Film formation method

Abstract

The embodiment of the present invention provides a method for forming a film layer, comprising: providing a substrate; performing a pretreatment step, wherein the pretreatment step comprises providing a reaction source gas, wherein the reaction source gas forms an attachment point on the substrate; and performing a deposition step, wherein the reaction source gas is plasmatized to form a plasma, wherein the plasma is deposited on the substrate based on the attachment point to form a first film layer. The embodiment of the present invention is conducive to forming more attachment points on the surface of the substrate, improving the deposition rate, rapidly depositing the film layer, and improving the step coverage of the film layer, thereby improving the quality of the film layer.

Description

Technical Field

[0001] The embodiments of the present invention relate to the semiconductor field, and in particular to a method for forming a film layer. Background Art

[0002] With the development of the semiconductor industry, the quality of semiconductor component manufacturing process is closely related to the deposition efficiency and film quality of the film deposition process. Therefore, the rate of film deposition and the step coverage of the film after deposition have become the key issues of the film deposition process.

[0003] In the existing film deposition process, the film is mostly deposited by using plasma reaction source gas reaction, and the deposition rate is low. The step coverage of the film after deposition is also low, which affects the quality of the film. Summary of the invention

[0004] The embodiment of the present invention provides a method for forming a film layer, which is conducive to forming more attachment points on the surface of the substrate, improving the deposition rate, quickly depositing the film layer, and improving the step coverage of the film layer, thereby improving the quality of the film layer.

[0005] To solve the above problems, an embodiment of the present invention provides a method for forming a film layer, which is characterized in that it includes: providing a substrate; performing a pretreatment step, the pretreatment step including providing a reaction source gas, the reaction source gas forming an attachment point on the substrate; performing a deposition step, plasmatizing the reaction source gas to form plasma, the plasma being deposited on the substrate based on the attachment point to form a first film layer.

[0006] In addition, the reaction source gas flow rate used in the pretreatment step is the same as the reaction source gas flow rate used in the deposition step.

[0007] In addition, the first film layer includes a titanium film layer, and the reaction source gas includes titanium tetrachloride and hydrogen.

[0008] In addition, the process time for providing the titanium tetrachloride in the pretreatment step is 2 to 10 seconds.

[0009] In addition, before the pretreatment step is performed, an oxide layer is formed on the substrate; before the pretreatment step is performed, the method further includes: a substrate surface treatment step to remove the oxide layer.

[0010] In addition, the substrate surface treatment step uses plasma ammonia, argon and hydrogen to react and remove the oxide layer.

[0011] In addition, in the substrate surface treatment step, the process parameters include: the ammonia flow rate is 1500-3500sccm, the argon flow rate is 1000-2000sccm, the hydrogen flow rate is 1000-3000sccm, the temperature of the reaction chamber is 450-650 degrees Celsius, and the power is 450-1200 watts.

[0012] In addition, before performing the substrate surface treatment step, a defective layer is formed on the substrate; before performing the substrate surface treatment step, it also includes: performing a pulse etching step, intermittently providing etching gas to the defective layer to remove the defective layer, and continuously providing inert gas to the defective layer to remove etching by-products.

[0013] In addition, the etching gas and the reaction source gas used to form the first film layer have the same element.

[0014] In addition, the etching gas is provided to the defective layer at intervals, the etching gas is provided for 0.1 to 40 seconds each time, and there is an interval of 0.1 to 5 seconds between two times of providing the etching gas.

[0015] In addition, the reaction chamber is evacuated between each two times of providing the etching gas to remove the etching byproducts, and the pressure during the evacuation is 0.1 to 1 Torr.

[0016] In addition, after forming the first film layer, the method further includes: a second deposition step of providing nitrogen source plasma to the first film layer to convert at least a portion of the first film layer into a second film layer containing nitrogen.

[0017] In addition, the pulse etching step, the substrate surface treatment step, the pretreatment step, the deposition step and the second deposition step are performed in the same reaction chamber.

[0018] Compared with the prior art, the technical solution provided by the embodiment of the present invention has the following advantages:

[0019] In the above technical scheme, by adding a pretreatment step before the deposition step, the provided reaction source gas forms a large number of attachment points on the substrate. In the subsequent deposition step, the plasmatized reaction source gas reacts. Since there are a large number of attachment points on the substrate, the rate of depositing the film layer is accelerated; and the attachment points are evenly distributed on the substrate, so the step coverage of the film layer is improved, thereby improving the quality of the film layer.

[0020] A defective layer is formed on the substrate before the substrate surface treatment step. By adopting the pulse etching method, the defective layer can be removed more gently, avoiding the risk of continuous and violent etching reaction causing part of the defective film layer to detach and the reaction chamber to be contaminated. The film layer can continue to be deposited after the pulse etching, preventing the wafer from being difficult to repair and directly scrapped after a machine abnormality occurs. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplifications do not constitute limitations on the embodiments. Unless otherwise stated, the pictures in the drawings do not constitute proportional limitations.

[0022] Figure 1 to Figure 6 A schematic structural diagram corresponding to each step in a method for forming a film layer provided in the first embodiment of the present invention;

[0023] Figure 7 A line graph comparing the effects of a pretreatment step in a method for forming a film layer provided in the first embodiment of the present invention;

[0024] Figure 8 A schematic structural diagram of a method for forming a film layer provided in a second embodiment of the present invention;

[0025] Fig. 9 A gas-time line graph provided for each step in a method for forming a film layer provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, it will be appreciated by those skilled in the art that in the embodiments of the present invention, many technical details are provided to enable the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical scheme claimed in the present application can be implemented.

[0027] Figure 1 to Figure 6 This is a schematic structural diagram corresponding to each step in a method for forming a film layer provided in the first embodiment of the present invention.

[0028] refer to Figure 4 and Figure 5 , a method for forming a film layer includes: providing a substrate 100; performing a pretreatment step, the pretreatment step includes providing a reaction source gas 105, the reaction source gas 105 forms an attachment point (not marked) on the substrate 100; performing a deposition step, plasmatizing the reaction source gas 105 to form a plasma 106, and the plasma 106 is deposited on the substrate 100 based on the attachment point to form a first film layer 107.

[0029] The material of the substrate 100 can be single crystal silicon, silicon on insulator (SOI), stacked silicon on insulator (SSOI), stacked silicon germanium on insulator (S-SiGeOI), silicon germanium on insulator (SiGeOI) and germanium on insulator (GeOI). In this embodiment, the substrate 100 is single crystal silicon.

[0030] refer to Figure 1 and Figure 2 In the first embodiment, a defective layer 101 is formed on the substrate 100. The defective layer 101 may be formed due to an abnormality in the film deposition process of the machine, resulting in poor quality of the deposited film, or partial oxidation on the surface of the film.

[0031] The defective layer 101 and the first film layer 107 (such as Figure 5 shown) have the same elements.

[0032] A pulse etching step is performed, wherein an etching gas 102 is intermittently provided to the defective layer 101 to remove the defective layer 101 , and an inert gas is continuously provided to the defective layer 101 to remove etching byproducts.

[0033] In this way, the pulse etching method can be used to remove the defective layer 101 more gently, avoiding the risk of continuous and violent etching reaction causing part of the defective film layer to fall off and contaminating the reaction chamber. The film layer can continue to be deposited after the pulse etching, preventing the wafer from being difficult to repair and directly scrapped after a machine abnormality occurs.

[0034] In the first embodiment, the defect layer 101 may be a titanium oxide layer.

[0035] In the first embodiment of the present invention, the etching gas 102 has the same element as the reaction source gas 105 for forming the first film layer 107. In this way, it is possible to reduce the introduction of redundant elements into the reaction chamber and reduce the impact on subsequent reactions; at the same time, the etching gas 102 is a type of the reaction source gas 105, and no new gas needs to be provided, which facilitates the pulse etching step, so that the defective layer 101 can be quickly etched after the defective layer 101 is formed, and the above steps can be performed in the same chamber.

[0036] In this embodiment, the etching gas 102 includes titanium tetrachloride, and the inert gas may be argon. Titanium tetrachloride gas will react violently with the titanium oxide layer. The pulse etching method can prevent the titanium tetrachloride from reacting too violently with titanium, causing partial film shedding and contamination of the chamber.

[0037] Specifically, the process parameters of the pulse etching step include: a titanium tetrachloride flow rate of 1 to 50 sccm (standard cubic centimeter per minute), specifically 10 sccm, 20 sccm, 30 sccm or 40 sccm; an argon flow rate of 1000 sccm to 2000 sccm, specifically 1300 sccm, 1500 sccm or 1800 sccm; a reaction chamber temperature of 400 to 710 degrees Celsius, specifically 500 degrees Celsius, 600 degrees Celsius or 700 degrees Celsius; a reaction chamber pressure of 1 to 20 Torr, specifically 5 Torr, 10 Torr or 15 Torr; and a pulsed etching gas 102 is provided 100 to 400 times, specifically 200 times, 250 times or 300 times.

[0038] In one embodiment, the etching gas 102 is provided to the defective layer 101 at intervals, and the time for each provision of the etching gas 102 is 0.1 to 40 seconds, specifically 10 seconds, 20 seconds or 30 seconds. The interval between each two provision of the etching gas 102 is 0.1 to 5 seconds, specifically 2 seconds, 3 seconds or 4 seconds.

[0039] When the etching gas 102 reacts with the defective layer 101, etching by-products will be generated. The etching by-products will contaminate the reaction chamber and affect the reaction conducted in the reaction chamber. Therefore, in this embodiment, inert gas is continuously provided to the defective layer 101 to remove the etching by-products and ensure the cleanliness of the reaction chamber.

[0040] In other embodiments, the reaction chamber is evacuated between each two times of providing etching gas to remove etching byproducts, thereby ensuring the cleanliness of the reaction chamber.

[0041] In one example, between each two times of providing etching gas, no inert gas is provided, but the reaction chamber is evacuated to remove etching byproducts.

[0042] Specifically, the chamber pressure during vacuuming is 0.1 to 1 Torr, specifically 0.4 Torr, 0.6 Torr or 0.8 Torr. Under this pressure, the etching byproducts in the chamber can be completely pumped away, thereby ensuring the cleanliness of the reaction chamber.

[0043] refer to Figure 3After the defective layer 101 is removed by etching, a titanium silicon layer (not shown in the figure) is exposed. The titanium silicon layer is generated by the reaction between the substrate 100 and the defective layer 101. The titanium silicon layer is easily oxidized in the air to generate an interface native oxide layer 103. The presence of the oxide layer 103 increases the surface contact resistance between the first film layer 107 and the substrate 100, affecting the product yield. In this embodiment, before depositing the first film layer 107, a substrate surface treatment step 104 is performed to remove the oxide layer 103.

[0044] The oxide layer 103 includes silicon oxide.

[0045] Specifically, the oxide layer 103 is silicon dioxide, and the substrate surface treatment step 104 uses plasma ammonia, argon and hydrogen to react to remove the oxide layer 103, and the specific reactions are NH3+H2+Ar-plasma->NHx+H+Ar and NHx+H+SiO2->Si+N2+H2+H2O.

[0046] The substrate surface treatment step 104 not only utilizes ammonia, argon and hydrogen plasma to reduce a portion of the oxide to remove the oxide layer 103, but also utilizes the bombardment effect of the plasma state itself to remove a portion of the oxide and some impurities. In this way, not only the oxide layer 103 irrelevant to the first film layer 107 deposited subsequently is removed, the contact resistance between the first film layer 107 and the substrate 100 is reduced, and the contact resistance is prevented from being too high, thereby causing the first film layer 107 and the substrate 100 to be disconnected, but also the uniformity of the surface of the first film layer 107 formed by subsequent deposition is improved.

[0047] In this embodiment, ammonia, argon and hydrogen are directly introduced into the deposition chamber to treat the surface of the substrate 100. This can further prevent the wafer from coming into contact with the atmospheric environment when performing the substrate surface treatment step 104 outside the machine, thereby improving the quality of the contact interface between the film layer and the substrate 100 and improving the product yield.

[0048] Specifically, in the substrate surface treatment step 104, the process parameters include: an ammonia flow rate of 1500 to 3500 sccm, specifically 2000 sccm, 2500 sccm or 3000 sccm; an argon flow rate of 1000 to 2000 sccm, specifically 1300 sccm, 1500 sccm or 1800 sccm; a hydrogen flow rate of 1000 to 3000 sccm, specifically 1500 sccm, 2000 sccm or 2500 sccm; a reaction chamber temperature of 450 to 650 degrees Celsius, specifically 500 degrees Celsius, 550 degrees Celsius or 600 degrees Celsius; a power of 450 to 1200 watts, specifically 600 watts, 800 watts or 1000 watts.

[0049] refer to Figure 4 In the first embodiment of the present invention, a pre-treatment step is performed after the substrate surface treatment step 104 to provide a reaction source gas 105 to form an attachment point on the substrate 100. Figure 7 , at the same optimal reaction temperature and the same reaction time, the thickness of the film layer deposited after the pretreatment step 104 is much greater than the thickness of the film layer deposited by plasma. In this way, there are a large number of attachment points on the substrate 100, which can be specifically nucleation sites. When the next deposition step is performed based on the nucleation sites, the deposition rate of the first film layer 107 can be accelerated; and the attachment points are evenly distributed on the substrate 100, which improves the step coverage of the first film layer 107, thereby improving the quality of the first film layer 107.

[0050] Specifically, the process time for providing titanium tetrachloride in the pretreatment step is 2 to 10 seconds, specifically 4 seconds, 6 seconds or 8 seconds. In this way, controlling the process time for providing titanium tetrachloride in the pretreatment step can effectively save process costs while ensuring the effect of the pretreatment step.

[0051] Before providing titanium tetrachloride, argon and hydrogen are introduced for 5 to 20 seconds, specifically 8 seconds, 12 seconds or 16 seconds. In this way, the reaction chamber can be cleaned so that there is no impurity gas in the pretreatment step, providing suitable reaction chamber conditions for the reaction of forming attachment points.

[0052] In the pretreatment step of this embodiment, the reaction source gas 105 includes titanium tetrachloride and hydrogen. By pretreating the surface of the substrate 100 with titanium tetrachloride, titanium attachment points can be formed on the surface of the substrate 100, which can increase the rate of subsequent film deposition and improve the step coverage of the film layer, thereby obtaining a high-quality film layer.

[0053] In one example, the flow rate of titanium tetrachloride is 1-50 sccm, specifically 20 sccm, 30 sccm or 40 sccm; the flow rate of hydrogen is 1000-3000 sccm, specifically 1500 sccm, 2000 sccm or 2500 sccm.

[0054] In another example, the reaction source gas 105 further includes an inert gas, and the inert gas is provided as a carrier gas. The inert gas includes argon gas, and the flow rate of the argon gas is 1000-2000 sccm, specifically 1200 sccm, 1400 sccm or 1600 sccm.

[0055] refer to Figure 5In the deposition step of the first embodiment of the present invention, the reaction source gas 105 is plasmatized to form a plasma 106, and the plasma 106 is deposited on the substrate 100 based on the attachment point to form a first film layer 107. In this way, the plasma 106 has a more active chemical property and can accelerate the reaction rate, so that the reaction rate of the deposition step is greater than the reaction rate of the pretreatment step, thereby improving the deposition rate.

[0056] The first film layer 107 includes a titanium film layer. In the deposition step, titanium chloride gaseous compound and hydrogen react to form the titanium film layer.

[0057] Specifically, the process parameters of the deposition step include: the pressure of the reaction chamber is 1 to 20 Torr, specifically 5 Torr, 10 Torr or 15 Torr; the temperature of the reaction chamber is 450 to 650 degrees Celsius, specifically 500 degrees Celsius, 550 degrees Celsius or 600 degrees Celsius; the RF power is 450 to 1200 watts, specifically 600 watts, 800 watts or 1000 watts.

[0058] In the first embodiment of the present invention, the flow rate of the reaction source gas 105 used in the pretreatment step is the same as the flow rate of the reaction source gas 105 used in the deposition step. In this way, the process difficulty can be simplified, and the flow rate of the reaction source gas 105 does not need to be changed between the pretreatment step and the deposition step, which is easy to operate.

[0059] In the first embodiment of the present invention, the pretreatment step and the deposition step are performed in the same reaction chamber. Thus, in the process of forming the first film layer 107, the operation steps are simplified, the process is more convenient, and the amount of contamination in the reaction chamber is reduced.

[0060] Furthermore, in the pretreatment step and the deposition step, the pressure of the reaction chamber is the same, and the temperature of the reaction chamber is the same. Thus, in the reaction chamber, between the pretreatment step and the deposition step, only the RF power of the reaction chamber needs to be changed, making the entire process easy to operate.

[0061] refer to Figure 6 In the first embodiment of the present invention, after forming the first film layer 107, a second deposition step is further included to provide nitrogen source plasma 108 to the first film layer 107 to convert at least part of the first film layer 107 into a second film layer 109 containing nitrogen.

[0062] The nitrogen source plasma 108 includes nitrogen plasma, and the second film layer 109 may be titanium nitride.

[0063] Specifically, the process parameters of the second deposition step include: an ammonia flow rate of 1500 to 3500 sccm, specifically 2000 sccm, 2500 sccm or 3000 sccm; a temperature of the reaction chamber of 450 to 650 degrees Celsius, specifically 500 degrees Celsius, 550 degrees Celsius or 600 degrees Celsius; and a RF power of 450 to 1200 watts, specifically 600 watts, 800 watts or 1000 watts.

[0064] In the first embodiment of the present invention, the pulse etching step, the substrate surface treatment step, the pretreatment step, the deposition step and the second deposition step are performed in the same reaction chamber. In this way, in the process of processing the defective layer 101 and continuing to form a new film layer, all reactions are performed in the same reaction chamber, and there is no need to replace the reaction chamber. The entire process operation can be performed more conveniently, which is conducive to rapid remediation after the film layer is damaged and reduces losses; all reactions are performed in the same reaction chamber to prevent the film layer from contacting the atmosphere and generate a thicker defective layer 101. In this embodiment, a PECVD (Plasma Enhanced Chemical Vapor Deposition) machine chamber can be used to perform the above reaction to obtain the second film layer 109.

[0065] The first embodiment of the present invention provides a method for forming a film layer. In the case of forming a defective layer on a substrate, a pulse etching method is used to remove the defective layer more gently, thereby avoiding the risk of continuous and violent etching reaction causing part of the defective film layer to fall off and the risk of contaminating the reaction chamber. The film layer can continue to be deposited after the pulse etching, thereby preventing the problem that the wafer is difficult to repair and is directly scrapped after a machine abnormality occurs. After etching and removing the defective layer, a substrate surface treatment step is performed to remove the interface native oxide layer. The substrate surface treatment step not only removes the interface native oxide layer that is not related to the subsequently deposited first film layer, but also reduces the contact resistance between the first film layer and the substrate, thereby preventing the contact resistance from being excessive. High, thereby causing the first film layer to be disconnected from the substrate, and also improving the uniformity of the surface of the first film layer formed by subsequent deposition; by adding a pretreatment step stage before the deposition step, the provided reaction source gas forms a large number of attachment points on the substrate, which can be specifically nucleation sites. In the subsequent deposition step, the plasmatized reaction source gas reacts. Since there are a large number of nucleation sites on the substrate, the deposition step is performed on the basis of the nucleation sites, which speeds up the deposition rate of the film layer; and the attachment points are evenly distributed on the substrate, so the step coverage of the film layer is improved, thereby improving the quality of the film layer. The film layer formation method of this embodiment is suitable for forming a bit line contact layer or a capacitor contact layer.

[0066] Figure 8 A schematic structural diagram of a method for forming a film layer provided in the second embodiment of the present invention.

[0067] refer to Figure 8 In the second embodiment of the present invention, due to the abnormality of the machine, the process of depositing the first film layer 107 or the second film layer 109 is forced to be suspended. Due to the high temperature of the reaction chamber, the deposited first film layer 107 or the second film layer 109 is oxidized to form a defective layer 101. The defective layer 101 has the same elements as the first film layer 107. At this time, the wafer can be repaired in the order of pulse etching step, substrate surface treatment step, pretreatment step, deposition step and second deposition step. In this way, the problem of the wafer being difficult to repair and directly scrapped after the machine abnormality occurs is prevented.

[0068] Fig. 9 A gas-time line graph provided for each step in a method for forming a film layer provided in an embodiment of the present invention.

[0069] refer to Fig. 9 In the embodiment of the present invention, in the process of processing the defective layer 101 formed due to the abnormality of the machine and continuing to form a new film layer, the time point of providing different gases in each stage is specifically explained.

[0070] When the machine is abnormal, a defective layer 101 is formed, and a pulse etching step S1 is started, titanium tetrachloride gas is introduced at intervals, and argon gas is introduced between two introductions of titanium tetrachloride gas; after the pulse etching step S1 is completely completed, the substrate surface treatment step S2 is started, and argon gas, ammonia gas and hydrogen gas are continuously introduced until the substrate surface treatment step S2 is completed; in the pretreatment step stage S3, argon gas and hydrogen gas are introduced, and then titanium tetrachloride gas is introduced until the deposition step S4 is completed, and the introduction of titanium tetrachloride gas is stopped, and argon gas and hydrogen gas are continuously introduced; in the gas exchange step S5, the flow rate of the continuously introduced argon gas and hydrogen gas is reduced, and ammonia gas is partially introduced after the gas exchange step S5, and the second deposition step S6 is entered; argon gas, ammonia gas and hydrogen gas are continuously introduced throughout the second deposition step S6, until the second deposition step S6 is completed, and the introduction of ammonia gas is stopped, and argon gas and hydrogen gas are still continuously introduced, and the cleaning step S7 is entered; in the cleaning step S7, argon gas and ammonia gas are introduced.

[0071] The second embodiment of the present invention provides a method for forming a film layer. In the event that a machine abnormality occurs during deposition of the film layer and the film layer is destroyed to form a defective layer, the wafer is repaired in the order of a pulse etching step, a substrate surface treatment step, a pretreatment step, a deposition step, and a second deposition step. This prevents the wafer from being difficult to repair and being directly scrapped after the machine abnormality occurs.

[0072] Those skilled in the art will appreciate that the above embodiments are specific examples of the present invention, and in practical applications, various changes may be made to the embodiments in form and detail without departing from the spirit and scope of the present invention. Any person skilled in the art may make changes and modifications without departing from the spirit and scope of the present invention, and therefore the scope of protection of the present invention shall be subject to the scope defined in the claims.

Claims

1. A method for forming a film layer, characterized in that: include: providing a substrate, on which a defective layer is formed; Performing a pulse etching step, intermittently supplying etching gas to the defective layer to remove the defective layer, and continuously supplying an inert gas to the defective layer to remove etching byproducts; After removing the defective layer, an oxide layer is formed on the substrate, and a substrate surface treatment step is performed to remove the oxide layer; performing a pretreatment step, the pretreatment step comprising providing a reactive source gas, the reactive source gas forming an attachment point on the substrate; Performing a deposition step, plasmatizing the reaction source gas to form plasma, wherein the plasma is deposited on the substrate based on the attachment point to form a first film layer; The etching gas and the reaction source gas used to form the first film layer have the same element, and the etching gas includes titanium tetrachloride.

2. The method for forming a film layer according to claim 1, characterized in that: The reaction source gas flow rate used in the pretreatment step is the same as the reaction source gas flow rate used in the deposition step.

3. The method for forming a film layer according to claim 1, characterized in that: The first film layer includes a titanium film layer, and the reaction source gas includes titanium tetrachloride and hydrogen.

4. The method for forming a film layer according to claim 3, characterized in that: The process time for providing the titanium tetrachloride in the pretreatment step is 2 to 10 seconds.

5. The method for forming a film layer according to claim 1, characterized in that: The substrate surface treatment step uses plasma ammonia, argon and hydrogen to react and remove the oxide layer.

6. The method for forming a film layer according to claim 5, characterized in that: In the substrate surface treatment step, the process parameters include: the ammonia flow rate is 1500~3500sccm, the argon flow rate is 1000~2000sccm, the hydrogen flow rate is 1000~3000sccm, the temperature of the reaction chamber is 450~650 degrees Celsius, and the power is 450~1200 watts.

7. The method for forming a film layer according to claim 1, characterized in that: The etching gas is provided to the defective layer at intervals, the etching gas is provided for 0.1 to 40 seconds each time, and there is an interval of 0.1 to 5 seconds between two times of providing the etching gas.

8. The method for forming a film layer according to claim 1, characterized in that: The reaction chamber is evacuated between each two times the etching gas is provided to remove the etching byproducts, and the pressure during the evacuation is 0.1-1 Torr.

9. The method for forming a film layer according to claim 1, characterized in that: After forming the first film layer, the method further includes: a second deposition step of providing nitrogen source plasma to the first film layer to convert at least a portion of the first film layer into a second film layer containing nitrogen.

10. The method for forming a film layer according to claim 9, characterized in that: The pulse etching step, the substrate surface treatment step, the pretreatment step, the deposition step and the second deposition step are performed in the same reaction chamber.

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