Abstract:
A method for forming a metal wiring of a semiconductor device capable of efficiently preventing a hillock phenomenon occurred in a subsequent annealing process of a metal wiring process. The method for forming a metal wiring of a semiconductor device includes forming an Al growth stop film on the upper interface of an Al wiring film by reacting implanted reactive ions with a Ti film or the Al in the Al wiring film.

Description:
[0001]    The present application claims priority under 35 U.S.C. 119 to Korean Patent Application No. 10-2006-0117377 (filed on Nov. 27, 2006), which is hereby incorporated by reference in its entirety. 
       BACKGROUND 
       [0002]    Aspects of semiconductor technology has focused high-speed semiconductor devices having enhanced storage capacities for various applications. In order to obtain such qualities, enhanced integration, response speed and metal wiring processing of semiconductor devices has been developed. 
         [0003]    Metal wiring processing may require the implementation of the paths of power supply and signal transfer constituting a circuit by interconnecting individual transistors in a semiconductor integrated circuit on and/or over silicon. A non-memory device has led the technique in this field. 
         [0004]    The metal wiring layer of a semiconductor device may be formed of copper, tungsten, aluminum or any alloys thereof. The metal wiring layer may function as a contact with devices, an interconnection therebetween, and a connection between a chip and an external circuit, etc. 
         [0005]    Integration of semiconductor devices has increased, and the size of metal wiring has become small so that the wiring can be formed by expanding the thickness of the metal wiring in order to secure the resistance of the metal wiring. 
         [0006]    As illustrated in example  FIG. 1 , first Ti film  120  and first TiN film  130  may be deposited on and/or over lower insulating interlayer  110  of a semiconductor substrate provided with a predetermined lower structure using a sputtering method. Al film  140  can be formed on and/or over TiN film  130 . Second Ti film  150  and second TiN film  160  can then be sequentially deposited. 
         [0007]    Thereafter, a photoresist can be applied and patterned on and/or over second TiN film  160  to form a predetermined pattern. Thereafter, a dry etching process using the pattern can be performed on the Al wiring stacked structure including a multi-layer film formed of first Ti film  120  and first TiN film  130  formed under Al film  140 , and second Ti film  150  and second TiN film  160  formed on and/or over Al film  140 . 
         [0008]    Upper dielectric interlayer  170  can be formed for insulating between the plurality of Al wiring stacked structure patterns formed using an etching process. 
         [0009]    When depositing Al film  140  using a sputtering method, the temperature can be gradually increased in order to lower resistance and to reinforce electro migration (EM) characteristics by enlarging the size of the metal grain. Accordingly, a grain boundary can be enlarged to an extent that the size of the metal grain enlarges, and in particular, the recession of the grain boundary also enlarges at a triple point as the thickness of Al becomes thicker. 
         [0010]    If a subsequent annealing process is performed in such a state, the Al moves along the grain boundary to form a hillock on the surface and grows in order to solve the stress due to the difference of thermal expansion coefficient between the Al and Si used as a semiconductor substrate. 
         [0011]    In order to prevent such a phenomenon, Ti/Tin has been formed on and/or over the Al. The film capable of preventing a hillock phenomenon is TiN. However, if the TiN film is formed too thick, it may lower the resistance of the wiring. Therefore, there is a restriction on the expansion of the thickness of the TiN for preventing the hillock phenomenon. 
       SUMMARY 
       [0012]    Embodiments relate to a method for forming a metal wiring of a semiconductor device capable of efficiently preventing a hillock phenomenon occurred in a subsequent annealing process of a metal wiring process. 
         [0013]    Embodiments relate to a method for forming a metal wiring of a semiconductor device including at least one of the following steps: forming an interlayer insulating layer over a semiconductor substrate including a predetermined lower structure; forming an Al wiring stacked structure over the interlayer insulating layer, wherein the Al wiring structure is composed of a plurality of films including an Al wiring film and a first Ti-based film formed over the Al wiring film; forming an Al growth stop film at an interface between the Al wiring film and the first Ti-based film; and then forming a plurality of Al wiring stacked structure patterns over the interlayer insulating layer. 
         [0014]    Embodiments relate to a method for forming a metal wiring of a semiconductor device including at least one of the following steps: forming an interlayer insulating layer over a semiconductor substrate including a predetermined lower structure; forming an Al wiring stacked structure over the interlayer insulating layer, wherein the Al wiring structure is composed of a plurality of films including an Al wiring film and a first Ti-based film formed over the Al wiring film; forming a plurality of Al wiring stacked structure patterns on the interlayer insulating layer; and then forming an Al growth stop film at an interface between the Al wiring film and the first Ti-based film. 
         [0015]    Embodiments relate to a metal wiring structure for a semiconductor device including an interlayer insulating layer formed over a semiconductor substrate; a plurality of Al wiring stacked structure patterns formed on the interlayer insulating layer. In accordance with embodiments, the plurality of Al wiring stacked structure patterns is composed of a plurality of films including an Al wiring film, a first Ti-based film formed over the Al wiring film and an Al growth stop film formed between the Al wiring film and the first Ti-based film. 
     
    
     
       DRAWINGS 
         [0016]    Example  FIG. 1  illustrates a method for forming a metal wiring of a semiconductor device. 
           [0017]    Example  FIGS. 2 to 5  illustrate a method for forming a metal wiring of a semiconductor device, in accordance with embodiments. 
       
    
    
     DESCRIPTION 
       [0018]    As illustrated in example  FIG. 2A , first interlayer insulating layer  210  can be formed on and/or over a semiconductor substrate having a predetermined lower structure. First Ti film  220  and first TiN film  230  can be sequentially formed on and/or over first interlayer insulating layer  210 . First metal wiring  240 , which can be composed of aluminum (Al), can be provided over first TiN film  230 . Second Ti film  250  and second TiN film  260  can be sequentially formed on and/or over first interlayer insulating layer  210  including first Al wiring  240  to form an Al stacked structure having a plurality of films. A sputtering method can be used in order to deposit the plurality of films and wiring. 
         [0019]    Nitride ions may be implanted in the semiconductor substrate including the Al wiring stacked structure provided with the plurality of films. The nitride ions can serve as reactive ions implanted into an interface between first Al wiring  240  and second Ti film  250  using an ion implantation method. 
         [0020]    As illustrated in example  FIG. 2B , the implanted nitride ions react with second Ti film  250  in the interface between first Al wiring  240  and second Ti film  250  to form first Al growth stop film  270  thinly and finely formed of TiN between first Al wiring  240  and second Ti film  250 . 
         [0021]    First Al growth stop layer  270  can serve to suppress movement of Al in the first Al wiring  240 , which in turn prevents hillock formation due to a subsequent annealing on the Al wiring stacked structure. 
         [0022]    First Al growth stop film  270  may be formed by directly forming a growth stop film composed of at least one of TiN and Al 2 O 3  on and/or over the Al wiring. However, if first Al growth stop film  270  is formed using a deposition process or an oxidation process, it may become difficult to control the thickness of the film, which in turn, may increase wire resistance. 
         [0023]    Accordingly, in accordance with embodiments, after formation of the Al wiring stacked structure provided with a plurality of films, the ion implantation method using nitride ions or oxygen ions can be used. Then, the reactive ions can be implanted and reacted at a desired position to form first Al growth stop film  270 . Therefore, deterioration of the reliability of the semiconductor device due to hillock formation occurrence can be prevented, while also minimizing the deterioration of the wiring characteristics. 
         [0024]    As illustrated in example  FIG. 2C , in order to form a plurality of Al wiring stacked structure patterns on and/or over first interlayer insulating layer  210 , a dry etching can be performed on the Al wiring stacked structure including first Al growth stop film  270  formed of TiN. Thereafter, a predetermined semiconductor device is implemented by performing a subsequent process such as an annealing, etc. 
         [0025]    As illustrated in example  FIG. 3A , second interlayer insulating layer  310  can be formed on and/or over a semiconductor substrate having a predetermined lower structure. Third Ti film  320  and third TiN film  330  can be sequentially formed on and/or over second interlayer insulating layer  310 . Second metal wiring  340 , which can be composed of aluminum (Al), can be provided over second TiN film  330 . Fourth Ti film  350  and fourth TiN film  360  can be sequentially formed on and/or over second interlayer insulating layer  310  including second Al wiring  340  to form an Al stacked structure having a plurality of films. A sputtering method can be used as the mode of deposition of the films and wiring. 
         [0026]    As illustrated in example  FIG. 3B , a dry etching can be performed on the Al wiring stacked structure to form a plurality of Al wiring stacked structure patterns on and/or over second interlayer insulating layer  310 . 
         [0027]    As illustrated in example  FIG. 3C , an ion implantation method can then be used to implant nitride ions as reactive ions into the interface between second Al wiring  340  pattern and fourth Ti film  350  of each Al wiring stacked structure pattern. 
         [0028]    The implanted nitride ions can react in the interface between second Al wiring  340  and fourth Ti film  350  to form second Al growth stop film  370  therebetween. 
         [0029]    As illustrated in example  FIG. 4A , third interlayer insulating layer  410  can be formed on and/or over a semiconductor substrate having a predetermined lower structure. Fifth Ti film  420  and fifth TiN film  430  can be sequentially formed on and/or over third interlayer insulating layer  310 . Third metal wiring  440 , which can be composed of aluminum (Al), can be provided over fifth TiN film  430 . Sixth Ti film  350  and sixth TiN film  360  can be sequentially formed on and/or over third interlayer insulating layer  410  including third Al wiring  340  to form an Al stacked structure having a plurality of films. A sputtering method can be used as the mode of deposition of the films and wiring. 
         [0030]    After formation of the Al wiring stacked structure an ion implantation method can then be used to implant oxygen ions as reactive ions into the interface between third Al wiring  440  pattern and sixth Ti film  450 . Alternatively, an ion implantation method implanting nitride ions as reactive ions into the interface between third Al wiring  440  pattern and sixth Ti film  450  may be used. 
         [0031]    As illustrated in example  FIG. 4B , the implanted oxygen ions react with the Al in third Al wiring  440  to form a thin layer of third Al growth stop film  470  composed of Al 2 O 3  between third Al wiring  440  pattern and sixth Ti film  450 . Third Al growth stop layer  470  can suppress movement of Al, making it possible to prevent hillock formation during subsequent annealing on the Al wiring stacked structure. Deterioration of the wiring characteristics can also be reduced. 
         [0032]    As illustrated in example  FIG. 4C , a dry etching can be performed on the resultant Al wiring stacked structure including third Al growth stop film  470  to form a plurality of Al wiring stacked structure patterns on and/or over third interlayer insulating layer  410 . 
         [0033]    As illustrated in example  FIG. 5A , Seventh Ti film  520 , seventh TiN film  530 , fourth Al wiring  540 , eighth Ti film  550  and eighth TiN film  560  can be sequentially formed on and/or fourth interlayer insulating layer  510 . Fourth interlayer insulating layer  510  can be formed on and/or over a semiconductor substrate having a predetermined lower structure. Seventh Ti film  520  and seventh TiN film  530  can be formed on and/or over fourth interlayer insulating layer  410 . Fourth metal wiring  540 , which can be composed of aluminum (Al), can be provided over seventh TiN film  530 . Eighth Ti film  550  and eighth TiN film  560  can be formed on and/or over fourth interlayer insulating layer  510  including fourth Al wiring  540  to form an Al stacked structure having a plurality of films. A sputtering method can be used as the mode of deposition of the films and wiring. 
         [0034]    As illustrated in example  FIG. 5B , a dry etching can be performed on the Al wiring stacked structure to form a plurality of Al wiring stacked structure patterns on and/or over fourth interlayer insulating layer  510 . 
         [0035]    As illustrated in example  FIG. 5C , an ion implantation method can then be performed to implant oxygen ions as reactive ions into the interface between fourth Al wiring  540  pattern and eighth Ti film  550  of each Al wiring stacked structure pattern. 
         [0036]    The implanted oxygen ions react at the interface between fourth Al wiring  540  and eighth Ti film  550  to form fourth Al growth stop film  570  pattern therebetween. Fourth Al growth stop film  570  can be composed of Al 2 O 3 . 
         [0037]    In accordance with embodiments, a method of forming a metal wiring structure whereby after formation of the Al wiring stacked structure, nitride or oxygen ions can be implanted into an interface between the Al wiring and a Ti film to react with the Ti film or the Al wiring. These reactions prevent formation of hillocks during subsequent annealing processing. In particular, such embodiments provide an Al growth stop film composed of at least one of TiN and Al 2 O 3  between the Al wiring and the TiN film to suppress movement of the Al, thereby enhancing the reliability of a semiconductor device. 
         [0038]    Although embodiments have been described herein, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.