A dual damascene process, an embodiment of a manufacturing method of a semiconductor device according to the present invention, is explained referring to
First, as shown in
The lower barrier film 12 may consist of a metal film, such as, Ta (tantalum), TaN (tantalum nitride), Ti (titanium) TiN, W (tungsten), WN (tungsten nitride), and Ru (ruthenium). Also, each of these films may be laminated in plurality as a laminated film. And the seed layer 13 functions as an electrode when performing the electrolytic plating, and it may be constituted by Ru, other than Cu.
Thereafter, as shown in
Accordingly, the seed layer 13 and a cathode are electrically connected by connecting an edge of the seed layer 13 to an external wiring 42 which is electrically connected to the cathode of a DC power supply 41. And, dip the substrate 1 into a solution 43 (shown in
Because the plating film 16 grows the resist pattern 15 with upward directionality and prevents an irregular growth, a void in the first wiring 21 forming from these plating films 16 may be prevented. As a result, the deterioration in the strength and the conductivity of the wiring 21 may be prevented. Also, because the plating film 16 grows with the directionality as described above, it can prevent an additive for controlling the direction of growth of the plating layer from mixing into, for example, a solution containing Cu ion to perform electrolytic plating. Therefore, incorporation of the additive into the first wiring 21 can be prevented, thereby the deterioration in the strength or the conductivity of the first wiring 21 can also be prevented.
For example, stop the application of voltage to the seed layer 13 and the cathode electrode 44 after a predetermined time is elapsed. Thereafter, remove the excess plating film 16 which overflowed from the resist pattern 15 and formed on the surface of the resist film 14, by CMP, and then the first wiring 21 is formed by planarizing the surface of the plating layer 16 as shown in
Consequently, form the resist film 22, which is a second sacrificial layer, on the resist film 14 and the wiring 21 as shown in
After forming the resist pattern 23, electrically connect the cathode of the power supply 42 and the seed layer 13 again by connecting the seed layer 13 to the external wiring 42 as shown in
For example, the application of voltage to the cathode electrode 44 and the seed layer 13 is stopped after a predetermined time is elapsed. Thereafter, excess plating film 24 which has overflowed from the resist pattern 23 and formed on the surface of the resist film 22, is removed by CMP, and then the second wiring 25 (electrode) is formed by planarizing the surface of the plating film 24 as shown in
As the plating film 16, the plating film 24 also grows the resist pattern 23 with upward directionality, thereby an occurrence of a void can be prevented in the second wiring 25 formed from this plating film 16.
After forming the second wiring 25, remove the resist film 14 and the resist film 22 by, for example, wet etching as shown in
The upper barrier film 31 may consist of an insulation film such as SiN (silicone nitride), other than SiC. Also, it may consist of various metals which are listed as materials, such as TiN, that can comprise the lower barrier film 12 as described above. In addition, it may be a laminated layer, laminating films made of these materials as the lower barrier film 12.
Next, form the repairing barrier film 32 which is the second diffusion barrier film consisting of, for example, SiC, on the substrate 1 (
In order to prevent the metal consisting of the first wiring 21 and the second wiring 25 from diffusing in the interlayer insulation film, the barrier film to cover those is required to have a certain degree of thickness. However, it is preferable not to mediate an extra film in between the interlayer insulation film 33 and the underlying film 11 which are formed to cover each wiring later, to prevent the change in the dielectric constant of the interlayer insulation film 33. When performing the etching after forming the barrier film 31, the barrier films 31 and 12 on the underlying film 11 are removed, and the barrier film 31 on the side faces of each wiring 21 and 25, and the upper faces of the first wiring 21 is removed or thinned. Consequently, the barrier characteristics are maintained by forming the repairing barrier film 32 to repair the barrier film 31 remaining on the side face of each wiring as well as, the harmful effect (an increase of dielectric constant) to the barrier film mediating in the interlayer insulation layer 33 is prevented by keeping this repairing barrier film 32 as thin as possible. In addition, other than SiC, insulating layer, such as SiCO, SiCN, or SiN, may be used as the material for the repairing barrier film 32. Also, the upper barrier film 31 and the repairing barrier film 32 described later constitute the upper diffusion barrier film referred in the claim, and the upper barrier film 31 and the repairing barrier film 32 correspond to the first diffusion barrier film and the second diffusion barrier film respectively.
Thereafter, apply, for example, a forming material of the interlayer insulation film 33 on the repairing film 32, and form the interlayer insulation film 33 in a way that covers the repairing barrier 32 (
According to the embodiment described above, after the first wiring 21 is formed in the resist pattern 15 of the resist film 14 formed on the substrate 1 and then the second wiring 25 is formed in the resist pattern 23 of the resist film 22 provided on the resist film 14 after forming the first wiring 21, the resist films 14 and 22 are removed, the barrier films 31 and 32 are formed around the first wiring 21 and the second wiring 25, and the interlayer insulation film 33 is formed so as to surround the barrier film 31 and 32, thereby the projection domain of the second wiring 25 to the substrate is smaller than the projection domain of the first wiring 21 to the substrate. Therefore, in order to form the first wiring and the second wiring in the interlayer insulation film in the conventional dual damascene process, it is necessary to perform a process that etching or ashing the interlayer insulation film 33 by using plasma under an environment in which the plasma is generated, however, in this embodiment described above, since the interlayer insulation film 33 is formed so as to cover the wiring after forming the first wiring 21 and the second wiring 25 as described above, the damage to the interlayer insulation film 33 is prevented because there's no necessity for such a process. Also, since the projection domain of the second wiring 25 to the substrate 1 is smaller than the projection domain of the first wiring 21 to the substrate 1, the second wiring acts as a mask when removing the resist film, thereby preventing the resist films 14 and 22 from remaining around the first wiring 21. As a result, an increase in parasitic capacity of the interlayer insulation film 33 coating the first wiring 21 and the second wiring 25 may be prevented, and also the reliability of the wiring may be improved. Also, a decrease in yield of the semiconductor device, which is formed by using these wirings, may be prevented.
Also, according to this embodiment, the interlayer insulation film 33 is simultaneously formed around the first wiring 21 and the second wiring 25, thereby through-put may be improved compared to the method of forming the interlayer insulation film 33 around each wiring separately. Also, since the removal of the resist films 14 and 22 is performed by wet etching, the damage to the wiring 21 and 25 may be prevented compared to ashing using plasma.
Also, the first sacrificial film and the second sacrificial film is not limited to being formed by the resist, it may be another organic film or inorganic film, and for example, it may be constituted with an insulator and form a pattern on this insulator by a lithography etching process, however, it is preferable to constitute by selecting a material that does not react with the metal consisting of the first wiring 21 and the second wiring 25. Further, the first sacrificial film and the second sacrificial film is preferably formed from an identical substance as described in the embodiment above to simplify the process by removing simultaneously after forming the first wiring 21 and the second wiring 25.
In addition, in the embodiment described above, it is not necessary to perform an anisotropic etching, such as dry etching, to remove the resist film 14 and the resist film 23, that are the sacrificial films, thereby, a removal process which is capable of preventing the deterioration of the first wiring 21 and the second wiring 25 can be selected due to a high degree of freedom in the removal process. For example, when the first sacrificial film and the second sacrificial film are constituted by an organic matter, such as a resist film, as described in the embodiment above, it is preferable to remove by wet etching as described above, and also the removal process of each sacrificial film may be performed by forming a reduction system plasma or radical atmosphere if the deterioration of the metal consisting of the wiring can be prevented. In addition, when the first sacrificial film and the second sacrificial film consists of, for example, SiO2 series inorganic materials, it is preferable to perform the removal process of each sacrificial film by wet etching using, for example, HF (fluorine) to reduce the damage to the first wiring 21 and the second wiring 25.
Forming of the interlayer insulating film 33 may be performed, for example, by CVD, and the second wiring 25 may be exposed by performing an etch back of the dry etching instead of CMP to remove any unnecessary surface portion of the interlayer insulating film 33 after forming the interlayer insulation film 33.
Also, when the barrier films 31 and 32 are insulators as shown in
Also, the first wiring 21 and the second wiring 25 are not limited to being formed by performing electrolyte plating in the embodiment described above, it may be formed, for example, by nonelectrolytic plating. For example, instead of forming the seed layer 13 on the lower barrier film 12, a catalytic layer for nonelectrolytic plating is formed, and constituted, for example by Pb, and forms the resist pattern 15 as the embodiment described above after forming the catalytic layer. Consequently, performing the nonelectrolytic plating by dipping the substrate 1 into a solution containing, for example, Cu ions, thereby forming the wiring 21 by depositing Cu on the catalytic layer with the catalytic ability of the catalytic layer. Thereafter, forming the resist pattern 23 as the embodiment described above, and then performing the nonelectrolytic plating by dipping the substrate 11 into the solution containing Cu ions again, thereby forming the wiring 25 by depositing Cu on the wiring 21. By using such methods, the plating film also grows upward in the resist pattern 15 and 23 as described in the embodiment above, thereby the formation of any voids in the first wiring 21 and the second wiring 25 can be prevented.
In addition, in the embodiment described above, after removing the resist films 14 and 22 as shown in
Next, a substrate processing system to embody the manufacturing method of the semiconductor device for the embodiment explained at first is explained in detail referring to
And, a multi-chamber system 6 which consists of a portion of the constituent of the substrate processing system, is explained. 61 is a placing portion for the carrier 52, and 62 in the figure is a loading portion provided with a first transfer arm 63 to take out the substrate 1 from the carrier 52. 64 in the figure is a vacuum transfer chamber provided with a second transfer arm 65 to transfer the substrate 1 with the first transfer arm 63, and the moving area of the second transfer arm 65 in this vacuum transfer chamber 64 remains at a vacuum at all times. 60 in the figure is a load lock chamber to connect the loading portion and the vacuum transfer chamber, and vacuum and normal pressure can be switched in the load lock chamber 60. The substrate 1 is transferred between the transfer arm 63 and the transfer arm 65 through this load lock chamber 60.
Various vacuum processing devices, which are provided with a processing container and capable of adjusting the pressure inside the processing container, are provided around the vacuum transfer chamber 64. A CVD device 66 for forming various films on the substrate 1, and an etching device 67 for dry etching are provided as the vacuum processing devices, and the transfer arm 65 transfers the substrate 1 between these vacuum processing devices.
71 in the figure is a resist application/development device to apply resist on the surface of the substrate 1 and for forming a predetermined pattern by developing the resist. 72 in the figure is an electrolytic plating device to form a copper wire by performing the electrolytic plating as described above. 73 in the figure is a wet etching device to remove the resist films 14 and 22, and 74 in the figure is an insulation film forming material application device to apply an insulation film forming material for forming the interlayer insulation film 33 on the substrate 1. 75 in the figure is a CMP device.
The substrate processing system described above is provided with subordinate computers to control the motion of each device, and further provided with a control portion 81, which is a host computer to control each subordinate computer. The control portion 81 has a data processing portion and the like consisting of a program, memory, and CPU. The program stored in the host computer is configured as a transfer sequence program for transferring the substrate 1 between each device, and the subordinate computers store a program for performing the above described process for forming wiring circuit layer portions including the interlayer insulation film 33 and wires 21 and 25 that comprise one or more layers on the substrate 1. By the program stored in the host computer as shown in “a” to “g” in the figure, the control portion 81 transmits a control signal to each device in the substrate processing system, and subordinate computers of each device receives this control signal controlling the motion of each part of each device.
The program described above may be stored in a memory media 82 consisting of, for example, a flexible disk, a compact disk, and/or a MO (magnetic-optical disk), and installed in the control portion 81.
Next, how the substrate 1 stored in the carrier 52 is transferred to each device of the substrate processing system in a factory, and the wiring and the interlayer insulation film are formed as described above is explained by referring to
Consequently, the carrier 52, which has the substrate 1 processed in the multi-chamber system 6, transfers it to the resist application/development device 71 as indicated by the arrow A2, and the resist film 14 and the resist pattern 15 are formed on the substrate 1 by this application/development device 71 (
In order to simplify the description in the explanation, an expression “the substrate 1 is transferred” is hereinafter used. Next, on the substrate 1 processed in the application/development device 71 as shown by the arrow A3 in
And, after the substrate 1 is transferred to the electrolytic plating device 72 and the plating film 24 is formed as shown by the arrow A6, (
Thereafter, the substrate 1 is transferred to the multi-chamber system 6 again as shown by the arrow A9, and processed by transferring between the etching device 67 and the CVD device 66, thereby the process shown in
Thereafter, the substrate 1 is transferred to the insulation film forming material application device 74 as shown by the arrow A10, and the interlayer insulation film 33 is formed therein (
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006-265285 | Sep 2006 | JP | national |