressure, temperature, reaction source, etc.

[0036] Among them, the fluid chemical vapor deposition (FCVD, Flowable CVD) process requires the use of remote plasma equipment to first dissociate ammonia into ammonia free radicals. However, ammonia free radicals are easy to recombine into ammonia. Practical research has found that introducing some oxygen during the deposition process can increase the deposition rate.

[0037] In order to overcome the above-mentioned defects of the prior art, the art is in urgent need of a method for generating a silicon-nitrogen polymer for preparing silicon dioxide film, by increasing the oxygen input during the dissociation of ammonia and adjusting the ratio of silicon source gas to nitrogen source gas to improve the quality of the prepared silicon dioxide film.

[0038] It should be noted that the method for generating silicon nitrogen polymer for preparing silicon dioxide film provided by the present invention can be used in the process and equipment of fluid chemical vapor deposition (FCVD, Flowable CVD). FCVD adopts remote plasma deposition technology, and the reaction precursor is introduced into the reaction chamber in a direction, and flows into the liquid film on the surface of the wafer, thereby filling the groove from bottom to top, meeting the hole filling capability required by the process below 14nm.

[0039] Figure 1 FIG. 4 is a schematic diagram of a method for producing a silicon-nitrogen polymer according to an embodiment of the present invention.

[0040] Please refer to Figure 1 In the method for producing a silicon nitrogen polymer provided by the present invention, the silicon nitrogen polymer is used for further curing to prepare a silicon dioxide film. The production method 100 comprises:

[0041] Step 101: dissociate ammonia gas in an environment where oxygen is introduced to obtain a nitrogen source gas.

[0042] Furthermore, in a preferred embodiment, the dissociation of ammonia gas in an environment where oxygen is introduced to obtain the nitrogen source gas may include: controlling the flow rate of the introduced oxygen to be in the range of 40 to 70 sccm.

[0043] Figure 2A 1 is a schematic diagram of a remote plasma source device for dissociating ammonia according to an embodiment of the present invention.

[0044] like Figure 2A As shown, both ammonia and oxygen can be introduced into the remote plasma source (RPS) device 200 through the gas pipeline 201 for dissociation. In particular, in the method for generating silicon nitrogen polymer provided by the present invention, some oxygen can be introduced through the gas pipeline 201 while dissociating ammonia, which can help prevent ammonia radicals and hydrogen radicals from polymerizing into ammonia again, thereby increasing process efficiency.

[0045] However, excessively increasing the oxygen flow rate is not conducive to the fluidity of the film. Therefore, the present invention provides a preferred oxygen flow rate value range, which can control the appropriate oxygen flow rate when dissociating ammonia, thereby improving process efficiency and ensuring process quality.

[0046] Please continue to refer to Figure 1 In the method for producing silicon-nitrogen polymer provided by the present invention, the production method 100 may further include:

[0047] Step 102: Depositing the silicon-nitrogen polymer using the nitrogen source gas and the silicon source gas, wherein the flow ratio of the silicon source gas to the nitrogen source gas is in a range of 0.3 to 0.9.

[0048] In a preferred embodiment, the silicon-nitrogen polymer is a long-chain silicon-nitrogen polymer.

[0049] In the method for producing silicon-nitrogen polymer provided by the present invention, when silicon source gas and nitrogen source gas are used to deposit silicon-nitrogen (Si-N) polymer, the significance of controlling the flow ratio of the two is that when the content of ammonia source gas is too high, the deposition reaction mostly produces some short-chain Si-N oligomers, and it is difficult to obtain long-chain Si-N polymers. However, these short-chain oligomers are more likely to absorb Si-OH bonds generated by water molecules in the air, thereby causing a white film to appear on the wafer surface, affecting the process quality.

[0050] It should be noted that the polymer generated by the method for generating silicon nitrogen polymer provided by the present invention is a long-chain silicon nitrogen polymer, rather than directly generating silicon dioxide or silicon nitride. The long-chain polymer needs to be further cured to form a silicon dioxide film.

[0051] In addition, further, in a more preferred embodiment, the flow ratio of the silicon source gas to the nitrogen source gas is in the range of 0.5 to 0.85.

[0052] At the same time, appropriately reducing the nitrogen source gas flow rate can help to increase the service life of the remote plasma source RPS equipment.

[0053] Preferably, the flow rate of the silicon source gas may range from 200 to 300 sccm, and the flow rate of the nitrogen source gas may range from 300 to 500 sccm.

[0054] For example, the flow rate of the silicon source gas can be fixed at 275 sccm, and the flow rate of the nitrogen source gas can be selected within the range of 300 to 500 sccm, wherein the flow rate of the nitrogen source gas is preferably 350 sccm.

[0055] In addition, when the flow rate of the silicon source gas is too small, short-chain silicon-nitrogen oligomers may be deposited on the wafer surface. The oligomers easily absorb water, causing the wafer film to turn white, affecting the process deposition effect. When the flow rate of the silicon source gas is too large, the silicon source gas and the ammonia plasma basically do not react, and the problem of film formation on the wafer surface may occur. Therefore, the present invention provides a preferred numerical ratio of silicon source gas to nitrogen source gas. Within this numerical range of the ratio, the process of generating the silicon-nitrogen polymer will not produce an unexpected white film, nor will it affect its own generation process.

[0056] In the method for producing silicon-nitrogen polymer provided by the present invention, optionally, the silicon source gas may include TSA gas, and the nitrogen source gas may include ammonia gas.

[0057] Figure 2B : is a chemical molecular structure formula of silicon source gas TSA for generating silicon nitrogen polymer according to an embodiment of the present invention.

[0058] Can be combined with reference Figure 2B TSA gas, also known as SCP gas, trimethylsilylamine, has the advantages of strong volatility, carbon-free and chlorine-free. It can enter the reactor in gaseous form without heating and can be used in a variety of semiconductor preparation processes.

[0059] It should be noted that the silicon source gas and nitrogen source gas involved in the deposition reaction are only exemplified here, which is intended to clearly explain the process steps and effects of the method for producing silicon-nitrogen polymers provided by the present invention, rather than to limit the scope of protection of the present invention. In fact, other silicon source gases and nitrogen source gases that can play a similar role can also be used in the method for producing silicon-nitrogen polymers provided by the present invention, and should also be included in the scope of protection of the present invention.

[0060] Figure 3 1 is a schematic diagram of the relative positions of a heating disk and a shower plate in a deposition chamber according to an embodiment of the present invention.

[0061] Further preferably, it can be combined with reference Figure 3In the method for producing silicon nitrogen polymer provided by the present invention, the distance between the heating disk 302 and the shower plate 301 can be controlled.

[0062] For example, the deposition of the silicon-nitrogen polymer using the nitrogen source gas and the silicon source gas may include: during the deposition process, the distance between the heating disk 302 and the shower plate 301 may be controlled to be in the range of 55 to 75 cm.

[0063] Combine the following Figures 4A to 4C The effect of controlling the distance between the hot plate and the shower plate in the method for producing silicon nitrogen polymer provided by the present invention is described.

[0064] Figure 4A FIG. 1 is a schematic diagram showing the position of the edge region of a wafer during a deposition process according to an embodiment of the present invention.

[0065] Figure 4B FIG. 4 is a schematic diagram showing the position of an annular region of a wafer for a deposition process according to an embodiment of the present invention.

[0066] Figure 4C FIG. 4 is a schematic diagram showing the position of the center area of ​​a wafer during a deposition process according to an embodiment of the present invention.

[0067] When the distance between the heating plate and the shower plate is large, the heating plate is closer to the vacuum pump port, resulting in the risk of wafer slippage. When the distance between the heating plate and the shower plate is small, the effect of the deposition process will be affected.

[0068] For example, you can combine reference Figure 3 and Figure 4A to Figure 4C When the distance between the heating plate 302 and the shower plate 301 is too small, the reaction gas is more likely to blow to Figure 4A The wafer edge region 401 and Figure 4B As shown in the wafer annular region 402, the deposition thickness at the wafer edge region 401 and the wafer annular region 402 is greater than that at the wafer edge region 401 and the wafer annular region 402. Figure 4C The thickness of the central region 403 of the wafer is shown to be much thicker, which causes uneven deposition of reactants on the entire surface of the wafer, affecting the process effect.

[0069] Further preferably, during the deposition process, the distance between the heating disk 302 and the shower plate 301 can be controlled to be in the range of 60 to 70 cm, thereby improving the uniformity of the reactant deposition and further improving the process effect.

[0070] Although the above methods are illustrated and described as a series of actions for simplicity of explanation, it should be understood and appreciated that these methods are not limited by the order of the actions, because according to one or more embodiments, some actions may occur in a different order and / or concurrently with other actions from those illustrated and described herein or not illustrated and described herein but understandable to those skilled in the art.

[0071] The method for generating silicon-nitrogen polymer for preparing silicon dioxide film provided by the present invention improves the quality of preparing silicon dioxide film and enhances the FCVD process level by increasing oxygen introduction and adjusting the ratio of silicon source gas to nitrogen source gas during the dissociation of ammonia.

[0072] The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the 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 the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein, but should be granted the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for producing a silicon nitrogen polymer, wherein the silicon nitrogen polymer is further cured to prepare a silicon dioxide film, the method comprising: Dissociating ammonia in an oxygen-filled environment to obtain nitrogen source gas; as well as The distance between the heating disk and the shower plate is controlled to be in the range of 55 to 75 cm, so as to obtain the silicon-nitrogen polymer by deposition using the nitrogen source gas and the silicon source gas, wherein the flow ratio of the silicon source gas to the nitrogen source gas is in the range of 0.3 to 0.

9.

2. The generation method according to claim 1, characterized in that: The silicon-nitrogen polymer is a long-chain silicon-nitrogen polymer.

3. The generation method according to claim 1, characterized in that: The step of dissociating ammonia gas to obtain nitrogen source gas under an environment where oxygen is introduced comprises: The flow rate of the oxygen gas is controlled to be in the range of 40 to 70 sccm.

4. The generation method according to claim 1, characterized in that: The flow rate ratio of the silicon source gas to the nitrogen source gas is in the range of 0.5 to 0.

85.

5. The generation method according to claim 1, characterized in that: The flow rate of the silicon source gas ranges from 200 to 300 sccm, and the flow rate of the nitrogen source gas ranges from 300 to 500 sccm.

6. The generation method according to claim 1, characterized in that: The silicon source gas includes TSA gas, and the nitrogen source gas includes ammonia gas.

7. The generation method according to claim 1, characterized in that: The distance between the heating plate and the spray plate is controlled to be in the range of 60 to 70 cm.

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