Semiconductor Structure and Method of Forming the Same

Abstract

A semiconductor structure and a method for forming the same, comprising: providing a substrate having a first metal layer therein; forming a dielectric layer on the substrate, the dielectric layer having a first opening exposing the top surface of the first metal layer; bombarding the surface of the first metal layer exposed at the bottom of the first opening by a first sputtering process, so that the metal material on the surface of the first metal layer is sputtered onto the sidewall surface of the first opening to form a first adhesion layer; forming a second metal on the surface of the first adhesion layer and the exposed surface of the first metal layer by a first metal selective growth process. In the technical solution of the present invention, by forming a first adhesion layer on the sidewall surface of the first opening, and then forming a second metal layer on the sidewall of the first adhesion layer and the surface of the first metal layer, the bonding property between the second metal layer and the sidewall surface of the first opening is improved, and effectively reduces the entry of external impurities into the first opening to cause metal contamination.

Description

Technical Field

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

[0002] With the continuous progress of semiconductor technology, the feature size of semiconductor devices has gradually become smaller. The reduction of the critical dimension means that more transistors can be arranged on the chip, while posing higher requirements for semiconductor processes. As the size of semiconductor devices shrinks, the contact resistance of MOS transistors has an increasingly greater impact on the performance of MOS transistors and the entire semiconductor chip. In order to improve the performance of semiconductor chips, it is necessary to reduce the contact resistance of MOS transistors.

[0003] Currently, the conductive plugs formed by the selective tungsten growth process can effectively increase the volume of the conductive plugs, and then increase the contact area at the bottom of the conductive plugs, so as to achieve the purpose of reducing the contact resistance.

[0004] However, in the prior art, the performance of the conductive plugs formed by the selective tungsten growth process needs to be improved. Summary of the Invention

[0005] The technical problem solved by the present invention is to provide a semiconductor structure and a method for forming the same, which effectively improve the bonding property between the first opening and the first metal layer by forming a first adhesion layer, and reduce the entry of external impurities into the first opening to cause metal contamination.

[0006] To solve the above problems, the present invention provides a method for forming a semiconductor structure, including: providing a substrate having a first metal layer therein; forming a dielectric layer on the top surface of the substrate, the dielectric layer having a first opening exposing the top surface of the first metal layer; bombarding the surface of the first metal layer exposed at the bottom of the first opening by using a first sputtering process, so that the metal material on the surface of the first metal layer is sputtered onto the sidewall surface of the first opening to form a first adhesion layer; forming a second metal layer on the surface of the first adhesion layer and the exposed surface of the first metal layer by using a first metal selective growth process.

[0007] Optionally, the substrate includes a substrate and device structures located in the substrate, and the first metal layer is located in the device structures.

[0008] Optionally, the material of the substrate includes silicon, germanium, silicon germanide, silicon carbide, gallium arsenide or indium gallium.

[0009] Optionally, the material of the first metal layer includes tungsten, cobalt or ruthenium.

[0010] Optionally, the material of the second metal layer includes tungsten.

[0011] Optionally, the method for forming the dielectric layer and the first opening includes: forming an initial dielectric layer on the surface of the substrate; forming a mask structure on the initial dielectric layer; forming a patterned layer on the mask structure, the patterned layer having an opening exposing a part of the mask structure; etching part of the mask structure and the initial dielectric layer using the patterned layer as a mask until the top surface of the device structure is exposed, to form the dielectric layer and the first opening; after forming the dielectric layer and the first opening, removing the patterned layer and the mask structure.

[0012] Optionally, the material of the initial dielectric layer includes silicon dioxide, low-k dielectric material or ultra-low-k dielectric material.

[0013] Optionally, the ions used in the first sputtering process include argon ions or helium ions.

[0014] Optionally, the process parameters of the first sputtering process include: sputtering time of 5 s to 10 s, sputtering power of 300 W to 400 W.

[0015] Optionally, the surface of the second metal layer is flush with the surface of the dielectric layer.

[0016] Optionally, the surface of the second metal layer is lower than the surface of the dielectric layer, and the method for forming the semiconductor structure further includes: performing one or more sputtering growth processes to form a conductive structure filling the first opening on the surface of the second metal layer and the surface of the first adhesion layer.

[0017] Optionally, each sputtering growth process includes: forming a second adhesion layer on the sidewall surface of the first opening by using a second sputtering process; forming a third metal layer in the first opening by using a second metal selective growth process.

[0018] Optionally, the second sputtering process bombards the surface of the second metal layer exposed at the bottom of the first opening, so that the metal material on the surface of the second metal layer is sputtered onto the sidewall surface of the first opening to form the second adhesion layer; or, the second sputtering process bombards the surface of the third metal layer exposed at the bottom of the first opening, so that the metal material on the surface of the third metal layer is sputtered onto the sidewall surface of the first opening to form the second adhesion layer.

[0019] Optionally, the second metal selective growth process forms the third metal layer on the surface of the second metal layer exposed at the bottom of the first opening and on the surface of the second adhesion layer exposed on the sidewall of the first opening; or, the second metal selective growth process forms the third metal layer on the surface of the third metal layer exposed at the bottom of the first opening and on the surface of the second adhesion layer exposed on the sidewall of the first opening.

[0020] Optionally, the ions used in the second sputtering process include argon ions or helium ions.

[0021] Optionally, the process parameters for each second sputtering process include: a sputtering time of 5 s to 10 s and a sputtering power of 300 W to 400 W.

[0022] Optionally, the material of the third metal layer includes tungsten.

[0023] Correspondingly, the present invention also provides a semiconductor structure formed by any one of the above methods, including: a substrate having a first metal layer therein; a dielectric layer on the top surface of the substrate, the dielectric layer having a first opening exposing the top surface of the first metal layer; a first adhesion layer on the sidewall surface of the first opening; and a second metal layer on the sidewall surface of the first adhesion layer and on the top surface of the first metal layer.

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

[0025] In the technical solution of the present invention, by performing a first sputtering process on the surface of the first metal layer, the material on the surface of the first metal layer is sputtered onto the sidewall surface of the first opening to form a first adhesion layer. Since the first sputtering process is used, the sputtered metal material will be embedded in the sidewall surface of the first opening. Therefore, there is a high bonding property between the first adhesion layer and the sidewall surface of the first opening. Furthermore, a second metal layer is formed on the sidewall surface of the first adhesion layer and on the top surface of the first metal layer, greatly improving the bonding property between the finally formed second metal layer and the sidewall surface of the first opening, effectively reducing the entry of external impurities into the first opening, thereby causing metal contamination, and thus improving the performance of the finally formed semiconductor structure. Description of the Drawings

[0026] Figure 1 and Figure 2 are schematic diagrams of the structures of the steps of a method for forming a semiconductor structure;

[0027] Figures 3 to 6 are schematic diagrams of the structures of the steps of a method for forming a semiconductor structure in an embodiment of the present invention;

[0028] Figures 7 to 10 It is a schematic structural diagram of each step in the method for forming a semiconductor structure in another embodiment of the present invention. Detailed implementation manners

[0029] As described in the background art, in the prior art, the performance of conductive plugs made by the selective tungsten growth process needs to be improved. The following will be described in conjunction with Figure 1 and Figure 2 for illustration. Figure 1 and Figure 2 are schematic structural diagrams of each step in a method for forming a semiconductor structure.

[0030] Please refer to Figure 1 , a substrate 100 is provided, and a device structure 101 is provided in the substrate 100; a first metal layer 102 is formed in the device structure 101; a dielectric layer 103 is formed on the top surface of the substrate 100 and the top surface of the first metal layer 102, and a first opening 104 exposing the top surface of the first metal layer 102 is provided in the dielectric layer 103.

[0031] Please refer to Figure 2 , a second metal layer 105 is formed on the top surface of the first metal layer 102 by using a metal selective growth process until the second metal layer 105 fills the first opening 104.

[0032] Since the metal selective growth process utilizes the property that tungsten can grow on the metal surface, in the above embodiment, only the top surface of the first metal layer 102 has metal, and the side wall surface of the first opening 104 is a dielectric layer material. Therefore, although the finally formed second metal layer 102 fills the entire first opening 104, the bonding property between the second metal layer 102 and the side wall surface of the first opening 104 is not very good. In this way, it is easy to generate a gap between the second metal layer 102 and the side wall surface of the first opening 104, which easily causes external impurities to enter the gap and then diffuse into the dielectric layer, resulting in metal contamination and affecting the performance of the finally formed semiconductor structure.

[0033] On this basis, the present invention provides a semiconductor structure and a method for forming the same. By sputtering the surface of the first metal layer, the material on the surface of the first metal layer is sputtered onto the side wall surface of the first opening to form a first adhesion layer, and then a second metal layer is formed on the side wall surface of the first adhesion layer and the top surface of the first metal layer, so as to enhance the bonding property between the second metal layer and the side wall of the first opening, and further improve the performance of the finally formed semiconductor structure.

[0034] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following will describe in detail the specific embodiments of the present invention with reference to the accompanying drawings.

[0035] Figures 3 to 6 It is a schematic structural diagram of each step in the formation process of a semiconductor structure according to an embodiment of the present invention.

[0036] Please refer to Figure 3 , a substrate 200 is provided, and a first metal layer 201 is disposed in the substrate 200.

[0037] In this embodiment, the substrate 200 includes a base 202 and a device structure 203 located in the base 202, and the first metal layer 201 is located in the device structure 203.

[0038] In this embodiment, the material of the base 202 is silicon; in other embodiments, the material of the base may also be germanium, silicon germanide, silicon carbide, gallium arsenide, or indium gallium.

[0039] The device structure 203 includes a gate structure, a resistor structure, a capacitor structure, an inductor structure, or a memory gate structure; in this embodiment, the device structure 203 is a resistor structure.

[0040] In this embodiment, the material of the first metal layer 201 is tungsten; in other embodiments, the material of the first metal layer may also be cobalt or ruthenium.

[0041] Please refer to Figure 4 , a dielectric layer 204 is formed on the substrate 200, and a first opening 205 exposing the top surface of the first metal layer 201 is formed in the dielectric layer 204.

[0042] In this embodiment, the depth of the first opening 205 is related to the number of sputtering growth times for forming the subsequent conductive structure. The deeper the depth of the first opening 205, the more sputtering growth times are required subsequently.

[0043] In this embodiment, the method for forming the dielectric layer 204 and the first opening 205 includes: forming an initial dielectric layer (not shown) on the surface of the substrate 200; forming a mask structure (not shown) on the initial dielectric layer; forming a patterned layer (not shown) on the mask structure, and an opening exposing a part of the mask structure is formed in the patterned layer; etching part of the mask structure and the initial dielectric layer with the patterned layer as a mask until the top surface of the first metal layer 201 is exposed, thereby forming the dielectric layer 204 and the first opening 205; after forming the dielectric layer 204 and the first opening 205, removing the patterned layer and the mask structure.

[0044] The material of the initial dielectric layer includes silicon dioxide, low-k dielectric material (referring to dielectric material with relative permittivity lower than 3.9), or ultra-low-k dielectric material (referring to dielectric material with relative permittivity lower than 2.5).

[0045] In this embodiment, the material of the initial dielectric layer is an ultra-low-k dielectric material (dielectric constant less than 2.5), and the ultra-low-k dielectric material is silicon carbon oxyhydride (SiCOH).

[0046] The process for forming the initial dielectric layer includes atomic layer deposition process, chemical vapor deposition, physical vapor deposition, or spin coating process; in this embodiment, the formation process of the initial dielectric layer adopts chemical vapor deposition process.

[0047] In this embodiment, the mask structure includes a first mask layer located on the substrate and a second mask layer located on the first mask layer; in other embodiments, the first mask structure can also be a single-layer mask layer.

[0048] In this embodiment, the patterned layer is formed on the second mask layer, the material of the patterned layer includes photoresist, and the formation process of the patterned layer includes photolithography patterning process.

[0049] The process for removing the patterned layer includes wet stripping process or ashing process, and the gas for the ashing process is an oxygen-containing gas, such as oxygen or ozone.

[0050] Please refer to Figure 5 , and use the first sputtering treatment to bombard the surface of the first metal layer 201 exposed at the bottom of the first opening 205, so that the metal material on the surface of the first metal layer 201 is sputtered onto the sidewall of the first opening 205 to form a first adhesion layer 206.

[0051] In this embodiment, the ions used in the first sputtering treatment are argon ions; in other embodiments, the ions used in the first sputtering treatment can also be helium ions.

[0052] Since the mass of the argon ions is relatively large, by bombarding the surface of the first metal layer 201 at high speed, the kinetic energy generated by the argon ions can cause the metal material on the surface of the first metal layer 201 to sputter outward, and the sputtered metal material will be embedded on the surface of the sidewall of the first opening 205 to form a first adhesion layer 206. Therefore, the formed first adhesion layer 206 has a relatively high bonding property with the surface of the sidewall of the first opening 205. In addition, since the material of the first metal layer 201 is tungsten with stable properties, the first adhesion layer 206 formed by the tungsten material will not cause metal contamination.

[0053] In this embodiment, the process parameters of the first sputtering treatment include: sputtering time 5s-10s, sputtering power 300W-400W.

[0054] In this embodiment, the thickness (referring to the direction perpendicular to the side wall of the first opening) and height (referring to the direction parallel to the side wall of the first opening) of the first adhesion layer 206 formed are related to the process parameters during the first sputtering treatment. The longer the sputtering time, the thicker the first adhesion layer 206 formed. For example, when the sputtering time is 5s to 10s, the thickness of the first adhesion layer 206 formed is 5 angstroms to 8 angstroms. The greater the sputtering power, the higher the height of the first adhesion layer 206 formed. For example, when the sputtering power is 300W to 400W, the height of the first adhesion layer 206 formed is 4nm to 5nm.

[0055] Please refer to Figure 6 A second metal layer 207 is formed on the surface of the first adhesion layer 206 and the exposed surface of the first metal layer 201 by using a first metal selective growth process.

[0056] In this embodiment, the second metal layer 207 is used to connect the device structure 203 to the outside world to form a circuit structure to achieve the electrical function of the semiconductor structure. In this embodiment, the material of the second metal layer 207 is tungsten.

[0057] In this embodiment, the precursor material used for the selective growth of the first metal includes: tungsten hexafluoride (WF 6 ) and hydrogen (H 2 ).

[0058] In this embodiment, the process parameters for the selective growth of the first metal include: a deposition temperature of 320° C. to 380° C., and a deposition time of 20 s to 80 s.

[0059] In this embodiment, the first metal selective growth process utilizes the property that metal tungsten can grow on the metal surface to form a second metal layer 207 on the surface exposed by the first adhesion layer 206 and the first metal layer 201. Since the second metal layer 207 and the side wall surface of the first opening 205 are connected through the first adhesion layer 206, the bonding between the formed second metal layer 207 and the side wall surface of the first opening 205 can be greatly improved, effectively reducing the entry of external impurities into the first opening 205 and causing metal contamination, thereby improving the performance of the semiconductor structure finally formed.

[0060] Since the depth of the first opening 205 is different under different process requirements, the formed second metal layer 207 may or may not completely fill the first opening 205. In this embodiment, the second metal layer 207 completely fills the first opening 205.

[0061] Correspondingly, please continue to refer to Figure 6 , the present invention also provides a semiconductor structure formed by the above method, including: a substrate 200 having a first metal layer 201 therein; a dielectric layer 204 located on the substrate 200, the dielectric layer 204 having a first opening 205 exposing the top surface of the first metal layer 201; a first adhesion layer 206 located on the sidewall surface of the first opening 205; and a second metal layer 207 located on the sidewall surface of the first adhesion layer 206 and the top surface of the first metal layer 201.

[0062] Figures 7 to 10 are schematic structural diagrams of each step in the method for forming a semiconductor structure in another embodiment of the present invention.

[0063] Please refer to Figure 7 , provide a substrate 300 having a first metal layer 301 therein; form a dielectric layer 302 on the substrate 300, the dielectric layer 302 having a first opening 303 exposing the top surface of the first metal layer 301.

[0064] In this embodiment, the substrate 300 includes a substrate and a device structure (not labeled) located in the substrate, and the first metal layer 301 is located in the device structure.

[0065] The substrate 300, the first metal layer 301, the dielectric layer 302, and the first opening 303 are as described in Embodiment Figure 3 and Figure 4 and related descriptions, and will not be elaborated here.

[0066] Please refer to Figure 8 , use a first sputtering process to bombard the surface of the first metal layer 301 exposed at the bottom of the first opening 303, so that the metal material on the surface of the first metal layer 301 is sputtered onto the sidewall surface of the first opening 303 to form a first adhesion layer 304; use a first metal selective growth process to form a second metal layer 305 on the surface of the first adhesion layer 304 and the exposed surface of the first metal layer 301.

[0067] If the thickness of the first adhesion layer 304 (in the direction perpendicular to the sidewall of the first opening) is too thick, the bombardment time of the first sputtering process on the first metal layer 301 is relatively long, which will affect the production efficiency. If the thickness of the first adhesion layer 304 is too thin, most of the metal material is embedded in the sidewall of the first opening 303, and only a very small amount is exposed on the surface of the sidewall of the first opening 303, which will affect the growth of the subsequent second metal layer 305, and further affect the bonding property between the second metal layer 305 and the sidewall of the first opening 303. Specifically, in this embodiment, the thickness of the first adhesion layer 304 is 5 Å to 8 Å, and the corresponding sputtering time of the first sputtering process is 5 s to 10 s.

[0068] If the height of the first adhesion layer 304 (in the direction parallel to the sidewall of the first opening) is too high, a relatively high sputtering power is required, which will cause greater damage to the first metal layer 301. If the height of the first adhesion layer 304 is too low, the number of subsequent sputtering growth processes will increase, which will affect the production efficiency. Specifically, in this embodiment, the height of the first adhesion layer 304 is 4 nm to 5 nm, and the corresponding sputtering power of the first sputtering process is 300 W to 400 W.

[0069] In this embodiment, the material of the second metal layer 305 is tungsten.

[0070] In this embodiment, the precursor materials used for the selective growth of the first metal include: tungsten hexafluoride (WF 6 ) and hydrogen (H 2 ).

[0071] In this embodiment, the process parameters for the selective growth of the first metal include: deposition temperature 320 °C to 380 °C, deposition time 20 s to 80 s.

[0072] In this embodiment, the second metal layer 305 does not fill the first opening 303, that is, the top surface of the second metal layer 305 is lower than the top surface of the dielectric layer 302.

[0073] When the second metal layer 305 does not fill the first opening 303, the method for forming the semiconductor structure further includes: performing one or more sputtering growth processes to form a conductive structure that fills the first opening 303 on the surface of the second metal layer 305 and the surface of the first adhesion layer 304.

[0074] In this embodiment, after performing the sputtering growth process multiple times, a conductive structure filling the first opening 303 is formed on the surface of the second metal layer 305 and the surface of the first adhesion layer 304. In other embodiments, after performing the sputtering growth process once, a conductive structure filling the first opening may also be formed on the surface of the second metal layer and the surface of the first adhesion layer.

[0075] In this embodiment, each sputtering growth process includes: forming a second adhesion layer on the sidewall surface of the first opening 303 by using a second sputtering treatment; forming a third metal layer in the first opening 303 by using a second metal selective growth process. For details, please refer to Figures 9 to 10 , in this embodiment, taking two sputtering growth processes as an example for illustration.

[0076] Please refer to Figure 9 , forming a first second adhesion layer 306a on the sidewall of the first opening 303 by using the first second sputtering treatment; forming a first third metal layer 307a in the first opening 303 by using the first second metal selective growth process.

[0077] In this embodiment, the first second sputtering treatment bombards the surface of the second metal layer 305 exposed at the bottom of the first opening 303, so that the metal material on the surface of the second metal layer 305 is sputtered onto the sidewall of the first opening 303 to form the first second adhesion layer 306a; the first second metal selective growth process forms a first third metal layer 307a on the surface of the second metal layer 305 exposed at the bottom of the first opening 303 and the surface of the first second adhesion layer 306a exposed on the sidewall of the first opening 303.

[0078] In this embodiment, the ions used in the first second sputtering treatment are argon ions; in other embodiments, the ions used in the first second sputtering treatment may also be helium ions.

[0079] In this embodiment, the process parameters of the first second sputtering treatment include: a sputtering time of 5 s to 10 s, and the corresponding thickness of the first second adhesion layer 306a is 5 Å to 8 Å; a sputtering power of 300 W to 400 W, and the corresponding height of the first second adhesion layer 306a is 4 nm to 5 nm.

[0080] In this embodiment, the precursor materials used in the first second metal selective growth include: tungsten hexafluoride (WF 6 ) and hydrogen (H 2 ).

[0081] In this embodiment, the process parameters for the selective growth of the first metal include: a deposition temperature of 320°C to 380°C and a deposition time of 20 s to 80 s.

[0082] Please refer to Figure 10 , and a second second adhesion layer 306b is formed on the sidewall of the first opening 303 by using a second second sputtering process; a second third metal layer 307b is formed in the second opening 303 by using a second second metal selective growth process.

[0083] In this embodiment, the second second sputtering process bombards the surface of the first third metal layer 307a exposed at the bottom of the first opening 303, so that the metal material on the surface of the first third metal layer 307a is sputtered onto the sidewall of the first opening 303 to form the second second adhesion layer 306b; the second metal selective growth process forms the second third metal layer 307b on the surface of the first third metal layer 307a exposed at the bottom of the first opening 303 and on the surface of the second second adhesion layer 306b exposed on the sidewall of the first opening 303.

[0084] In this embodiment, the ions used in the second second sputtering process are argon ions; in other embodiments, the ions used in the second second sputtering process can also be helium ions.

[0085] In this embodiment, the process parameters of the second second sputtering process include: a sputtering time of 5 s to 10 s, and the corresponding thickness of the second second adhesion layer 306b is 5 Å to 8 Å; a sputtering power of 300 W to 400 W, and the corresponding height of the second second adhesion layer 306b is 4 nm to 5 nm.

[0086] In this embodiment, the materials of the first third metal layer 307a and the second third metal layer 307b are tungsten.

[0087] In this embodiment, the precursor materials used in the second second metal selective growth include: tungsten hexafluoride (WF 6 ) and hydrogen (H 2 ).

[0088] In this embodiment, the process parameters for the selective growth of the first metal include: a deposition temperature of 320°C to 380°C and a deposition time of 20 s to 80 s.

[0089] In this embodiment, the conductive structure formed by the first second adhesion layer 306a, the first third metal layer 307a, the second second adhesion layer 306b, and the second third metal layer 307b is used to form a circuit connection structure between the device structure in the substrate 200 and the outside, so as to realize the electrical function of the semiconductor structure.

[0090] Correspondingly, in this embodiment, a semiconductor structure as follows is also provided. Figure 10 shown.

[0091] 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 should be subject to the scope defined by the claims.

Claims

1. A method for forming a semiconductor structure, characterized in that, comprising: providing a substrate having a first metal layer therein; forming a dielectric layer on the substrate, the dielectric layer having a first opening exposing the top surface of the first metal layer; bombarding the surface of the first metal layer exposed at the bottom of the first opening by a first sputtering process, so that the metal material on the surface of the first metal layer is sputtered and embedded into the sidewall of the first opening to form a first adhesion layer, improving the bonding property between the first adhesion layer and the sidewall surface of the first opening; forming a second metal layer on the surface of the first adhesion layer and the exposed surface of the first metal layer by a first metal selective growth process, improving the bonding property between the second metal layer and the sidewall surface of the first opening; wherein, the substrate includes a substrate and a device structure located in the substrate, and the first metal layer is located in the device structure; the top surface of the second metal layer is lower than the top surface of the dielectric layer, and the method for forming the semiconductor structure further includes: performing one or more sputtering growth processes to form a conductive structure filling the first opening on the surface of the second metal layer and the surface of the first adhesion layer.

2. The method for forming a semiconductor structure according to claim 1, characterized in that, the material of the substrate includes silicon, germanium, silicon germanide, silicon carbide, gallium arsenide or indium gallium.

3. The method for forming a semiconductor structure according to claim 1, characterized in that, the material of the first metal layer includes tungsten, cobalt or ruthenium.

4. The method for forming a semiconductor structure according to claim 1, the material of the second metal layer includes tungsten.

5. The method for forming a semiconductor structure according to claim 1, characterized in that, the method for forming the dielectric layer and the first opening includes: forming an initial dielectric layer on the surface of the substrate; forming a mask structure on the initial dielectric layer; forming a patterned layer on the mask structure, the patterned layer having an opening exposing a part of the mask structure; etching a part of the mask structure and the initial dielectric layer with the patterned layer as a mask until the top surface of the device structure is exposed, to form the dielectric layer and the first opening; after forming the dielectric layer and the first opening, removing the patterned layer and the mask structure.

6. The method for forming a semiconductor structure according to claim 5, characterized in that, the material of the initial dielectric layer includes silicon dioxide, low-k dielectric material or ultra-low-k dielectric material.

7. The method for forming a semiconductor structure according to claim 1, characterized in that, the ions used in the first sputtering process include argon ions or helium ions.

8. The method for forming a semiconductor structure according to claim 1, characterized in that, the process parameters of the first sputtering process include: sputtering time 5s - 10s, sputtering power 300W - 400W.

9. The method for forming a semiconductor structure according to claim 1, characterized in that, the second metal layer fills the first opening.

10. The method for forming a semiconductor structure according to claim 1, characterized in that, Each time the sputtering growth process includes: forming a second adhesion layer on the sidewall surface of the first opening by using a second sputtering treatment; forming a third metal layer in the first opening by using a second metal selective growth process.

11. The method for forming a semiconductor structure according to claim 10, wherein, the second sputtering treatment bombards the surface of the second metal layer exposed at the bottom of the first opening, so that the metal material on the surface of the second metal layer is sputtered onto the sidewall surface of the first opening to form the second adhesion layer; or, the second sputtering treatment bombards the surface of the third metal layer exposed at the bottom of the first opening, so that the metal material on the surface of the third metal layer is sputtered onto the sidewall surface of the first opening to form the second adhesion layer.

12. The method for forming a semiconductor structure according to claim 10, wherein, the second metal selective growth process forms the third metal layer on the surface of the second metal layer exposed at the bottom of the first opening and on the surface of the second adhesion layer exposed on the sidewall of the first opening; or, the second metal selective growth process forms the third metal layer on the surface of the third metal layer exposed at the bottom of the first opening and on the surface of the second adhesion layer exposed on the sidewall of the first opening.

13. The method for forming a semiconductor structure according to claim 10, wherein, the ions used in the second sputtering treatment include argon ions or helium ions.

14. The method for forming a semiconductor structure according to claim 10, wherein, the process parameters of each second sputtering treatment include: sputtering time of 5 s to 10 s and sputtering power of 300 W to 400 W.

15. The method for forming a semiconductor structure according to claim 10, wherein, the material of the third metal layer includes tungsten.

16. A semiconductor structure formed by the method according to any one of claims 1 to 15, wherein, it includes: a substrate having a first metal layer therein; a dielectric layer located on the substrate, and the dielectric layer has a first opening exposing the top surface of the first metal layer; a first adhesion layer located on the sidewall surface of the first opening; a second metal layer located on the sidewall surface of the first adhesion layer and on the top surface of the first metal layer.

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