Method for manufacturing fuse structure

Abstract

The present application discloses a method for manufacturing a fuse structure, and relates to the field of semiconductor manufacturing. The method for manufacturing the fuse structure includes forming a fuse part in a metal layer above a dielectric layer, and a barrier layer is arranged between the metal layer and the dielectric layer; forming a passivation layer; forming grooves in the dielectric layer on both sides of the fuse part through photolithography and etching processes; removing residual photoresist through ashing processes and wet cleaning processes, and introducing CF4 gas during the ashing process; after the photoresist is removed, the width of the barrier layer below the fuse part is smaller than the width of the fuse part; solving the problem that the current fuse structure takes a long time to blow; achieving the effect of improving the fuse structure blowing efficiency without increasing the process steps.

Description

Technical Field

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

[0002] The metal fuse in the semiconductor device is usually made at the same time as the metal wire. The metal wire is usually aluminum wire. In order to prevent the aluminum wire from oxidation or corrosion, a barrier layer is added between the aluminum wire and the dielectric layer below the aluminum wire. At nodes with relatively large line widths, the barrier layer is generally a Ti / TiN barrier layer.

[0003] However, the melting point of TiN is as high as 3000°C, and it is difficult to blow the fuse for a metal fuse structure using electric melting. Summary of the invention

[0004] In order to solve the problems in the related art, the present application provides a method for manufacturing a fuse structure. The technical solution is as follows:

[0005] On the one hand, an embodiment of the present application provides a method for manufacturing a fuse structure, the method comprising:

[0006] A fuse is formed in the metal layer above the dielectric layer, and a barrier layer is provided between the metal layer and the dielectric layer;

[0007] forming a passivation layer;

[0008] By means of photolithography and etching processes, grooves are formed in the dielectric layer on both sides of the fuse portion;

[0009] Residual photoresist is removed by an ashing process and a wet cleaning process, and CF4 gas is introduced during the ashing process;

[0010] After the photoresist is removed, the width of the barrier layer below the fuse portion is smaller than the width of the fuse portion.

[0011] Optionally, after removing the residual photoresist by an ashing process and a wet cleaning process, the method further comprises:

[0012] A protective layer is formed on both sides of the fuse portion.

[0013] Optionally, forming a fuse portion in a metal layer above the dielectric layer includes:

[0014] forming a barrier layer above the dielectric layer;

[0015] forming a metal layer over the barrier layer;

[0016] The metal layer and the barrier layer are etched to form a fuse portion.

[0017] Optionally, grooves are formed in the dielectric layer on both sides of the fuse portion by photolithography and etching processes, including:

[0018] Defining the fuse region by photolithography process;

[0019] The passivation layer and the dielectric layer in the fuse area are etched to form grooves in the dielectric layer on both sides of the fuse portion.

[0020] Optionally, a protective layer is formed on both sides of the fuse portion, including:

[0021] forming a protective layer on the substrate;

[0022] The protective layer is etched, and the etched protective layer covers the side walls of the grooves on both sides of the fuse part.

[0023] Optionally, the barrier layer is a Ti / TiN layer.

[0024] Optionally, the material of the protective layer is oxide and / or oxynitride.

[0025] The technical solution of this application has at least the following advantages:

[0026] A fuse part is formed in a metal layer above a dielectric layer, and a barrier layer is arranged between the metal layer and the dielectric layer; a passivation layer is formed, and grooves are formed in the dielectric layer on both sides of the fuse part through photolithography and etching processes, and residual photoresist is removed through ashing and wet cleaning processes. CF4 gas is introduced during the ashing process to remove a portion of the barrier layer under the fuse part; the problem of long time consumption for the current fuse structure to be blown is solved; and the effect of improving the blowing efficiency of the fuse structure without increasing the process steps is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 is a flow chart of a method for manufacturing a fuse structure provided in an embodiment of the present application;

[0029] Figure 2 is a cross-sectional view of a device during the manufacturing process of a fuse structure provided by an embodiment of the present application;

[0030] Figure 3 is a cross-sectional view of a device during the manufacturing process of a fuse structure provided by an embodiment of the present application;

[0031] Figure 4is a cross-sectional view of a device during the manufacturing process of a fuse structure provided by an embodiment of the present application;

[0032] Figure 5 is a cross-sectional view of a device during the manufacturing process of a fuse structure provided by an embodiment of the present application;

[0033] Figure 6 is a SEM cross-sectional view of a fuse structure provided by another embodiment of the present application;

[0034] Figure 7 is a cross-sectional view of a device during the manufacturing process of a fuse structure provided by another embodiment of the present application;

[0035] Figure 8 It is a device cross-sectional view of a fuse structure provided in another embodiment of the present application during the manufacturing process. DETAILED DESCRIPTION

[0036] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0037] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0038] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, it can also be the internal connection of two components, it can be a wireless connection, or it can be a wired connection. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0039] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0040] Please refer to Figure 1 , which shows a flow chart of a method for manufacturing a fuse structure provided in an embodiment of the present application, the method at least comprising the following steps:

[0041] Step 101: forming a fuse in a metal layer above a dielectric layer, with a barrier layer disposed between the metal layer and the dielectric layer.

[0042] A metal fuse is formed in the process of forming a metal line on the dielectric layer. In the process of patterning the metal layer, the metal layer and the barrier layer below the metal layer are etched to form the metal line and the fuse.

[0043] like Figure 2 As shown, a fuse part 20 is formed in the metal layer 23, and a barrier layer 22 is provided between the dielectric layer 21 and the metal layer 23; the surfaces of the dielectric layer 21 on both sides of the fuse part 20 are exposed.

[0044] Optionally, the material of the metal layer is aluminum or copper.

[0045] Step 102: forming a passivation layer.

[0046] Optionally, a passivation layer is deposited on the substrate.

[0047] like Figure 3 As shown, after the passivation layer 24 is deposited, the surface of the metal layer 23 is covered by the passivation layer 24 , and the surface of the fuse part 20 and the surfaces of the dielectric layer 21 exposed on both sides of the fuse part 20 are also covered by the passivation layer 24 .

[0048] Step 103, forming grooves in the dielectric layer on both sides of the fuse part through photolithography and etching processes.

[0049] Through photolithography and etching processes, the passivation layer and the dielectric layer on both sides of the fuse are removed to form a groove in the dielectric layer. In the process of etching the passivation layer, the passivation layer on the surface of the fuse is also removed.

[0050] Step 104, removing the residual photoresist through an ashing process and a wet cleaning process, and introducing CF4 gas during the ashing process.

[0051] After the photoresist is removed, the width of the barrier layer below the fuse portion is smaller than the width of the fuse portion.

[0052] After the passivation layer is etched, residual photoresist still remains on the substrate, and the photoresist on the substrate needs to be removed.

[0053] The residual photoresist on the substrate is ashed by an ashing process, and CF4 gas is introduced during the ashing process. Due to the introduction of CF4 gas during the ashing process, the barrier layer below the fuse part is undercut, so that the width of the barrier layer below the fuse part 20 is reduced.

[0054] like Figure 4 As shown, grooves 25 and 26 are formed in the dielectric layer 21 on both sides of the fuse part 20, and the width of the barrier layer 21 below the fuse part 20 is reduced; comparing the fuse part 20 and the barrier layer located below the fuse part 20, the width of the barrier layer 21 below the fuse part 20 is smaller than the width of the fuse part 20.

[0055] After the ashing process, the substrate is wet cleaned to remove the photoresist on the surface of the substrate.

[0056] Since the barrier layer has a higher melting point than the metal layer, reducing the volume of the barrier layer below the fuse portion 20 helps to reduce the time consumption of electrical fusing of the barrier layer and improve the fusing efficiency of the fuse structure.

[0057] In summary, the manufacturing method of the fuse structure provided in the embodiment of the present application is to form a fuse part in the metal layer above the dielectric layer, and a barrier layer is arranged between the metal layer and the dielectric layer; a passivation layer is formed, and grooves are formed in the dielectric layer on both sides of the fuse part through photolithography and etching processes, and residual photoresist is removed through ashing process and wet cleaning process. CF4 gas is introduced during the ashing process to remove a portion of the barrier layer under the fuse part; the problem of long time consumption for the current fuse structure to be blown is solved; and the effect of improving the blowing efficiency of the fuse structure without increasing the process steps is achieved.

[0058] In one example, the fuse structure manufactured by the method provided in the embodiment of the present application is as follows: Figure 6 As shown, it can be seen that Figure 6 The barrier layer 61 under the fuse part is reduced. In some devices, the size of the barrier layer under the fuse part can be reduced by 40% compared with the fuse structure manufactured by the existing method by using the fuse structure manufactured by the method provided in the embodiment of the present application.

[0059] Since the size of the barrier layer below the fuse part is reduced, in order to prevent the fuse structure from being broken during dicing, the embodiment of the present application further provides a method for manufacturing the fuse structure, the method comprising the following steps:

[0060] Step 201: forming a barrier layer on the dielectric layer.

[0061] In order to prevent corrosion or oxidation of metal lines in the device, a barrier layer is formed above the dielectric layer. Optionally, the barrier layer is a Ti / TiN layer.

[0062] Step 202: forming a metal layer on the barrier layer.

[0063] A metal layer is deposited over the barrier layer.

[0064] Step 203, etching the metal layer and the barrier layer to form a fuse.

[0065] A fuse pattern and a metal line pattern are defined on the surface of the metal layer by a photolithography process; and the metal layer and the barrier layer corresponding to the fuse pattern and the metal line pattern are etched by an etching process to form a fuse and a metal line.

[0066] Step 204: forming a passivation layer.

[0067] Optionally, a passivation layer is deposited on the substrate.

[0068] like Figure 3 As shown, after the passivation layer 24 is deposited, the surface of the metal layer 23 is covered by the passivation layer 24 , and the surface of the fuse part 20 and the surfaces of the dielectric layer 21 exposed on both sides of the fuse part 20 are also covered by the passivation layer 24 .

[0069] Step 205 , forming grooves in the dielectric layer on both sides of the fuse part through photolithography and etching processes.

[0070] The fuse area is defined by a photolithography process.

[0071] Optionally, a fuse region and a pad region are defined on the surface of the metal layer by a photolithography process.

[0072] The substrate is etched, the passivation layer corresponding to the fuse area is removed, the dielectric layer corresponding to the fuse area is etched, and grooves 25 and 26 are formed in the dielectric layer on both sides of the fuse portion 20. At the same time, the passivation layer corresponding to the pad area is removed, and the metal layer corresponding to the pad area is exposed as a pad 28. Figure 5 shown.

[0073] During the process of etching the passivation layer, the passivation layer on the surface of the fuse part 20 is also removed.

[0074] Step 206, removing the residual photoresist through an ashing process and a wet cleaning process, and introducing CF4 gas during the ashing process.

[0075] This step has been described in the above step 104 and will not be repeated here.

[0076] Step 207, forming a protective layer on both sides of the fuse portion.

[0077] A protective layer is formed on the substrate.

[0078] like Figure 7 As shown, the protection layer 29 covers the surface of the passivation layer 24, the surface of the fuse 20, the sidewalls and bottom of the grooves on both sides of the fuse 20, and the surface of the metal layer 23 not covered by the passivation layer.

[0079] Optionally, the material of the protective layer is oxide and / or oxynitride.

[0080] The protective layer is etched, and the etched protective layer covers the side walls of the grooves on both sides of the fuse part.

[0081] Optionally, the substrate is etched back to remove the protective layer on the surface of the passivation layer, the protective layer on the surface of the fuse portion, the protective layer on the surface of the dielectric layer, and the protective layer on the surface of the metal layer.

[0082] like Figure 8 As shown, after etching the protective layer, the groove sidewalls on both sides of the fuse part 20 and the sidewalls of the passivation layer 24 on both sides of the pad are still covered by the protective layer 29; the groove sidewalls on both sides of the fuse part 20 include the sidewalls of the passivation layer, the metal layer, the barrier layer, and the dielectric layer.

[0083] Since the protection layer protects the fuse structure, the fuse structure is not easily broken during dicing.

[0084] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection created by this application.

Claims

1. A method for manufacturing a fuse structure, characterized in that: The method comprises: forming a fuse portion in a metal layer above the dielectric layer, wherein a barrier layer is disposed between the metal layer and the dielectric layer; forming a passivation layer; Forming grooves in the dielectric layer on both sides of the fuse part by photolithography and etching processes; Residual photoresist is removed by an ashing process and a wet cleaning process, and CF4 gas is introduced during the ashing process; After the photoresist is removed, the width of the barrier layer below the fuse portion is smaller than the width of the fuse portion.

2. The method according to claim 1, characterized in that After removing the residual photoresist by the ashing process and the wet cleaning process, the method further comprises: A protective layer is formed on both sides of the fuse portion.

3. The method according to claim 1, characterized in that The forming of a fuse portion in the metal layer above the dielectric layer comprises: forming a barrier layer above the dielectric layer; forming a metal layer over the barrier layer; The metal layer and the barrier layer are etched to form a fuse.

4. The method according to claim 1, characterized in that The method of forming grooves in the dielectric layer on both sides of the fuse part by photolithography and etching processes includes: Defining the fuse region by photolithography process; The passivation layer and the dielectric layer in the fuse region are etched to form grooves in the dielectric layer on both sides of the fuse portion.

5. The method according to claim 2, characterized in that: The forming of a protective layer on both sides of the fuse portion comprises: forming a protective layer on the substrate; The protective layer is etched, and the etched protective layer covers the side walls of the grooves on both sides of the fuse part.

6. The method according to any one of claims 1 to 5, characterized in that: The barrier layer is a Ti / TiN layer.

7. The method according to claim 2 or 5, characterized in that: The material of the protective layer is oxide and / or oxynitride.

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