阅读说明：本技术 半导体结构及其形成方法 (Semiconductor structure and forming method thereof ) 是由 周飞 于 2018-05-25 设计创作，主要内容包括：一种半导体结构及其形成方法,其中形成方法包括：提供基底,所述基底表面具有栅极结构,所述栅极结构两侧的基底内分别具有源漏掺杂区；在所述栅极结构的部分侧壁形成保护层；在所述基底和源漏掺杂区上、以及保护层的侧壁形成第一介质层；去除部分第一介质层,直至暴露出源漏掺杂区的顶部表面,在所述第一介质层内形成接触孔；在所述接触孔内形成插塞。所述方法形成的半导体器件的性能较好。(A kind of semiconductor structure and forming method thereof, wherein forming method includes: offer substrate, and the substrate surface has gate structure, is respectively provided with source and drain doping area in the substrate of the gate structure two sides；Protective layer is formed in the partial sidewall of the gate structure；In the substrate and source and drain doping area and the side wall of protective layer forms first medium floor；Part first medium layer is removed, until exposing the top surface in source and drain doping area, forms contact hole in the first medium layer；Plug is formed in the contact hole.The better performances for the semiconductor devices that the method is formed.)

1. a kind of forming method of semiconductor structure characterized by comprising

Substrate is provided, the substrate surface has gate structure, is respectively provided with source and drain in the substrate of the gate structure two sides and mixes Miscellaneous area；

Protective layer is formed in the partial sidewall of the gate structure；

In the substrate and source and drain doping area and the side wall of protective layer forms first medium floor；

Part first medium is removed, until exposing the top surface in source and drain doping area, is formed and is connect in the first medium layer Contact hole；

Plug is formed in the contact hole.

2. the forming method of semiconductor structure as described in claim 1, which is characterized in that the material of the protective layer includes nitrogen SiClx or silicon oxynitride；The thickness of the protective layer are as follows: 1 nanometer~35 nanometers.

3. the forming method of semiconductor structure as described in claim 1, which is characterized in that formed before the protective layer, institute State forming method further include: in the substrate and source and drain doping area and the partial sidewall of gate structure forms second medium Layer, and it is lower than the top surface of gate structure at the top of the second dielectric layer；The contact hole also extends through second dielectric layer.

4. the forming method of semiconductor structure as claimed in claim 3, which is characterized in that formed before second dielectric layer, institute State forming method further include: form stop-layer in the side wall of source and drain doping area surface and gate structure.

5. the forming method of semiconductor structure as claimed in claim 4, which is characterized in that the material of the stop-layer includes nitrogen SiClx；The thickness of the stop-layer are as follows: 1 nanometer~25 nanometers.

6. the forming method of semiconductor structure as claimed in claim 4, which is characterized in that the side wall of the gate structure also has There is sidewall structure, and the sidewall structure is between gate structure and stop-layer；The material of the sidewall structure includes nitridation Silicon；The thickness of the sidewall structure are as follows: 5 nanometers~60 nanometers；The sidewall structure includes positioned at the first of gate structure sidewall Side wall and the second side wall positioned at the first side wall side wall；The thickness of first side wall are as follows: 3 nanometers~20 nanometers；Described second The thickness of side wall are as follows: 2 nanometers~40 nanometers.

7. the forming method of semiconductor structure as claimed in claim 3, which is characterized in that the protective layer also covers second Jie Matter layer top surface；The gate structure includes grid layer.

8. the forming method of semiconductor structure as claimed in claim 7, which is characterized in that when the material of the grid layer is more When crystal silicon, the first medium layer also covers the top of gate structure；The forming method of the contact hole includes: removal part the One dielectric layer forms the first opening until exposing protective layer in the first medium layer；Remove first opening The protective layer and second dielectric layer of bottom form the second opening in the protective layer and second dielectric layer；The contact hole packet Include the first opening and the second opening.

9. the forming method of semiconductor structure as claimed in claim 7, which is characterized in that when the material of the grid layer is gold When category, the gate structure, source and drain doping area, second dielectric layer, the forming method of first medium floor and protective layer include: in institute It states substrate surface and forms pseudo- grid structure；Source and drain doping area is formed in the substrate of dummy gate structure two sides；In the substrate and In source and drain doping area and the partial sidewall of pseudo- grid structure forms the second dielectric layer；In the second medium layer surface and The partial sidewall of pseudo- grid structure forms protective layer；First medium layer is formed in the protective layer, the first medium layer is sudden and violent Expose the top surface of pseudo- grid structure；Dummy gate structure is removed, is formed in the first medium layer and second dielectric layer pseudo- Grid opening；Gate structure is formed in the pseudo- grid opening.

10. the forming method of semiconductor structure as claimed in claim 7, which is characterized in that when the material of the grid layer is When metal, the first medium layer exposes the top surface of gate structure；Formed first medium layer after, formed contact hole it Before, the forming method includes: the formation third dielectric layer at the top of the first medium layer and gate structure.

11. the forming method of semiconductor structure as claimed in claim 10, which is characterized in that the forming method of the contact hole It include: the third dielectric layer and first medium floor at the top of the removal source and drain doping area, until exposing at the top of protective layer, in institute It states and forms the first opening in third dielectric layer and first medium layer；Remove the protective layer and second medium of first open bottom Layer forms the second opening in the protective layer and second dielectric layer；The contact hole includes the first opening and the second opening.

12. the forming method of the semiconductor structure as described in claim 8 or 11, which is characterized in that the depth of first opening Wide ratio are as follows: 30:1~100:1；, the depth-to-width ratio of second opening are as follows: 10:1~50:1.

13. a kind of semiconductor structure characterized by comprising

Substrate, the substrate surface have gate structure, have source and drain doping area in the substrate of the gate structure two sides；

Positioned at the protective layer of the gate structure partial sidewall；

In the substrate and source and drain doping area and the first medium floor of protective layer side wall；

Contact hole in the first medium layer, the contact hole bottom-exposed go out the top surface in source and drain doping area；

Plug in the contact hole.

14. semiconductor structure as claimed in claim 13, which is characterized in that the material of the protective layer include silicon nitride or Silicon oxynitride；The thickness of the protective layer are as follows: 1 nanometer~35 nanometers.

15. semiconductor structure as claimed in claim 13, which is characterized in that the semiconductor structure further include be located at substrate and In source and drain doping area and the second dielectric layer of gate structure partial sidewall, the second dielectric layer are located at first medium layer bottom Portion, and the protective layer also covers second dielectric layer top surface.

16. semiconductor structure as claimed in claim 15, which is characterized in that the semiconductor structure further includes being located at second to be situated between Stop-layer between matter floor and source and drain doping area and gate structure；The material of the stop-layer includes silicon nitride；The stop-layer Thickness are as follows: 1 nanometer~25 nanometers.

17. semiconductor structure as claimed in claim 16, which is characterized in that the semiconductor structure further includes being located at stop-layer Sidewall structure between gate structure；The material of the sidewall structure includes silicon nitride；The thickness of the sidewall structure are as follows: 5 Nanometer~60 nanometers；The sidewall structure includes the first side wall positioned at gate structure sidewall and the positioned at the first side wall side wall Two side walls；The thickness of first side wall are as follows: 3 nanometers~20 nanometers；The thickness of second side wall are as follows: 2 nanometers~40 nanometers.

18. semiconductor structure as claimed in claim 15, which is characterized in that the gate structure includes grid layer, the grid When pole layer is polysilicon, the first medium layer also covers grid structural top；The contact hole includes being located at first medium layer The first interior opening and the second opening in the first open bottom protective layer and second dielectric layer.

19. semiconductor structure as claimed in claim 15, which is characterized in that the gate structure includes grid layer, the grid When pole layer is metal, the first medium layer exposes the top of gate structure；The semiconductor structure further includes being located at first Third dielectric layer at the top of dielectric layer and gate structure；The contact hole includes being located in third dielectric layer and first medium layer First opening and the second opening in the first open bottom protective layer and second dielectric layer.

20. the semiconductor structure as described in claim 18 or 19, which is characterized in that the depth-to-width ratio of first opening are as follows: 30: 1~100:1；The depth-to-width ratio of second opening are as follows: 10:1~50:1.

Technical field

The present invention relates to field of semiconductor manufacture more particularly to a kind of semiconductor structure and forming method thereof.

Background technique

MOS (Metal-oxide-semicondutor) transistor is a kind of important semiconductor devices, the basic knot of MOS transistor Structure includes: semiconductor substrate；Positioned at the gate structure of semiconductor substrate surface；In the semiconductor substrate of gate structure side Source region and the gate structure other side semiconductor substrate in drain region.

However, the performance of MOS transistor is poor with the raising of semiconductor devices integrated level.

Summary of the invention

The technical problem to be solved by the present invention is to provide a kind of semiconductor structures and forming method thereof, to improve semiconductor devices Performance.

In order to solve the above technical problems, the embodiment of the present invention provides a kind of forming method of semiconductor structure, comprising: provide Substrate, the substrate surface have gate structure, are respectively provided with source and drain doping area in the substrate of the gate structure two sides；Institute The partial sidewall for stating gate structure forms protective layer；In the substrate and source and drain doping area and the side wall of protective layer is formed First medium layer；Part first medium layer is removed, until the top surface in source and drain doping area is exposed, in the first medium layer Interior formation contact hole；Plug is formed in the contact hole.

Optionally, the material of the protective layer includes silicon nitride or silicon oxynitride；The thickness of the protective layer are as follows: 1 receives Rice~35 nanometers.

Optionally, it is formed before the protective layer, the forming method further include: in the substrate and source and drain doping area Upper and gate structure partial sidewall forms second dielectric layer, and is lower than the top of gate structure at the top of the second dielectric layer Portion surface；The contact hole also extends through second dielectric layer.

Optionally, formed before second dielectric layer, the forming method further include: on source and drain doping area surface and The side wall of gate structure forms stop-layer.

Optionally, the material of the stop-layer includes silicon nitride；The thickness of the stop-layer are as follows: 1 nanometer~25 nanometers.

Optionally, the side wall of the gate structure also has a sidewall structure, and the sidewall structure be located at gate structure and Between stop-layer；The material of the sidewall structure includes silicon nitride；The thickness of the sidewall structure are as follows: 5 nanometers~60 nanometers；Institute Stating sidewall structure includes the second side wall positioned at the first side wall of gate structure sidewall and positioned at the first side wall side wall；Described first The thickness of side wall are as follows: 3 nanometers~20 nanometers；The thickness of second side wall are as follows: 2 nanometers~40 nanometers.

Optionally, the protective layer also covers second dielectric layer top surface；The gate structure includes grid layer.

Optionally, when the material of the grid layer is polysilicon, the first medium layer also covers the top of gate structure Portion；The forming method of the contact hole includes: removal part first medium layer, until expose protective layer, described the The first opening is formed in one dielectric layer；The protective layer and second dielectric layer for removing first open bottom, in the protective layer It is open with forming second in second dielectric layer；The contact hole includes the first opening and the second opening.

Optionally, when the material of the grid layer be metal when, the gate structure, source and drain doping area, second dielectric layer, The forming method of first medium layer and protective layer includes: to form pseudo- grid structure in the substrate surface；In dummy gate structure two Source and drain doping area is formed in the substrate of side；In the substrate and source and drain doping area and the partial sidewall of pseudo- grid structure is formed The second dielectric layer；Protective layer is formed in the partial sidewall of the second medium layer surface and pseudo- grid structure；In the protection Layer surface forms first medium layer, and the first medium layer exposes the top surface of pseudo- grid structure；Dummy gate structure is removed, Pseudo- grid opening is formed in the first medium layer and second dielectric layer；Gate structure is formed in the pseudo- grid opening.

Optionally, when the material of the grid layer is metal, the first medium layer exposes the top of gate structure Surface；It is formed after first medium layer, is formed before contact hole, the forming method includes: in the first medium layer and grid Pole structural top forms third dielectric layer.

Optionally, the forming method of the contact hole include: third dielectric layer at the top of the removal source and drain doping area and First medium layer forms the first opening until exposing at the top of protective layer in the third dielectric layer and first medium layer；It goes Except the protective layer and second dielectric layer of first open bottom, second is formed in the protective layer and second dielectric layer and is opened Mouthful；The contact hole includes the first opening and the second opening.

Optionally, the depth-to-width ratio of first opening are as follows: 30:1~100:1；The depth-to-width ratio of second opening are as follows: 10:1 ~50:1.

The present invention also provides a kind of semiconductor structures, comprising: substrate, the substrate surface have gate structure, the grid Source and drain doping area is respectively provided in the substrate of pole structure two sides；Positioned at the protective layer of the gate structure partial sidewall；Positioned at institute It states in substrate and source and drain doping area and the first medium floor of protective layer partial sidewall；Connecing in the first medium layer Contact hole, the contact hole bottom-exposed go out the top surface in source and drain doping area；Plug in the contact hole.

Optionally, the material of the protective layer includes silicon nitride or silicon oxynitride；The thickness of the protective layer are as follows: 1 receives Rice~35 nanometers.

Optionally, the semiconductor structure further includes in substrate and source and drain doping area and the side of gate structure part The second dielectric layer of wall, the second dielectric layer is located at first medium layer bottom, and the protective layer also covers second dielectric layer Top surface.

Optionally, the semiconductor structure further includes between second dielectric layer and source and drain doping area and gate structure Stop-layer；The material of the stop-layer includes silicon nitride；The thickness of the stop-layer are as follows: 1 nanometer~25 nanometers.

Optionally, the semiconductor structure further includes the sidewall structure between stop-layer and gate structure；The side The material of wall construction includes silicon nitride；The thickness of the sidewall structure are as follows: 5 nanometers~60 nanometers；The sidewall structure includes position The first side wall in gate structure sidewall and the second side wall positioned at the first side wall side wall；The thickness of first side wall are as follows: 3 receive Rice~20 nanometers；The thickness of second side wall are as follows: 2 nanometers~40 nanometers.

Optionally, the gate structure includes grid layer, and when the grid layer is polysilicon, the first medium layer also covers At the top of lid gate structure；The contact hole includes the first opening in first medium layer and is located at the first open bottom The second opening in protective layer and second dielectric layer.

Optionally, the gate structure includes grid layer, and when the grid layer is metal, the first medium layer exposes The top of gate structure；The semiconductor structure further includes the third dielectric layer at the top of first medium layer and gate structure； The contact hole includes the first opening in third dielectric layer and first medium layer and protects positioned at the first open bottom The second opening in layer and second dielectric layer.

Optionally, the depth-to-width ratio of first opening are as follows: 30:1~100:1；The depth-to-width ratio of second opening are as follows: 10:1 ~50:1.

Compared with prior art, the technical solution of the embodiment of the present invention has the advantages that

In the forming method for the semiconductor structure that technical solution of the present invention provides, formed before first medium layer, described The partial sidewall of gate structure forms protective layer so that gate structure and the subsequent plug distance in first medium layer compared with Far, then the protective layer between gate structure and plug and first medium layer be not easy it is breakdown, therefore, between gate structure and plug It is not susceptible to leak electricity, is conducive to the performance for improving semiconductor devices.

Further, it is formed before the protective layer, the forming method further includes in source and drain doping area surface and grid Structure side wall forms stop-layer.Wherein, positioned at source and drain doping area stop-layer for when being subsequently formed contact hole as stop-layer, For protecting source and drain doping area top surface；And be located at the stop-layer of gate structure sidewall so that gate structure to plug away from From farther.

Further, also there is sidewall structure, the sidewall structure arrives plug between the stop-layer and gate structure The distance between gate structure further increases.

Further, it is formed after the stop-layer, is formed before protective layer, the forming method includes forming described second Dielectric layer, the second dielectric layer top is lower than at the top of gate structure.The protective layer also covers the top table of second dielectric layer Face, subsequent touch hole are formed by two steps, it may be assumed that form the first opening；It is formed after the first opening, in first open bottom Form the second opening.Formation first be open during, the protective layer be used as stop-layer, then first be open depth-to-width ratio compared with It is small, so that the difficulty for forming the first opening is lower.It is formed after the first opening, forms the second opening, so that the depth of the second opening Wide smaller than also, therefore, also helping reduces the difficulty for forming the second opening.

Detailed description of the invention

Fig. 1 is a kind of structural schematic diagram of semiconductor structure；

Fig. 2 to Figure 14 is the structural schematic diagram of each step of one embodiment of forming method of semiconductor structure of the present invention.

Specific embodiment

As described in background, the performance of semiconductor devices is still poor.

Fig. 1 is a kind of structural schematic diagram of semiconductor structure.

Referring to FIG. 1, substrate 100；Gate structure 101 positioned at 100 surface of substrate, the gate structure 101 Side wall has side wall 102；Source and drain doping area 103 in 102 two sides substrate 100 of the gate structure 101 and side wall；It is located at The dielectric layer 104 of substrate 100 and 101 surface of gate structure and 103 side wall of side wall 102 and source and drain doping area, the dielectric layer There is contact hole (not marking in figure) in 104, the contact hole bottom-exposed goes out 103 top of source and drain doping area；It is opened positioned at described Plug 105 in mouthful.

In above-mentioned semiconductor structure, the forming method of the contact hole includes: to form exposure mask on 104 surface of dielectric layer Layer, the mask layer expose the top surface of dielectric layer 104 in source and drain doping area 103；Using the mask layer as exposure mask, etching The dielectric layer 104 forms contact hole in the dielectric layer 104 until exposing the top surface in source and drain doping area 103. Using the mask layer as exposure mask, the technique for etching the dielectric layer 104 includes dry etch process, the dry etch process packet Etching gas is included, in order to which the top for enabling etching gas to reach source and drain doping area 103 exposes the top in source and drain doping area 103 Portion, need to reduce the depth-to-width ratio of contact hole, specifically, increasing the contact hole along perpendicular in 101 sidewall direction of gate structure Size.

However, when one timing of maximum distance in the source and drain doping area 103 to 101 side wall of gate structure, the contact hole Edge is larger perpendicular to the size in 101 sidewall direction of gate structure, so that the dielectric layer between plug 105 and gate structure 101 104 and side wall 102 along smaller perpendicular to the size in 101 sidewall direction of gate structure.And the plug 105 and gate structure Dielectric layer 104 between 101 and side wall 102 are therefore, described for realizing the electric isolution between gate structure 101 and plug 105 The ability of dielectric layer 104 and the isolation plug 105 of side wall 102 and gate structure 101 between plug 105 and gate structure 101 is not It is enough, it may be assumed that the dielectric layer 104 and side wall 102 between plug 105 and gate structure 101 are easily breakdown, then the plug 105 and gold Belong to and easily leaking electricity between grid 101, is unfavorable for improving the performance of semiconductor devices.

To solve the technical problem, the present invention provides a kind of forming methods of semiconductor structure, comprising: in the grid The partial sidewall of pole structure forms protective layer；In the substrate and source and drain doping area and the side wall of protective layer forms first Dielectric layer；Part first medium layer is removed, until exposing the top surface in source and drain doping area, the shape in the first medium layer At contact hole.The better performances for the semiconductor devices that the method is formed.

It is understandable to enable above-mentioned purpose of the invention, feature and beneficial effect to become apparent, with reference to the accompanying drawing to this The specific embodiment of invention is described in detail.

Fig. 2 to Figure 14 is the structural schematic diagram of each step of one embodiment of forming method of semiconductor structure of the present invention.

Referring to FIG. 2, providing substrate 200.

In the present embodiment, the substrate 200 includes: substrate 201 and the fin 202 on substrate 201.

In other embodiments, when the semiconductor devices is the MOS transistor of plane formula, the substrate is plane formula Semiconductor base.

In the present embodiment, the forming method of the substrate 200 includes: offer initial substrate, is had on the initial substrate There is the first mask layer (not shown), first mask layer exposes the top surface of part initial substrate；With described One mask layer is exposure mask, etches the initial substrate, forms substrate 201 and the fin 202 on substrate 201.

In other embodiments, the forming method of the substrate includes: offer substrate；It is epitaxially formed in the substrate surface The fin.

In the present embodiment, the material of the initial substrate is silicon.Correspondingly, the material of the substrate 201 and fin 202 For silicon.

In other embodiments, the material of the initial substrate includes: germanium, SiGe, silicon-on-insulator or germanium on insulator. Correspondingly, the material of substrate includes: germanium, SiGe, silicon-on-insulator or germanium on insulator.The material of fin include: germanium, SiGe, Silicon-on-insulator or germanium on insulator.

The material of first mask layer includes silicon nitride, and the formation process of first mask layer includes: chemical gaseous phase Depositing operation.First mask layer is used to form the exposure mask of substrate 201 and fin 202.

Using first mask layer as exposure mask, the technique for etching the initial substrate includes: dry etch process and wet process One of etching technics or two kinds.

Also there is the isolation structure (not marking in figure) for covering the fin 202, the isolation structure in the substrate 200 Top surface be lower than the fin 202 top surface, and cover fin 202 partial sidewall.

The material of the isolation structure includes: silica.In other embodiments, the material of the isolation structure can be with For silicon oxynitride, silicon nitride.

The isolation structure is for realizing the electrical isolation between semiconductor different components.

In the present embodiment, the substrate 200 includes the first area A and the second area B, and the firstth area A is used to form PMOS Transistor, the secondth area B are used to form NMOS transistor.

In other embodiments, the substrate only includes the firstth area, and firstth area is used to form PMOS transistor；Or Person, firstth area are used to form NMOS transistor.

Referring to FIG. 3, being developed across several pseudo- grid structures 203 of fin 202；In the side wall shape of dummy gate structure 203 At the first side wall 204.

In the present embodiment, the substrate 200 includes the first area A and the second area B, and several puppet grid structures 203 are across first The fin 202 of area A, fin 202 of several puppet grid structures 203 across the second area B.

The forming method of dummy gate structure 203 includes: that pseudo- gate dielectric film is formed in the substrate 200；In the puppet Dummy grid film is formed on gate dielectric film, there is the second mask layer (not marking in figure) on the dummy grid film, second exposure mask Layer exposes part dummy grid film；Using second mask layer as exposure mask, the dummy grid film and pseudo- gate dielectric film are etched, is formed Pseudo- grid structure 203.

The material of the puppet gate dielectric film includes silica, and the formation process of the puppet gate dielectric film includes: chemical gaseous phase Depositing operation.

The material of the dummy grid film includes silicon, and the formation process of the dummy grid film includes: chemical vapor deposition process.

Dummy gate structure 203 includes pseudo- gate dielectric layer (not shown) and the dummy grid positioned at pseudo- gate dielectric layer surface Layer (not shown).

The puppet gate dielectric film is used to form pseudo- gate dielectric layer, and therefore, the material of the puppet gate dielectric layer includes silica.

The dummy grid film is used to form dummy gate layer, and therefore, the material of the dummy gate layer includes silicon.

In the present embodiment, dummy gate structure 203 is for being subsequently formed gate structure.In other embodiments, described Pseudo- grid structure is gate structure.

The forming method of first side wall 204 includes: in the isolation structure and 200 surface of substrate and pseudo- grid knot The side wall and top surface of structure 203 form the first side wall film；Remove the of 203 top of isolation structure, substrate 200 and pseudo- grid structure One side wall film forms the first side wall 204 in the side wall of dummy gate structure 203.

The material of the first side wall film includes silicon nitride or silicon oxynitride, correspondingly, the material of first side wall 204 Material includes silicon nitride or silicon oxynitride.The formation process of the first side wall film includes: chemical vapor deposition process, physics gas Phase depositing operation or atom layer deposition process.

First side wall 204 is used to define the position of subsequent lightly doped district.

First side wall 204 is along perpendicular to the size in pseudo- 203 sidewall direction of grid structure are as follows: 3 nanometers~20 nanometers.Institute It states the first side wall 204 and makes the distance between the subsequent plug in source and drain doping area and gate structure farther out, be conducive to prevent Only leak electricity between plug and gate structure.

Referring to FIG. 4, the side wall in first side wall 204 forms the second side wall 205；In dummy gate structure 203, Source and drain doping area 206 is formed in the fin 202 of 205 two sides of one side wall 204 and the second side wall.

It is formed after first side wall 204, is formed before the second side wall 205, the forming method further include: with described Pseudo- grid structure 203 and the first side wall 204 are exposure mask, in the fin 202 of 204 two sides of dummy gate structure 203 and the first side wall Form lightly doped district (not shown).

It is exposure mask with dummy gate structure 203 and the first side wall 204, in 204 liang of dummy gate structure 203 and the first side wall It includes ion implantation technology that the technique of lightly doped district is formed in the fin 202 of side.

Have in the lightly doped district and ion, the type phase of the conduction type that ion is lightly doped and transistor is lightly doped It closes.In the present embodiment, the firstth area A is used to form PMOS transistor, and therefore, the ion that is lightly doped of the firstth area A is P Type ion, such as: boron ion；The secondth area B is used to form NMOS transistor, and therefore, the ion that is lightly doped of the secondth area B is N-type ion, such as: phosphonium ion or arsenic ion.

The forming method of second side wall 205 includes: in the isolation structure, source and drain doping area 206 and pseudo- grid structure The side wall of 203 top surface and the first side wall 204 forms the second side wall film；Remove isolation structure, source and drain doping area 206 With the second side wall film of the top surface of pseudo- grid structure 203, the second side wall 205 is formed in the side wall of first side wall 204.

The material of the second side wall film includes: silicon nitride or silicon oxynitride, the formation process of the second side wall film It include: chemical vapor deposition process, physical gas-phase deposition or atom layer deposition process.

Remove the technique packet of the second side wall film of the top surface of isolation structure, source and drain doping area 206 and pseudo- grid structure 203 It includes: one of dry etch process and wet-etching technology or two kinds of combinations.

Second side wall 205 is used to define the position of subsequent source and drain doped region 206.

The thickness of second side wall 205 are as follows: 2 nanometers~40 nanometers.

Second side wall 205 and the first side wall 204 constitute sidewall structure, and the sidewall structure is along perpendicular to pseudo- grid structure Size in 203 sidewall directions are as follows: 5 nanometers~60 nanometers.The sidewall structure is along perpendicular in pseudo- 203 sidewall direction of grid structure Size it is larger so that the subsequent plug formed at the top of source and drain doping area 206 to pseudo- 203 side wall of grid structure distance farther out, Since dummy gate structure 203 is for being subsequently formed gate structure, then the distance between plug to gate structure farther out so that slotting It fills in and is not susceptible to leak electricity between the gate structure that is subsequently formed, be conducive to the better performances for improving semiconductor devices.

The forming method in the source and drain doping area 206 includes: in dummy gate structure 203, the first side wall 204 and second side Source and drain opening is formed in the fin 202 of 205 two sides of wall；Epitaxial layer (not shown) is formed in the source and drain is open；Institute It states and mixes source and drain ion in epitaxial layer, form the source and drain doping area 206.

The material and the conduction type of source and drain ion and the type of transistor of the epitaxial layer are related.In the present embodiment, The firstth area A is used to form PMOS transistor, and therefore, the material of the epitaxial layer of the firstth area A includes: SiGe or silicon, The source and drain ion in the firstth area is P-type ion, such as: boron ion；The secondth area B is used to form NMOS transistor, therefore, described The material of the epitaxial layer of two area B includes: silicon carbide or silicon, and the source and drain ion in the secondth area is N-type ion, such as: phosphonium ion or Arsenic ion.

In the present embodiment, it is formed after the source and drain doping area in the firstth area, forms the source and drain doping area in the secondth area.At other It in embodiment, is formed before the source and drain doping area in the firstth area, forms the source and drain doping area in the secondth area.

Referring to FIG. 5, in the isolation structure, the surface in source and drain doping area 206 and pseudo- grid structure 203 and second side The side wall of wall 205 forms stop-layer 207.

The material of the stop-layer 207 includes silicon nitride or silicon oxynitride.The formation process of the stop-layer 207 includes Chemical vapor deposition process, physical gas-phase deposition or atom layer deposition process.

The thickness of the stop-layer 207 are as follows: 1 nanometer~25 nanometers.

The stop-layer 207 protects the top surface in source and drain doping area 206 when being used to be subsequently formed contact hole.The stopping Layer 207 is also located at the side wall of pseudo- grid structure 203, so that the distance of the plug being subsequently formed to gate structure further increases, then It is not susceptible to leak electricity between plug and gate structure.The better performances for the semiconductor devices that the method is formed.

Referring to FIG. 6, forming second dielectric layer 208,208 top of second dielectric layer on 207 surface of stop-layer Lower than the top surface of pseudo- grid structure 203.

The forming method of the second dielectric layer 208 includes: to form second medium film on 207 surface of stop-layer；It returns Etched portions second medium film forms the second dielectric layer 208.

The material of the second medium film includes silica or silicon oxynitride, the formation process packet of the second medium film It includes: chemical vapor deposition process or physical gas-phase deposition.

Be etched back to part second medium film technique include: one of dry etch process and wet-etching technology or Two kinds of combinations.

The second dielectric layer 208 is for realizing the electric isolution between semiconductor different components.

It is formed after the second dielectric layer 208, so that the depth-to-width ratio of groove reduces between adjacent puppet grid structure 203, is had It is subsequently formed the difficulty of first medium layer conducive to reducing, the consistency for being formed by first medium layer is preferable, is conducive to raising the The isolation performance of one dielectric layer.

Referring to FIG. 7, being formed after the second dielectric layer 208, is formed and protected in the partial sidewall of dummy gate structure 203 Sheath 209.

The material of the protective layer 209 includes: silicon nitride or silicon oxynitride, the formation process packet of the protective layer 209 It includes: chemical vapor deposition process or physical gas-phase deposition.

The thickness of the protective layer 209 are as follows: 1 nanometer~35 nanometers, the meaning of the protective layer 209 is selected to be: if institute The thickness of protective layer 209 is stated less than 1 nanometer, so that the subsequent plug formed at the top of source and drain doping area 206 is to gate structure Distance is still smaller, so that easily leaking electricity between plug and gate structure；When one timing of making space of semiconductor devices, if institute The thickness for stating protective layer 209 is greater than 35 nanometers, so that the subsequent contact hole formed at the top of source and drain doping area 206 is along perpendicular to grid Undersized on the structure side wall direction of pole, then etching gas is difficult to reach the bottom of contact hole, so that source and drain doping area 206 is pushed up Portion is difficult to be opened, so that the subsequent plug in contact hole is difficult to be electrically connected with source and drain doping area 206.

In the present embodiment, the protective layer 209 also covers 208 top surface of second dielectric layer.In other embodiments, The protective layer is only located at the side wall of pseudo- grid structure 203.

In the present embodiment, the protective layer 209 covers the top surface of second dielectric layer 208, so that being subsequently formed the When one opening, the protective layer 209 is used as stop-layer, so that the depth-to-width ratio of the first opening is smaller, advantageously reduces to form first The difficulty of opening.

Referring to FIG. 8, forming first medium film 210 on 209 surface of protective layer.

The material of the first medium film 210 includes silica or silicon oxynitride, the formation of the first medium film 210 Technique includes chemical vapor deposition process or physical gas-phase deposition.

The first medium film 210 is for realizing the electric isolution between semiconductor different components.

In the present embodiment, for dummy gate structure 203 for being subsequently formed gate structure, the gate structure includes grid Layer, the material of the grid layer are metal, and the first medium film 210 is for being subsequently formed first medium layer.

In other embodiments, dummy gate structure is gate structure, and the material of the grid layer is polysilicon, described First medium film is first medium layer, it may be assumed that the first medium layer also covers the top surface of gate structure.

Referring to FIG. 9, removal part first medium film 210 is formed until exposing the top surface of pseudo- grid structure 203 First medium layer 211.

The technique for removing part first medium film 210 includes: chemical mechanical milling tech.

During removing part first medium film 210, protective layer 209, the stop-layer at 203 top of dummy gate structure 207 and second mask layer be removed.

Part first medium film 210 is removed, the top surface of pseudo- grid structure 203 is exposed, is conducive to the pseudo- grid of subsequent removal Structure 203.

Referring to FIG. 10, removal dummy gate structure 203, the shape in the first medium layer 211 and second dielectric layer 208 (not marking in figure) is open at pseudo- grid；Gate structure 212 is formed in the pseudo- grid opening.

The method of removal dummy gate structure 203 includes: the removal dummy gate layer；After removing the dummy gate layer, Remove pseudo- gate dielectric layer.

The technique for removing the dummy gate layer includes one of dry etch process and wet-etching technology or two kinds Combination.

The technique for removing pseudo- gate dielectric layer includes one of dry etch process and wet-etching technology or two kinds of groups It closes.

The puppet grid opening is for accommodating gate structure 212.

The gate structure 212 includes gate dielectric layer (not shown) and the grid layer (figure positioned at gate dielectric layer surface In be not shown).

The material of the gate dielectric layer is high dielectric constant (dielectric constant K is greater than 3.9) material.In the present embodiment, institute The material for stating gate dielectric layer is hafnium oxide.In other embodiments, the material of the gate dielectric layer includes: La₂O₃、HfSiON、 HfAlO₂、ZrO₂、Al₂O₃Or HfSiO₄。

The material of the grid layer is metal.In the present embodiment, the material of the grid layer is aluminium.In other embodiments In, the material of the grid layer includes: Al, Cu, Ag, Au, Ni, Ti, W, WN or WSi.

Figure 11 is please referred to, forms third dielectric layer 213 in the first medium layer 211 and 212 surface of gate structure, it is described 213 surface of third dielectric layer has third mask layer (not marking in figure), and the third mask layer exposes part third medium The top surface of layer 213.

The material of the third dielectric layer 213 includes silica or silicon oxynitride.The formation of the third dielectric layer 213 Technique includes chemical vapor deposition process or physical gas-phase deposition.

The third dielectric layer 213 is for realizing the electric isolution between semiconductor different components.

The third mask layer is used to define the positions and dimensions of 206 top contact hole of source and drain doping area.

The material of the third mask layer includes silicon nitride or titanium nitride.

Figure 12 is please referred to, using the third mask layer as exposure mask, etches the third dielectric layer 213 and second dielectric layer 211, until expose the top surface of protective layer 209, the is formed in the third dielectric layer 213 and first medium layer 211 One opening 214.

Using the third mask layer as exposure mask, the technique for etching the third dielectric layer 213 and first medium layer 211 includes One of dry etch process and wet-etching technology or two kinds of combinations.

During forming first opening 214, the protective layer 209 at 208 top of second dielectric layer is used as stop-layer, So that the depth-to-width ratio of the first opening 214 is smaller, specifically, the depth-to-width ratio of first opening 214 are as follows: 30:1~100:1, so that The difficulty for forming the first opening 214 is smaller.

Figure 13 is please referred to, protective layer 209, second dielectric layer 208 and the stop-layer of first opening, 214 bottoms are removed 207, until exposing the top surface in source and drain doping area 206, the second opening 215 is formed in first opening, 214 bottoms.

The technique for removing the protective layer 209 of first opening, 214 bottoms includes dry etch process and wet etching work One of skill or two kinds of combinations.

The technique for removing the first medium layer 208 of first opening, 214 bottoms includes that dry etch process and wet process are carved One of etching technique or two kinds of combinations.

The technique for removing the stop-layer 207 of first opening, 214 bottoms includes dry etch process and wet etching work One of skill or two kinds of combinations.

It is formed after the first opening 214, forms the second opening 215, so that the depth-to-width ratio of the second opening 215 is smaller, therefore, Advantageously reduce the difficulty to form the second opening 215.Specifically, the depth-to-width ratio of second opening 215 are as follows: 10:1~50:1.

First opening 214 and the second opening 215 constitute contact hole, and the contact hole is used for subsequent receiving plug.

Figure 14 is please referred to, forms plug in described first 214 (see Figure 13) of opening and second 215 (see Figure 13) of opening 216。

The forming method of the plug 216 includes: in 213 surface of third dielectric layer and the first opening 214 and the Plug film is formed in two openings 215；Partial plugs film is removed, until the top surface of third dielectric layer 213 is exposed, described Plug 216 is formed in first opening 214 and the second opening 215.

The material of the plug film is metal.In the present embodiment, the material of the plug film is tungsten.In other embodiments In, the material of the plug film includes aluminium or copper.The plug film is used to form plug 216, therefore, the plug 216 Material is metal.In the present embodiment, the material of the plug 216 is tungsten.In other embodiments, the material packet of the plug Include aluminium or copper.

The formation process of the plug film includes: chemical vapor deposition process or physical gas-phase deposition.

The technique for removing Partial plugs film includes chemical mechanical milling tech.

Since the side wall between the gate structure 212 and plug 216 not only covers the first side wall 204, the second side wall 205, stop-layer 207 and first medium layer 211 also have protective layer 209 between the gate structure 212 and plug 216, so that The distance between gate structure 212 and plug 216 farther out so that being not susceptible to leak between the gate structure 212 and plug 216 Electricity is conducive to the performance for improving semiconductor devices.

Correspondingly, the present invention also provides a kind of semiconductor structures, please continue to refer to Figure 14, comprising: substrate 200, the base 200 surface of bottom has gate structure 212, has source and drain doping area 206 in the substrate 200 of 212 two sides of gate structure；It is located at The protective layer 209 of 212 partial sidewall of gate structure；In the substrate 200 and source and drain doping area 206 and protect The first medium layer of 209 side wall of layer；Contact hole in the first medium layer, the contact hole bottom-exposed go out source and drain and mix The top surface in miscellaneous area 206；Plug 216 in the contact hole.

The material of the protective layer 209 includes silicon nitride or silicon oxynitride；The thickness of the protective layer 209 are as follows: 1 nanometer ~35 nanometers.

The semiconductor structure further includes in substrate 200 and source and drain doping area 206 and 212 part of gate structure The second dielectric layer 208 of side wall, the second dielectric layer 208 is located at 211 bottom of first medium layer, and the protective layer 209 is also Cover 208 top surface of second dielectric layer.

The semiconductor structure further includes between second dielectric layer 208 and source and drain doping area 206 and gate structure 212 Stop-layer 207；The material of the stop-layer 207 includes silicon nitride；The thickness of the stop-layer 207 are as follows: 1 nanometer~25 receive Rice.

The semiconductor structure further includes the sidewall structure between stop-layer 207 and gate structure 212；The side wall The material of structure includes silicon nitride；The thickness of the sidewall structure are as follows: 5 nanometers~60 nanometers；The sidewall structure includes being located at First side wall 204 of 212 side wall of gate structure and the second side wall 205 positioned at 204 side wall of the first side wall；First side wall 204 thickness are as follows: 3 nanometers~20 nanometers；The thickness of second side wall 205 are as follows: 2 nanometers~40 nanometers.

The gate structure 212 includes grid layer, and when the grid layer is polysilicon, the first medium layer 211 also covers 212 top of lid gate structure；The contact hole include first 214 (see Figure 13) of opening in the first medium layer 211 and Second 215 (see Figure 13) of opening in the first 214 bottom protective layers 209 of opening and second dielectric layer 208.

The gate structure includes grid layer, and when the grid layer is metal, the first medium layer 211 exposes grid The top of structure 212；The semiconductor structure further includes the third dielectric layer at the top of first medium layer and gate structure 213；The contact hole include first 214 (see Figure 13) of opening in the third dielectric layer 213 and first medium layer 211, with And second 215 (see Figure 13) of opening in the first 214 bottom protective layers 209 of opening and second dielectric layer 208.

The depth-to-width ratio of first opening 214 are as follows: 30:1~100:1；The depth-to-width ratio of second opening 215 are as follows: 10:1 ~50:1.

Although present disclosure is as above, present invention is not limited to this.Anyone skilled in the art are not departing from this It in the spirit and scope of invention, can make various changes or modifications, therefore protection scope of the present invention should be with claim institute Subject to the range of restriction.