Formation method of semiconductor structure

Abstract

A method for forming a semiconductor structure comprises the following steps: providing a wafer which comprises a functional surface and a non-functional surface; forming a first stress film layer structure on the non-functional surface; carrying out laser annealing treatment on the wafer; after the wafer is subjected to laser annealing treatment, the warping degree of the wafer is obtained, and whether the wafer is warped or not is judged; if the wafer is warped, acquiring the warpage condition of the wafer; and performing ion implantation on the non-functional surface of the wafer according to the warping condition of the wafer until the warping degree of the wafer returns to a normal state. According to the method, the warping degree of the wafer is improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing, and in particular to a method for forming a semiconductor structure. Background Art

[0002] During the semiconductor manufacturing process, the wafer will deform itself after passing through some stations such as stress engineering and annealing, generally with a downward-bending "saddle shape" and an upward-bending "bowl shape". The degree of wafer warpage is a very important parameter in the integrated circuit manufacturing process, which determines whether the subsequent process steps can proceed normally and is related to the quality and yield of chip products.

[0003] Therefore, it is particularly important to solve the problem of wafer warpage effectively and quickly. Summary of the invention

[0004] The technical problem solved by the present invention is to provide a method for forming a semiconductor structure to improve wafer warpage.

[0005] To solve the above technical problems, the technical solution of the present invention provides a method for forming a semiconductor structure, including: providing a wafer, the wafer including a functional surface and a non-functional surface; forming a first stress film layer structure on the non-functional surface; performing laser annealing on the wafer; after performing laser annealing on the wafer, obtaining the warpage of the wafer to determine whether the wafer is warped; if the wafer is warped, obtaining the warpage condition of the wafer; and performing ion implantation on the non-functional surface of the wafer according to the warpage condition of the wafer until the warpage of the wafer returns to a normal state.

[0006] Optionally, the warping condition of the wafer includes: a warping direction, the warping direction includes upward warping and downward warping, the upward warping includes: the center of curvature of the warping surface of the wafer is located on the side of the functional surface; the downward warping includes: the center of curvature of the warping surface of the wafer is located on the side of the non-functional surface.

[0007] Optionally, according to the warping of the wafer, ion implantation is performed on the non-functional surface of the wafer, including: if the warping direction of the wafer is upward, ion implantation of first ions is performed on the non-functional surface of the wafer; if the warping direction of the wafer is downward, ion implantation of second ions is performed on the non-functional surface of the wafer; the molar mass of the first ion is greater than the molar mass of the second ion.

[0008] Optionally, the molar mass of the first ion is greater than 10, and the molar mass of the second ion is less than 10.

[0009] Optionally, the warping condition of the wafer also includes: the curvature of the wafer.

[0010] Optionally, before ion implantation is performed on the non-functional surface of the wafer, the process also includes: when the curvature of the wafer is greater than a preset value range, performing a first thinning treatment on the first stress film layer structure; when the curvature of the wafer is less than a preset value range, performing a second thinning treatment on the first stress film layer structure.

[0011] Optionally, the preset value range is: the curvature is less than 100.

[0012] Optionally, the thinning thickness of the first thinning process is greater than the thinning thickness of the second thinning process.

[0013] Optionally, the warping direction of the wafer is upward warping; after performing a first thinning treatment on the first stress film layer structure, ion implantation is performed on the non-functional surface of the wafer, including: obtaining a continuous warping surface, the continuous warping surface includes a first zone and a second zone located on both sides of the first zone, and the curvature of the first zone is greater than the curvature of the second zone; performing ion implantation of first ions on the non-functional surface of the first zone, and performing ion implantation of second ions on the non-functional surface of the second zone.

[0014] Optionally, the warping direction of the wafer is downward warping; after performing a first thinning treatment on the first stress film layer structure, ion implantation is performed on the non-functional surface of the wafer, including: obtaining a continuous warping surface, the continuous warping surface includes a first zone and a second zone located on both sides of the first zone, and the curvature of the first zone is greater than the curvature of the second zone; performing ion implantation of second ions on the non-functional surface of the first zone, and performing ion implantation of first ions on the non-functional surface of the second zone.

[0015] Optionally, when the curvature of the wafer is greater than a preset value range, after performing a first thinning treatment on the first stress film layer structure and before performing ion implantation on the non-functional surface of the wafer, it also includes: removing part of the remaining first stress film layer structure so that the remaining first stress film layer structure forms a patterned layer on the non-functional surface.

[0016] Optionally, the projection pattern of the patterned layer on the non-functional surface includes a circle or a square.

[0017] Optionally, the warping direction of the wafer is upward warping; after performing a second thinning treatment on the first stress film layer structure, ion implantation is performed on the non-functional surface of the wafer, including: obtaining a continuous warping surface, the continuous warping surface includes a first zone and a second zone located on both sides of the first zone, the curvature of the first zone is greater than the curvature of the second zone; performing ion implantation of a first ion on the non-functional surface of the first zone; after performing ion implantation of the first ion on the non-functional surface of the first zone, obtaining the degree of warping relief of the wafer; if the degree of warping of the wafer is alleviated and the warping degree of the wafer is greater than a preset value range, performing ion implantation of a second ion on the non-functional surface of the second zone.

[0018] Optionally, the warping direction of the wafer is downward warping; after performing a second thinning treatment on the first stress film layer structure, ion implantation is performed on the non-functional surface of the wafer, including: obtaining a continuous warping surface, the continuous warping surface includes a first zone and a second zone located on both sides of the first zone, the curvature of the first zone is greater than the curvature of the second zone; ion implantation of second ions is performed on the non-functional surface of the first zone; after performing ion implantation of second ions on the non-functional surface of the first zone, the degree of warping relief of the wafer is obtained; if the degree of warping of the wafer is alleviated and the warping degree of the wafer is greater than a preset value range, ion implantation of first ions is performed on the non-functional surface of the second zone.

[0019] Optionally, the warping direction of the wafer is upward warping; after performing a second thinning treatment on the first stress film layer structure, ion implantation is performed on the non-functional surface of the wafer, including: obtaining a continuous warping surface, the continuous warping surface includes a first zone and a second zone located on both sides of the first zone, the curvature of the first zone is greater than the curvature of the second zone; and first ions are implanted into the non-functional surface of the first zone and the non-functional surface of the second zone.

[0020] Optionally, the warping direction of the wafer is downward warping; after performing a second thinning treatment on the first stress film layer structure, ion implantation is performed on the non-functional surface of the wafer, including: obtaining a continuous warping surface, the continuous warping surface includes a first zone and a second zone located on both sides of the first zone, and the curvature of the first zone is greater than the curvature of the second zone; and performing ion implantation of second ions on the non-functional surface of the first zone and the non-functional surface of the second zone.

[0021] Optionally, according to the warping condition of the wafer, after ion implantation is performed on the non-functional surface of the wafer, the method further includes: performing rapid thermal annealing treatment on the wafer.

[0022] Optionally, the method of obtaining the warpage of the wafer and determining whether the wafer is warped includes: obtaining the warpage of the wafer, and if the warpage is within a preset range, determining that the wafer is not warped; if the warpage is greater than the preset range, determining that the wafer is warped; the warpage of the wafer returns to a normal state, including: the warpage of the wafer satisfies a preset range.

[0023] Optionally, while forming the first stress film layer structure on the non-functional surface, the method further includes: forming a second stress film layer structure on the functional surface.

[0024] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0025] The technical solution of the present invention, after the wafer is subjected to laser annealing treatment, the warpage of the wafer is obtained to determine whether the wafer is warped, and according to the warpage of the wafer, ion implantation is performed on the non-functional surface of the wafer until the warpage of the wafer returns to a normal state. The method only needs to detect the warpage of the wafer on the original machine, and select the corresponding solution based on the direction and degree of the warpage, so that the operation is convenient and the cost is low; in addition, the stress can be flexibly adjusted by adjusting the energy, implantation dose and type of ions of the ion implantation according to the degree of warpage of the wafer, thereby effectively and flexibly adjusting the warpage of the wafer. In summary, the method can effectively reduce the risks of subsequent processes caused by wafer warpage deformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic flow chart of a semiconductor structure forming process according to an embodiment of the present invention;

[0027] Figures 2 to 5 is a structural schematic diagram of a semiconductor structure forming process in one embodiment of the present invention;

[0028] Figure 6 is a structural schematic diagram of a semiconductor structure forming process in another embodiment of the present invention;

[0029] Figure 7 and Figure 8 is a structural schematic diagram of a semiconductor structure forming process in another embodiment of the present invention;

[0030] Fig. 9 and Fig.10 is a structural schematic diagram of a semiconductor structure forming process in another embodiment of the present invention;

[0031] Fig.11 is a structural schematic diagram of a semiconductor structure forming process in another embodiment of the present invention;

[0032] Fig.12It is a structural schematic diagram of a semiconductor structure forming process in another embodiment of the present invention. DETAILED DESCRIPTION

[0033] As described in the background art, it is necessary to effectively and quickly solve the problem of wafer warpage.

[0034] Specifically, the wafer includes a functional surface and a non-functional surface. After a series of film layers are deposited on the surface of the wafer and the wafer is annealed, the wafer is deformed. The deformed wafer is saddle-shaped or bowl-shaped. The saddle-shaped wafer is deformed downward, and the center of curvature of the warped surface of the deformed wafer is located on the side of the non-functional surface; the bowl-shaped wafer is deformed upward, and the center of curvature of the warped surface of the deformed wafer is located on the side of the functional surface. The deformed wafer affects the yield of the subsequent products.

[0035] In order to solve the above problems, the technical solution of the present invention provides a method for forming a semiconductor structure. After the wafer is subjected to laser annealing, the warpage of the wafer is obtained to determine whether the wafer is warped. According to the warpage of the wafer, ions are implanted into the non-functional surface of the wafer until the warpage of the wafer returns to normal. The method only needs to detect the warpage of the wafer on the original machine and select the corresponding scheme based on the direction and degree of the warpage, so that the operation is convenient and the cost is low. In addition, the stress can be flexibly adjusted by adjusting the energy, implantation dose and type of ions of the ion implantation according to the degree of warpage of the wafer, thereby effectively and flexibly adjusting the warpage of the wafer. In summary, the method can effectively reduce the risks of subsequent processes caused by wafer warpage and deformation.

[0036] In order to make the above-mentioned objects, features and beneficial effects 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.

[0037] Figure 1 is a schematic flow chart of a method for forming a semiconductor structure in an embodiment of the present invention; Figures 2 to 5 It is a structural schematic diagram of a semiconductor structure forming process in one embodiment of the present invention.

[0038] Please refer to Figure 1 , the method for forming the semiconductor structure comprises:

[0039] Step S10: providing a wafer, wherein the wafer includes a functional surface and a non-functional surface;

[0040] Step S20: forming a first stress film layer structure on the non-functional surface;

[0041] Step S30: performing laser annealing on the wafer;

[0042] Step S40: after laser annealing the wafer, obtaining the warpage of the wafer to determine whether the wafer is warped;

[0043] Step S50: if the wafer is warped, obtaining the warping condition of the wafer;

[0044] Step S60: performing ion implantation on the non-functional surface of the wafer according to the warpage of the wafer, until the warpage of the wafer returns to a normal state.

[0045] The method only needs to detect the warpage of the wafer on the original machine, and select the corresponding solution based on the direction and degree of the warpage, so that the operation is convenient and the cost is low; in addition, the stress can be flexibly adjusted by adjusting the energy, injection dose and type of ions of the ion implantation according to the degree of the warpage of the wafer, thereby effectively and flexibly adjusting the warpage of the wafer. In summary, the method can effectively reduce the risk of subsequent processes caused by the warpage deformation of the wafer.

[0046] Each step is now analyzed and explained with reference to the accompanying drawings.

[0047] Please combine Figure 2 Continue to refer Figure 1 , performing step S10: providing a wafer 200, wherein the wafer 200 includes a functional surface A and a non-functional surface B; performing step S20: forming a first stress film layer structure 202 on the non-functional surface B.

[0048] In this embodiment, while forming the first stress film layer structure 202 on the non-functional surface B, the method further includes: forming a second stress film layer structure 201 on the functional surface A.

[0049] The functional surface A is used to form a semiconductor device structure, and a series of processes such as deposition, etching, and ion implantation are usually performed on the functional surface A to form a semiconductor device. When a series of film layers are deposited on the functional surface A to form a second stress film layer structure 201, a series of film layers are also deposited on the non-functional surface B to form a first stress film layer structure 202. The stacking of multiple film layers generates stress on the wafer 200. The stress film layer on the functional surface A undergoes various subsequent processes to form a semiconductor structure, and the stress film layer on the non-functional surface B does not form a semiconductor structure. After the stress of each party is released after the subsequent annealing treatment, the stress of the non-functional surface B and the functional surface A of the wafer 200 is unbalanced, and the wafer 200 warps.

[0050] In this embodiment, the material of the wafer 200 is silicon.

[0051] In other embodiments, the material of the wafer includes silicon carbide, silicon germanium, a multi-component semiconductor material composed of group III-V elements, silicon on insulator (SOI) or germanium on insulator (GOI). Among them, the multi-component semiconductor material composed of group III-V elements includes InP, GaAs, GaP, InAs, InSb, InGaAs or InGaAsP.

[0052] Please combine Figure 3 Continue to refer Figure 1 , executing step S30: performing laser annealing treatment on the wafer 200 .

[0053] Laser annealing is a CO2 laser annealing method with a wavelength of 9.2 to 10.8 μm, which is used to eliminate stress and repair lattice defects.

[0054] Please continue to combine Figure 3 Continue to refer Figure 1 , executing step S40: after performing laser annealing on the wafer 200 , obtaining the warpage of the wafer 200 , and determining whether the wafer 200 is warped.

[0055] The method for obtaining the warpage of the wafer 200 and determining whether the wafer 200 is warped includes: obtaining the warpage of the wafer 200, and if the warpage is within a preset range, determining that the wafer 200 is not warped; if the warpage is greater than the preset range, determining that the wafer 200 is warped.

[0056] Please continue to combine Figure 3 Continue to refer Figure 1 , executing step S50: if the wafer 200 is warped, obtaining the warping condition of the wafer 200 .

[0057] The warping conditions of the wafer 200 include: warping direction, the warping direction includes upward warping and downward warping, the upward warping includes: the center of curvature of the warping surface of the wafer 200 is located on the side of the functional surface A, that is, bowl-shaped, and tensile stress is generated on the wafer surface; the downward warping includes: the center of curvature of the warping surface of the wafer 200 is located on the side of the non-functional surface B, that is, saddle-shaped, and compressive stress is generated on the wafer surface.

[0058] Figure 3 The warping direction of the wafer 200 shown in FIG. 2 is upward warping, and the curvature center R of the warping surface of the wafer 200 is located on the side of the functional surface A, that is, a bowl shape. The surface of the wafer generates tensile stress.

[0059] In this embodiment, the warping condition of the wafer 200 further includes: a curvature (bow value) of the wafer 200. The curvature is used to measure the curvature of the wafer 200. The greater the curvature, the greater the curvature of the wafer 200.

[0060] The method for forming the semiconductor structure also includes: when the curvature of the wafer 200 is greater than a preset value range, performing a first thinning process on the first stress film layer structure 202; when the curvature of the wafer 200 is less than the preset value range, performing a second thinning process on the first stress film layer structure 202.

[0061] In this embodiment, the preset value range is: the curvature is less than 100.

[0062] In this embodiment, the first thinning process has a greater thinning thickness than the second thinning process, that is, the greater the curvature of the wafer 200, the greater the thinning degree of the first stress film layer structure 202, and thinning the first stress film layer structure 202 can relieve certain stress.

[0063] Please refer to Figure 4 , Figure 4 The curvature of the wafer 200 is greater than 100, and the first stress film layer structure 202 is subjected to a first thinning process.

[0064] In this embodiment, when the curvature of the wafer 200 is greater than a preset value range, after the first stress film layer structure 202 is subjected to a first thinning treatment, it also includes: removing a portion of the remaining first stress film layer structure 202 so that the remaining first stress film layer structure 202 forms a patterned layer (not shown) on the non-functional surface B.

[0065] The projection pattern of the patterned layer on the non-functional surface B includes a circle or a square, which can further disperse the stress of the first stress film layer structure 202 on the non-functional surface B.

[0066] Please continue to refer to Figure 1 , executing step S60: performing ion implantation on the non-functional surface B of the wafer 200 according to the warping condition of the wafer 200 until the warping degree of the wafer 200 returns to a normal state.

[0067] The warpage of the wafer 200 returns to a normal state, that is, the warpage of the wafer 200 meets a preset range.

[0068] According to the warping of the wafer 200, ion implantation is performed on the non-functional surface B of the wafer 200, including: if the warping direction of the wafer 200 is upward, ion implantation of first ions is performed on the non-functional surface B of the wafer 200; if the warping direction of the wafer 200 is downward, ion implantation of second ions is performed on the non-functional surface B of the wafer 200. The energy, implantation dose and type of ions of the ion implantation can be adjusted according to the needs to flexibly adjust the magnitude of the stress.

[0069] In this embodiment, the molar mass of the first ion is greater than the molar mass of the second ion. The first ion is a heavy ion, and the second ion is a light ion.

[0070] In this embodiment, the molar mass of the first ions is greater than 10, and the first ions include phosphorus ions or silicon ions.

[0071] In this embodiment, the molar mass of the second ions is less than 10. The second ions include hydrogen ions or helium ions.

[0072] By adjusting the energy, implantation dose and type of ions, the magnitude of stress can be flexibly adjusted, thereby effectively and flexibly adjusting the warpage of the wafer. The reason is that the ion implantation process will cause the host atoms of the wafer to shift, thereby causing lattice damage. This damage will cause silicon to expand, thereby generating stress on the silicon surface. Moreover, as the ion implantation dose increases, the wafer will gradually change from a single crystal state to an amorphous state. In addition, ion implantation is often accompanied by annealing. After a certain amount of radiation annealing and thermal annealing, the silicon substrate atoms will shift more before amorphization. The type of ions implanted determines different stresses. When the implanted ions are light ions, tensile stress is generated; when the implanted ions are heavy-ions, compressive stress is generated.

[0073] When the warping direction of the wafer 200 is upward, tensile stress is generated on the surface of the wafer 200, and heavy ions are implanted into the non-functional surface B of the wafer 200, and the compressive stress generated by the heavy ions can neutralize the tensile stress; if the warping direction of the wafer 200 is downward, compressive stress is generated on the surface of the wafer 200, and light ions are implanted into the non-functional surface B of the wafer 200, and the tensile stress generated by the light ions can neutralize the compressive stress. Thus, the purpose of improving the warpage of the wafer is achieved.

[0074] Please combine Figure 5 Continue to refer Figure 1 , Figure 5The wafer 200 in the wafer 200 is warped upward, and after the first stress film layer structure 202 is subjected to a first thinning treatment, ion implantation is performed on the non-functional surface B of the wafer 200, including: obtaining a continuous warped surface, the continuous warped surface comprising a first region I and a second region II located on both sides of the first region I, the curvature of the first region I being greater than the curvature of the second region II; performing ion implantation of first ions P1 on the non-functional surface B of the first region I, and performing ion implantation of second ions P2 on the non-functional surface B of the second region II.

[0075] After ion implantation is performed on the non-functional surface B of the wafer 200 , the warpage of the wafer 200 is restored to within a preset range.

[0076] After the non-functional surface B of the wafer 200 is ion implanted, the method further includes: performing a rapid thermal annealing treatment on the wafer 200. The rapid thermal annealing treatment is more conducive to uniform ion diffusion on the non-functional surface B of the wafer 200, thereby balancing the stress on the non-functional surface B of the wafer 200 and repairing the lattice damage caused by the ion implantation process.

[0077] In this embodiment, the wafer 200 warps upward, and tensile stress is generated on the surface of the wafer 200. By injecting heavy ions into the first region I with a large curvature and injecting light ions into the second region II with a small curvature, the stress on the surface of the wafer 200 can be further neutralized and adjusted in different regions, so that the warpage cannot be easily adjusted accurately by a single ion implantation.

[0078] After the wafer 200 is subjected to the rapid thermal annealing treatment, the first stress film layer structure 202 on the non-functional surface B of the wafer 200 may be removed or not removed according to requirements.

[0079] Figure 6 It is a structural schematic diagram of a semiconductor structure forming process in another embodiment of the present invention.

[0080] Please combine Figure 6 Continue to refer Figure 1 , Figure 6 and Figure 5 The difference in structure is that the warping direction of the wafer 200 is downward warping, and the curvature center R of the warping surface of the wafer 200 is located on the side of the non-functional surface B, that is, saddle-shaped. Compressive stress is generated on the surface of the wafer 200. The curvature of the wafer 200 is greater than 100.

[0081] After the first stress film layer structure 202 is subjected to the first thinning treatment, ion implantation is performed on the non-functional surface B of the wafer 200, including: obtaining a continuous warped surface, the continuous warped surface including a first region I and a second region II located on both sides of the first region I, the curvature of the first region I being greater than the curvature of the second region II; performing ion implantation of second ions P2 on the non-functional surface B of the first region I, and performing ion implantation of first ions P1 on the non-functional surface B of the second region II.

[0082] After ion implantation is performed on the non-functional surface B of the wafer 200 , the warpage of the wafer 200 is restored to within a preset range.

[0083] After the non-functional surface B of the wafer 200 is ion implanted, the method further includes: performing a rapid thermal annealing treatment on the wafer 200 .

[0084] In this embodiment, the wafer 200 warps downward and compressive stress is generated on the surface of the wafer 200. By injecting light ions into the first area I with a large curvature and injecting heavy ions into the second area II with a small curvature, the stress on the surface of the wafer 200 can be further neutralized and adjusted in different regions to prevent the warping from being difficult to accurately adjust by a single ion implantation.

[0085] Figure 7 and Figure 8 It is a structural schematic diagram of a semiconductor structure forming process in another embodiment of the present invention.

[0086] Please combine Figure 1 refer to Figure 7 , Figure 7 and Figure 5 The structural difference is that the wafer 200 is warped upward, the center of curvature of the warped surface of the wafer 200 is located on the side of the functional surface A, that is, bowl-shaped, tensile stress is generated on the surface of the wafer 200, and the curvature of the wafer 200 is less than the preset value range, that is, the curvature of the wafer 200 is less than 100.

[0087] In this embodiment, the curvature of the wafer 200 is less than 100, and the first stress film layer structure 202 is subjected to a second thinning process, so as to disperse the stress of the first stress film layer structure 202 on the non-functional surface B.

[0088] After the first stress film layer structure 202 is subjected to a second thinning treatment, ion implantation is performed on the non-functional surface B of the wafer 200, including: obtaining a continuous warped surface, the continuous warped surface including a first region I and a second region II located on both sides of the first region I, the curvature of the first region I being greater than the curvature of the second region II; and implanting the first ion P1 into the non-functional surface B of the first region I.

[0089] Please combine Figure 1 refer to Figure 8 After the non-functional surface B of the first zone I is ion-implanted with the first ion P1, the degree of warping relief of the wafer 200 is obtained; if the warping degree of the wafer 200 is relieved and the warping degree of the wafer 200 is greater than a preset value range, the non-functional surface B of the second zone II is ion-implanted with the second ion P2.

[0090] In this embodiment, the wafer 200 warps upward, and tensile stress is generated on the surface of the wafer 200. Heavy ions are injected into the first region I with large curvature, and light ions are injected into the second region II with small curvature in steps, so that the stress on the surface of the wafer 200 can be further neutralized in different regions, so as to avoid the difficulty of accurately adjusting the warpage by single ion implantation.

[0091] Fig. 9 and Fig.10 It is a structural schematic diagram of a semiconductor structure forming process in another embodiment of the present invention.

[0092] Please combine Figure 1 refer to Fig. 9 , Fig. 9 and Figure 7 The difference in structure is that the warping direction of the wafer 200 is downward warping, and the curvature center R of the warping surface of the wafer 200 is located on the side of the non-functional surface B, that is, saddle-shaped. Compressive stress is generated on the surface of the wafer 200. The curvature of the wafer 200 is less than 100.

[0093] After the first stress film layer structure 202 is subjected to a second thinning treatment, ion implantation is performed on the non-functional surface B of the wafer 200, including: obtaining a continuous warped surface, the continuous warped surface including a first region I and a second region II located on both sides of the first region I, the curvature of the first region I being greater than the curvature of the second region II; and implanting second ions P2 into the non-functional surface B of the first region I.

[0094] Please combine Figure 1 refer to Fig.10 After the non-functional surface B of the first zone I is ion-implanted with the second ion P2, the degree of warping relief of the wafer 200 is obtained; if the warping degree of the wafer 200 is relieved and the warping degree of the wafer 200 is greater than the preset value range, the non-functional surface B of the second zone II is ion-implanted with the first ion P1.

[0095] In this embodiment, the wafer 200 is warped downward, and compressive stress is generated on the surface of the wafer 200. Light ions are injected into the first region I with large curvature, and heavy ions are injected into the second region II with small curvature in steps, so that the stress on the surface of the wafer 200 can be further neutralized in different regions, so as to avoid the difficulty of accurately adjusting the warpage by single ion implantation.

[0096] Fig.11 It is a structural schematic diagram of a semiconductor structure forming process in another embodiment of the present invention.

[0097] Please combine Figure 1 refer to Fig.11 , Fig.11 The structure and Figure 5 The structural difference is that the wafer 200 is warped upward, the center of curvature of the warped surface of the wafer 200 is located on the side of the functional surface A, that is, bowl-shaped, tensile stress is generated on the surface of the wafer 200, and the curvature of the wafer 200 is less than the preset value range, that is, the curvature of the wafer 200 is less than 100.

[0098] In this embodiment, the curvature of the wafer 200 is less than 100, and the first stress film layer structure 202 is subjected to a second thinning process, so as to disperse the stress of the first stress film layer structure 202 on the non-functional surface B.

[0099] After the first stress film layer structure 202 is subjected to a second thinning treatment, ion implantation is performed on the non-functional surface B of the wafer 200, including: obtaining a continuous warped surface, the continuous warped surface including a first region I and a second region II located on both sides of the first region I, the curvature of the first region I being greater than the curvature of the second region II; and implanting first ions P1 into the non-functional surface B of the first region I and the non-functional surface B of the second region II.

[0100] In this embodiment, the wafer 200 warps upward, and tensile stress is generated on the surface of the wafer 200. By implanting heavy ions into the non-functional surface B of the wafer 200, the compressive stress generated by the heavy ions can neutralize and adjust the tensile stress on the surface of the wafer 200.

[0101] Fig.12 It is a structural schematic diagram of a semiconductor structure forming process in another embodiment of the present invention.

[0102] Please combine Figure 1 refer to Fig.12 , Fig.12 The structure and Fig.11 The structural difference is that the wafer 200 is warped downward, the center of curvature of the warped surface of the wafer 200 is located on the side of the non-functional surface B, that is, a saddle shape, compressive stress is generated on the surface of the wafer 200, and the curvature of the wafer 200 is less than a preset value range, that is, the curvature of the wafer 200 is less than 100.

[0103] After the first stress film layer structure 202 is subjected to a second thinning treatment, ion implantation is performed on the non-functional surface B of the wafer 200, including: obtaining a continuous warped surface, the continuous warped surface including a first region I and a second region II located on both sides of the first region I, the curvature of the first region I being greater than the curvature of the second region II; and implanting second ions P2 into the non-functional surface B of the first region I and the non-functional surface B of the second region II.

[0104] In this embodiment, the wafer 200 warps downward, and compressive stress is generated on the surface of the wafer 200. By injecting light ions into the non-functional surface B of the wafer 200, the tensile stress generated by the light ions can neutralize and adjust the compressive stress on the surface of the wafer 200.

[0105] 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 protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A method for forming a semiconductor structure, characterized in that: include: Providing a wafer, wherein the wafer comprises a functional surface and a non-functional surface; forming a first stress film layer structure on the non-functional surface; performing laser annealing on the wafer; After the wafer is subjected to laser annealing treatment, a warpage degree of the wafer is obtained to determine whether the wafer is warped; If the wafer is warped, obtaining the warping condition of the wafer; According to the warping condition of the wafer, ion implantation is performed on the non-functional surface of the wafer until the warping degree of the wafer returns to a normal state.

2. The method for forming a semiconductor structure according to claim 1, wherein: The warping condition of the wafer includes: a warping direction, the warping direction includes upward warping and downward warping, the upward warping includes: the center of curvature of the warping surface of the wafer is located on the side of the functional surface; the downward warping includes: the center of curvature of the warping surface of the wafer is located on the side of the non-functional surface.

3. The method for forming a semiconductor structure according to claim 2, wherein: According to the warping condition of the wafer, ion implantation is performed on the non-functional surface of the wafer, including: if the warping direction of the wafer is upward, ion implantation of first ions is performed on the non-functional surface of the wafer; if the warping direction of the wafer is downward, ion implantation of second ions is performed on the non-functional surface of the wafer; the molar mass of the first ion is greater than the molar mass of the second ion.

4. The method for forming a semiconductor structure according to claim 3, wherein: The molar mass of the first ion is greater than 10, and the molar mass of the second ion is less than 10.

5. The method for forming a semiconductor structure according to claim 3, wherein: The warping condition of the wafer also includes: the curvature of the wafer.

6. The method for forming a semiconductor structure according to claim 5, wherein: Before ion implantation is performed on the non-functional surface of the wafer, the method also includes: when the curvature of the wafer is greater than a preset value range, performing a first thinning treatment on the first stress film layer structure; when the curvature of the wafer is less than a preset value range, performing a second thinning treatment on the first stress film layer structure.

7. The method for forming a semiconductor structure according to claim 6, wherein: The preset value range is: the curvature is less than 100.

8. The method for forming a semiconductor structure according to claim 6, wherein: The thinning thickness of the first thinning process is greater than the thinning thickness of the second thinning process.

9. The method for forming a semiconductor structure according to claim 6, wherein: The warping direction of the wafer is upward warping; After the first stress film layer structure is subjected to a first thinning treatment, ion implantation is performed on the non-functional surface of the wafer, including: obtaining a continuous warped surface, the continuous warped surface including a first area and a second area located on both sides of the first area, the curvature of the first area being greater than the curvature of the second area; ion implantation of first ions is performed on the non-functional surface of the first area, and ion implantation of second ions is performed on the non-functional surface of the second area.

10. The method for forming a semiconductor structure according to claim 6, wherein: The warping direction of the wafer is downward warping; after the first stress film layer structure is subjected to a first thinning treatment, ion implantation is performed on the non-functional surface of the wafer, including: obtaining a continuous warping surface, the continuous warping surface includes a first area and a second area located on both sides of the first area, and the curvature of the first area is greater than the curvature of the second area; ion implantation of second ions is performed on the non-functional surface of the first area, and ion implantation of first ions is performed on the non-functional surface of the second area.

11. The method for forming a semiconductor structure according to claim 6, wherein: When the curvature of the wafer is greater than a preset value range, after the first stress film layer structure is subjected to a first thinning treatment and before ion implantation is performed on the non-functional surface of the wafer, it also includes: removing part of the remaining first stress film layer structure so that the remaining first stress film layer structure forms a patterned layer on the non-functional surface.

12. The method for forming a semiconductor structure according to claim 11, wherein: The projection pattern of the patterned layer on the non-functional surface includes a circle or a square.

13. The method for forming a semiconductor structure according to claim 6, wherein: The warping direction of the wafer is upward warping; After performing a second thinning treatment on the first stress film layer structure, ion implantation is performed on the non-functional surface of the wafer, including: obtaining a continuous warped surface, the continuous warped surface including a first area and a second area located on both sides of the first area, the curvature of the first area being greater than the curvature of the second area; implanting a first ion into the non-functional surface of the first area; after performing the first ion implantation on the non-functional surface of the first area, obtaining the degree of warping relief of the wafer; if the degree of warping of the wafer is relieved and the warping of the wafer is greater than a preset value range, implanting a second ion into the non-functional surface of the second area.

14. The method for forming a semiconductor structure according to claim 6, wherein: The warping direction of the wafer is downward warping; after performing a second thinning treatment on the first stress film layer structure, ion implantation is performed on the non-functional surface of the wafer, including: obtaining a continuous warping surface, the continuous warping surface includes a first area and a second area located on both sides of the first area, and the curvature of the first area is greater than the curvature of the second area; ion implantation of second ions is performed on the non-functional surface of the first area; after performing ion implantation of second ions on the non-functional surface of the first area, the degree of warping relief of the wafer is obtained; if the degree of warping of the wafer is alleviated and the warping degree of the wafer is greater than a preset value range, ion implantation of first ions is performed on the non-functional surface of the second area.

15. The method for forming a semiconductor structure according to claim 6, wherein: The warping direction of the wafer is upward warping; After performing a second thinning treatment on the first stress film layer structure, ion implantation is performed on the non-functional surface of the wafer, including: obtaining a continuous warped surface, the continuous warped surface including a first area and a second area located on both sides of the first area, the curvature of the first area being greater than the curvature of the second area; and implanting first ions into the non-functional surface of the first area and the non-functional surface of the second area.

16. The method for forming a semiconductor structure according to claim 6, wherein: The warping direction of the wafer is downward warping; after performing a second thinning treatment on the first stress film layer structure, ion implantation is performed on the non-functional surface of the wafer, including: obtaining a continuous warping surface, the continuous warping surface includes a first area and a second area located on both sides of the first area, and the curvature of the first area is greater than the curvature of the second area; and second ion implantation is performed on the non-functional surface of the first area and the non-functional surface of the second area.

17. The method for forming a semiconductor structure according to claim 1, wherein: After ion implantation is performed on the non-functional surface of the wafer according to the warpage of the wafer, the method further includes: performing a rapid thermal annealing treatment on the wafer.

18. The method for forming a semiconductor structure according to claim 1, wherein: The method of obtaining the warpage of the wafer and determining whether the wafer is warped includes: obtaining the warpage of the wafer, and if the warpage is within a preset range, determining that the wafer is not warped; if the warpage is greater than the preset range, determining that the wafer is warped; the warpage of the wafer returns to a normal state, including: the warpage of the wafer satisfies the preset range.

19. The method for forming a semiconductor structure according to claim 1, wherein: While forming the first stress film layer structure on the non-functional surface, the method further includes: forming a second stress film layer structure on the functional surface.

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