Patent Document

TECHNICAL FIELD 
       [0001]    The present inventive concept relates to a fabricating method of a semiconductor device. 
       DISCUSSION OF RELATED ART 
       [0002]    Semiconductor devices have multi-level interconnection structures having a via electrically connecting a lower conductor and an upper conductor. As semiconductor devices gradually scale down, sizes of lower conductors, upper conductors, vias, etc. are decreasing and a distance between neighboring conductors is gradually becoming reduced. 
       SUMMARY 
       [0003]    According to an exemplary embodiment of the present inventive concept, a semiconductor device is fabricated by forming a lower conductor in a first interlayer dielectric film. A second interlayer dielectric film is formed on the lower conductor and the first interlayer dielectric film. A first hard mask pattern is formed on the second interlayer dielectric film. The first hard mask pattern has a first opening. A planarization layer is formed on the first hard mask pattern. A mask layer is formed on the planarization layer. A second hard mask pattern, having a second opening, is formed on the mask layer. The second hard mask pattern includes SiN. A mask pattern is formed by patterning the mask layer using the second hard mask pattern. The second hard mask pattern is removed. Trenches and via holes are formed in the second interlayer dielectric film using the mask pattern and the first hard mask pattern. 
         [0004]    According to an exemplary embodiment of the present inventive concept, a semiconductor device is fabricated by forming a lower conductor in a first interlayer dielectric film. A second interlayer dielectric film is formed on the lower conductor and the first interlayer dielectric film. A first hard mask pattern is formed on the second interlayer dielectric film. The first hard mask pattern includes a metal layer. The first hard mask pattern includes a first opening extending in a first direction. A planarization layer is formed on the first hard mask pattern. A mask layer is formed on the planarization layer. A second hard mask pattern is formed on the mask layer. The second hard mask pattern includes SiN. The second mask pattern has a second opening extending in a second direction different from the first direction. A mask pattern is formed by patterning the mask layer using the second hard mask pattern. The second hard mask pattern is removed by using a wet process. Trenches and via holes are formed in the second interlayer dielectric film using the mask pattern and the first hard mask pattern. 
         [0005]    According to an exemplary embodiment of the present inventive concept, a semiconductor device is fabricated by forming a lower conductor in a first interlayer dielectric film. A second interlayer dielectric film is formed on the lower conductor and the first interlayer dielectric film. A first hard mask pattern is formed on the second interlayer dielectric film. The first mask pattern has a first opening extending in a first direction. A planarization layer is formed on the first hard mask pattern. A mask pattern is formed on the planarization layer. The mask pattern has a second opening extending in a second direction perpendicular to the first direction. The lower conductor is positioned under a region where the first opening and the second opening overlap. A via hole and a trench connected to the via hole is formed using the first hard mask pattern and the mask pattern. The via hole exposes an upper surface of the lower conductor. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    These and other features of the inventive concept will become more apparent by describing in detail exemplary embodiments thereof with reference to the accompanying drawings of which: 
           [0007]      FIGS. 1 to 12  show intermediate process steps in a fabricating method of a semiconductor device according to an embodiment of the present inventive concept; 
           [0008]      FIG. 13  is a block diagram of an electronic system incorporating a semiconductor device fabricated by the method shown in  FIGS. 1 to 12 ; and 
           [0009]      FIGS. 14 and 15  show an exemplary semiconductor system that includes an semiconductor device fabricated by an exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0010]    Exemplary embodiments of the inventive concept will be described below in more detail with reference to the accompanying drawings. However, the inventive concept may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these exemplary embodiments are provided so that this disclosure will be thorough and complete and will fully convey the inventive concept to those skilled in the art. In the drawings, the thickness of layers and regions may be exaggerated for clarity. Like reference numerals may refer to the like elements throughout the specification and drawings. 
         [0011]    Hereinafter, a fabricating method of a semiconductor device according to an exemplary embodiment of the present inventive concept will now be described with reference to  FIGS. 1 to 12 .  FIGS. 1 to 12  illustrate intermediate process steps in a fabricating method of a semiconductor device according to an exemplary embodiment of the present inventive concept. Specifically,  FIG. 2  is a cross-sectional view taken along the line X-X of  FIG. 1 ,  FIG. 4  is a cross-sectional view taken along the line X-X of  FIG. 3 ,  FIG. 6  is a cross-sectional view taken along the line X-X of  FIG. 5 , and  FIG. 12  is a perspective view illustrating interconnections and vias. 
         [0012]    Referring to  FIGS. 1 and 2 , lower conductors  171  to  175  are formed on a substrate and a first interlayer dielectric film  180  is formed around the lower conductors  171  to  175 . 
         [0013]    For example, the lower conductors  171  to  175  may be contacts or interconnections, but the present inventive concept is not limited thereto. As shown in  FIGS. 1 and 2 , the lower conductors  171  to  175  may be island-shaped or may be formed to extend in a direction. The lower conductors  171  to  175  may include, for example, aluminum or tungsten, but the present inventive concept is not limited thereto. 
         [0014]    A bather layer (not shown) may be formed along the sidewalls and bottom surface of the lower conductors  171  to  175 . The barrier layer may include, for example, Ti and/or TiN. The barrier layer may be a stacked layer of Ti/TiN. The lower conductors  171  to  175  may be spaced apart from each other in a second direction D 2 . 
         [0015]    The first interlayer dielectric film  180  may include SiO 2 , SiN, SiON, SiCN, and/or a low dielectric constant (low-k) material, but the present inventive concept is not limited thereto. 
         [0016]    An insulation layer  190  and a second interlayer dielectric film  195  may be formed on the lower conductors  171  to  175  and the first interlayer dielectric film  180 . For example, the insulation layer  190  may include SiCN and have a dielectric constant of approximately 4.5. The second interlayer dielectric film  195  may include a low-k dielectric material, but the present inventive concept is not limited thereto. 
         [0017]    Insulation layers  302  and  303  may be formed on the second interlayer dielectric film  195 . The insulation layer  302  may include, for example, octamethylcyclotetrasiloxane (OMCTS) having a dielectric constant of approximately 2.7, but the present inventive concept is not limited thereto. The insulation layer  303  may include tetraethoxysilane (TEOS) SiO 2 , but the present inventive concept is not limited thereto. 
         [0018]    The insulation layers  302  and  303  may serve to protect the second interlayer dielectric film  195  from plasma damages that may occur in a subsequent process of forming a metallic hard mask pattern  305 . 
         [0019]    Referring to  FIGS. 3 and 4 , a first hard mask pattern  301  having first openings  311  to  315  is formed on the insulation layers  302  and  303 . 
         [0020]    For example, the first hard mask pattern  301  may include a metallic hard mask pattern  305  and an insulating hard mask pattern  307 . For example, the metallic hard mask pattern  305  may include TiN, Ta and/or TaN. The insulating hard mask pattern  307  may include SiO 2 , SiN, SiON, and/or SiCN. For example, the first hard mask pattern  301  may include the metallic hard mask pattern  305  having TiN and the insulating hard mask pattern  307  having TEOS SiO 2 , but the inventive concept is not limited thereto. 
         [0021]    The metallic hard mask pattern  305  has high etch selectivity with respect to the second interlayer dielectric film  195 . For example, the etch selectivity of the metallic hard mask pattern  305  to the second interlayer dielectric film  195  may be 1:20 or higher. 
         [0022]    The metallic hard mask pattern  305  may serve to maintain/adjust widths of via holes ( 296  to  299  of  FIG. 11 ) and trenches ( 291  to  294  of  FIG. 11 ) 
         [0023]    The insulating hard mask pattern  307  may serve to reduce etch by-products of metallic polymers that are generated from the metallic hard mask pattern  305  in etching the second interlayer dielectric film  195  using the first hard mask pattern. The insulating hard mask pattern  307  covers the metallic hard mask pattern  305 , and the formation of the metallic polymers may be reduced. If the metallic hard mask pattern  305  is used alone without using the insulating hard mask pattern  307  in etching the second interlayer dielectric film  195 , metallic polymers may be generated formed from the metallic hard mask pattern  305  and may be deposited around the via holes  296  to  299 . It is difficult to remove the deposited metallic polymers. 
         [0024]    The insulating hard mask pattern  307 , covering the metallic hard mask pattern  305 , reduces the metallic polymers deposited on the via holes  296  to  299 , thereby improving bottom profiles of the via holes  296  to  299 . 
         [0025]    For example, the insulating hard mask pattern  307  may have a thickness in a range of 350 Å to 450 Å and the metallic hard mask pattern  305  may have a thickness in a range of 250 Å to 350 Å, but the present inventive concept is not limited thereto. The thickness of the metallic hard mask pattern  305  may be reduced using the insulating hard mask pattern  307 . 
         [0026]    The first openings  311  to  315  may be formed to extend in the first direction D 1 . The first openings  311  to  315  may be arranged to be adjacent to each other in the second direction D 2 . 
         [0027]    Referring to  FIGS. 5 and 6 , a planarization layer  350  and a mask layer  360   a  are sequentially formed on the resulting structure of  FIG. 4 . 
         [0028]    The planarization layer  350  may include, for example, an optical planarization layer (OPL), but the present inventive concept is not limited thereto. The planarization layer  350  may have a thickness to sufficiently fill the first openings  311  to  315  and may cover the first hard mask pattern  301 . The mask layer  360   a  and a second hard mask pattern  370  are formed on the planarization layer  350 . The mask layer  360   a  may include, for example, low temperature oxide (LTO), but the present inventive concept is not limited thereto. 
         [0029]    Next, a second hard mask pattern  370  having a second opening  371  is formed on the mask layer  360   a.    
         [0030]    The second hard mask pattern  370  may be used when the mask layer  360   a  is etched. 
         [0031]    The second hard mask pattern  370  may include SiNC x O y  (where, 0≦x≦1, and x+y=1). Since SiNC x O y  transmits light, an alignment signal is well transmitted in a lithography process. Therefore; misalignment may be reduced, thereby increasing process accuracy. The second hard mask pattern  370  does not include a metal that may scatter the alignment signal. Such scattering may lower the process accuracy in a lithography process. 
         [0032]    The first hard mask pattern  301  and the second hard mask pattern  370  may include different materials. As described above, the first hard mask pattern  301  may include a stacked layer of TiN and TEOS SiO 2 , and the second hard mask pattern  370  may include SiNC x O y . 
         [0033]    The second opening  371  may be formed to extend in the second direction D 2  different from the first direction D 1 . In  FIG. 5 , the first direction D 1  and the second direction D 2  are disposed at right angle, but the present inventive concept is not limited thereto. The second opening  371  is formed to overlap part of the first openings  311  to  315 . For example, the second opening  371  overlaps the first openings  312  to  315 , but the present inventive concept is not limited thereto. As shown in  FIG. 5 , the lower conductors  172  to  175  are positioned under corresponding overlapped regions that the first openings  312  to  315  and the second opening  371  overlap. The vias ( 161  to  164  of  FIG. 11 ) are also positioned under the corresponding overlapped regions between the first openings  312  to  315  and the second opening  371 . The vias  161  to  164  of  FIG. 11  contact the lower conductors  172  to  175 . 
         [0034]    Referring to  FIG. 7 , a mask pattern  360  is formed by patterning the mask layer  360   a  using the second hard mask pattern  370 . 
         [0035]    Referring to  FIG. 8 , the second hard mask pattern  370  is removed. 
         [0036]    For example, when the second hard mask pattern  370  includes SiNC x P y , it may be removed using a wet process. For example, the second hard mask pattern  370  may be removed by performing a stripping process using a phosphoric acid solution. 
         [0037]    The second hard mask pattern  370  does not include a metal. If the second hard mask pattern  370  includes a metal, a reactive ion etching (RIE) process may generate a metal residue, and this metal residue may hinder the second hard mask pattern  370  from completely being removed. 
         [0038]    Referring to  FIGS. 9 and 10 , the trenches  291  to  294  and the via holes  296  to  299  are formed in the second interlayer dielectric film  195  using the mask pattern  360  and the first hard mask pattern  301 . 
         [0039]    For example, referring to  FIG. 9 , preliminary via holes  296   a  to  299   a  are formed in the second interlayer dielectric film  195  using the mask pattern  360  and the first hard mask pattern  301 . 
         [0040]    The preliminary via holes  296   a  to  299   a  are formed by selectively etching the second interlayer dielectric film  195  to a predetermined depth and stopping the etching process before a top surface of the insulation layer  190  is exposed. The preliminary via holes  296   a  to  299   a  may be formed using, for example, a dry etching process. 
         [0041]    Referring to  FIG. 10 , the mask pattern  360  and the planarization layer  350  are removed. 
         [0042]    Next, the second interlayer dielectric film  195  having the preliminary via holes  296   a  to  299   a  is further etched to form via holes  296  to  299  that expose corresponding upper surfaces of the lower conductors  171  to  175  using the first hard mask pattern  301  and the preliminary via holes  296   a  to  299   a . While the trenches  291  to  294  are formed using the first hard mask pattern  301 , the via holes  296  to  299  are simultaneously formed using the preliminary via holes  296   a  to  299   a.    
         [0043]    The via holes  296  to  299  and trenches  291  to  294  may be formed using, for example, a dry etching process. According to an exemplary embodiment, the insulating hard mask pattern  307  may have a predetermined thickness completely removed by the dry etching process, and the metallic hard mask pattern  305  may be partially removed. 
         [0044]    Referring to  FIGS. 11 and 12 , the interconnections  165  to  169  and the vias  161  to  164  are formed in the via holes  296  to  299  and the trenches  291  to  294 . 
         [0045]    For example, a conductive material (not shown) is formed in the via holes  296  to  299  and the trenches  291  to  294  to sufficiently fill the via holes  296  to  299  and the trenches  291  to  294 . The conductive material may be, for example, copper, but the present inventive concept is not limited thereto. Next, a planarization process (e.g., a chemical mechanical polishing (CMP) process) is performed to remove the conductive material except in the via holes  296  to  299  and the trenches  291  and  294 , thereby forming the interconnections  165  to  169  and the vias  161  to  164  in the trenches  291  to  295  and the via holes  296  to  299 , respectively. 
         [0046]      FIG. 13  is a block diagram of an electronic system incorporating a semiconductor device fabricated according to an embodiment of the inventive concept. 
         [0047]    Referring to  FIG. 13 , the electronic system  1100  may include a controller  1110 , an input/output (I/O) device  1120 , a memory device  1130 , an interface  1140  and a bus  1150 . The controller  1110 , the I/O device  1120 , the memory device  1130  and/or the interface  1140  may be connected to each other through the bus  1150 . The bus  1150  may corresponds to a path through which data is transmitted. 
         [0048]    The controller  1110  may include a microprocessor, a digital signal processor, a microcontroller, and/or logic devices. For example, the logic device may perform similar functions to those performed by the processor or microcontroller. The I/O device  1120  may include a keypad, a keyboard, and/or a display device. The memory device  1130  may store data and/or instructions. The interface  1140  may transmit/receive data to/from a communication network. The interface  1140  may be wired or wireless. For example, the interface  1140  may include an antenna or a wired/wireless transceiver. The electronic system  1100  may be used as an operating memory (not shown) for improving the operation of the controller  1110  and may further include a high-speed DRAM and/or SRAM. The fin-type transistor according to embodiments of the present inventive concept may be provided within the memory device  1130  or may be provided as a component of the controller  1110  or the I/O device  1120 . 
         [0049]    The electronic system  1100  may be applied to a personal digital assistant (PDA), a portable computer, a web tablet, a wireless phone, a mobile phone, a digital music player, a memory card, or any type of electronic device capable of transmitting and/or receiving information in a wireless environment. 
         [0050]      FIGS. 14 and 15  illustrate an exemplary semiconductor system to which a semiconductor device fabricated according to an embodiment of the inventive concept. For example,  FIGS. 14 and 15 , respectively, illustrate a tablet PC and a notebook computer including semiconductor devices according to embodiments of the present inventive concept. The application is not limited to the above, but any electronic system may include semiconductor devices according to embodiments of the present inventive concept. While the present inventive concept has been shown and described with reference to exemplary embodiments thereof, it will be apparent to those of ordinary skill in the art that various changes in form and detail may be made therein without departing from the sprit and scope of the inventive concept as defined by the following claims.

Technology Category: 5