Epitaxial growth method, size compensation method, and method of forming mask pattern

Abstract

The application discloses a selective epitaxial growth method, a mask pattern size compensation method and a mask pattern forming method, and belongs to the technical field of semiconductor processing. The selective epitaxial growth method comprises the following steps: conveying a first gas into a process chamber, so that the first gas is adsorbed on the surface of a substrate; the substrate is provided with a groove; the first gas forms a first molecular layer on the top surface of the substrate, the bottom surface and the sidewall of the groove; the top surface and the bottom surface are struck by a first plasma, so that the first molecular layer on the top surface and the bottom surface is removed; a third gas is conveyed into the process chamber, so that the third gas is adsorbed on the top surface, the bottom surface and the sidewall; a second molecular layer is formed on the top surface, the bottom surface and the sidewall; and the remaining first molecular layer and the second molecular layer react to generate a target film layer on the sidewall; and the top surface and the bottom surface are struck by a second plasma, so that the second molecular layer on the top surface and the bottom surface is removed.

Description

Technical Field

[0001] This application belongs to the field of semiconductor processing technology, specifically relating to a selective epitaxial growth method, a mask pattern size compensation method, and a method for forming a mask pattern. Background Technology

[0002] In semiconductor processing, atomic force deposition (ALD) is often used to prepare film structures of specific thicknesses. ALD can not only precisely control the thickness of the film, but also enable gas molecules to achieve good step coverage on uneven substrate surfaces. That is, by utilizing the self-limiting properties of gas molecules, gas molecules can spontaneously adsorb onto the substrate surface.

[0003] However, since gas molecules can be adsorbed on all surfaces of the substrate, meaning the thin film will be deposited on all surfaces of the substrate except the bottom surface, the ALD process cannot achieve the purpose of regional selective deposition of thin films, which limits the application of this semiconductor processing method to some extent.

[0004] In summary, the semiconductor processing methods involved in the relevant technologies have the problem that they cannot achieve regional selective deposition of thin films on the substrate surface. Summary of the Invention

[0005] This application discloses a selective epitaxial growth method, a mask pattern size compensation method, and a method for forming a mask pattern, in order to solve the problem that the semiconductor processing methods involved in the related technologies cannot achieve regional selective deposition of thin films on the substrate surface.

[0006] To solve the above-mentioned technical problems, this application adopts the following technical solution:

[0007] A selective epitaxial growth method, comprising:

[0008] A first gas is delivered into the process chamber so that the first gas is adsorbed on the surface of the substrate, and a groove is formed on the substrate. The first gas forms a first molecular layer on the top surface of the substrate, the bottom surface of the groove, and the sidewalls.

[0009] The top and bottom surfaces are bombarded with a first plasma to remove the first molecular layer from the top and bottom surfaces;

[0010] A third gas is delivered into the process chamber so that the third gas is adsorbed on the top surface, the bottom surface and the sidewall, so that a second molecular layer is formed on the top surface, the bottom surface and the sidewall, and the remaining first molecular layer and the second molecular layer react to generate a target film layer on the sidewall.

[0011] The top and bottom surfaces are bombarded with a second plasma to remove the second molecular layer from the top and bottom surfaces.

[0012] A method for compensating the size of a mask pattern includes:

[0013] Obtain the spacing between the mask patterns;

[0014] If the spacing is greater than a preset distance value, the selective epitaxial growth method described above is performed to generate the target film layer on the sidewall of the mask pattern where the spacing is greater than the preset distance value.

[0015] A method for forming a mask pattern includes:

[0016] At least one mandrel is formed on the substrate;

[0017] Perform the selective epitaxial growth method described above to generate the target film on the sidewalls of each of the mandrels;

[0018] Remove the mandrel to form the mask pattern.

[0019] The technical solution adopted in this application can achieve the following beneficial effects:

[0020] In this application, the first gas can spontaneously adsorb onto the surface of the substrate, i.e., onto the top surface, bottom surface, and sidewalls of the trench, to form a first molecular layer on the top, bottom, and sidewalls. The first plasma in the process chamber can bombard the top and bottom surfaces, i.e., exert a force on the first molecular layer on the top and bottom surfaces to remove the first molecular layer on the top and bottom surfaces. The third gas can also spontaneously adsorb onto the top, bottom, and sidewalls to form a second molecular layer on the top, bottom, and sidewalls. The remaining first and second molecular layers react to generate the target film layer on the sidewalls. The second plasma in the process chamber can bombard the top and bottom surfaces, i.e., exert a force on the second molecular layer on the top and bottom surfaces to remove the second molecular layer on the top and bottom surfaces. Thus, the purpose of selectively depositing the target film layer only on the sidewalls of the trench can be achieved. That is, the selective epitaxial growth method disclosed in this application can achieve the purpose of regionally selectively depositing thin films on the surface of the substrate. Therefore, the selective epitaxial growth method disclosed in this application can solve the problem that the semiconductor processing methods involved in the related technologies cannot achieve regional selective deposition of thin films on the substrate surface. Attached Figure Description

[0021] Figure 1 and Figure 2 This is a schematic flowchart of the selective epitaxial growth method disclosed in the embodiments of this application;

[0022] Figures 3 to 10This is a schematic diagram illustrating the process of processing the substrate as disclosed in an embodiment of this application;

[0023] Figures 11 to 14 This is a schematic diagram illustrating the process of forming a mask pattern on a substrate as disclosed in an embodiment of this application.

[0024] Figure 15 This is a schematic flowchart of the mask pattern size compensation method disclosed in the embodiments of this application;

[0025] Figure 16 This is a flowchart illustrating the method for forming a mask pattern disclosed in an embodiment of this application.

[0026] Explanation of reference numerals in the attached figures:

[0027] 100-Substrate, 110-Bottom surface, 120-Sidewall, 130-Top surface, 140-Silica hard mask, 150-Organic dielectric layer, 160-Polycrystalline silicon, 170-Silicon oxide, 180-Silicon substrate, 190-Photoresist;

[0028] 200 - Target film layer, 210 - First molecular layer, 220 - Second molecular layer;

[0029] 300-Plasma;

[0030] 400-mandrel. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0032] The selective epitaxial growth method disclosed in this application will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios.

[0033] Please refer to Figures 1-16 This application discloses a selective epitaxial growth method, which includes:

[0034] S200: A first gas is supplied to the process chamber so that the first gas is adsorbed onto the surface of the substrate 100. Grooves are formed on the substrate 100. The first gas forms a first molecular layer 210 on the top surface 130 of the substrate 100, the bottom surface 110 of the groove, and the sidewall 120. The first molecular layer 210 is a monolayer.

[0035] The process chamber is a reaction chamber where the reaction takes place, and the substrate 100 is a semiconductor component, such as a wafer, used for processing. For details, please refer to... Figure 3 The surface of the substrate 100 is generally uneven, i.e., grooves are formed on the substrate 100. In this application, a first gas is delivered to the process chamber through an inlet pipe that connects the process chamber to the outside. The first gas can be, for example, a gas that does not readily react with the substrate 100, such as SiH4 and trimethylaluminum.

[0036] For details, please refer to Figure 4 The first gas can spontaneously adsorb onto the surface of the substrate 100. Even if the surface of the substrate 100 is uneven, the first gas can still achieve good step coverage, meaning that the first gas can be uniformly adsorbed onto the surface of the substrate 100 except for the bottom surface. Specifically, this can be the top surface 130 of the substrate 100, the bottom surface 110 of the trench, and the sidewall 120. The first gas adsorbed on the top surface 130, the bottom surface 110, and the sidewall 120 eventually forms a first molecular layer 210 on all three surfaces. The top surface 130 intersects with the sidewall 120, and the bottom surface 110 also intersects with the sidewall 120. All three surfaces can be planar or curved.

[0037] S300, the top surface 130 and the bottom surface 110 are bombarded with the first plasma 310 to remove the first molecular layer 210 on the top surface 130 and the bottom surface 110.

[0038] For details, please refer to Figure 5 and Figure 6 This application can use the first plasma 310 formed in the process chamber to bombard the top surface 130 and the bottom surface 110 to remove the first molecular layer 210 on the top surface 130 and the bottom surface 110, that is, to remove the first molecular layer 210 adsorbed on the top surface 130 and the bottom surface 110, while retaining the first molecular layer 210 on the sidewall 120, so as to achieve the purpose of regional selective adsorption of the first molecular layer 210.

[0039] Optionally, the process chamber is equipped with a vacuum system, which can remove the remaining unadsorbed first gas on the top surface 130, bottom surface 110 and side wall 120, as well as the first molecular layer 210 bombarded by the first plasma 310, so as to provide a good chamber environment for the next process.

[0040] In other embodiments, the first plasma 310 can also be used to bombard the sidewall 120, i.e., the bombardment direction of the first plasma 310 can be controlled to remove the first molecular layer 210 on the sidewall 120, i.e., to remove the first molecular layer 210 adsorbed on the sidewall 120, while retaining the first molecular layer 210 on the top surface 130 and the bottom surface 110, thereby achieving the purpose of regional selective adsorption of the first molecular layer 210. Therefore, by controlling the bombardment direction of the first plasma 310, the purpose of selectively depositing thin films on different surfaces of the substrate 100 can be achieved.

[0041] S400: A third gas is supplied to the process chamber, causing it to adsorb onto the top surface 130, bottom surface 110, and sidewall 120, forming a second molecular layer 220 on all three surfaces. The remaining first molecular layer 210 reacts with the second molecular layer 220 to generate a target film layer 200 on the sidewall 120. The second molecular layer 220 is a monolayer. Through the above steps, a target film layer 200 of one monolayer thickness can be selectively generated on the sidewall 120 of the trench.

[0042] Please refer to Figure 7 and Figure 8 A third gas can be delivered into the process chamber through an inlet pipe that connects the process chamber to the outside. The third gas can be, for example, N2, CO2, or water vapor, which are gases that do not readily react with the substrate 100.

[0043] The third gas can spontaneously adsorb onto the top surface 130, bottom surface 110 and sidewall 120 of the substrate 100. The third gas can also achieve a good step coverage rate, that is, the third gas can also be uniformly adsorbed onto the top surface 130, bottom surface 110 and sidewall 120. The third gas adsorbed on the top surface 130, bottom surface 110 and sidewall 120 eventually forms a second molecular layer 220 on the top surface 130, bottom surface 110 and sidewall 120.

[0044] Since the first plasma 310 bombards the first molecular layer 210 on the top surface 130 and the bottom surface 110, the second molecular layer 220 on the top surface 130 and the bottom surface 110 is in direct contact with the top surface 130 and the bottom surface 110. The second molecular layer 220 on the sidewall 120 is stacked on the first molecular layer 210 on the sidewall 120 so that the first molecular layer 210 and the second molecular layer 220 come into contact and react to generate the target film layer 200, that is, the target film layer 200 is selectively deposited on the sidewall 120.

[0045] Specifically, when the first gas is SiH4 gas and the third gas is N2, the target film 200 is SiN. x:H thin film; when the first gas is SiH4 gas and the third gas is CO2, the target film layer 200 is a SiO2 thin film; when the first gas is trimethylaluminum gas and the third gas is water vapor, the target film layer 200 is an Al2O3 thin film. Of course, the embodiments of this application do not specifically limit the types of the first and third gases.

[0046] Optionally, after step S300 and before step S400, in order to avoid affecting the formation of the second molecular layer 220, that is, to ensure that the third gas can be easily adsorbed on the bottom surface 110 and the side wall 120, this application needs to stop generating the first plasma 310 to prevent the first plasma 310 from affecting the third gas, thereby avoiding the phenomenon that the third gas is not easily adsorbed on the top surface 130, the bottom surface 110 and the side wall 120.

[0047] S500, the top surface 130 and the bottom surface 110 are bombarded with the second plasma 320 to remove the second molecular layer 220 on the top surface 130 and the bottom surface 110.

[0048] Please refer to Figure 9 and Figure 10 This application can use a second plasma 320 to bombard the surface of the substrate 100 to remove the second molecular layer 220 that has not reacted with the first molecular layer 210. Specifically, the second plasma 320 is used to bombard the top surface 130 and the bottom surface 110 to remove the second molecular layer 220 on the top surface 130 and the bottom surface 110, so that no molecular layer is adsorbed on the top surface 130 and the bottom surface 110, and the target film layer 200 is grown on the sidewall 120, so that the obtained substrate 100 meets the usage requirements.

[0049] Optionally, after removing the second molecular layer 220 from the top surface 130 and the bottom surface 110, the remaining third gas not adsorbed on the top surface 130, the bottom surface 110 and the sidewall 120, as well as the second molecular layer 220 bombarded by the second plasma 320, can be discharged again through the vacuum system to provide a good chamber environment for the next process.

[0050] In this application, the first gas can spontaneously adsorb onto the surface of the substrate 100, specifically onto the top surface 130, the bottom surface 110, and the sidewall 120 of the substrate 100, to form a first molecular layer 210 on the top surface 130, the bottom surface 110, and the sidewall 120. The first plasma 310 within the process chamber can bombard the top surface 130 and the bottom surface 110, thereby exerting a force on the first molecular layer 210 on the top surface 130 and the bottom surface 110 to remove it. The third gas can also spontaneously adsorb onto the top surface 130, the bottom surface 110, and the sidewall 120 to form a first molecular layer 210 on the top surface 130 and the bottom surface 110. A second molecular layer 220 is formed on the sidewall 120. The remaining first molecular layer 210 and second molecular layer 220 react to generate a target film layer 200 on the sidewall 120. The second plasma 320 in the process chamber can bombard the top surface 130 and the bottom surface 110, thereby exerting a force on the second molecular layer 220 on the top surface 130 and the bottom surface 110 to remove the second molecular layer 220 from the top surface 130 and the bottom surface 110. This achieves the purpose of selectively depositing the target film layer only on the sidewall 120 of the trench. That is, the selective epitaxial growth method disclosed in this application can achieve the purpose of regional selective deposition of thin films on the surface of the substrate 100. Therefore, the selective epitaxial growth disclosed in this application can solve the problem that the semiconductor processing methods involved in the related technology cannot achieve regional selective deposition of thin films on the surface of the substrate 100.

[0051] Optionally, the top surface 130 and the bottom surface 110 can be horizontal surfaces in the upper surface of the base 100, that is, the top surface 130 is the horizontal surface at the top of the base 100, and the bottom surface 110 is the horizontal surface in the trench wall, and the extension direction of the top surface 130 is parallel to the extension direction of the bottom surface 110. The side wall 120 can be a vertical surface in the trench wall. Of course, since the base 100 has a side surface, the side wall 120 can also be a vertical surface in the side surface of the base 100.

[0052] In one embodiment, this application may not remove the residual first plasma 310 and second plasma 320 on the bottom surface 110 or sidewall 120.

[0053] In another embodiment, the selective epitaxial growth method further includes:

[0054] S600, heat the substrate 100 to remove the first plasma 310 and the second plasma 320 remaining on the surface of the substrate 100.

[0055] Specifically, in order to avoid the residual first plasma 310 and second plasma 320 on the surface of the substrate 100, namely the top surface 130, the bottom surface 110 and the sidewall 120, affecting the subsequent processing of the substrate 100, this application needs to remove the residual first plasma 310 and second plasma 320 on the top surface 130, the bottom surface 110 and the sidewall 120 to clean the surface of the substrate 100. Specifically, this can be done by heating the substrate 100. This method of removing the residual first plasma 310 and second plasma 320 on the top surface 130, the bottom surface 110 and the sidewall 120 by heating has the advantages of simple operation and easy implementation.

[0056] Optionally, the selective epitaxial growth method further includes:

[0057] S700, Obtain the total film thickness of the target film layer 200.

[0058] Specifically, this application can obtain the total film thickness value of the target film layer 200. If the total film thickness value is equal to the preset film thickness value, it indicates that the total film thickness value of the target film layer 200 has met the process requirements, and the substrate 100 has been processed. It should be noted that the total film thickness value here refers to the thickness value of each target film layer 200 after being superimposed when the target film layer 200 formed by the first molecular layer 210 and the second molecular layer 220 consists of at least two layers.

[0059] S800: Determine whether the total thickness of the target film layer 200 has reached the preset film thickness value. If the preset film thickness value has not been reached, return to step S200. If the preset film thickness value has been reached, execute step S900 as described below.

[0060] Specifically, if the total film thickness is less than the preset film thickness, it means that the total film thickness of the target film layer 200 does not meet the process requirements, and the substrate 100 needs to be further processed. At this time, step S200 can be entered to cyclically generate the target film layer 200. Each time the cycle is executed, the thickness of the target film layer 200 increases by the thickness of one monolayer. That is, the total film thickness of the target film layer 200 is increased by cyclically generating the target film layer 200, so as to achieve precise control of the film thickness of the target film layer 200 and thus meet the requirements of subsequent processes.

[0061] Optionally, in this embodiment, the operation of cyclically generating the target film layer 200 can be stopped until the total film thickness of the target film layer 200 generated in the cycle is equal to the preset film thickness value, that is, until the final generated target film layer 200 meets the process requirements.

[0062] Optionally, after step S800, the selective epitaxial growth method further includes:

[0063] S900, transfer substrate 100 out of the process chamber.

[0064] Specifically, after the final generated target film layer 200 meets the process requirements, the substrate 100 can be transferred out of the process chamber to end the processing of the substrate 100.

[0065] In one embodiment, the present application may execute steps S700 and S800 sequentially before step S600.

[0066] In another embodiment, this application may execute steps S700 and S800 sequentially after step S600. That is, this setting can avoid the first plasma 310 and the second plasma 320 remaining on the top surface 130, bottom surface 110 and sidewall 120 from affecting the adsorption effect of the first gas and the third gas on the substrate 100, thereby affecting the formation of the target film layer 200.

[0067] Optionally, prior to step S200, the selective epitaxial growth method further includes:

[0068] S100, transfer the substrate 100 into the process chamber.

[0069] Specifically, when processing the substrate 100, this application requires first transferring the substrate 100 into the process chamber before performing subsequent processing operations on the substrate 100.

[0070] In an optional embodiment, step S300, which involves bombarding the top surface 130 and the bottom surface 110 with the first plasma 310 to remove the first molecular layer 210 on the top surface 130 and the bottom surface 110, specifically includes:

[0071] S310, apply a bias voltage to the substrate 100 to attract the first plasma 310 to bombard the top surface 130 and the bottom surface 110 to remove the first molecular layer 210 on the top surface 130 and the bottom surface 110.

[0072] Specifically, this application applies a bias voltage to the substrate 100 so that the substrate 100 can generate a force that attracts the first plasma 310, that is, the first plasma 310 can move toward the substrate 100 to bombard the top surface 130 and the bottom surface 110, thereby removing the first molecular layer 210 on the top surface 130 and the bottom surface 110, while retaining the first molecular layer 210 on the sidewall 120.

[0073] Optionally, in step S310, a first plasma 310 can be generated by an RF coil. To make the first plasma 310 have a better bombardment effect, the gas pressure in the process chamber can be 5 to 50 mTorr, the RF power of the voltage applied to the RF coil can be 100 to 2000 W, that is, the RF power used to generate the first plasma 310 is 100 to 2000 W, and the RF power of the bias voltage applied to the substrate 100 is 100 to 2000 W.

[0074] Specifically, the energy of the first plasma 310 bombarding the surface of the substrate 100 is controlled by the radio frequency power of the bias voltage. Since the high-energy first plasma 310 may cause the first molecular layer 210 to decompose, when using the first plasma 310 to remove the first molecular layer 210, the radio frequency power of the bias voltage should be selected according to the stability of the first gas. Under the premise of not causing the first molecular layer 210 to decompose, a higher radio frequency power of the bias voltage can be used appropriately. This is beneficial to achieve a smaller ion incident angle. For example, in order to remove the first molecular layer 210 on the horizontal surface of the upper surface of the substrate 100, the first plasma 310 needs to bombard the horizontal surface as much as possible in a direction perpendicular to the horizontal surface. That is, by using a smaller ion incident angle, the first plasma 310 can more easily remove the first molecular layer 210 on the horizontal surface, thereby suppressing the influence on the first molecular layer 210 on the vertical surface. Specifically, in order to remove the first molecular layer 210 on the top surface 130 and the bottom surface 110, this application requires that the first plasma 310 bombard the top surface 130 and the bottom surface 110 as much as possible in a direction perpendicular to the top surface 130 or the bottom surface 110, so as to more easily remove the first molecular layer 210 on the top surface 130 and the bottom surface 110, thereby suppressing the influence of the first plasma 310 on the first molecular layer 210 on the sidewall 120.

[0075] Similarly, in an optional embodiment, step S500, which involves bombarding the top surface 130 and the bottom surface 110 with the second plasma 320 to remove the second molecular layer 220 on the top surface 130 and the bottom surface 110, specifically includes:

[0076] S510, apply a bias voltage to the substrate 100 to attract the second plasma 320 to bombard the top surface 130 and the bottom surface 110 to remove the second molecular layer 220 on the top surface 130 and the bottom surface 110.

[0077] Specifically, this application applies a bias voltage to the substrate 100 so that the substrate 100 can generate a force that attracts the second plasma 320, that is, the second plasma 320 can move toward the substrate 100 to bombard the top surface 130 and the bottom surface 110, thereby removing the second molecular layer 220 on the top surface 130 and the bottom surface 110, while retaining the second molecular layer 220 on the sidewall 120.

[0078] Optionally, in step S510, a second plasma 320 can be generated by an RF coil. To make the second plasma 320 have a better bombardment effect, the gas pressure in the process chamber can be 5 to 50 mTorr, the RF power of the voltage applied to the RF coil can be 100 to 2000 W, that is, the RF power used to generate the second plasma 320 is 100 to 2000 W, and the RF power of the bias voltage applied to the substrate 100 is 100 to 2000 W.

[0079] Specifically, the energy of the second plasma 320 bombarding the surface of the substrate 100 is controlled by the radio frequency power of the bias voltage. Since the high-energy second plasma 320 may cause the second molecular layer 220 to decompose, when using the second plasma 320 to remove the second molecular layer 220, the radio frequency power of the bias voltage should be selected according to the stability of the third gas. Under the premise of not causing the second molecular layer 220 to decompose, a higher radio frequency power of the bias voltage can be used appropriately. This is beneficial to achieve a smaller ion incident angle. For example, in order to remove the second molecular layer 220 on the horizontal surface of the upper surface of the substrate 100, the second plasma 320 needs to bombard the horizontal surface as much as possible in a direction perpendicular to the horizontal surface. That is, by using a smaller ion incident angle, the second plasma 320 can more easily remove the second molecular layer 220 on the horizontal surface, thereby suppressing the influence on the second molecular layer 220 on the vertical surface. Specifically, in order to remove the second molecular layer 220 on the top surface 130 and the bottom surface 110, this application requires that the second plasma 320 bombard the top surface 130 and the bottom surface 110 as much as possible in a direction perpendicular to the top surface 130 or the bottom surface 110, so as to more easily remove the second molecular layer 220 on the top surface 130 and the bottom surface 110, thereby suppressing the influence of the second plasma 320 on the second molecular layer 220 on the sidewall 120.

[0080] Optionally, the bombardment of the top surface 130 and the bottom surface 110 with the first plasma 310 in step S300 includes:

[0081] A second gas is delivered into the process chamber to generate a first plasma 310, which bombards the top surface 130 and the bottom surface 110.

[0082] Specifically, the process chamber contains a radio frequency coil. The second gas is delivered into the process chamber through an air inlet pipe that connects the process chamber to the outside. At the same time, a voltage with a certain radio frequency power is applied to the radio frequency coil so that the radio frequency coil acts on the second gas and reacts to generate the first plasma 310 in the process chamber. The first plasma 310 is then controlled to bombard the top surface 130 and the bottom surface 110.

[0083] Step S500, which involves bombarding the top surface 130 and the bottom surface 110 with the second plasma 320, includes:

[0084] A second gas is delivered into the process chamber to generate a second plasma 320, which bombards the top surface 130 and the bottom surface 110.

[0085] Specifically, a second gas is supplied to the process chamber again through an inlet pipe connecting the process chamber to the outside. Simultaneously, a voltage with a certain radio frequency power is applied to the radio frequency coil, causing the coil to act on the second gas and react within the process chamber to generate a second plasma 320. The second plasma 320 is then controlled to bombard the top surface 130 and the bottom surface 110. Optionally, the inlet pipe supplying the second gas, the inlet pipe supplying the first gas, and the inlet pipe supplying the third gas can all be the same inlet pipe. Alternatively, they can be different inlet pipes. This arrangement prevents residual gas in the inlet pipes from affecting the delivery of other gases.

[0086] In this embodiment, the second gas can be a gas that does not readily decompose the first molecular layer 210 and the second molecular layer 220, for example, the second gas can be neon gas among inert gases.

[0087] In another embodiment, the second gas can be argon. Since argon is relatively easy to obtain, this can reduce production costs to some extent. Furthermore, argon is less likely to react with the first and third gases mentioned above, and it is also less likely to react with other substances.

[0088] Optionally, the gas used to generate the first plasma 310 and the gas used to generate the second plasma 320 can be different gases. That is, the gas used to remove the first molecular layer 210 and the gas used to remove the second molecular layer 220 can be different. In this embodiment, the first molecular layer 210 and the second molecular layer 220 are removed using the same second gas, thereby reducing process costs. Simultaneously, this embodiment utilizes the same second gas to generate both the first plasma 310 and the second plasma 320. In this case, the first plasma 310 and the second plasma 320 can be the same plasma. Of course, the first plasma 310 and the second plasma 320 can also be different; this embodiment does not impose specific limitations on this.

[0089] Optionally, this application also discloses a mask pattern size compensation method, which includes:

[0090] S1100, Obtain the spacing between mask patterns.

[0091] Specifically, this application can obtain the spacing between mask patterns, that is, obtain the distance value between two adjacent patterns etched on the mask. If the distance value is equal to the preset distance value, it indicates that the etched mask pattern has met the process requirements.

[0092] S1200: If the spacing is greater than a preset distance value, perform the selective epitaxial growth method described above to generate a target film layer 200 on the sidewall of the mask pattern with a spacing greater than the preset distance value.

[0093] Specifically, when the spacing between two adjacent patterns is greater than a preset distance value, it indicates that over-etching has occurred during the pattern etching process, resulting in a reduction in the mask's critical dimension (CD). Since the CD determines the size of the CD of subsequent patterns, compensation for the mask CD needs to be performed laterally. This means that the vertical surface of the mask pattern, i.e., the sidewall of the mask pattern, needs to be compensated. Specifically, the sidewall of the mask pattern can be compensated using the selective epitaxial growth method described above. That is, the selective epitaxial growth method described above is executed to generate the target film layer 200 on the sidewall of the mask pattern with a spacing greater than the preset distance value, thereby reducing the aforementioned spacing and making the aforementioned spacing equal to the preset distance value to meet the process requirements.

[0094] In this application, since the sidewalls of the mask pattern can be compensated, it is possible to compensate the mask's CD (cutoff distance) only in the lateral direction without changing the mask's height. Furthermore, in subsequent etching processes, it is not necessary to consider the issue of changes in mask etching amount in the height direction caused by compensation of the mask CD.

[0095] Optionally, this application also discloses a method for forming a mask pattern, the disclosed method for forming a mask pattern including:

[0096] S2100, at least one mandrel 400 is formed on the substrate 100.

[0097] For details, please refer to Figure 11 and Figure 12 In a double exposure process, such as in the self-aligned spacing technique in double patterning technology, the substrate 100 may include a silicon oxide hard mask 140, an organic dielectric layer 150, polysilicon 160, silicon oxide 170 and a silicon substrate 180 stacked sequentially. A photoresist 190 is provided on the side of the silicon oxide hard mask 140 away from the organic dielectric layer 150. By etching the substrate 100, i.e., etching the silicon oxide hard mask 140, the organic dielectric layer 150 and the polysilicon 160 sequentially, at least one mandrel 400 is formed, which is a polysilicon mandrel.

[0098] S2200, Perform the selective epitaxial growth method described above to generate the target film layer 200 on the sidewalls of each mandrel 400.

[0099] For details, please refer to Figure 13 This application can proceed to step S200, which is to perform the selective epitaxial growth method described above, so as to generate a target film layer 200 that meets the process requirements only on the sidewalls of each mandrel 400, that is, to deposit spacers, which may be silicon nitride.

[0100] S2300, Remove mandrel 400 to form a mask pattern.

[0101] For details, please refer to Figure 14 In the self-aligned spacer technique of dual patterning technology, after the target film layer 200 is generated on the sidewall of each mandrel 400, i.e., spacers are deposited, the mandrel 400 can be removed to form a mask pattern, i.e., the final mask pattern is etched out.

[0102] In this application, since the target film 200 can be selectively deposited on the substrate 100, that is, the required target film 200 can be deposited in one go, this application does not need to perform large-area deposition first, and then obtain the required target film 200 by selective etching on the surface of the substrate 100. That is, this application can reduce one etching process on the top surface of the mandrel 400 in the double exposure process, which can improve the deposition efficiency to a certain extent.

[0103] Similarly, this application can reduce two etching steps in a quadruple exposure process, which can improve the deposition efficiency of the quadruple exposure process to some extent. As the number of exposure steps increases, the number of etching steps saved increases further, resulting in a more significant improvement in deposition efficiency.

[0104] The above embodiments of this application focus on describing the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. For the sake of brevity, they will not be described in detail here.

[0105] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A selective epitaxial growth method, characterized in that, include: A first gas is delivered into the process chamber so that the first gas is adsorbed on the surface of the substrate (100), and a groove is formed on the substrate (100). The first gas forms a first molecular layer (210) on the top surface (130) of the substrate (100), the bottom surface (110) of the groove and the sidewall (120). The top surface (130) and the bottom surface (110) are bombarded with a first plasma (310) to remove the first molecular layer (210) on the top surface (130) and the bottom surface (110); A third gas is supplied to the process chamber so that the third gas is adsorbed on the top surface (130), the bottom surface (110) and the sidewall (120) to form a second molecular layer (220) on the top surface (130), the bottom surface (110) and the sidewall (120), and the remaining first molecular layer (210) and the second molecular layer (220) react to generate a target film layer (200) on the sidewall (120); The top surface (130) and the bottom surface (110) are bombarded with a second plasma (320) to remove the second molecular layer (220) on the top surface (130) and the bottom surface (110).

2. The method according to claim 1, characterized in that, After removing the second molecular layer (220) from the top surface (130) and the bottom surface (110), the method further includes: The substrate (100) is heated to remove the first plasma (310) and the second plasma (320) remaining on the surface of the substrate (100).

3. The method according to claim 1, characterized in that, After removing the second molecular layer (220) from the top surface (130) and the bottom surface (110), the method further includes: Obtain the total film thickness of the target film layer (200); If the total film thickness is less than the preset film thickness, the process returns to the step of delivering the first gas into the process chamber so that the first gas is adsorbed on the surface of the substrate (100) to cyclically generate the target film layer (200).

4. The method according to claim 1, characterized in that, The bombardment of the top surface (130) and the bottom surface (110) with the first plasma (310) to remove the first molecular layer (210) on the top surface (130) and the bottom surface (110) specifically includes: A bias voltage is applied to the substrate (100) to attract the first plasma (310) to bombard the top surface (130) and the bottom surface (110) to remove the first molecular layer (210) on the top surface (130) and the bottom surface (110).

5. The method according to claim 4, characterized in that, In the step of applying a bias voltage to the substrate (100) to attract the first plasma (310) to bombard the top surface (130) and the bottom surface (110) to remove the first molecular layer (210) on the top surface (130) and the bottom surface (110), the gas pressure in the process chamber is 5 to 50 mTorr, the radio frequency power used to generate the first plasma (310) is 100 to 2000 W, and the radio frequency power of the bias voltage is 100 to 2000 W.

6. The method according to claim 1, characterized in that, The method of bombarding the top surface (130) and the bottom surface (110) with a second plasma (320) to remove the second molecular layer (220) on the top surface (130) and the bottom surface (110) specifically includes: A bias voltage is applied to the substrate (100) to attract the second plasma (320) to bombard the top surface (130) and the bottom surface (110) to remove the second molecular layer (220) on the top surface (130) and the bottom surface (110).

7. The method according to claim 6, characterized in that, In the step of applying a bias voltage to the substrate (100) to attract the second plasma (320) to bombard the top surface (130) and the bottom surface (110) to remove the second molecular layer (220) on the top surface (130) and the bottom surface (110), the gas pressure in the process chamber is 5 to 50 mTorr, the radio frequency power used to generate the second plasma (320) is 100 to 2000 W, and the radio frequency power of the bias voltage is 100 to 2000 W.

8. The method according to claim 1, characterized in that, The bombardment of the top surface (130) and the bottom surface (110) with the first plasma (310) includes: A second gas is supplied to the process chamber to generate the first plasma (310), and the first plasma (310) bombards the top surface (130) and the bottom surface (110); The bombardment of the top surface (130) and the bottom surface (110) with the second plasma (320) includes: The second gas is delivered into the process chamber to generate the second plasma (320), which bombards the top surface (130) and the bottom surface (110). The second gas is argon.

9. A method for compensating the size of a mask pattern, characterized in that, include: Obtain the spacing between the mask patterns; If the spacing is greater than a preset distance value, the method of any one of claims 1-8 is performed to generate the target film layer (200) on the sidewall of the mask pattern where the spacing is greater than the preset distance value.

10. A method for forming a mask pattern, characterized in that, include: At least one mandrel (400) is formed on the substrate (100); Perform the method of any one of claims 1-8 to generate the target film layer (200) on the sidewall of each of the mandrels (400); Remove the mandrel (400) to form the mask pattern.

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