Method for forming silicon epitaxy

Abstract

The invention discloses a silicon epitaxy forming method. The method comprises the following steps: providing a substrate; performing oxidation enhancement treatment on the surface of the substrate to form an oxide layer covering the surface of the substrate, or performing reduction treatment on the surface of the substrate; after the reduction treatment, performing oxidation treatment on the surface of the substrate to form an oxide layer; removing the oxide layer; a silicon epitaxial layer is formed on a substrate. The surface of the substrate is subjected to oxidation enhancement treatment or reduction treatment, so that the surface of the substrate can be fully oxidized, the probability of forming low-valence oxides on the surface of the substrate is reduced, the oxide layer on the surface of the substrate can be completely removed in the subsequent oxide layer removal process, and the yield of the substrate is improved. According to the method, the probability that an oxide layer or organic impurities remain on the surface of the substrate is reduced, correspondingly, in the subsequent silicon epitaxial layer forming process, the forming quality of the epitaxial layer is improved, and the probability that defects (such as cavities or amorphous regions located in the epitaxial layer) appear in the epitaxial layer is reduced.

Description

Technical Field

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

[0002] In semiconductor manufacturing, with the development trend of ultra-large-scale integrated circuits, the feature size of integrated circuits and the area of ​​transistor devices continue to decrease. As the size shrinks, in order to overcome short channel effects (SCE, short channel effects), transistors gradually begin to transition from planar structures to three-dimensional structures with higher efficiency, such as fin field-effect transistors (FinFETs) and gate-all-around (GAA) transistors. The manufacturing process of three-dimensional transistor structures requires overcoming complex material processes and integration issues. Due to the high cost, three-dimensional transistors need to introduce high-mobility materials such as silicon germanium materials to balance manufacturing costs through higher energy efficiency.

[0003] Silicon epitaxy is a key technology for integrating high-mobility materials, such as silicon germanium (SiGe) as a sacrificial layer or as a passivation layer between SiGe and metal gates. High-mobility materials like SiGe place high demands on stress loss and elemental contamination control in Si epitaxy, requiring strict thermal budget and reaction condition control.

[0004] At present, the high-quality silicon epitaxial growth process at lower temperatures (200-500°C) still needs to be improved. Summary of the Invention

[0005] The problem solved by the embodiments of the present invention is to provide a method for forming silicon epitaxy, which is conducive to further improving the performance of silicon epitaxy at a lower process temperature.

[0006] To solve the above problems, the present invention also provides a method for forming silicon epitaxy, comprising: providing a substrate; performing an oxidation enhancement treatment on the surface of the substrate to form an oxide layer covering the surface of the substrate; or, performing a reduction treatment on the surface of the substrate, and after performing the reduction treatment, performing an oxidation treatment on the surface of the substrate to form an oxide layer; removing the oxide layer; and after removing the oxide layer, forming a silicon epitaxial layer on the substrate.

[0007] Optionally, the step of performing reduction treatment on the surface of the substrate includes: performing reduction treatment on the surface of the substrate using reducing ions or hydrogen-containing free radicals.

[0008] Optionally, the reducing ions include hydrogen-containing reducing ions.

[0009] Optionally, the reducing ions include a mixture of H2 and N2, or one or more of H2 and NH3.

[0010] Optionally, the reducing ions are generated by plasma.

[0011] Optionally, the process temperature for performing the reduction treatment on the surface of the substrate is 50°C to 400°C.

[0012] Optionally, after the reduction treatment, in the process of performing an oxidation treatment on the surface of the substrate to form an oxide layer, the reactants used in the oxidation treatment include one or more of clean air, ozone or hydrogen peroxide.

[0013] Optionally, the step of performing an oxidation enhancement treatment on the surface of the substrate to form an oxide layer covering the surface of the substrate includes: performing an oxidation enhancement treatment on the surface of the substrate using plasma.

[0014] Optionally, the plasma includes oxygen-containing ions or oxygen-containing free radicals.

[0015] Optionally, in the step of forming the oxide layer, the thickness of the oxide layer is 10 angstroms to 60 angstroms.

[0016] Optionally, the process of removing the oxide layer includes a dry etching process.

[0017] Optionally, the process of forming the silicon epitaxial layer on the substrate includes a deposition process, an atomic layer epitaxial process, or a plasma enhanced process.

[0018] Optionally, process parameters for forming the silicon epitaxial layer on the substrate include: a process temperature of 200° C. to 500° C.; and a silicon source including one or more of disilane, trisilane, silane, and dichlorosilane.

[0019] Optionally, during the process of forming the silicon epitaxial layer, the silicon epitaxial layer is further subjected to heat treatment.

[0020] Optionally, the process of forming the silicon epitaxial layer on the substrate further includes: introducing an inert gas or a reducing gas to place the substrate in an inert gas environment.

[0021] Optionally, the inert gas includes one or more of helium, neon and argon; and the reducing gas includes H2.

[0022] Compared with the prior art, the technical solution of the embodiment of the present invention has the following advantages:

[0023] An embodiment of the present invention provides a method for forming silicon epitaxy, wherein the surface of the substrate is subjected to an oxidation enhancement treatment to form an oxide layer covering the surface of the substrate, or the surface of the substrate is subjected to a reduction treatment; after the reduction treatment, the surface of the substrate is subjected to an oxidation treatment to form an oxide layer, so that the surface of the substrate can be fully oxidized, thereby reducing the probability of forming low-valent oxides on the surface of the substrate. In the subsequent process of removing the oxide layer, the oxide layer on the surface of the substrate can be completely removed, thereby reducing the probability of residual oxide layer or organic impurities on the surface of the substrate. Accordingly, in the subsequent process of forming the silicon epitaxial layer, the formation quality of the silicon epitaxial layer is improved, and the probability of defects in the silicon epitaxial layer (for example, voids or amorphous regions in the epitaxial layer) is reduced, thereby improving the performance of the silicon epitaxial layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figures 1 to 6 1 is a schematic structural diagram corresponding to each step in the first embodiment of the method for forming silicon epitaxy according to the present invention;

[0025] Figure 7 1 is a schematic structural diagram corresponding to each step in the second embodiment of the method for forming silicon epitaxy of the present invention. DETAILED DESCRIPTION

[0026] As can be seen from the background art, the performance of epitaxial processes still needs to be improved. In particular, during the process of forming an epitaxial layer using a low-temperature epitaxial process, the material on the substrate surface is prone to forming a low-valent oxide layer in a low-temperature environment, which prevents the material on the substrate surface from being fully oxidized in the low-temperature environment. This increases the difficulty of removing the oxide layer in the subsequent process, thereby increasing the probability of a residual oxide layer on the substrate surface. Accordingly, during the subsequent process of forming the epitaxial layer, the residual oxide layer affects the formation quality of the epitaxial layer and increases the probability of epitaxial defects (such as voids or amorphous regions in the epitaxial layer) appearing in the epitaxial layer, thereby affecting the performance of silicon epitaxy.

[0027] In order to solve the technical problem, an embodiment of the present invention provides a method for forming silicon epitaxy, including: providing a substrate; performing an oxidation enhancement treatment on the surface of the substrate to form an oxide layer covering the surface of the substrate; or, performing a reduction treatment on the surface of the substrate, and after performing the reduction treatment, performing an oxidation treatment on the surface of the substrate to form an oxide layer; removing the oxide layer; and after removing the oxide layer, forming a silicon epitaxial layer on the substrate.

[0028] In the embodiment of the present invention, the surface of the substrate is subjected to an oxidation enhancement treatment to form an oxide layer covering the surface of the substrate, or the surface of the substrate is subjected to a reduction treatment; after the reduction treatment, the surface of the substrate is subjected to an oxidation treatment to form an oxide layer, so that the surface of the substrate can be fully oxidized, thereby reducing the probability of forming low-valent oxides on the surface of the substrate. In the subsequent process of removing the oxide layer, the oxide layer on the surface of the substrate can be completely removed, reducing the probability of residual oxide layer or organic impurities on the surface of the substrate. Accordingly, in the subsequent process of forming a silicon epitaxial layer, the formation quality of the epitaxial layer is improved, and the probability of defects in the epitaxial layer (for example, voids or amorphous regions in the epitaxial layer) is reduced, thereby improving the performance of the silicon epitaxial layer.

[0029] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0030] Figures 1 to 6 It is a schematic structural diagram corresponding to each step in the first embodiment of the method for forming silicon epitaxy of the present invention.

[0031] refer to Figure 1 , providing a substrate 102.

[0032] Specifically, the substrate 102 provides a process platform for the subsequent silicon epitaxial formation process.

[0033] As an example, the base 102 includes a substrate 100 and a fin 101 protruding from the substrate 100 .

[0034] In this embodiment, the substrate 100 is a silicon substrate 100. In other embodiments, the substrate material may be other materials such as germanium, silicon germanium, silicon carbide, gallium arsenide, or indium gallium. The substrate may also be other types of substrates such as a silicon-on-insulator substrate or a germanium-on-insulator substrate. The substrate material may be a material suitable for process requirements or easy to integrate.

[0035] In this embodiment, the substrate 100 and the fin 101 are an integrated structure.

[0036] Specifically, the material of the fin 101 is the same as that of the substrate 100 , and therefore, the material of the fin 101 is also silicon. In other embodiments, the material of the fin may also be germanium, silicon germanium, or a Group III-V semiconductor material.

[0037] In other embodiments, the base further includes a substrate and a channel structure layer suspended on the substrate, and the channel structure layer includes a plurality of channel layers stacked in sequence and spaced apart in the longitudinal direction.

[0038] The material of the channel layer is silicon, silicon-germanium, germanium or Group III-V semiconductor material.

[0039] refer to Figure 2 Before subsequently forming an oxide layer on the surface of the substrate 102 , the method further includes: performing a cleaning treatment 103 on the surface of the substrate 102 .

[0040] Specifically, the surface of the substrate 102 is cleaned 103 to remove natural oxides or pollutants remaining on the surface of the substrate 102. This is beneficial for improving the effect of the reduction treatment 104 on the surface of the substrate 102 in the subsequent process of reducing the surface of the substrate 102, thereby improving the formation quality of the subsequently formed oxide layer. At the same time, in the subsequent process of forming the silicon epitaxial layer, the adhesion of the epitaxial layer to the surface of the substrate 102 can be improved.

[0041] It should be noted that the natural oxide refers to an oxide film layer formed by a chemical reaction between the surface of the substrate 102 and the air environment.

[0042] It should also be noted that pollutants refer to organic matter on the surface of the substrate due to residues from the previous process or adsorbed from the environment.

[0043] As an example, the process of performing the cleaning treatment 103 on the surface of the substrate 102 includes a surface pre-cleaning process.

[0044] Pre-cleaning mainly uses wet processes, including purified water, SPM, O3, SC1, SC2 or HF, etc. It is mainly used to remove inorganic and organic residues on the surface.

[0045] As an example, the process gas may be one or both of argon and helium.

[0046] refer to Figures 3 and 4 , the surface of the substrate 102 is subjected to a reduction treatment 104 , and after the reduction treatment 104 , the surface of the substrate 102 is subjected to an oxidation treatment to form an oxide layer 106 .

[0047] It should be noted that the surface of the substrate 102 is subjected to a reduction treatment 104; after the reduction treatment 104, the surface of the substrate 102 is oxidized to form an oxide layer 106, so that the surface of the substrate 102 can be fully oxidized, thereby reducing the probability of forming low-valent oxides on the surface of the substrate 102. In the subsequent process of removing the oxide layer 106, the oxide layer 106 on the surface of the substrate 102 can be completely removed, thereby reducing the probability of the oxide layer 106 or organic impurities remaining on the surface of the substrate 102. Accordingly, in the subsequent process of forming the silicon epitaxial layer, the formation quality of the silicon epitaxial layer is improved, and the probability of defects in the silicon epitaxial layer (for example, voids or amorphous regions in the epitaxial layer) is reduced, thereby improving the performance of the silicon epitaxial layer.

[0048] In this embodiment, the step of performing a reduction treatment 104 on the surface of the substrate 102 includes: performing a reduction treatment 104 on the surface of the substrate 102 using reducing ions or hydrogen-containing free radicals.

[0049] It should be noted that by using reducing ions or hydrogen-containing free radicals to reduce the material on the surface of the substrate 102 into free radicals, the material on the surface of the substrate 102 reduced into free radicals can fully react with other materials. This means that the material on the surface of the substrate 102 can be fully oxidized during the subsequent oxidation treatment, reducing the probability of forming low-valent oxides on the surface of the substrate 102. In the subsequent process of removing the oxide layer, the oxide layer oxidized on the surface of the substrate 102 can be completely removed, reducing the probability of an oxide layer remaining on the surface of the substrate 102.

[0050] As an example, performing the reduction treatment 104 on the surface of the substrate 102 using reducing ions or hydrogen-containing radicals refers to performing the reduction treatment 104 on the surface of the fin 101 .

[0051] In other embodiments, performing the reduction treatment 104 on the substrate surface using reducing ions or hydrogen-containing free radicals may also refer to performing the reduction treatment 104 on the surface of the channel layer in the channel structure layer.

[0052] As an example, the reducing ions include hydrogen-containing reducing ions. Specifically, the hydrogen-containing reducing ions have high reducing properties and can reduce the material on the surface of the substrate 102 into free radicals.

[0053] In this embodiment, reducing ions are generated by plasma.

[0054] In this embodiment, the reducing ions include a mixture of H2 and N2, or one or more of H2 and NH3.

[0055] Specifically, the mixture of H2 and N2, and H2 and NH3 are both commonly used reducing ions, and the mixture of H2 and N2, and H2 and NH3 have strong reducing properties, which can fully reduce the material on the surface of the substrate 102 into free radicals.

[0056] It should be noted that the process temperature for the reduction treatment 104 on the surface of the substrate 102 should not be too high or too low. If the process temperature for the reduction treatment 104 on the surface of the substrate 102 is too high or too low, it will affect the interface properties of the substrate 102 surface to a certain extent, thereby affecting the reliability of silicon epitaxy. Therefore, in this embodiment, the process temperature for the reduction treatment 104 on the surface of the substrate 102 is 50°C to 400°C.

[0057] Specifically, an oxide layer 106 is formed on the surface of the substrate 102. In the subsequent process of removing the oxide layer 106, the oxide layer 106 on the surface of the substrate can be completely removed, thereby reducing the probability of the oxide layer 106 or organic impurities remaining on the surface of the substrate. In the subsequent process of forming a silicon epitaxial layer, a clean crystal surface can be provided for the growth of the silicon epitaxial layer, thereby improving the formation quality of the subsequently formed silicon epitaxial layer.

[0058] Specifically, after the reduction treatment 104, the surface of the substrate 102 is oxidized, so that the material on the surface of the substrate 102 can be fully oxidized into an oxide layer 106, thereby reducing the probability of forming low-valent oxides on the surface of the substrate 102. In the subsequent process of removing the oxide layer 106, the oxide layer 106 that has been fully oxidized on the surface of the substrate 102 can be completely removed, thereby reducing the probability of the oxide layer 106 remaining on the surface of the substrate 102. In the subsequent process of forming a silicon epitaxial layer, the probability of void defects in the silicon epitaxial layer is also reduced.

[0059] In this embodiment, forming the oxide layer 106 on the surface of the substrate 102 refers to forming the oxide layer 106 on the surface of the fin 101 .

[0060] As an example, the process gas used in the oxidation treatment includes one or more of clean air, ozone or hydrogen peroxide.

[0061] Specifically, clean air, ozone or hydrogen peroxide are all gases commonly used in the oxidation treatment process to form the oxide layer 106. In addition, the high oxygen content in clean air, ozone or hydrogen peroxide can enable the surface material of the substrate 102 to fully react with other process materials, thereby forming the oxide layer 106 on the surface of the substrate 102.

[0062] It should be noted that the thickness of the oxide layer 106 should not be too large or too small. If the thickness of the oxide layer 106 is too large, it is easy to cause the thickness of the remaining substrate 102 material (such as the fin 101) to be too small, thereby affecting the carrier mobility of the silicon epitaxial growth. At the same time, it also increases the difficulty of the subsequent process of removing the oxide layer 106 and reduces the process efficiency of removing the oxide layer 106. If the thickness of the oxide layer 106 is too small, it increases the probability that native oxide will still remain on the surface of the substrate 102. For this reason, in this embodiment, the thickness of the oxide layer 106 is 10 angstroms to 60 angstroms.

[0063] refer to Figure 5 , remove the oxide layer 106.

[0064] It should be noted that removing the oxide layer 106 can expose the top surface of the substrate 102, providing a clean crystal surface for the subsequent growth of the silicon epitaxial layer, facilitating the subsequent formation of the silicon epitaxial layer on the top surface of the substrate 102, thereby further improving the performance of the device through the silicon epitaxial layer (for example, forming a silicon epitaxial layer on the surface of the fin 101 can further improve the mobility of carriers in the conductive channel).

[0065] In this embodiment, the process of removing the oxide layer 106 includes a dry etching process.

[0066] Specifically, for example, one or both of the Certas process and the SiCoNi process.

[0067] Specifically, both the Certas process and the SiCoNi process have the characteristics of high removal efficiency and relatively complete volatilization of by-products. By adopting the Certas process and the SiCoNi process, the oxide layer 106 on the surface of the substrate 102 can be completely removed, further reducing the probability of the oxide layer 106 remaining on the surface of the substrate 102. In the subsequent process of forming the epitaxial layer, the probability of epitaxial defects in the epitaxial layer (such as the appearance of voids in the epitaxial layer) is also reduced, thereby improving the performance of silicon epitaxy.

[0068] refer to Figure 6 After removing the oxide layer 106 , a silicon epitaxial layer 108 is formed on the substrate 102 .

[0069] Specifically, the silicon epitaxial layer 108 can improve device performance.

[0070] As an example, a silicon epitaxial layer 108 is formed on the substrate 102, that is, a silicon epitaxial layer 108 is formed on the surface of the fin 101. The silicon epitaxial layer 108 and the fin 101 together serve as a conductive channel of the transistor, thereby further improving the mobility of carriers in the conductive channel of the transistor, thereby improving the electrical performance of the transistor.

[0071] In this embodiment, the process of forming the silicon epitaxial layer 108 on the substrate 102 includes a deposition process, a low-temperature atomic layer epitaxy process, or a plasma enhanced process.

[0072] Specifically, taking the low-temperature atomic layer epitaxy process as an example, the film formation quality of the silicon epitaxial layer 108 can be improved by adopting the low-temperature atomic layer epitaxy process. At the same time, forming the silicon epitaxial layer 108 in a low-temperature environment can reduce the stress of the silicon epitaxial layer 108 and improve the reliability of the silicon epitaxial layer.

[0073] It should be noted that during the process of forming the silicon epitaxial layer 108 on the substrate 102, the process temperature should not be too high or too low. If the process temperature is too high or too low, it is easy to result in poor film quality of the silicon epitaxial layer 108 and excessive stress in the silicon epitaxial layer 108, affecting the performance of the conductive channel of the transistor and thus affecting the reliability of the device. Therefore, in this embodiment, during the process of forming the silicon epitaxial layer 108 on the substrate 102, the process temperature is 200°C to 500°C.

[0074] It should also be noted that, in the process of forming the silicon epitaxial layer 108 on the substrate 102 , the silicon source includes one or more of disilane, trisilane, silane and dichlorosilane.

[0075] As an example, during the process of forming the silicon epitaxial layer, the silicon epitaxial layer 108 is further subjected to a heat treatment to improve the crystallinity of the silicon epitaxial layer 108 .

[0076] It should be noted that, in this embodiment, the process of forming the silicon epitaxial layer 108 on the substrate 102 further includes: introducing an inert gas or a reducing gas to place the substrate 102 in an inert gas environment.

[0077] Specifically, the introduction of inert gas or reducing gas can reduce the activity of the surface material of the substrate 102, and reduce the probability of the surface material of the substrate 102 chemically reacting with oxygen to form oxides. This means that in the process of forming the silicon epitaxial layer 108, the probability of epitaxial defects in the silicon epitaxial layer 108 is reduced, thereby improving the performance of the device.

[0078] As an example, the inert gas includes one or more of helium, neon, and argon.

[0079] Specifically, helium, neon, and argon are all inert gases commonly used in semiconductor formation processes and have the characteristic of low process costs.

[0080] As an example, the reducing gas includes hydrogen.

[0081] Figure 7 1 is a schematic structural diagram corresponding to each step in the second embodiment of the method for forming silicon epitaxy of the present invention.

[0082] The similarities between the embodiment of the present invention and the first embodiment are not repeated here. The difference between the embodiment of the present invention and the first embodiment is that: the surface of the substrate 202 is subjected to oxidation enhancement treatment 212 to form an oxide layer 206 covering the surface of the substrate 202.

[0083] Specifically, after providing the substrate 202, an oxidation enhancement treatment 212 is directly performed on the surface of the substrate 202 to form an oxide layer 206 covering the surface of the substrate 202, so that the surface of the substrate 202 can be fully oxidized, thereby reducing the probability of forming low-valent oxides on the surface of the substrate 202. In the subsequent process of removing the oxide layer 206, the oxide layer 206 on the surface of the substrate 202 can be completely removed, thereby reducing the probability of the oxide layer 206 or organic impurities remaining on the surface of the substrate 202. Accordingly, in the subsequent process of forming the silicon epitaxial layer, the formation quality of the silicon epitaxial layer is improved, and the probability of defects in the silicon epitaxial layer (for example, voids or amorphous regions in the epitaxial layer) is reduced, thereby improving the performance of the silicon epitaxial layer.

[0084] As an example, the step of performing oxidation enhancement treatment 212 on the surface of the substrate 202 to form an oxide layer 206 covering the surface of the substrate 202 includes: performing oxidation enhancement treatment on the surface of the substrate 202 using plasma.

[0085] Specifically, by using plasma to perform oxidation enhancement treatment on the surface of the substrate 202, the oxygen content in the surface material of the substrate 202 is increased, so that the surface material of the substrate 202 can be fully oxidized into an oxide layer 206, reducing the probability of forming low-valent oxides on the surface of the substrate 202. In the process of removing the oxide layer 206, the oxide layer 206 that is fully oxidized on the surface of the substrate 202 can be completely removed, reducing the probability of the oxide layer 206 remaining on the surface of the substrate 202.

[0086] As an example, the plasma includes oxygen-containing ions or oxygen-containing radicals.

[0087] Specifically, by using oxygen-containing ions or oxygen-containing free radicals, the oxygen content in the surface material of the substrate 202 can be increased, so that the surface material of the substrate 202 can be fully oxidized to form the oxide layer 206 .

[0088] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. A method for forming silicon epitaxy, characterized in that: include: providing a substrate; performing an oxidation enhancement treatment on the surface of the substrate to form an oxide layer covering the surface of the substrate; Alternatively, the substrate surface is subjected to a reduction treatment, and after the reduction treatment, the substrate surface is subjected to an oxidation treatment to form an oxide layer; removing the oxide layer; After removing the oxide layer, a silicon epitaxial layer is formed on the substrate.

2. The method for forming silicon epitaxy according to claim 1, wherein: The step of performing reduction treatment on the surface of the substrate includes: performing reduction treatment on the surface of the substrate using reducing ions or hydrogen-containing free radicals.

3. The method for forming silicon epitaxy according to claim 2, wherein: The reducing ions include hydrogen-containing reducing ions.

4. The method for forming silicon epitaxy according to claim 2, wherein: The reducing ions include a mixture of H2 and N2, or one or more of H2 and NH3.

5. The method for forming silicon epitaxy according to claim 2, wherein: The reducing ions are generated by means of plasma.

6. The method for forming silicon epitaxy according to claim 1, wherein: The process temperature for performing the reduction treatment on the surface of the substrate is 50° C. to 400° C.

7. The method for forming silicon epitaxy according to claim 6, wherein: After the reduction treatment, the substrate surface is oxidized to form an oxide layer, and the reactants used in the oxidation treatment include one or more of clean air, ozone or hydrogen peroxide.

8. The method for forming silicon epitaxy according to claim 1, wherein: The step of performing an oxidation enhancement treatment on the surface of the substrate to form an oxide layer covering the surface of the substrate includes: performing an oxidation enhancement treatment on the surface of the substrate using plasma.

9. The method for forming silicon epitaxy according to claim 8, wherein: The plasma includes oxygen-containing ions or oxygen-containing radicals.

10. The method for forming silicon epitaxy according to claim 1, wherein: In the step of forming the oxide layer, the oxide layer has a thickness of 10 angstroms to 60 angstroms.

11. The method for forming silicon epitaxy according to claim 1, wherein: The process of removing the oxide layer includes a dry etching process.

12. The method for forming silicon epitaxy according to claim 1, wherein: The process of forming the silicon epitaxial layer on the substrate includes a deposition process, an atomic layer epitaxial process, or a plasma enhanced process.

13. The method for forming silicon epitaxy according to claim 1, wherein: The process parameters for forming the silicon epitaxial layer on the substrate include: a process temperature of 200° C. to 500° C.; and a silicon source including one or more of disilane, trisilane, silane and dichlorosilane.

14. The method for forming silicon epitaxy according to claim 1, wherein: During the process of forming the silicon epitaxial layer, the silicon epitaxial layer is further subjected to heat treatment.

15. The method for forming silicon epitaxy according to claim 1, wherein: The process of forming the silicon epitaxial layer on the substrate further includes: introducing an inert gas or a reducing gas to place the substrate in an inert gas environment.

16. The method for forming silicon epitaxy according to claim 15, wherein: The inert gas includes one or more of helium, neon and argon; The reducing gas includes hydrogen.

Images