Preparation method of silicon dioxide film for supplying TEOS (tetraethyl orthosilicate) in hot box

Abstract

The invention provides a preparation method of a silicon dioxide film for supplying TEOS (tetraethyl orthosilicate) in a hot box, and relates to the technical field of semiconductor deposition, the preparation method comprises the following steps: introducing a first preset flux of oxygen into a reaction chamber until the reaction chamber reaches a preset pressure; introducing a second preset flux of TEOS supplied by the hot box into the reaction chamber, and keeping the pressure of the reaction chamber at a preset pressure; oxygen and TEOS (tetraethyl orthosilicate) are used as precursors by using a plasma enhanced chemical vapor deposition method, a silicon dioxide film is prepared by deposition, and the radio frequency power of the plasma enhanced chemical vapor deposition is any one value in the range of 300W-1200W; wherein the ratio of the first preset flux to the second preset flux is any value in the range of 2.5-4.0, and the preset pressure is any value in the range of 5.0 Torr to 12.0 Torr. The silicon dioxide film prepared by the method has relatively high corrosion resistance, uniformity and stress matching degree, and the condition that the silicon dioxide film is easy to generate undercutting phenomenon due to the fact that TEOS is conveyed by a hot box can be avoided.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor deposition, and in particular to a method for preparing a silicon dioxide film using a hot box to supply TEOS (Tetraethylorthosilicate, tetraethoxysilane). Background Art

[0002] Plasma-enhanced chemical vapor deposition technology is widely used in the semiconductor and MEMS (Micro-Electro-Mechanical System) fields due to its high efficiency, low temperature and controllable characteristics. It is used to deposit silicon dioxide films, which significantly improves the production efficiency and film quality of semiconductor devices and MEMS devices. Among them, silicon dioxide films play a key role in MEMS devices, such as forming microstructures such as structural layers, passivation layers and insulating layers, and silicon dioxide films deposited by plasma-enhanced chemical vapor deposition based on TEOS are particularly important in these applications, that is, the film quality of silicon dioxide films may affect the morphology of subsequent wet etching processes and the integrity of the covering metal layer.

[0003] TEOS is liquid at room temperature. In order to obtain an ideal silicon dioxide film, TEOS needs to be kept in a high-temperature vaporized state before entering the reaction chamber. When the hot box is used as a TEOS gas source delivery device, the gas pipeline in the hot box is partially blocked due to TEOS crystals. The pressure in the pipeline increases, and a very small amount of the originally vaporized TEOS will be liquefied, resulting in the TEOS gas output to the reaction chamber not being completely vaporized at high temperature. As a result, the silicon dioxide film deposited by the reaction of TEOS and oxygen is prone to undercutting. Summary of the invention

[0004] An object of the present invention is to provide a method for preparing a silicon dioxide film using TEOS supplied by a hot box, so as to solve the technical problem that the silicon dioxide film prepared by using a hot box to transport high-temperature vaporized TEOS easily leads to poor anti-penetration properties of the film.

[0005] Another object of the present invention is to further improve the deposition quality of silicon dioxide thin films.

[0006] According to the purpose of the present invention, the present invention provides a method for preparing a silicon dioxide film for hot box supply of TEOS, comprising the following steps:

[0007] Passing a first preset flux of oxygen into the reaction chamber until the reaction chamber reaches a preset pressure;

[0008] Passing a second preset flux of TEOS supplied by the hot box into the reaction chamber, and maintaining the pressure of the reaction chamber at the preset pressure;

[0009] The oxygen and the TEOS are subjected to silicon dioxide film deposition by plasma enhanced chemical vapor deposition to prepare the silicon dioxide film, and the radio frequency power of the plasma enhanced chemical vapor deposition is any value in the range of 300W-1200W; wherein,

[0010] The ratio of the second preset flux to the first preset flux is any value in the range of 2.5-4.0, and the preset pressure is any value in the range of 5.0 Torr-12.0 Torr.

[0011] Optionally, the first preset flux is any value in the range of 100 sccm-1200 sccm, and the second preset flux is any value in the range of 100 sccm-1000 sccm.

[0012] Optionally, the deposition temperature of the plasma enhanced chemical vapor deposition is any value in the range of 300°C-400°C.

[0013] Optionally, the deposition rate of the plasma enhanced chemical vapor deposition is in the range of Any value in .

[0014] Optionally, after the step of depositing a silicon dioxide film on the oxygen and the TEOS by plasma enhanced chemical vapor deposition, the following step is further included:

[0015] The reaction chamber is evacuated to make the pressure of the reaction chamber a vacuum pressure.

[0016] Optionally, the vacuum pressure is any value in the range of 0.05 Torr-0.1 Torr.

[0017] Optionally, the ratio of the first preset flux to the second preset flux is any value in the range of 2.5-3.5.

[0018] Optionally, the preset pressure is any value in the range of 5.2 Torr-7.2 Torr.

[0019] The present invention introduces oxygen and TEOS into a deposition chamber, controls the flux ratio of oxygen to TEOS to be any value in the range of 2.5-4.0, and regulates the preset pressure in the reaction chamber and the radio frequency power of plasma enhanced chemical vapor deposition, that is, controls the preset pressure to be any value in the range of 5.0 Torr-12.0 Torr, and the radio frequency power to be any value in the range of 300 W-1200 W, so that the TEOS supplied by the hot box can fully react with the oxygen to deposit a silicon dioxide film with high quality and uniform thickness, prevents the occurrence of undercutting problems when the silicon dioxide film is subsequently etched by a wet etching process, and the silicon dioxide film prepared by the preparation method can keep stress parameters unchanged.

[0020] Furthermore, after the deposition of the silicon dioxide film in the reaction chamber is completed, the present invention turns off the radio frequency power supply and evacuates the reaction chamber so that the pressure in the reaction chamber is in a vacuum state, so as to remove the residual gas in the reaction chamber and prevent the residual gas from remaining in the reaction chamber to contaminate the silicon dioxide film and affect its purity and performance, thereby avoiding performance changes of the film due to gas adsorption, desorption and other processes during subsequent processing or use.

[0021] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Hereinafter, some specific embodiments of the present invention will be described in detail in an exemplary and non-limiting manner with reference to the accompanying drawings. The same reference numerals in the accompanying drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the accompanying drawings:

[0023] Figure 1 is a schematic flow chart of a method for preparing a silicon dioxide thin film according to an embodiment of the present invention;

[0024] Figure 2 is a schematic overall flow chart of a method for preparing a silicon dioxide thin film according to an embodiment of the present invention;

[0025] Figure 3 is a scanning electron microscope image of the silicon dioxide thin film prepared in Example 1 and Comparative Example 5, Comparative Example 8 and Comparative Examples 11-14 of the present invention;

[0026] Figure 4 is a schematic thickness variation diagram of the silicon dioxide films prepared in Example 1 and Comparative Examples 1-14 of the present invention;

[0027] Figure 5Schematic diagram of stress variation of silicon dioxide films prepared in Example 1 and Comparative Examples 1-14 of the present invention. DETAILED DESCRIPTION

[0028] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0029] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. It is to be understood that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. It should also be noted that, for ease of description, only some structures related to the present application are shown in the accompanying drawings, rather than all structures. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0030] The terms "including" and "having" and any variations thereof in this application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products or devices.

[0031] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0032] In particular, the present invention provides a method for preparing a silicon dioxide film for supplying TEOS with a hot box, and the method for preparing a silicon dioxide film is used in a silicon dioxide film deposition device that supplies TEOS with a hot box. It should be noted that the deposition of high-quality silicon dioxide films usually requires the use of a machine with a precision liquid injection system to supply gas source TEOS to ensure that TEOS is always gasified during the process of being transported to the reaction chamber. However, in a deposition device that has been configured with a hot box to supply gas source TEOS, since the delivery pipeline of the hot box is an insulation pipeline, the originally gasified TEOS will be very slightly liquefied during the process of being transported to the reaction chamber, resulting in the TEOS gas output to the reaction chamber not being completely gasified at high temperature, affecting the deposition quality of the silicon dioxide film, and due to the high cost of machine modification and accessory adaptation problems, the hot box cannot be simply replaced with a precision liquid injection system to supply TEOS, so the deposition device that uses the hot box to supply TEOS cannot maintain continuous high-temperature gasification, TEOS and oxygen do not react completely in the initial stage of deposition, resulting in poor quality of the silicon dioxide film, and after the wet etching process, the silicon dioxide film layer will have a serious drilling phenomenon, resulting in the subsequent covering metal layer fracture. Technical personnel in this field usually choose to modify the hardware configuration of the deposition equipment, for example, replacing the TEOS gas source delivery device, that is, replacing the hot box with a precision liquid injection system, which usually requires high financial and time costs.

[0033] In order to solve the problem of undercutting caused by the TEOS gas source delivered by the hot box, the inventors conducted a large number of attempts. For example, they increased the oxygen flux delivered to the reaction chamber and performed multiple parameter adjustments. Although the prepared silicon dioxide film has good corrosion resistance, its uniformity and stress are quite different from the original process conditions and cannot meet the needs of subsequent products.

[0034] By chance, the inventor adjusted the RF power and deposition pressure of the deposition equipment and found that the prepared silicon dioxide film not only had good corrosion resistance and uniformity, but also the uniformity and stress of the silicon dioxide film met the requirements of subsequent products.

[0035] Figure 1 is a schematic flow chart of a method for preparing a silicon dioxide film according to an embodiment of the present invention.

[0036] like Figure 1 As shown, the present invention provides a method for preparing a silicon dioxide film for hot box supply of TEOS, comprising the following steps:

[0037] Step S100: introducing a first preset flux of oxygen into the reaction chamber until the reaction chamber reaches a preset pressure;

[0038] Step S200: introducing a second preset flux of TEOS supplied by the hot box into the reaction chamber, and maintaining the pressure of the reaction chamber at a preset pressure;

[0039] Step S300: Using plasma enhanced chemical vapor deposition to deposit silicon dioxide film on oxygen and TEOS to prepare a silicon dioxide film, the RF power of the plasma enhanced chemical vapor deposition is any value in the range of 300W-1200W, wherein the ratio of the second preset flux to the first preset flux is any value in the range of 2.5-4.0, and the preset pressure is any value in the range of 5.0Torr-12.0Torr.

[0040] In this embodiment, in the deposition device of silicon dioxide film using TEOS supplied by a hot box, oxygen with a first preset flux is first introduced into the reaction chamber to make the reaction chamber reach a preset pressure, and then TEOS is introduced into the reaction chamber through the hot box, and the pressure of the reaction chamber is always maintained at the preset pressure, and then the plasma enhanced chemical vapor deposition method is used to deposit and prepare the silicon dioxide film using oxygen and TEOS as precursors. Here, the preset pressure can be 5.0 Torr, 6.0 Torr, 7.0 Torr,

[0041] The radio frequency power may be 8.0 Torr, 9.0 Torr, 10.0 Torr, 11.0 Torr or 12.0 Torr, or any value in the range of 5.0 Torr-12.0 Torr. The radio frequency power may be 300 W, 400 W, 500 W, 600 W, 700 W, 800 W, 900 W, 1000 W, 1100 W or 1200 W, or any value in the range of 300 W-1200 W. The ratio of the first preset flux to the second preset flux may be 2.5, 3.0, 3.5 or 4.0, or any value in the range of 2.5-4.0.

[0042] In this embodiment, the method for preparing a silicon dioxide film is applicable to a deposition device that uses a hot box as a TEOS supply device, by introducing oxygen and TEOS into a deposition chamber, and controlling the flux ratio of oxygen to TEOS to be any value in the range of 2.5-4.0, and by adjusting the preset pressure in the reaction chamber and the radio frequency power of plasma enhanced chemical vapor deposition, that is, controlling the preset pressure to be any value in the range of 5.0 Torr-12.0 Torr, and the radio frequency power to be any value in the range of 300W-1200W, so that the TEOS supplied by the hot box can fully react with oxygen to deposit a silicon dioxide film with high quality and uniform thickness, thereby preventing the occurrence of undercutting problems when the silicon dioxide film is subsequently etched using a wet etching process, and the silicon dioxide film prepared by the above preparation method can keep the stress parameters unchanged. That is, by improving the deposition process conditions of plasma enhanced chemical vapor deposition silicon dioxide film, the poor quality of the silicon dioxide film caused by insufficient reaction of TEOS and oxygen can be avoided, which leads to severe undercutting after the wet etching process. This is suitable for deposition equipment equipped with a hot box to supply TEOS, reducing the cost of machine modification, improving production efficiency, and improving product quality.

[0043] In this embodiment, in the method for preparing a silicon dioxide film, the ratio of the first preset flux to the second preset flux is controlled to be any value in the range of 2.5-4.0, that is, the oxygen content in the reaction chamber is greater than the TEOS content, so that the incompletely high-temperature vaporized TEOS supplied by the hot box can react completely with the oxygen to prepare a high-quality silicon dioxide film, thereby improving the anti-undercutting ability of the silicon dioxide film. Here, the carrier gas is helium.

[0044] In this embodiment, in the method for preparing the silicon dioxide film, by adjusting the preset pressure in the reaction chamber to any value between 5.0 Torr and 12.0 Torr, that is, by controlling the deposition pressure of plasma enhanced chemical vapor deposition to be within the above range, the silicon dioxide film is deposited, so that the mean free path of the TEOS molecules input into the reaction chamber through the hot box is increased, and they are fully excited and ionized, thereby increasing the plasma intensity in the reaction chamber and the expansion range of the plasma in the chamber, so that the plasma formed in the reaction chamber forms a uniformly distributed silicon dioxide film on the surface of the substrate, thereby improving the compactness of the silicon dioxide film and optimizing the thickness uniformity of the silicon dioxide film. Here, oxygen and TEOS are configured to be introduced into the reaction chamber, and the reaction chamber includes an exhaust port, which is used to control the pressure in the reaction chamber to always be within the preset pressure range.

[0045] In this embodiment, in the method for preparing the silicon dioxide film, the radio frequency power in the plasma enhanced chemical vapor deposition process is regulated to any value between 300W and 1200W, that is, by increasing the radio frequency power, the TEOS gas or TEOS liquid transported to the reaction chamber by the hot box obtains more energy to form plasma more fully, so as to improve the TEOS plasmaization efficiency in the reaction chamber of the deposition equipment using the hot box to supply the TEOS gas source, so that TEOS can react completely with oxygen, and the density and energy of the plasma are controlled, so as to regulate the deposition rate and stress state of the silicon dioxide film, so as to prepare a silicon dioxide film with the same stress as the original process conditions, which is convenient for the subsequent process of the silicon dioxide film to be uniformly processed. In addition, by controlling the radio frequency power within the above range, it is prevented that the radio frequency power is too large to cause stress accumulation and increase of surface roughness in the silicon dioxide film, thereby avoiding warping or cracking of the deposited silicon dioxide film and improving the product yield.

[0046] In a further embodiment, the first preset flux is any value in the range of 100sccm-1200sccm, and the second preset flux is any value in the range of 100sccm-1000sccm, that is, the first preset flux can be 100sccm, 200sccm, 300sccm, 400sccm, 500sccm, 600sccm, 700sccm, 800sccm, 900sccm or 1200sccm, or it can be any value in the range of 100sccm-1200sccm, and the second preset flux can be 100sccm, 200sccm, 300sccm, 400sccm, 500sccm, 600sccm, 700sccm, 800sccm, 900sccm or 1000sccm, or it can be any value in the range of 100sccm-1000sccm. In this embodiment, the flux of oxygen introduced into the reaction chamber is controlled to be a first preset flux, the flux of TEOS introduced into the reaction chamber by the hot box is controlled to be a second preset flux, and the ratio of the first preset flux to the second preset flux is any value in the range of 2.5-4.0, so as to ensure the continuity of the deposition of the silicon dioxide film and ensure that the TEOS in the reaction chamber can react completely with the oxygen to form a silicon dioxide film with uniform thickness and high quality.

[0047] In a further embodiment, the deposition temperature of the plasma enhanced chemical vapor deposition is any value in the range of 300° C.-400° C., that is, the deposition temperature can be 300° C., 310° C., 320° C., 330° C., 340° C., 350° C., 360° C., 370° C., 380° C., 390° C. or 300° C., or any value in the range of 300° C.-400° C. In this embodiment, since the plasma formed by the plasma enhanced chemical vapor deposition has high activity, a dense and uniform silicon dioxide film is generated at a relatively low temperature, which can significantly reduce the thermal stress between the silicon dioxide film and the substrate compared to the traditional high temperature deposition method, and is conducive to obtaining a higher quality silicon dioxide film.

[0048] In a further embodiment, the deposition rate of the plasma enhanced chemical vapor deposition is in the range of Any value of , that is, the deposition rate can be or It can also be In this embodiment, when the deposition rate of plasma enhanced chemical vapor deposition is within the above range, it can ensure the formation of a uniform and dense silicon dioxide film, prevent the occurrence of undercutting during subsequent wet etching, and at the same time, shorten the entire production cycle, improve production efficiency, and due to the reduction in production time, the corresponding energy consumption and labor costs will also be reduced, which is helpful to reduce the overall production cost.

[0049] Figure 2 A schematic overall flow chart of a method for preparing a silicon dioxide film according to an embodiment of the present invention is shown.

[0050] In a further embodiment, after step S300, the following steps are further included:

[0051] Step S400: evacuate the reaction chamber to make the pressure of the reaction chamber a vacuum pressure.

[0052] In this embodiment, after the deposition of the silicon dioxide film in the reaction chamber is completed, the RF power supply is turned off, and the reaction chamber is evacuated so that the pressure in the reaction chamber is in a vacuum state, so as to remove the residual gas in the reaction chamber and prevent the residual gas from remaining in the reaction chamber to contaminate the silicon dioxide film and affect its purity and performance, thereby avoiding the performance change of the film due to gas adsorption, desorption and other processes during subsequent processing or use. At the same time, the evacuated reaction chamber provides a clean and interference-free working environment for the subsequent silicon dioxide film processing steps, which helps to ensure the smooth progress of the subsequent process and the accuracy of the process parameters.

[0053] In a further embodiment, the vacuum pressure is any value in the range of 0.05 Torr-0.1 Torr, that is, the vacuum pressure can be 0.05 Torr, 0.06 Torr, 0.07 Torr, 0.08 Torr, 0.09 Torr or 0.1 Torr, or any value in the range of 0.05 Torr-0.1 Torr. In this embodiment, low vacuum pressure helps to increase the molecular mean free path, and the reactant molecules are more likely to obtain sufficient energy to participate in the plasma reaction, reducing the defects caused by unnecessary side reactions, thereby improving the density and uniformity of the silicon dioxide film. When the vacuum pressure is within the above range, various parameters in the reaction process, such as gas composition, can be better controlled to improve the stability and controllability of the deposition process. .

[0054] In a preferred embodiment, the ratio of the first preset flux to the second preset flux is any value in the range of 2.5-3.5, that is, the ratio of the first preset flux to the second preset flux in this embodiment can be 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4 or 3.5, or any value in the range of 2.5-3.5. In this embodiment, when the ratio of the flux of oxygen to the flux of TEOS is within the above range, that is, the ratio of the oxygen content in the reaction chamber to the TEOS content is any value in the range of 2.5-3.5, it can ensure that TEOS reacts completely with oxygen, and prevent excessive oxygen flux from causing waste of resources, thereby improving resource utilization.

[0055] In a preferred embodiment, the preset pressure is any value in the range of 5.2 Torr-7.2 Torr, that is, the preset pressure is 5.2 Torr, 5.6 Torr, 6.0 Torr, 6.4 Torr, 6.8 Torr or 7.2 Torr, and can also be any value in the range of 5.2 Torr-7.2 Torr. In this embodiment, when the preset pressure of plasma enhanced chemical vapor deposition is within the above range, the concentration of plasma in the reaction chamber can be increased, the deposition uniformity of the silicon dioxide film can be improved, and the silicon dioxide film can be prevented from being affected by the preset pressure being too large or too small.

[0056] The present application will be further described in detail below with reference to specific embodiments.

[0057] Example 1

[0058] First, 900 sccm of oxygen was introduced into the reaction chamber until the pressure in the reaction chamber reached 6.0 Torr. Then, 300 sccm of TEOS supplied by the hot box was introduced into the reaction chamber, and the pressure in the reaction chamber was maintained at 6.2 Torr. A silicon dioxide film was deposited using oxygen and TEOS as precursors using plasma enhanced chemical vapor deposition. The RF power of the plasma enhanced chemical vapor deposition was 600 W. After the deposition of the silicon dioxide film was completed, the RF power was turned off, and the reaction chamber was evacuated to a vacuum pressure of 0.05 Torr.

[0059] Comparative Example 1

[0060] The only difference between Comparative Example 1 and Example 1 is that the RF power is 800 W and the preset pressure is 8.0 Torr.

[0061] Comparative Example 2

[0062] The only difference between Comparative Example 2 and Example 1 is that the RF power is 500 W and the preset pressure is 8.2 Torr.

[0063] Comparative Example 3

[0064] The only difference between Comparative Example 3 and Example 1 is that the flux of oxygen is 1050 sccm.

[0065] Comparative Example 4

[0066] The only difference between Comparative Example 4 and Example 1 is that the oxygen flux is 1050 sccm, the RF power is 800 W, and the preset pressure is 8.0 Torr.

[0067] Comparative Example 5

[0068] The only difference between Comparative Example 5 and Example 1 is that the oxygen flux is 1050 sccm, the RF power is 500 W, and the preset pressure is 8.2 Torr.

[0069] Comparative Example 6

[0070] The only difference between Comparative Example 6 and Example 1 is that the flux of oxygen gas is 1200 sccm.

[0071] Comparative Example 7

[0072] The only difference between Comparative Example 7 and Example 1 is that the oxygen flux is 1200 sccm, the RF power is 800 W, and the preset pressure is 8.0 Torr.

[0073] Comparative Example 8

[0074] The only difference between Comparative Example 8 and Example 1 is that the oxygen flux is 1050 sccm, the RF power is 500 W, and the preset pressure is 8.2 Torr.

[0075] Comparative Example 9

[0076] The only difference between Comparative Example 9 and Example 1 is that the flux of oxygen is 750 sccm.

[0077] Comparative Example 10

[0078] The only difference between Comparative Example 10 and Example 1 is that the oxygen flux is 750 sccm, the RF power is 800 W, and the preset pressure is 8.0 Torr.

[0079] Comparative Example 11

[0080] The only difference between Comparative Example 11 and Example 1 is that the oxygen flux is 750 sccm, the RF power is 500 W, and the preset pressure is 8.2 Torr.

[0081] Comparative Example 12

[0082] The only difference between Comparative Example 12 and Example 1 is that the oxygen flux is 600 sccm, the RF power is 500 W, and the preset pressure is 8.2 Torr.

[0083] Comparative Example 13

[0084] The only difference between Comparative Example 13 and Example 1 is that the oxygen flux is 450 sccm, the RF power is 500 W, and the preset pressure is 8.2 Torr.

[0085] Comparative Example 14

[0086] The only difference between Comparative Example 14 and Example 1 is that the oxygen flux is 390 sccm, the RF power is 500 W, and the preset pressure is 8.2 Torr.

[0087] Among them, Comparative Example 14 is a silicon dioxide film prepared under the original process conditions of the deposition equipment, and has a film uniformity and stress that meet the standards of subsequent products.

[0088] First, scanning electron microscopy was performed on Example 1 and Comparative Examples 5, 8 and 11-14 to verify the corrosion resistance of the silicon dioxide film after wet etching. Figure 3 It is a scanning electron microscope image of the silicon dioxide thin film prepared in Example 1 and Comparative Example 5, Comparative Example 8 and Comparative Examples 11-14 of the present invention.

[0089] like Figure 3 As shown, when the flux ratio of oxygen to TEOS is in any value between 2.5 and 4.0, the prepared silicon dioxide film has good corrosion resistance, while when the flux ratio of oxygen to TEOS is less than 2.5, the corrosion resistance of the prepared silicon dioxide film is poor.

[0090] The uniformity and stress of the silicon dioxide films prepared in Example 1 and Comparative Examples 1-14 were further characterized. Figure 4 is a schematic diagram of thickness variation of silicon dioxide films prepared in Example 1 and Comparative Examples 1-14 of the present invention, Figure 5 Schematic diagram of stress variation of silicon dioxide films prepared in Example 1 and Comparative Examples 1-14 of the present invention.

[0091] like Figure 4 and Figure 5 As shown, the uniformity and stress of the silicon dioxide film prepared in Example 1 are the same as those of the silicon dioxide film prepared under the original process conditions, and can meet the requirements of subsequent products.

[0092] In summary, the silicon dioxide film prepared in Example 1 not only has a strong anti-drilling ability, but also meets the film uniformity and stress requirements of subsequent processes.

[0093] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0094] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing a silicon dioxide film for hot box supply of TEOS, characterized in that: The steps include: Passing a first preset flux of oxygen into the reaction chamber until the reaction chamber reaches a preset pressure; Passing a second preset flux of TEOS supplied by the hot box into the reaction chamber, and maintaining the pressure of the reaction chamber at the preset pressure; The oxygen and the TEOS are subjected to silicon dioxide film deposition by plasma enhanced chemical vapor deposition to prepare the silicon dioxide film, and the radio frequency power of the plasma enhanced chemical vapor deposition is any value in the range of 300W-1200W; wherein, The ratio of the first preset flux to the second preset flux is any value in the range of 2.5-4.0, and the preset pressure is any value in the range of 5.0 Torr-12.0 Torr.

2. The method for preparing a silicon dioxide thin film according to claim 1, characterized in that: The first preset flux is any value in the range of 100 sccm-1200 sccm, and the second preset flux is any value in the range of 100 sccm-1000 sccm.

3. The method for preparing a silicon dioxide thin film according to claim 2, characterized in that: The deposition temperature of the plasma enhanced chemical vapor deposition is any value in the range of 300° C. to 400° C.

4. The method for preparing a silicon dioxide thin film according to claim 3, characterized in that: The deposition rate of the plasma enhanced chemical vapor deposition is in the range of Any value in .

5. The method for preparing a silicon dioxide thin film according to claim 4, characterized in that: After the step of depositing a silicon dioxide film on the oxygen and the TEOS by plasma enhanced chemical vapor deposition, the following step is also included: The reaction chamber is evacuated to make the pressure of the reaction chamber a vacuum pressure.

6. The method for preparing a silicon dioxide thin film according to claim 5, characterized in that: The vacuum pressure is any value in the range of 0.05 Torr-0.1 Torr.

7. The method for preparing a silicon dioxide thin film according to any one of claims 1 to 6, characterized in that: The ratio of the first preset flux to the second preset flux is any value between 2.5 and 3.

5.

8. The method for preparing a silicon dioxide thin film according to claim 7, characterized in that: The preset pressure is any value in the range of 5.2 Torr-7.2 Torr.

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