Patent Publication Number: US-2020295016-A1

Title: Semiconductor memory device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2019-044879, filed Mar. 12, 2019, the entire contents of which are incorporated herein by reference. 
     FIELD 
     Embodiments described herein relate generally to a semiconductor memory device. 
     BACKGROUND 
     A NAND-type flash memory capable of storing data in a nonvolatile manner is known. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram illustrating a configuration example of a semiconductor memory device according to a first embodiment; 
         FIG. 2  is a circuit diagram illustrating an example of a circuit configuration of a memory cell array included in the semiconductor memory device according to the first embodiment; 
         FIG. 3  is a plan view illustrating an example of a planar layout of the memory cell array included in the semiconductor memory device according to the first embodiment; 
         FIG. 4  is a plan view illustrating an example of a detailed planar layout in a cell area of the memory cell array included in the semiconductor memory device according to the first embodiment; 
         FIG. 5  is a cross-sectional view, taken along line V-V in  FIG. 4 , illustrating an example of a cross-sectional structure in the cell area of the memory cell array included in the semiconductor memory device according to the first embodiment; 
         FIG. 6  is a cross-sectional view, taken along line VI-VI in  FIG. 5 , illustrating an example of a cross-sectional structure of a memory pillar in the semiconductor memory device according to the first embodiment; 
         FIG. 7  is a plan view illustrating an example of a detailed planar layout in a hookup area of the memory cell array included in the semiconductor memory device according to the first embodiment; 
         FIG. 8  is a cross-sectional view, taken along line VIII-VIII in  FIG. 7 , illustrating an example of a cross-sectional structure in the hookup area of the memory cell array included in the semiconductor memory device according to the first embodiment; 
         FIG. 9  is a cross-sectional view, taken along line IX-IX in  FIG. 7 , illustrating an example of a cross-sectional structure in the hookup area of the memory cell array included in the semiconductor memory device according to the first embodiment; 
         FIG. 10  is a cross-sectional view, taken along line X-X in  FIG. 9 , illustrating an example of a cross-sectional structure of a contact in the semiconductor memory device according to the first embodiment; 
         FIG. 11  is a cross-sectional view, taken along line XI-XI in  FIG. 9 , illustrating an example of a cross-sectional structure of a support pillar in the semiconductor memory device according to the first embodiment; 
         FIG. 12  is a flowchart illustrating an example of a manufacturing method of the semiconductor memory device according to the first embodiment; 
         FIG. 13  is a cross-sectional view of a memory cell array, illustrating an example of a cross-sectional structure during the manufacture of the semiconductor memory device according to the first embodiment; 
         FIG. 14  is a plan view of the memory cell array, illustrating an example of a planar layout during the manufacture of the semiconductor memory device according to the first embodiment; 
         FIG. 15  is a cross-sectional view of the memory cell array, taken along line XV-XV in  FIG. 14 , illustrating an example of the cross-sectional structure during the manufacture of the semiconductor memory device according to the first embodiment; 
         FIG. 16  is a cross-sectional view of the memory cell array, illustrating an example of the cross-sectional structure during the manufacture of the semiconductor memory device according to the first embodiment; 
         FIG. 17  is a plan view of the memory cell array, illustrating an example of the planar layout during the manufacture of the semiconductor memory device according to the first embodiment; 
         FIG. 18  is a cross-sectional view of the memory cell array, taken along line XVIII-XVIII in  FIG. 17 , illustrating an example of the cross-sectional structure during the manufacture of the semiconductor memory device according to the first embodiment; 
         FIG. 19 ,  FIG. 20  and  FIG. 21  are cross-sectional views of the memory cell array, illustrating examples of the cross-sectional structure during the manufacture of the semiconductor memory device according to the first embodiment; 
         FIG. 22  is a plan view of the memory cell array, illustrating an example of the planar layout during the manufacture of the semiconductor memory device according to the first embodiment; 
         FIG. 23  is a cross-sectional view of the memory cell array, taken along line XXIII-XXIII in  FIG. 22 , illustrating an example of the cross-sectional structure during the manufacture of the semiconductor memory device according to the first embodiment; 
         FIG. 24  is a plan view of the memory cell array, illustrating an example of the planar layout during the manufacture of the semiconductor memory device according to the first embodiment; 
         FIG. 25  is a cross-sectional view of the memory cell array, taken along line XXV-XXV in  FIG. 24 , illustrating an example of the cross-sectional structure during the manufacture of the semiconductor memory device according to the first embodiment; 
         FIG. 26  is a cross-sectional view of the memory cell array, illustrating an example of the cross-sectional structure during the manufacture of the semiconductor memory device according to the first embodiment; 
         FIG. 27  is a plan view of the memory cell array, illustrating an example of the planar layout during the manufacture of the semiconductor memory device according to the first embodiment; 
         FIG. 28  is a cross-sectional view of the memory cell array, taken along line XXVIII-XXVIII in  FIG. 27 , illustrating an example of the cross-sectional structure during the manufacture of the semiconductor memory device according to the first embodiment; 
         FIG. 29  is a cross-sectional view of the memory cell array, illustrating an example of the cross-sectional structure during the manufacture of the semiconductor memory device according to the first embodiment; 
         FIG. 30  is a flowchart illustrating an example of a manufacturing method of a semiconductor memory device according to a second embodiment; 
         FIG. 31 ,  FIG. 32 ,  FIG. 33  and  FIG. 34  are cross-sectional views of the memory cell array, illustrating examples of the cross-sectional structure during the manufacture of the semiconductor memory device according to the second embodiment; 
         FIG. 35  is a flowchart illustrating an example of a manufacturing method of a semiconductor memory device according to a third embodiment; 
         FIG. 36  is a plan view of the memory cell array, illustrating an example of the planar layout during the manufacture of the semiconductor memory device according to the third embodiment; 
         FIG. 37  is a cross-sectional view of the memory cell array, taken along line XXXVII-XXXVII in  FIG. 36 , illustrating an example of the cross-sectional structure during the manufacture of the semiconductor memory device according to the third embodiment; 
         FIG. 38  is a plan view of the memory cell array, illustrating an example of the planar layout during the manufacture of the semiconductor memory device according to the third embodiment; 
         FIG. 39  is a cross-sectional view of the memory cell array, illustrating an example of the cross-sectional structure during the manufacture of the semiconductor memory device according to the third embodiment; 
         FIG. 40  is a plan view illustrating an example of a detailed planar layout in a hookup area of a memory cell array included in a semiconductor memory device according to a fourth embodiment; 
         FIG. 41  is a cross-sectional view, taken along line XLI-XLI in  FIG. 40 , illustrating an example of a cross-sectional structure in the hookup area of the memory cell array included in the semiconductor memory device according to the fourth embodiment; 
         FIG. 42  is a cross-sectional view, taken along line XLII-XLII in  FIG. 41 , illustrating an example of a cross-sectional structure of a contact in the semiconductor memory device according to the fourth embodiment; 
         FIG. 43  is a flowchart illustrating an example of a manufacturing method of the semiconductor memory device according to the fourth embodiment; 
         FIG. 44  is a plan view of the memory cell array, illustrating an example of the planar layout during the manufacture of the semiconductor memory device according to the fourth embodiment; 
         FIG. 45  is a cross-sectional view, taken along line XLV-XLV in  FIG. 44 , illustrating an example of the cross-sectional structure during the manufacture of the semiconductor memory device according to the fourth embodiment; and 
         FIG. 46  is a cross-sectional view illustrating an example of a cross-sectional structure of a support pillar in a semiconductor memory device according to a modification of the first embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     In general, according to one embodiment, a semiconductor memory device includes a substrate, a plurality of first conductive layers, a second conductive layer, a third conductive layer, a first pillar, a second pillar, a first contact, a second contact, a first member, a second member, and a third member. The substrate includes a first area and a second area adjacent to the first area. The plurality of first conductive layers are provided above the substrate of the first area and the second area. The first conductive layers are stacked at intervals in a first direction. The second conductive layer is provided above an uppermost first conductive layer of the first conductive layers. The third conductive layer is provided above the uppermost first conductive layer and is provided in the same layer as the second conductive layer. The third conductive layer and the second conductive layer are separated from each other. The first pillar is provided to penetrate the first conductive layers and the second conductive layer in the first area. An intersection portion between the first pillar and each of the first conductive layers functions as a memory cell transistor. An intersection portion between the first pillar and the second conductive layer functions as a select transistor. A second pillar is provided to penetrate the first conductive layers and the third conductive layer in the first area. An intersection portion between the second pillar and each of the first conductive layers functions as a memory cell transistor. An intersection portion between the second pillar and the third conductive layer is functions as a select transistor. The first contact is provided on the second conductive layer in the second area. The second contact is provided on the third conductive layer in the second area. The first member is provided between the second conductive layer and the third conductive layer in the first area. The second member is provided between the second conductive layer and the third conductive layer in the second area. The third member is extending in the first direction and is provided to penetrate the first conductive layers. The third member is in contact with each of the second conductive layer, the third conductive layer, the first member and the second member. 
     Hereinafter, the embodiments will be described with reference to the accompanying drawings. Each embodiment is an example of a device or a method for embodying a technical concept of the invention. The drawings are schematic or conceptual ones. The dimensions, ratios, etc. in the drawings do not necessarily agree with the actual ones. The technical concept of the present invention is not specified by shapes, structures, dispositions, etc. of constituent elements. 
     In the description below, constituent elements having substantially the same functions and configurations will be denoted by the same reference symbols. The numbers after the letters constituting the reference symbols are used to distinguish elements which are denoted by the reference symbols including the same letters and which have similar configurations. If there is no need of mutually distinguishing the elements which are denoted by the reference symbols that include the same letters, the same elements are denoted by the reference symbols that include only the same letters. 
     [1] First Embodiment 
     Hereinafter, a semiconductor memory device  1  according to a first embodiment will be described. 
     [1-1] Configuration of Semiconductor Memory Device  1   
     [1-1-1] Entire Configuration of Semiconductor Memory Device  1   
       FIG. 1  illustrates a configuration example of the semiconductor memory device  1  according to the first embodiment. The semiconductor memory device  1  is a NAND-type flash memory which can store data nonvolatilely, and is controlled by an external memory controller  2 . Communication between the semiconductor memory device  1  and the memory controller  2  supports, for example, a NAND interface standard. 
     As illustrated in  FIG. 1 , the semiconductor memory device  1  includes, for example, a memory cell array  10 , a command register  11 , an address register  12 , a sequencer  13 , a driver module  14 , a row decoder module  15 , and a sense amplifier module  16 . 
     The memory cell array  10  includes a plurality of blocks BLK 0  to BLKn (n is an integer of 1 or more). The block BLK is a set of a plurality of memory cells which can store data nonvolatilely, and the block BLK is used, for example, as an erase unit of data. In addition, in the memory cell array  10 , a plurality of bit lines and a plurality of word lines are provided. Each memory cell is associated with, for example, one bit line and one word line. A detailed configuration of the memory cell array  10  will be described later. 
     The command register  11  holds a command CMD which the semiconductor memory device  1  has received from the memory controller  2 . The command CMD includes, for example, instructions to cause the sequencer  13  to perform a read operation, a write operation, an erase operation and the like. 
     The address register  12  holds address information ADD which the semiconductor memory device  1  has received from the memory controller  2 . The address information ADD includes a block address BAd, a page address PAd, and a column address CAd. For example, the block address BAd, page address PAd and column address CAd are used to select a block BLK, a word line and a bit line, respectively. 
     The sequencer  13  controls the operation of the entire semiconductor memory device  1 . For example, the sequencer  13  controls the driver module  14 , the row decoder module  15 , the sense amplifier module  16  and the like, based on the command CMD held in the command register  11 , thereby executing a read operation, a write operation, an erase operation and the like. 
     The driver module  14  generates a voltage that is to be used in the read operation, write operation, erase operation and the like. Then, the driver module  14  applies the generated voltage to a signal line corresponding to a selected word line, for example, based on the page address PAd held in the address register  12 . 
     The row decoder module  15  selects one block BLK in the memory cell array  10 , based on the block address BAd held in the address register  12 . Then, the row decoder module  15  transfers, for example, a voltage applied to the signal line corresponding to the selected word line, to the selected word line in the selected block BLK. 
     In the write operation, the sense amplifier module  16  apples a desired voltage to each bit line in accordance with write data DAT received from the memory controller  2 . In the read operation, the sense amplifier module  16  determines data stored in a memory cell, based on the voltage of the bit line, and transfers a result of the determination to the memory controller  2  as read data DAT. 
     The above-described semiconductor memory device  1  and memory controller  2  may be combined to constitute one semiconductor device. Examples of this semiconductor device include a memory card such as an SD™ card, a solid-state drive (SSD), and the like. 
     [1-1-2] Circuit Configuration of Memory Cell Array  10   
       FIG. 2  illustrates an example of a circuit configuration of the memory cell array  10  included in the semiconductor memory device  1  according to the first embodiment, by extracting one of the blocks BLK included in the memory cell array  10 . As illustrated in  FIG. 2 , the block BLK includes, for example, four string units SU 0  to SU 3 . 
     Each string unit SU includes a plurality of NAND strings NS which are associated with bit lines BL 0  to BLm (m is an integer of 1 or more), respectively. Each NAND string NS includes, for example, memory cell transistors MT 0  to MT 11 , and select transistors ST 1   a , ST 1   b , ST 1   c , and ST 2 . The memory cell transistor MT includes a control gate and a charge storage layer, and stores data nonvolatilely. Each of the select transistors ST 1   a , ST 1   b , ST 1   c , and ST 2  is used to select the string unit SU during various operations. 
     In each NAND string NS, the select transistors ST 1   a , ST 1   b  and ST 1   c  are connected in series, and the memory transistors MT 0  to MT 11  are connected in series. One end of the series-connected select transistors ST 1   a , ST 1   b  and ST 1   c  is connected to the associated bit line BL, and the other end thereof is connected to one end of the series-connected memory transistors MT 0  to MT 11 . One end of the select transistor ST 2  is connected to the other end of the series-connected memory transistors MT 0  to Mil, and the other end of the select transistor ST 2  is connected to the source line SL. 
     In the same block BLK, the control gates of the memory cell transistors MT 0  to MT 11  are commonly connected to word lines WL 0  to WL 11 , respectively. The gates of the select transistors ST 1   a , ST 1   b  and ST 1   c  in the string unit SU 0  are commonly connected to select gate lines SGD 0   a , SGD 0   b  and SGD 0   c , respectively. The gates of the select transistors ST 1   a , ST 1   b  and ST 1   c  in the string unit SU 1  are commonly connected to select gate lines SGD 1   a , SGD 1   b  and SGD 1   c , respectively. The gates of the select transistors ST 1   a , ST 1   b  and ST 1   c  in the string unit SU 2  are commonly connected to select gate lines SGD 2   a , SGD 2   b  and SGD 2   c , respectively. The gates of the select transistors ST 1   a , ST 1   b  and ST 1   c  in the string unit SU 3  are commonly connected to select gate lines SGD 3   a , SGD 3   b  and SGD 3   c , respectively. The gates of the select transistors ST 2  in the same block BLK are commonly connected to a select gate line SGS. 
     In the above-described circuit configuration of the memory cell array  10 , the word lines WL 0  to WL 5  correspond to memory holes LMH to be described later, and the word lines WL 6  to WL 11  correspond to memory holes UMH to be described later. Each bit line BL is shared by the NAND strings NS to which the same column address is allocated in each string unit SU. The source line SL is shared by, for example, a plurality of blocks BLK. 
     A set of memory cell transistors MT connected to a common word line WL in one string unit SU is referred to as, for example, a cell unit CU. For example, the storage capacity of the cell unit CU including memory cell transistors MT each storing one-bit data is defined as “one-page data.” The cell unit CU may have a storage capacity of data of two or more pages, according to the number of bits of data to be stored in the memory cell transistor MT. 
     Note that the circuit configuration of the memory cell array  10  included in the semiconductor memory  1  according to the first embodiment is not limited to the configuration described above. For example, the number of memory cell transistors MT and the number of select transistors ST 1  and ST 2 , which are included in each NAND string NS, may be freely selected. The number of string units SU included in each block BLK may be freely selected. 
     Besides, one or more dummy word lines may be provided between the word lines WL 5  and WL 6 . When a dummy word line is provided, a dummy transistor is provided between the memory cell transistors MT 5  and MT 6  of each NAND string NS, with the number of dummy transistors being set according to the number of dummy word lines. The dummy transistor has the same structure as the memory cell transistor MT, and is a transistor which is not used to store data. Similarly, a dummy word line may be provided between the word line WL 0  and select gate line SGS, and between the word line WL 11  and select gate line SGDa. 
     [1-1-3] Structure of Memory Cell Array  10   
     An example of a structure of the memory cell array  10  in the first embodiment will be described below. 
     In the drawings to be referred to below, an X direction corresponds to the extending direction of the word line. WL, a Y direction corresponds to the extending direction of the bit line BL, and a Z direction corresponds to a direction perpendicular to the surface of a semiconductor substrate  20  on which the semiconductor memory device  1  is formed. Hatching is added to plan views as appropriate for clarification. The hatching added to the plan views is not necessarily related to the materials or properties of the constituent elements to which hatching is added. In cross-sectional views, constituent elements such as insulator layers (interlayer insulator films), interconnects and contacts are omitted as appropriate for clarification. 
     (Planar Layout of Memory Cell Array  10 ) 
       FIG. 3  illustrates an example of a planar layout of the memory cell array  10  included in the semiconductor memory device  1  according to the first embodiment.  FIG. 3  illustrates, in an extracted manner, an area corresponding to one block BLK (i.e. string units SU 0  to SU 3 ). As illustrated in  FIG. 3 , the planar layout of the memory cell array  10  is divided into, for example, a cell area CA and a hookup area HA in the X direction. In addition, the memory cell array  10  includes slits SLT 1 , SLT 2  and SLT 3 , and slits SHE 1  and SHE 2 . 
     The cell area CA is an area where the NAND strings NS are formed. The hookup area HA is an area where contacts are formed for electrically connecting the word lines WL and select gate lines SGS and SGD, which are connected to the NAND strings NS, and the row decoder module  15 . Further, the hookup area HA includes a through-contact area C 4 T which is provided to extend, for example, in the Y direction. The through-contact area C 4 T is an area where a contact is provided which penetrates stacked word lines WL and the like and electrically connects circuitry on the memory cell array  10  and circuitry under the memory cell array  10 . 
     Each of the slits SLT 1 , SLT 2  and SLT 3  and slits SHE 1  and SHE 2  divides stacked interconnect layers. Further, each of the slits SLT 1 , SLT 2  and SLT 3  and slits SHE 1  and SHE 2  has such a structure that an insulator member is buried in the inside thereof, and insulates conductive layers which are provided in the same interconnect layer and are adjacent each other via the slit SLT. 
     Specifically, each of the slits SLT 1 , SLT 2  and SLT 3  divides, for example, a plurality of interconnect layers corresponding to the word lines WL 0  to WL 11 , select gate lines SGDa, SGDb and SGDc, and select gate line SGS, respectively. Each of the slits SHE 1  and SHE 2  divides a plurality of interconnect layers corresponding to the select gate lines SGDa, SGDb and SGDc, respectively. 
     The slits SLT 1  are provided to extend in the X direction, and are arranged in the Y direction. The slits SLT 1  extend across the hookup area HA and cell area CA in the X direction. Each of the slits SLT 2  and SLT 3  is provided to extend in the X direction between two adjacent slits SLT 1 . The slit SLT 2  extends from an end area in the hookup area HA, and extends across the cell area CA in the X direction. The slit SLT 3  is disposed separated from the slit SLT 2  in the hookup area HA. 
     In addition, the slits SLT 2  and SLT 3  are disposed, for example, such that the slits SLT 2  and SLT 3  are adjacent each other in the X direction. A gap portion GP 1  is disposed between the slits SLT 2  and SLT 3 . In other words, between the two slits SLT 1  which are adjacent in the Y direction, a slit SLT extending from the hookup area HA to cell area CA is provided except for the gap portion GP 1 . The gap portion GP 1  is disposed, for example, in the through-contact area C 4 T in the hookup area HA. 
     Between each slit SLT 1  and the SLT  2  which are adjacent each other, for example, a pair of one slit SHE 1  and one slit SHE 2  is disposed. The slit SHE 1  is provided to extend in the X direction and extends across the cell area CA in the X direction. The slit SHE 2  is provided to extend in the X direction, and is disposed separated from the slit SHE 1  in the hookup area HA. 
     Besides, the slits SHE 1  and SHE 2  are disposed, for example, such that the slits SHE 1  and SHE 2  are adjacent each other in the X direction. A gap portion GP 2  is disposed between the slits SHE 1  and SHE 2 . The gap portion GP 2  is disposed near a boundary portion between the cell area CA and hookup area HA. 
     In the above-described planar layout of the memory cell array  10 , each of the areas divided by the slits SLT 1 , SLT 2  and SHE 1  in the cell area CA corresponds to one string unit SU. Specifically, in this example, the string units SU 0  to SU 3  extending in the X direction are arranged in the Y direction. In addition, in the memory cell array  10 , the layout illustrated in, for example,  FIG. 3  is repeatedly arranged in the Y direction. 
     In the above-described planar layout of the memory cell array  10 , the number of slits SLT 2  and SLT 3  disposed between the two adjacent slits SLT 1  may be freely selected. The number of slits SHE 1  and SHE 2  disposed between the adjacent slits SLT 1  and SLT 2  may be freely selected. The number of string units SU between the two adjacent slits SLT 1  varies based on the number of slits SLT 2 , SHE 1  and SHE 2  arranged between the two adjacent slits SLT 1 . 
     (Structure of Memory Cell. Array  10  in Cell Area CA) 
       FIG. 4  illustrates an example of a detailed planar layout of the memory cell array  10  in the cell area CA of the semiconductor memory device  1  according to the first embodiment, by extracting an area corresponding to the string units SU 0  and SU 1 . As illustrated in  FIG. 4 , in the cell area CA, the memory cell array  10  further includes a plurality of memory pillars MP, a plurality of contacts CV, and a plurality of bit lines BL. 
     Each of the memory pillars MP functions, for example, as one NAND string NS. The memory pillars MP are arranged in a staggering fashion in nine rows, for example, in an area between the adjacent slits SLT 1  and SLT 2 . Memory pillars MP, which are arranged in the X direction in an intermediate portion between the adjacent slits SLT 1  and SLT 2 , are disposed to overlap the slit SHE 1 . Specifically, the pillars MP include pillars MP which penetrate the slit SHE 1  and are put in contact with adjacent select gate lines SGD. 
     The bit lines BL extend in the Y direction and are arranged in the X direction. Each bit line BL is disposed to overlap at least one memory pillar MP in each string unit SU. In this example, two bit lines BL are disposed to overlap each memory pillar MP. A contact CV is provided between one bit line BL of the bit lines BL overlapping the memory pillar MP, and the memory pillar MP. Each memory pillar MP is electrically connected to the corresponding bit line BL via the contact CV. 
     Note that the contact CV between the memory pillar MP, which overlaps the slit SHE 1 , and the bit line BL is omitted. In other words, the contact. CV between the memory pillar MP, which is in contact with two different select gate lines SGD, and the bit line BL is omitted. The numbers of memory pillars MP, slits SHE 1  and the like between the adjacent slits SLT, and their dispositions are not limited to the structure described with reference to  FIG. 4 , and may be changed as appropriate. 
     The planar layout of the memory cell array  10  in the area corresponding to the string units SU 2  and SU 3  is similar to, for example, the planar layout of the memory cell array  10  in the area corresponding to the string units SU 0  and SU 1 , so a description thereof is omitted. 
       FIG. 5  is a cross-sectional view, taken along line V-V in  FIG. 4 , illustrating an example of a cross-sectional structure in the cell area CA of the memory cell array  10  included in the semiconductor memory device  1  according to the first embodiment. In addition, in  FIG. 5 , a part overlapping the slit SHE 1  in the X direction is indicated by a broken line. As illustrated in  FIG. 5 , the memory cell array  10  further includes conductive layers  21  to  26 . The conductive layers  21  to  26  are provided above the semiconductor substrate  20 . 
     Specifically, the conductive layer  21  is provided above the semiconductor substrate  20  via an insulator layer. Although depiction is omitted, circuitry corresponding to, for example, the row decoder module  15 , sense amplifier module  16  and the like is provided in the insulator layer between the semiconductor substrate  20  and conductive layer  21 . The conductive layer  21  is formed, for example, in a plate shape extending along the XY plane, and is used as the source line SL. The conductive layer  21  includes, for example, silicon (Si). 
     The conductive layer  22  is provided above the conductive layer  21  via an insulator layer. The conductive layer  22  is formed, for example, in a plate shape extending along the XY plane, and is used as the select gate line SGS. The conductive layer  22  includes, for example, silicon. 
     Above the conductive layer  22 , insulator layers and the conductive layers  23  are alternately stacked. Each conductive layer  23  is formed, for example, in a plate shape extending along the XY plane. For example, the stacked conductive layers  23  are used as word lines WL 0  to WL 5  in an order from the semiconductor substrate  20  side. The conductive layers  23  include, for example, tungsten (W). 
     Above the uppermost conductive layer  23 , insulator layers and the conductive layers  24  are alternately stacked. Each conductive layer  24  is formed, for example, in a plate shape extending along the XY plane. For example, the stacked conductive layers  24  are used as word lines WL 6  to WL 11  in an order from the semiconductor substrate  20  side. The conductive layers  24  include, for example, tungsten. 
     Note that the thickness of the insulator layer between the uppermost conductive layer  23  and lowermost conductive layer  24  is greater than the thickness of the insulator layer between adjacent conductive layers  23 , and is greater than the thickness of the insulator layer between adjacent conductive layers  24 . In other words, the distance in the Z direction between the uppermost conductive layer  23  and lowermost conductive layer  24  is greater than the distance in the Z direction between adjacent conductive layers  23 , and is greater than the distance in the Z direction between adjacent conductive layers  24 . 
     Above the uppermost conductive layer  24 , insulator layers and the conductive layers  25  are alternately stacked. Each conductive layer  25  is formed, for example, in a plate shape extending along the XY plane. For example, the stacked conductive layers  25  are used as select gate lines SGDa, SGDb and SGDc in an order from the semiconductor substrate  20  side. The conductive layers  25  include, for example, tungsten. 
     The conductive layer  26  is provided above the uppermost conductive layer  25  via an insulator layer. The conductive layer  26  is formed, for example, in a line shape extending in the Y direction, and is used as a bit line BL. Specifically, in an area not shown, a plurality of conductive layers  26  are arranged in the X direction. Each conductive layer  26  includes, for example, copper (Cu). 
     Each of the memory pillars MP is provided to extend in the Z direction, and penetrates the conductive layers  22  to  25 . Each memory pillar MP includes a first portion formed in the inside of a memory hole LMH corresponding to lower-layer stacked interconnects, and a second portion formed in the inside of a memory hole UMH corresponding to upper-layer stacked interconnects. 
     The first portion corresponding to the memory hole LMH penetrates the conductive layers  22  and  23 , and a bottom part of the first portion is in contact with the conductive layer  21 . The second portion corresponding to the memory hole UMH is provided above the first portion corresponding to the memory hole LMH, and penetrates the conductive layers  24  and  25 . For example, in each memory pillar MP, the outside diameter at an upper end of the first portion is greater than the outside diameter at a lower end of the second portion. 
     In addition, each memory pillar MP includes, for example, a core member  30 , a semiconductor layer  31 , and a stacked film  32 . For example, each of the core member  30 , semiconductor layer  31  and stacked film  32  is continuously provided between the first portion and second portion of the memory pillar MP. 
     Specifically, the core member  30  is provided to extend in the Z direction. For example, an upper end of the core member  30  is included in a layer which is higher than the uppermost conductive layer  25 , and a lower end of the core member  30  is included in a layer in which the conductive layer  21  is provided. The semiconductor layer  31  includes, for example, a portion covering a side surface and a bottom surface of the core member  30 , and a columnar portion extending in the Z direction at a bottom portion of the core member  30 . For example, a bottom portion of the columnar portion of the semiconductor layer  31  is in contact with the conductive layer  21 . The stacked film  32  covers a side surface and a bottom surface of the semiconductor layer  31 , except for a portion where the columnar portion of the semiconductor layer  31  is provided. The core member  30  includes, for example, an insulator such as silicon oxide (SiO 2 ). The semiconductor layer  31  includes, for example, silicon. 
     The columnar contact CV is provided on a top surface of the semiconductor layer  31  in the memory pillar MP. In the area illustrated, contacts CV corresponding to two memory pillars MP among five memory pillars MP are depicted. In an area not illustrated, contacts CV are connected to the memory pillars MP which, in the illustrated area, do not overlap the slit SHE 1  and are not connected to the contacts CV. 
     One conductive layer  26 , i.e., one bit line BL, is in contact with a top surface of the contact CV. One contact CV is connected to one conductive layer  26  in each of spaces which are divided by the slits SLT 1 , SLT 2  and SHE 1  and by the memory pillar MP which is in contact with the slit SHE 1 . Specifically, for example, one memory pillar MP between the adjacent slit. SLT 1  and SHE 1 , and one memory pillar MP between the adjacent slit SHE 1  and SLT 2 , are electrically connected to each of the conductive layers  26 . 
     The slit SLT is formed, for example, in a plate shape extending along the XZ plane, and divides the conductive layers  22  to  25 . An upper end of the slit SLT is included in a layer between the uppermost conductive layer  25  and the conductive layer  26 . A lower end of the slit SLT is included, for example, in the layer in which the conductive layer  21  is provided. The slit SLT includes, for example, an insulator such as silicon oxide. 
     The slit SHE 1  is formed, for example, in a plate shape extending along the XZ plane, and divides the stacked conductive layers  25 . An upper end of the slit SHE 1  is included in the layer between the uppermost conductive layer  25  and the conductive layer  26 . A lower end of the slit SHE 1  is included, for example, in a layer between the uppermost conductive layer  24  and lowermost conductive layer  25 . The slit SHE 1  includes, for example, an insulator such as silicon oxide. For example, the upper end of the slit SHE 1  and the upper end of the memory pillar MP are aligned with each other. However, the embodiment is not limited to this, and the upper end of the memory pillar MP may not be aligned with the upper end of the slit SLT, SHE. 
       FIG. 6  is a cross-sectional view, taken along line VI-VI in  FIG. 5 , illustrating an example of a cross-sectional structure of the memory pillar MP in the semiconductor memory device  1  according to the first embodiment. More specifically,  FIG. 6  illustrates a cross-sectional structure of the memory pillar MP in a layer which is parallel to the surface of the semiconductor substrate  20  and includes the conductive layer  23 . 
     As illustrated in  FIG. 6 , in the layer including the conductive layer  23 , the core member  30  is provided, for example, in a central part of the memory pillar MP. The semiconductor layer  31  surrounds the side surface of the core member  30 . The stacked film  32  surrounds the side surface of the semiconductor layer  31 . The stacked film  32  includes, for example, a tunnel insulator film  33 , an insulator film  34  and a block insulator film  35 . 
     The tunnel insulator film  33  surrounds the side surface of the semiconductor layer  31 . The insulator film  34  surrounds a side surface of the tunnel insulator film  33 . The block insulator film  35  surrounds a side surface of the insulator film  34 . The conductive layer  23  surrounds a side surface of the block insulator film  35 . Each of the tunnel insulator film  33  and block insulator film  35  includes, for example, silicon oxide. The insulator film  34  includes, for example, silicon nitride (SiN). 
     In the above-described structure of the memory pillar MP, an intersection portion between the memory pillar MP and conductive layer  22  functions as the select transistor ST 2 . Each of an intersection portion between the memory pillar MP and conductive layer  23  and an intersection portion between the memory pillar MP and conductive layer  24  functions as the memory cell transistor MT. An intersection portion between the memory pillar MP and conductive layer  25  functions as the select transistor ST 1 . 
     Specifically, the semiconductor layer  31  is used as a channel of each of the memory cell transistors MT 0  to MT 11  and select transistors ST 1   a , ST 1   b , ST 1   c  and ST 2 . The insulator film  34  is used as a charge storage layer of the memory cell transistor MT. Thereby, each of the memory pillars MP functions as one NAND string NS. 
     (Structure of Memory Cell Array  10  in Hookup Area HA) 
       FIG. 7  illustrates an example of a detailed planar layout of the memory cell array  10  in the hookup area HA of the semiconductor memory device  1  according to the first embodiment, by extracting an area corresponding to one block BLK (i.e. string units SU 0  to SU 3 ).  FIG. 7  also illustrates a part of the cell area CA near the hookup area HA. 
     As illustrated in  FIG. 7 , in the hookup area HA, end portions of the select gate line SGS, word lines WL 0  to WL 11  and select gate lines SGDa, SGDb and SGDc are provided in a stepped shape. In addition, in the hookup area HA, the memory cell array  10  further includes a plurality of contacts CC and C 4 , and a plurality of support pillars HR. 
     Specifically, each of the select gate line SGS, word lines WL 0  to WL 11  and select gate lines SGDa, SGDb and SGDc includes, in an end portion thereof, a terrace portion which does not overlap upper-layer interconnect layers (conductive layers). For example, the end portions of the word lines WL 0  to WL 11  are provided in a stepped shape of three rows, the stepped shape including two steps in the Y direction and a plurality of steps in the X direction. The end portions of the select gate lines SGDa, SGDb and SGDc are provided in a stepped shape in which steps are formed in the X direction. The select gate line SGS is led out from the area of the end portions of the word lines WL 0  to WL 11  which are formed in the stepped shape. 
     In this stepped structure of the stacked interconnects, the slit SLT 3  is disposed, for example, in an intermediate portion between two adjacent slits SLT 1 , and extends across the terrace portions corresponding to the word lines WL 1 , WL 4 , WL 7  and WL 10  in the X direction. The slit SLT 3  may or may not extend across the terrace portion of the select gate line SGS in the X direction. The slit SHE 2  is disposed, for example, in an intermediate portion between the adjacent slits SLT 1  and SLT 2 , and extends across the terrace portions corresponding to the select gate lines SGDa, SGDb and SGDc in the X direction. 
     Note that in this example, the word lines WL provided in the same layer in the same block BLK are short-circuited via the gap GP 1 . In other words, the word line WL, which is in contact with one slit SLT 1  of the two adjacent slits SLT 1 , and the word line WL, which is in contact with the other slit SLT 1 , are electrically connected via the gap portion GP 1 . 
     The contacts CC are provided on the terrace portions of the select gate line SGS, word lines WL 0  to WL 11  and select gate lines SGDa, SGDb and SGDc. Each of the select gate line SGS, word lines WL 0  to WL 11  and select gate lines SGDa, SGDb and SGDc is electrically connected to the row decoder module  15  via the corresponding contact CC. 
     The contacts C 4  are provided in the through-contact area C 4 T. The contacts C 4  penetrate the stacked interconnect layers (e.g. source line SL, select gate line SGS and word lines WL) and are connected to an interconnect below the memory cell array  10 . In addition, in this example, the contacts C 4  are disposed to overlap the terrace portion of the word line WL 11 . The number of contacts C 4  provided in the through-contact area C 4 T, and the dispositions of the contacts C 4 , may be changed as appropriate. 
     The support pillars HR are disposed as appropriate, for example, in the hookup area HA, in areas excluding the areas where the slits SLT 1  and SLT 2  are formed and areas where the contacts CC and C 4  are formed. The support pillar HR has such a structure that an insulator member is buried in a hole extending in the Z direction, and the support pillar HR penetrates the stacked interconnect layers (e.g. word lines WL and select gate lines SGD). For example, a plurality of support pillars HR are disposed around the contact CC in the terrace portion of the word line WL 0 , and a plurality of support pillars HR are disposed around the contact C 4  in the through-contact area C 4 T. The outside diameter of the support pillar HR is less than the outside diameter of the contact C 4 . 
     In addition, the support pillar HR is disposed in each of the gap portions GP 2 . Specifically, the support pillar HR is disposed, for example, between one slit SHE 1  and one slit SHE 2  which are adjacent in the X direction, and the support pillar HR couples the slits SHE 1  and SHE 2 . Thereby, the select gate lines SGDa, SGDb and SGDc between the two adjacent slits SLT 1  are separated by the paired slits SHE 1  and SHE 2  which are adjacent in the X direction and by the support pillar HR disposed between the slits SHE 1  and SHE 2 . 
       FIG. 8  is a cross-sectional view, taken along line VIII-VIII in  FIG. 7 , illustrating an example of a cross-sectional structure in the hookup area HA of the memory cell array  10  included in the semiconductor memory device  1  according to the first embodiment. In addition,  FIG. 8  illustrates a cross-sectional area including the contacts CC. As illustrated in  FIG. 8 , in the hookup area HA, the end portions of the conductive layers corresponding to the word lines WL and select gate lines SGD are provided in a stepped shape. Besides, in the hookup area HA, the memory cell array  10  further includes a plurality of conductive layers  27 . 
     The illustrated area includes a plurality of terrace portions corresponding to the word lines WL 1 , WL 4 , WL 7  and WL 10  and select gate lines SGDa, SGDb and SGDc. Further, one contact CC is provided on the terrace portion of each of the conductive layer  23  corresponding to the word line WL 0 , the conductive layer  23  corresponding to the word line WL 4 , the conductive layer  24  corresponding to the word line WL 7 , and the conductive layer  24  corresponding to the word line WL 10 , and each of the three conductive layers  25  corresponding to the select gate lines SGDa, SGDb and SGDc. One conductive layer  27  is provided on each contact CC and is electrically connected to each contact CC. Each conductive layer  27  is included, for example, in a layer above the conductive layer  26 . 
     The support pillar HR is provided to extend in the Z direction, and penetrates, for example, the conductive layers  22  to  24  in the through-contact area C 4 T. An upper end of the support pillar HR is included, for example, in a layer between the conductive layer  26  and the upper end of the memory pillar MP. A lower end of the support pillar HR is included, for example, in the layer in which the conductive layer  21  is provided. Aside from this, the lower end of the support pillar HR reaches at least the conductive layer  22 . 
       FIG. 9  is a cross-sectional view, taken along line IX-IX in  FIG. 7 , illustrating an example of a cross-sectional structure in the hookup area HA of the memory cell array  10  included in the semiconductor memory device  1  according to the first embodiment. In addition,  FIG. 9  illustrates a cross-sectional area including support pillars HR between the slits SHE 1  and SHE 2 , and indicates, by a broken line, a portion overlapping the three conductive layers  25  in the Y direction. As illustrated in  FIG. 9 , in the hookup area HA, the memory cell array  10  further includes conductive layers  28  and  29 , and a contact CP. 
     The conductive layer  28  is an interconnect which is used in circuitry below the memory cell array  10 . The conductive layer  29  is an interconnect which is used in circuitry above the memory cell array  10 . The conductive layers  28  and  29  are electrically connected via the contact C 4  on the conductive layer  28  and the contact CP on the contact C 4 . 
     The contact C 4  is provided to extend in the Z direction, and penetrates, for example, the conductive layers  21  to  24  in the through-contact area C 4 T. An upper end of the contact C 4  is aligned with, for example, an upper end of the support pillar HR. A lower end of the contact C 4  is in contact with the conductive layer  28 . 
     In addition, the contact C 4  includes, for example, a conductive layer  36  and an insulator layer  37 . The conductive layer  36  is provided in a columnar shape extending in the Z direction, and the contact CP is provided on the conductive layer  36 . The insulator layer  37  covers a side surface of the conductive layer  36 . The insulator layer  37  insulates the contact C 4  from each conductive layer which the contact C 4  penetrates. 
     The slit SHE 2  is formed, for example, in a plate shape extending along the XZ plane, and divides the stacked conductive layers  25 . An upper end of the slit SHE 2  is included in the layer between the upper end of the memory pillar MP and the conductive layer  26 . A lower end of the slit SHE 2  is included, for example, in the layer between the uppermost conductive layer  24  and lowermost conductive layer  25 . The slit SHE 2  includes, for example, an insulator such as silicon oxide. 
     The support pillar HR, which is provided between the slits SHE 1  and SHE 2  that are adjacent in the X direction, that is, which is provided in the gap portion GP 2 , is in contact with each of the adjacent slits SHE 1  and SHE 2 . Thereby, the three conductive layers  25  corresponding to the select gate lines SGDa, SGDb and SGDc, respectively, are separated by the slits SHE 1  and SHE 2 , support pillar HR, and memory pillars MP overlapping the slit SHE 1 . 
       FIG. 10  is a cross-sectional view, taken along line X-X in  FIG. 9 , illustrating an example of a cross-sectional structure of the contact C 4  in the semiconductor memory device  1  according to the first embodiment. More specifically,  FIG. 10  illustrates a cross-sectional structure of the contact C 4  in a layer which is parallel to the surface of the semiconductor substrate  20  and includes the conductive layer  24 . 
     As illustrated in  FIG. 10 , in the layer including the conductive layer  24 , the conductive layer  36  is provided, for example, in a central part of the contact C 4 . The insulator layer  37  surrounds a side surface of the conductive layer  36 . The conductive layer  24  surrounds a side surface of the insulator layer  37 . 
       FIG. 11  is a cross-sectional view, taken along line XI-XI in  FIG. 9 , illustrating an example of a cross-sectional structure of the support pillar HR in the semiconductor memory device  1  according to the first embodiment. More specifically,  FIG. 11  illustrates a cross-sectional structure of the support pillar HR provided between the adjacent slits SHE 1  and SHE 2 , in a layer which is parallel to the surface of the semiconductor substrate  20  and includes the conductive layer  25 . 
     As illustrated in  FIG. 11 , the support pillar HR is composed of an insulator member. Aside from this, at least a side surface portion of the support pillar HR is composed of an insulator member. In the layer including the conductive layer  25 , the support pillar HR between the slits SHE 1  and SHE 2  is in contact with, for example, an end portion of the slit SHE 1 , an end portion of the slit SHE 2 , a conductive layer  25  corresponding to a select gate line SGD 0   c , and a conductive layer  25  corresponding to a select gate line SGD 1   c . Specifically, the support pillar HR between the slits SHE 1  and SHE 2  is in contact with each of the two select gate lines SGD (conductive layers  25 ) which are provided in the same interconnect layer and are adjacent each other. 
     In the above-described structure of the memory cell array  10 , the number of conductive layers  23  and the number of conductive layers  24  are designed based on the number of word lines WL corresponding to the memory holes LMH and UMH. A plurality of conductive layers  22  provided in a plurality of layers may be assigned to the select gate line SGS. When the select gate line SGS is provided in a plurality of layers, a conductor different from the conductive layer  22  may be used. The number of conductive layers  25  used as the select gate lines SGD may be freely selected. 
     Each of the contacts CP and CV may be configured such that a plurality of contacts are coupled in the Z direction. An interconnect layer may be inserted between the contacts coupled in the Z direction. The conductive layers  28  and  29  may pass through the area illustrated in  FIG. 8 . Similarly, the conductive layer  27  may pass through the area illustrated in  FIG. 9 . 
     In the present specification, the case in which the hookup area HA includes the through-contact area C 4 T is described by way of example. However, the embodiment is not limited to this. For example, the through-contact area C 4 T may be disposed in some other region, or a plurality of through-contact areas C 4 T may be provided. The through-contact area C 4 T may be inserted in the cell area CA. The contact C 4  disposed in the cell area CA penetrates the source line SL, select gate lines SGS and SGD, and word lines WL. 
     [1-2] Manufacturing Method of Semiconductor Memory Device  1   
     Hereinafter, referring to  FIG. 12  as needed, a description will be given of an example of serial manufacturing steps relating to the formation of a stacked interconnect structure in the memory cell array  10  in the semiconductor memory device  1  according to the first embodiment.  FIG. 12  is a flowchart illustrating an example of a manufacturing method of the semiconductor memory device  1  according to the first embodiment. Each of  FIG. 13  to  FIG. 29  illustrates an example of a planar layout or a cross-sectional structure during the manufacture of the semiconductor memory device  1  according to the first embodiment. In the following description of the manufacturing method, plan views to be referred to correspond to the area illustrated in  FIG. 7 , and cross-sectional views to be referred to correspond to the area illustrated in  FIG. 9 . 
     To begin with, by a process of step S 101 , sacrificial members  43  of a lower-layer interconnect portion are stacked as illustrated in  FIG. 13 . The sacrificial members  43  of the lower-layer interconnect portion correspond to stacked interconnects which a memory hole LMH that is formed in a later step penetrates. In the present step, an insulator layer  40  including a conducive layer  28 , a conductive layer  21 , an insulator layer  41 , and a conductive layer  22  are successively stacked on a semiconductor substrate  20 . Although not illustrated, circuitry corresponding to the row decoder module  15 , sense amplifier module  16  and the like is formed in the insulator layer  40 . Thereafter, insulator layers  42  and sacrificial members  43  are alternately stacked on the conductive layer  22 . An insulator layer  44  is formed on the uppermost sacrificial member  43 . 
     The conductive layer  21  is used as a source line SL. The conductive layer  21  includes, for example, silicon (Si). The conductive layer  22  is used as a select gate line SGS. The conductive layer  22  includes, for example, silicon. Each of the insulator layers  41 ,  42  and  44  includes, for example, silicon oxide (SiO 2 ). For example, the number of layers, in which the sacrificial layers  43  are formed, corresponds to the number of word lines WL which a memory hole LMH penetrates. The sacrificial member  43  includes, for example, silicon nitride (SiN). 
     Next, by a process of step S 102 , memory holes LMH are formed as illustrated in  FIG. 14  and  FIG. 15 . Specifically, a mask with an opening corresponding to the memory holes LMH is first formed by photolithography or the like. Then, the memory holes LMH are formed by anisotropic etching using the formed mask. In plan view, the memory holes LMH formed in this step are disposed, for example, in a staggering fashion. Then, a sacrificial member  45  is buried in the inside of the memory holes LMH. 
     The memory holes LMH formed in this step penetrates the insulator layers  41 ,  42  and  44  and sacrificial layers  43 . A bottom portion of the memory hole LMH stops, for example, in the conductive layer  21 . The anisotropic etching in this step is, for example, RIE (Reactive Ion Etching). 
     Next, by a process of step S 103 , sacrificial members  47  and  49  of an upper-layer interconnect portion are stacked as illustrated in  FIG. 16 . The sacrificial members  47  and  49  of the upper-layer interconnect portion correspond to stacked interconnects which memory holes UMH penetrates by a later step. In the present step, to begin with, insulator layers  46  and sacrificial members  47  are alternately stacked on the insulator layer  44  and sacrificial member  45 , and an insulator layer  48  is formed on the uppermost sacrificial member  47 . Then, sacrificial members  49  and insulator layers  50  are alternately stacked on the insulator layer  48 , and an insulator layer  51  is formed on the uppermost sacrificial member  49 . 
     Each of the insulator layers  46 ,  48 ,  50  and  51  includes, for example, silicon oxide. For example, the number of layers, in which the sacrificial layers  47  are formed, corresponds to the number of word lines WL which a memory holes UMH penetrates. The number of layers, in which the sacrificial layers  49  are formed, corresponds to the number of select gate lines SGD which the memory holes UMH penetrates. The sacrificial members  47  and  49  are formed of, for example, the same material as the sacrificial members  43 , and include silicon nitride. 
     Next, by a process of step S 104 , a slit SHE 1  is formed as illustrated in  FIG. 17  and  FIG. 18 . Specifically, a mask with an opening corresponding to the slit SHE 1  is first formed by photolithography or the like. Then, the slit SHE 1  is formed by anisotropic etching using the formed mask. Subsequently, an insulator is buried in the inside of the slit SHE 1 . 
     The slit SHE 1  formed in this step divides the sacrificial members  49  stacked in the cell area. CA. A bottom portion of the slit SHE 1  stops, for example, in the layer in which the insulator layer  48  is formed. The anisotropic etching in this step is, for example, RIE. 
     Next, by a process of step S 105 , memory holes UMH are formed as illustrated in  FIG. 19 . Specifically, a mask with an opening in an area corresponding to the memory holes UMH, i.e. an area overlapping the memory holes LMH in plan view, is first formed by photolithography or the like. Then, the memory holes UMH is formed by anisotropic etching using the formed mask. 
     The memory holes UMH formed in this step penetrates the insulator layers  46 ,  48 ,  50  and  51 . At a bottom portion of the memory hole UMH, a part of the sacrificial member  45  in the memory hole LMH is exposed. Note that in the present step, the memory hole UMH overlapping the slit SHE 1  removes a part of the insulator in the slit SHE 1 . The anisotropic etching in this step is, for example, RIE. 
     Next, by a process of step S 106 , memory pillars MP are formed as illustrated in  FIG. 20 . Specifically, the sacrificial member  45  in the memory hole LMH is first removed via the memory hole UMH. Then, memory holes, which opens in the shape of the memory pillar MP, is formed. Then, a block insulator film  35 , an insulator film  34  and a tunnel insulator film  33  are successively formed on a side surface and bottom surface of the memory hole and on a top surface of the insulator layer  51 . 
     Thereafter, a part of the block insulator film  35 , insulator film  34  and tunnel insulator film  33  at a memory hole bottom portion is removed, and a part of the conductive layer  21  is exposed at the memory hole bottom portion. Subsequently, a semiconductor layer  31  and a core member  30  are successively formed, and the core member  30  is buried in the memory hole. Then, a part of the core member  30  formed at a memory hole top portion is removed, and a semiconductor material is buried in the space corresponding to the removed part of the core member  30 . 
     In the present step, the block insulator film  35 , insulator film  34 , tunnel insulator film  33  and semiconductor layer  31 , which remain in a layer above the insulator layer  51 , are removed by, for example, CMP (Chemical Mechanical Polishing). Thereby, a structure corresponding to the memory pillar MP is formed in the memory hole. After the memory pillar MP is formed, an insulator layer  52 , for example, is formed on a top surface of the memory pillar MP and on the insulator layer  51 . The insulator layer  52  includes, for example, silicon oxide. 
     Next, by a process of step S 107 , a stepped structure in the hookup area HA is formed as illustrated in  FIG. 21 . Specifically, a mask covering, for example, a part of a stepped area in the hookup area HA is first formed by photolithography or the like. Then, Y-directional steps are formed in the sacrificial members  43  and  47  provided in the hookup area HA, by a combination of the anisotropic etching using the formed mask and a slimming process of the mask. 
     Subsequently, like the formation of the Y-directional steps, the formation of a mask covering a part of the stepped area in the hookup area HA, etching and slimming process are performed, and X-directional steps are formed in the sacrificial members  43 ,  47  and  49  provided in the hookup area HA. Thereby, a stepped structure similar to the stepped structure of interconnect layers described with reference to  FIG. 7  to  FIG. 9  is formed in the stacked sacrificial members  43 ,  47  and  49 . Thereafter, an insulator layer  53  is formed in a manner to fill the space formed on the stepped structure in the hookup area HA, and a top surface of the insulator layer  53  is planarized by CMP or the like. 
     Next, by a process of step S 108 , a slit SHE 2  is formed as illustrated in  FIG. 22  and  FIG. 23 . Specifically, a mask with an opening in an area corresponding to the slit SHE 2  is first formed by photolithography or the like. Then, the slit SHE 2  is formed by anisotropic etching using the formed mask. Further, an insulator is buried in the slit SHE 2 . 
     The slit SHE 2  formed in the present step divides the sacrificial members  49  stacked in the hookup area HA. A bottom portion of the slit SHE 2  stops, for example, in the layer in which the insulator layer  48  is formed. The anisotropic etching in this step is, for example, RIE. 
     Next, by a process of step S 109 , support pillars HR and contacts C 4  are formed. Specifically, a mask with openings in areas corresponding to the support pillars HR and contacts C 4  is first formed by lithography or the like. Then, holes HRH and C 4 H are formed as illustrated in  FIG. 24  and  FIG. 25 , by anisotropic etching using the formed mask. The hole HRH corresponds to an area where the support pillar HR is formed. The hole C 4 H corresponds to an area where the contact C 4  is formed. A plurality of holes HRH formed in the first embodiment include a hole HRH which is provided to overlap end portions of the slits SHE 1  and SHE 2  that are adjacent each other in the X direction. 
     The hole HRH formed in this step penetrates, for example, the conductive layer  22 , insulator layers  41 ,  42 ,  44 ,  46 ,  48 ,  50 ,  51 ,  52  and  53  and sacrificial members  43 ,  47  and  49 . A bottom portion of the hole HRH stops, for example, in the layer in which the conductive layer  21  is provided. The hole C 4 H formed in this step penetrates, for example, the conductive layers  21  and  22 , insulator layers  41 ,  42 ,  44 ,  46 ,  48  and  53  and sacrificial members  43  and  47 . At a bottom portion of the hole C 4 H, for example, a surface of the conductive layer  28  is exposed. 
     Thereafter, an insulator layer  37  is formed on a side surface and bottom surface of the hole C 4 H and in the inside of the hole HRH, and the insulator layer  37  is buried in the inside of the hole HRH. In addition, a part of the insulator layer  37  formed in the bottom portion of the hole C 4 H is removed by etch-back, and subsequently a conductive layer  36  is buried in the inside of the hole C 4 H. The conductive layer  36  formed outside the hole C 4 H is removed by, for example, CMP. 
     Thereby, as illustrated in  FIG. 26 , support pillars HR and contacts C 4  are formed. In this example, the case was exemplarily described in which the surface of the conductive layer  28  is exposed when the holes HRH and C 4 H are processed. However, the embodiment is not limited to this example. For example, the process of exposing the surface of the conductive layer  28  at the bottom portion of the hole C 4 H may be executed by etching which is different from the etching for simultaneously forming the holes HRH and C 4 H. 
     Next, by a process of step S 110 , slits SLT are formed as illustrated in  FIG. 27 . Specifically, a mask with openings in areas corresponding to slits SLT 1 , SLT 2  and SLT 3  is first formed by photolithography or the like. Then, the slits SLT are formed by anisotropic etching using the formed mask. 
     The slit SLT formed in this step divides the insulator layers  41 ,  42 ,  44 ,  46 ,  48 ,  50 ,  51 ,  52  and  53  and sacrificial layers  43 ,  47  and  49 . A bottom portion of the slit SLT stops, for example, in the layer in which the conductive layer  21  is provided. Note that in this example, the bottom portion of the slit SLT reaches at least the layer in which the insulator layer  41  is formed. The anisotropic etching in this step is, for example, RIE. 
     Next, by a process of step S 111 , a replacement process of stacked interconnects is executed. Specifically, to begin with, as illustrated in  FIG. 28 , the sacrificial layers  43 ,  47  and  49  are selectively removed by, for example, wet etching by hot phosphoric acid. A structure in which the sacrificial layers  43 ,  47  and  49  are removed keeps its three-dimensional structure by the memory pillars MP, support pillars HR, contacts C 4  and the like. 
     Then, as illustrated in  FIG. 29 , conductors are buried in the spaces from which the sacrificial layers  43 ,  47  and  49  are removed. For example, CVD is used for the formation of the conductors in this step. Thereafter, by an etch-back process, the conductors formed in the inside of the slit SLT and on the top surface of the insulator layer  53  are removed. In the present step, the conductors formed in adjacent interconnect layers are separated at least in the slit SLT. 
     Thereby, conductive layers  23  corresponding to the word lines WL 0  to WL 5 , conductive layers  24  corresponding to the word lines WL 6  to WL 11 , and conductive layers  25  corresponding to the select gate lines SGDa, SGDb and SGDc are formed. The conductive layers  23  to  25  formed in the present step may include barrier metals. In this case, in the formation of conductors after the removal of the sacrificial members  43 ,  47  and  49 , for example, a film of titanium nitride is formed as a barrier metal, and then tungsten is formed. The slit SLT used in this step is filled with an insulator, after stacked interconnects are formed. 
     By the above-described manufacturing steps of the semiconductor device  1  according to the first embodiment, the memory pillars MP, and the source line SL, word lines WL and select gate lines SGDa, SGDb, SGDc and SGS, which are connected to the memory pillars MP, are formed. Note that the above-described manufacturing steps are merely examples, and other processes may be inserted between the respective manufacturing steps. 
     [1-3] Advantageous Effects of the First Embodiment 
     According to the above-described semiconductor memory device  1  of the first embodiment, the yield of semiconductor memory devices  1  can be improved. Hereinafter, the advantageous effects of the semiconductor memory device  1  according to the first embodiment will be described in detail. 
     In a semiconductor memory device in which memory cells are three-dimensionally stacked, plate-shaped interconnects that are used, for example, as word lines WL, are stacked. In addition, a multilayer film for enabling a function as a memory cell transistor MT is formed in a memory pillar MP which penetrates the stacked interconnects. Further, like the word lines WL, plate-shaped select gate lines SGD, penetrated by the memory pillar MP, are formed. In the semiconductor memory device, the select gate line SGD in an identical interconnect layer is divided as appropriate and insulated by a slit SHE, and thereby an operation on a page-by-page basis can be implemented. 
     One conceivable method of increasing a storage capacity per unit area of this type of semiconductor memory device is a method of increasing the number of stacked layers of word lines WL, that is, a method of increasing the number of stacked layers of memory cell transistors MT. If the number of stacked layers of word lines WL is increased, the difficulty in processing the hole for forming the memory pillar MP increases. Thus, it is also conceivable to perform, in two stages, the hole processing for forming the memory pillar MP. 
     For example, when the hole processing for forming the memory pillar MP is performed in two stages, sacrificial members  43  corresponding to a lower-layer interconnect portion are first stacked, a memory hole LMH is formed, and a sacrificial member is buried in the inside of the memory hole LMH. Then, sacrificial members  47  corresponding to an upper-layer interconnect portion are stacked, and sacrificial members  49  corresponding to select gate lines SGD are divided by the slit SHE. Subsequently, the processing for a stepped structure in the hookup area HA is performed, and the formation of a memory hole UMH and the formation of the memory pillar MP are carried out. 
     In this manufacturing method of the semiconductor memory device, it is possible that the stacked-layer structure of the insulator layers and sacrificial members in the cell area CA is distorted by an insulator film which is buried in the area where the processing for the stepped structure in the hookup area HA was performed. If the stacked-layer structure in the cell area CA is distorted, it is possible that a misalignment occurs between the memory hole LMH that penetrates the lower-layer interconnect portion, and the memory hole UMH that penetrates the upper-layer interconnect portion, resulting in a defect due to the memory pillar MP. It is thus preferable that the processing for the stepped structure in the hookup area HA is performed after the formation of the memory pillar MP. 
     However, when the processing for the stepped structure is performed after the formation of the memory pillar MP, there is concern that, at the time of performing the processing for the stepped structure, a part of the sacrificial members  49  corresponding to the select gate lines SGD is removed via the part of the slit SHE formed in the hookup area HA. If such a change in shape occurs in the sacrificial members  49  in the hookup area HA, a variance occurs among the shapes of end portions of conductive layers  25  corresponding to the select gate lines SGD, and a defect may occur due to connections between the select gate lines SGD and contacts CC. 
     In addition, in the planar layout in the cell area CA, the disposition of the slit SHE overlaps, for example, the disposition of the memory pillar MP. Since a multilayer film is provided in the memory pillar MP, it is difficult to process the slit SHE after the formation of the memory pillar MP. It is thus preferable that the slit SHE in the cell area CA is formed before the formation of the memory pillar MP. 
     Taking the above into account, in the manufacturing method of the semiconductor memory device  1  according to the first embodiment, the slit SHE 1  in the cell area CA and the slit SHE 2  in the hookup area HA are formed in different manufacturing steps. In addition, in the manufacturing method of the semiconductor memory device  1  according to the first embodiment, the processing for the stepped structure in the hookup area HA is performed after the formation of the slit SHE 1  and before the formation of the slit SHE 2 . 
     Specifically, in the manufacturing method of the semiconductor memory device  1  according to the first embodiment, the sacrificial members  49  in the cell area CA are first divided by the slit SHE 1 , and then the memory pillar MP is formed. Further, the processing for the stepped structure in the hookup area HA is executed, and then the sacrificial members  49  in the hookup area HA are divided by the slit SHE 2 . 
     In addition, the semiconductor memory device  1  according to the first embodiment includes the gap portion GP 2  between the slits SHE 1  and SHE 2 , in order to avoid an overlap between the adjacent slits SHE 1  and SHE 2 . In this manner, if the gap portion GP 2  is provided at the time point of designing the planar layout of the memory cell array  10 , an overlap between the adjacent slits SHE 1  and SHE 2  due to the misalignment at the time of manufacture is suppressed. In the area of the gap portion GP 2 , the sacrificial member  49  corresponding to the select gate line SGD remains in the continuous state. However, the support pillar HR, which is subsequently formed, is provided in a manner to overlap the gap GP 2 . 
     As a result, in the semiconductor memory device  1  according to the first embodiment, such a structure is formed that the adjacent sacrificial members  49  in the same interconnect layer are separated by the slits SHE 1  and SHE 2 , support pillar HR, and memory pillars MP penetrating the slit SHE 1 . Specifically, in the semiconductor memory device  1  according to the first embodiment, the adjacent select gate lines SGD (conductive layers  25 ) can be insulated by the slit SHE 1  in the cell area CA, the slit SHE 2  in the hookup area HA, the support pillar HR between the slits SHE 1  and SHE 2 , and the memory pillars MP penetrating the slit SHE 1 . 
     As described above, in the manufacturing method of the semiconductor memory device  1  according to the first embodiment, the slit SHE 2  is formed after the formation of the stepped structure in the hookup area HA. Thus, a change in shape of the sacrificial members  49  in the hookup area HA at the time of the processing for the stepped structure is suppressed. Furthermore, in the manufacturing method of the semiconductor memory device  1  according to the first embodiment, since the processing for the stepped structure in the hookup area HA is performed after the formation of the memory pillars MP, the alignment at the time of forming the memory hole UMH is not affected by a distortion after the processing for the stepped structure in the hookup area HA. 
     Therefore, the semiconductor memory device  1  according to the first embodiment can suppress the occurrence of a defect due to the contacts CC of the select gate lines SGD, and the occurrence of a defect due to a misalignment between the memory holes LMH and UMH. In short, the semiconductor memory device  1  according to the first embodiment can improve the yield of semiconductor memory devices  1 . 
     [2] Second Embodiment 
     A semiconductor memory device  1  according to a second embodiment relates to a modification of the manufacturing method of the semiconductor memory device  1  described in the first embodiment, and a stepped structure corresponding to the lower-layer interconnect portion and a stepped structure corresponding to the upper-layer interconnect portion are formed in different manufacturing steps. Hereinafter, the semiconductor memory device  1  according to the second embodiment will be described with respect to different points from the first embodiment. 
     [2-1] Manufacturing Method of Semiconductor Memory Device  1   
     Hereinafter, referring to  FIG. 30  as needed, a description will be given of an example of serial manufacturing steps relating to the formation of a stacked interconnect structure in the memory cell array  10  in the semiconductor memory device  1  according to the second embodiment.  FIG. 30  is a flowchart illustrating an example of a manufacturing method of the semiconductor memory device  1  according to the second embodiment. Each of  FIG. 31  to  FIG. 34  illustrates an example of a cross-sectional structure during the manufacture of the semiconductor memory device  1  according to the second embodiment. 
     To begin with, the processes of steps S 101  and S 102  in the first embodiment are successively executed. Thereby, the same structure as the structure on the semiconductor substrate  20  in  FIG. 14  and  FIG. 15  described in the first embodiment is formed. In brief, the sacrificial members  43  are stacked, the memory holes LMH is formed, and the sacrificial member  45  is formed in the inside of the memory hole LMH. 
     Next, by a process of step S 201 , a stepped structure of the lower-layer interconnect portion is formed. Specifically, a mask covering, for example, a part of a stepped area in the hookup area HA is first formed by photolithography or the like. Then, Y-directional steps are formed in the sacrificial members  43  provided in the hookup area HA, by a combination of the anisotropic etching using the formed mask and a slimming process of the mask. 
     Subsequently, like the formation of the Y-directional steps, the formation of a mask covering a part of the stepped area in the hookup area HA, etching and slimming process are performed, and X-directional steps are formed in the sacrificial members  43  provided in the hookup area HA. Thereby, as illustrated in  FIG. 31 , a stepped structure corresponding to the lower-layer interconnect portion is formed in the stacked sacrificial members  43 . Thereafter, an insulator layer  46  is formed in a manner to fill the part of the stepped structure in the hookup area HA, and a top surface of the insulator layer  46  is planarized by CMP or the like. 
     Next, the processes of steps S 103  to S 106  in the first embodiment are successively performed. Specifically, as illustrated in  FIG. 32 , sacrificial members  47  and  49  of the upper-layer interconnect portion are first stacked. At this time, the sacrificial members  47  and  49  are also stacked above the area where the stepped structure corresponding to the lower-layer interconnect portion is formed. Then, by the same method as in the first embodiment, a slit SHE 1 , a memory pillar MP and an insulator layer  52  are formed as illustrated in  FIG. 33 . 
     Next, by a process of step S 202 , a stepped structure of the upper-layer interconnect portion is formed. Specifically, a mask covering, for example, a part of a stepped area in the hookup area HA is first formed by photolithography or the like. Then, Y-directional steps are formed in the sacrificial members  47  provided in the hookup area HA, by a combination of the anisotropic etching using the formed mask and a slimming process of the mask. 
     Subsequently, like the formation of the Y-directional steps, the formation of a mask covering a part of the stepped area in the hookup area HA, etching and slimming process are performed, and X-directional steps are formed in the sacrificial members  47  and  49  provided in the hookup area HA. Thereby, as illustrated in  FIG. 34 , a stepped structure corresponding to the upper-layer interconnect portion is formed in the stacked sacrificial members  47  and  49 . Thereafter, an insulator layer  53  is formed in a manner to fill the space formed on the stepped structure in the hookup area HA, and a top surface of the insulator layer  53  is planarized by CMP or the like. 
     Next, the processes of steps S 108  to S 111  in the first embodiment are successively executed. In brief, the formation of the slit SHE 2 , the formation of the support pillars HR and contracts C 4 , the formation of the slits SLT, and the replacement process of the stacked interconnect portions are carried out. Thereby, the memory pillars MP, and the source line SL, word lines WL and select gate lines SGDa, SGDb, SGDc and SGS, which are connected to the memory pillars MP, are formed. 
     The details of the other manufacturing steps in the semiconductor memory device  1  according to the second embodiment are the same as in the first embodiment, so a description of the details is omitted here. In the above description, the case in which the step of forming Y-directional steps is inserted in each of steps S 201  and S 202  was described by way of example. However, the embodiment is not limited this. For example, in the processing of the lower-layer interconnect portion in step S 201 , the step of forming Y-directional steps may be omitted. In this case, in step S 202 , the processing for forming the Y-directional steps in the lower-layer interconnect portion and the processing for forming the Y-directional steps in the upper-layer interconnect portion are executed batchwise. 
     [2-2] Advantageous Effects of the Second Embodiment 
     As described above, in the manufacturing method of the semiconductor memory device  1  according to the second embodiment, the stepped structure of the lower-layer interconnect portion is formed before the formation of the memory pillar MP. Specifically, in the manufacturing method of the semiconductor memory device  1  according to the second embodiment, at the time of forming the memory hole UMH, an influence of a distortion by the insulator layer  46  formed in the stepped part in the hookup area HA may occur in the stacked structure of the insulator layers and sacrificial layers in the cell area CA. 
     However, in the semiconductor memory device  1  according to the second embodiment, the total amount of the insulator layer  46  buried in the hookup area HA is much smaller than the total amount of the insulator layer which is buried in the case where the entire stepped structure in the hookup area HA is formed. Specifically, in the hookup area HA, the amount of distortion by the insulator layer  46  buried in association with the lower-layer interconnect portion is smaller than the amount of distortion by the insulator layer  53  which is buried when the stepped structure corresponding to the lower-layer interconnect portion and upper-layer interconnect portion is formed. 
     As a result, like the first embodiment, the semiconductor memory device  1  according to the second embodiment can suppress the occurrence of a defect due to the contacts CC of the select gate lines SGD, and the occurrence of a defect due to a misalignment between the memory holes LMH and UMH. In short, the semiconductor memory device  1  according to the second embodiment can improve the yield of semiconductor memory devices  1 . 
     [3] Third Embodiment 
     A semiconductor memory device  1  according to a third embodiment relates to a modification of the manufacturing method of the semiconductor memory device  1  described in the first embodiment, and the step of forming the slit SHE 2  and the step of forming the slit SLT are integrated. Hereinafter, the semiconductor memory device  1  according to the third embodiment will be described with respect to different points from the first embodiment. 
     [3-1] Manufacturing Method of Semiconductor Memory Device  1   
     Hereinafter, referring to  FIG. 35  as needed, a description will be given of an example of serial manufacturing steps relating to the formation of a stacked interconnect structure in the memory cell array  10  in the semiconductor memory device  1  according to the third embodiment.  FIG. 35  is a flowchart illustrating an example of a manufacturing method of the semiconductor memory device  1  according to the third embodiment. Each of  FIG. 36  to  FIG. 39  illustrates an example of a planar layout or a cross-sectional structure during the manufacture of the semiconductor memory device  1  according to the third embodiment. 
     To begin with, the processes of steps S 101  to S 107  in the first embodiment are successively performed. Thereby, the same structure as the structure on the semiconductor substrate  20  in  FIG. 21  described in the first embodiment is formed. In brief, the sacrificial members  43 ,  47  and  49  are stacked, the slit SHE 1  is formed, the memory pillars MP is formed, and the stepped structure of the end portions of the sacrificial members  43 ,  47  and  49  is formed. 
     Next, by the process of step S 109 , support pillars HR and contacts C 4  are formed. Specifically, a mask with openings in areas corresponding to the support pillars HR and contacts C 4  is first formed by lithography or the like. Then, holes HRH and C 4 H are formed as illustrated in  FIG. 36 , by anisotropic etching using the formed mask. 
     Thereafter, an insulator layer  37  is formed on a side surface and bottom surface of the hole C 4 H and in the inside of the hole HRH, and the insulator layer  37  is buried in the inside of the hole HRH. In addition, a part of the insulator layer  37  formed in the bottom portion of the hole C 4 H is removed by etch-back, and subsequently a conductive layer  36  is buried in the inside of the hole C 4 H. The conductive layer  36  formed outside the hole C 4 H is removed by, for example, CMP. 
     Thereby, as illustrated in  FIG. 37 , support pillars HR and contacts C 4  are formed. Note that, as described in the first embodiment, the process of exposing the surface of the conductive layer  28  at the bottom portion of the hole C 4 H may be executed by etching which is different from the etching for simultaneously forming the holes HRH and C 4 H. 
     Next, by a process of step S 301 , slits SLT and SHE 2  are formed as illustrated in  FIG. 38 . Specifically, a mask with openings in areas corresponding to slits SLT 1 , SLT 2  and SLT 3  and in areas corresponding to slits SHE 2  is first formed by photolithography or the like. Then, the slits SLT and SHE 2  are formed by anisotropic etching using the formed mask. Note that in the third embodiment, as illustrated in  FIG. 39 , the slit SHE 2  may be formed such that the slit SHE 2  not only divides the sacrificial members  49 , but also penetrates, like the support pillar HR, the sacrificial members  43  and  47  and conductive layer  22  below the sacrificial members  49 . 
     Next, by a process of step S 111 , a replacement process similar to the replacement process in the first embodiment is executed. Thereby, the memory pillars MP, and the source line SL, word lines WL and select gate lines SGDa, SGDb, SGDc and SGS, which are connected to the memory pillars MP, are formed. The details of the other manufacturing steps in the semiconductor memory device  1  according to the third embodiment are the same as in the first embodiment, so a description of the details is omitted here. 
     [3-2] Advantageous Effects of the Third Embodiment 
     As described above, in the manufacturing method of the semiconductor memory device  1  according to the third embodiment, the support pillar HR and contact C 4  are formed before the formation of the slit SHE 2 . In addition, the processing of the slit SLT and the processing of the slit SHE 2  are performed by the same manufacturing step. 
     As a result, the manufacturing method of the semiconductor memory device  1  according to the third embodiment can make smaller the number of manufacturing steps than in the first embodiment. Therefore, the semiconductor memory device  1  according to the third embodiment can reduce the manufacturing cost, in addition to the same advantageous effects as in the first embodiment. 
     [4] Fourth Embodiment 
     In a semiconductor memory device  1  according to a fourth embodiment, as a dividing member which is disposed between the slits SHE 1  and SHE 2  and divides, together with the slits SHE 1  and SHE 2 , the select gate lines SGD, use is made of a contact C 4  in place of the support pillar HR in the first to third embodiments. Hereinafter, the semiconductor memory device  1  according to the fourth embodiment will be described with respect to different points from the first to third embodiments. 
     [4-1] Structure of Memory Cell Array  10   
       FIG. 40  illustrates an example of a detailed planar layout of the memory cell array  10  in the hookup area HA of the semiconductor memory device  1  according to the fourth embodiment, by extracting an area corresponding to one block BLK (i.e. string units SU 0  to SU 3 ). As illustrated in  FIG. 40 , the planar layout of the memory cell array  10  in the hookup area HA in the fourth embodiment differs from the planar layout of the memory cell array  10  described with reference to  FIG. 7  in the first embodiment, with respect to constituent elements disposed in the gap portion GP 2 . 
     Specifically, in the semiconductor memory device  1  according to the fourth embodiment, the contact C 4  in place of the support pillar HR is disposed in the gap portion GP 2 . In other words, in the semiconductor memory device  1  according to the fourth embodiment, the contact C 4  is disposed between the paired slits SHE 1  and SHE 2  which is adjacent in the X direction. 
     Thereby, in the semiconductor memory device  1  according to the fourth embodiment, the select gate lines SGDa, SGDb and SGDc between the two adjacent slits SLT 1  are separated by the paired slits SHE 1  and SHE 2  adjacent in the X direction, the contact C 4  between the slits SHE 1  and SHE 2 , and the memory pillars MP overlapping the slit SHE 1 . 
       FIG. 41  is a cross-sectional view, taken along line XLI-XLI in  FIG. 40 , illustrating an example of a cross-sectional structure in the hookup area HA of the memory cell array  10  included in the semiconductor memory device  1  according to the fourth embodiment. As illustrated in  FIG. 41 , in the fourth embodiment, the contact C 4  is disposed between the slits SHE 1  and SHE 2 , and the contact C 4  penetrates the stacked conductive layers  25 , too. The conductive layer  36  in the contact C 4  is insulated by the insulator layer  37  from the conductive layers  25  which the contact C 4  penetrates. 
       FIG. 42  is a cross-sectional view, taken along line XLII-XLII in  FIG. 41 , illustrating an example of a cross-sectional structure of the contact C 4  in the semiconductor memory device  1  according to the fourth embodiment. More specifically,  FIG. 42  illustrates a cross-sectional structure of the contact C 4  provided between the adjacent slits SHE 1  and SHE 2 , in a layer which is parallel to the surface of the semiconductor substrate  20  and includes the conductive layer  25 . 
     As illustrated in  FIG. 42 , in the layer including the conductive layer  25 , the contact C 4  between the slits SHE 1  and SHE 2  is in contact with, for example, an end portion of the slit SHE 1 , an end portion of the slit SHE 2 , a conductive layer  25  corresponding to a select gate line SGD 0   a , and a conductive layer  25  corresponding to a select gate line SGD 1   a . Specifically, the contact C 4  between the slits SHE 1  and SHE 2  is in contact with each of the two select gate lines SGD (conductive layers  25 ) which are provided in the same interconnect layer and are adjacent each other. The other configuration of the semiconductor memory device  1  according to the fourth embodiment is the same as in the semiconductor memory device  1  according to the first embodiment, so a description thereof is omitted here. 
     [4-2] Manufacturing Method of Semiconductor Memory Device  1   
     Hereinafter, referring to  FIG. 43  as needed, a description will be given of an example of serial manufacturing steps relating to the formation of a stacked interconnect structure in the memory cell array  10  in the semiconductor memory device  1  according to the fourth embodiment.  FIG. 43  is a flowchart illustrating an example of a manufacturing method of the semiconductor memory device  1  according to the fourth embodiment.  FIG. 44  to  FIG. 45  illustrate examples of a planar layout and a cross-sectional structure during the manufacture of the semiconductor memory device  1  according to the fourth embodiment. 
     To begin with, the processes of steps S 101  to S 108  in the first embodiment are successively executed. Thereby, the same structure as the structure on the semiconductor substrate  20  in  FIG. 22  and  FIG. 23  described in the first embodiment is formed. In brief, the sacrificial members  43 ,  47  and  49  are stacked, the slits SHE 1  and SHE 2  are formed, the memory pillars MP are formed, and the stepped structure of the end portions of the sacrificial members  43 ,  47  and  49  is formed. 
     Next, by a process of step S 401 , support pillars HR and contacts C 4  are formed. Specifically, a mask with openings in areas corresponding to the support pillars HR and contacts C 4  is first formed by photolithography or the like. Then, as illustrated in  FIG. 44  and  FIG. 45 , holes HRH and C 4 H are formed by anisotropic etching using the formed mask. The holes C 4 H formed in the fourth embodiment include a hole C 4 H which is provided in a manner to overlap the end portions of the slits SHE 1  and SHE 2  which are adjacent in the X direction. 
     Thereafter, an insulator layer  37  is formed on a side surface and bottom surface of the hole C 4 H and in the inside of the hole HRH, and the insulator layer  37  is buried in the inside of the hole HRH. In addition, a part of the insulator layer  37  formed in the bottom portion of the hole C 4 H is removed by etch-back, and subsequently a conductive layer  36  is buried in the inside of the hole C 4 H. The conductive layer  36  formed outside the hole C 4 H is removed by, for example, CMP. Thereby, the support pillars HR and contacts C 4  are formed. 
     Next, by the processes of steps S 110  and S 111  in the first embodiment, the formation of the slits SLT and the replacement process of the stacked interconnect portions are carried out. Thereby, the memory pillars MP, and the source line SL, word lines WL and select gate lines SGDa, SGDb, SGDc and SGS, which are connected to the memory pillars MP, are formed. The details of the other manufacturing steps in the semiconductor memory device  1  according to the fourth embodiment are the same as in the first embodiment, so a description of the details is omitted here. 
     [4-3] Advantageous Effects of the Fourth Embodiment 
     As described above, the semiconductor memory device  1  according to the fourth embodiment has such a structure that the support pillar HR disposed in the gap portion GP 2  is replaced with the contact C 4 . Like the support pillar HR in the first embodiment, the contact C 4  disposed in the gap portion GP 2  is used as a structure which couples the adjacent slits SHE 1  and SHE 2 . 
     Thereby, like the first embodiment, the semiconductor memory device  1  according to the fourth embodiment can suppress the occurrence of a defect due to the contacts CC of the select gate lines SGD, and the occurrence of a defect due to a misalignment between the memory holes LMH and UMH. In short, the semiconductor memory device  1  according to the fourth embodiment can improve the yield of semiconductor memory devices  1 . 
     [5] Other Modifications, Etc. 
     A semiconductor memory device according to an embodiment includes a substrate, a plurality of first conductive layers, a second conductive layer, a third conductive layer, a first pillar, a second pillar, a first contact, a second contact, a first member, a second member, and a third member. The substrate includes a first area and a second area adjacent to the first area. The plurality of first conductive layers are provided above the substrate of the first area and the second area. The first conductive layers are stacked at intervals in a first direction. The second conductive layer is provided above an uppermost first conductive layer of the first conductive layers. The third conductive layer is provided above the uppermost first conductive layer and is provided in the same layer as the second conductive layer. The third conductive layer and the second conductive layer are separated from each other. The first pillar is provided to penetrate the first conductive layers and the second conductive layer in the first area. An intersection portion between the first pillar and each of the first conductive layers functions as a memory cell transistor. An intersection portion between the first pillar and the second conductive layer functions as a select transistor. A second pillar is provided to penetrate the first conductive layers and the third conductive layer in the first area. An intersection portion between the second pillar and each of the first conductive layers functions as a memory cell transistor. An intersection portion between the second pillar and the third conductive layer is functions as a select transistor. The first contact is provided on the second conductive layer in the second area. The second contact is provided on the third conductive layer in the second area. The first member is provided between the second conductive layer and the third conductive layer in the first area. The second member is provided between the second conductive layer and the third conductive layer in the second area. The third member is extending in the first direction and is provided to penetrate the first conductive layers. The third member is in contact with each of the second conductive layer, the third conductive layer, the first member and the second member. Thereby, the yield of semiconductor memory devices can be improved. 
     The method in which the stepped structure of the lower-layer interconnect portion and the stepped structure of the upper-layer interconnect portion are formed in different manufacturing steps, as in the second embodiment, is also applicable to the other embodiments. The method in which the slit SHE 2  and slit SLT are processed in the same step, as in the third embodiment, is applicable to the first embodiment. 
     In the above-described embodiments, the configuration of the memory cell array  10  may be some other configuration. For example, the memory pillars MP may be configured such that three or more pillars are coupled in the Z direction. In addition, the memory pillars MP may be configured such that a pillar corresponding to the select gate lines SGD and a pillar corresponding to the word lines WL are coupled. An inside of the slit SLT may be composed of a plurality of kinds of insulators. The number of bit lines BL overlapping each memory pillar MP may be freely selected. 
     The drawings used in the descriptions of the above embodiments illustrate the case in which the thickness (e.g. the width in the Y direction) of the slit SHE 1  and the thickness of the slit SHE 2  are substantially equal, but the embodiments are not limited to this.  FIG. 46  illustrates an example of a cross-sectional structure of a support pillar HR in a modification of the first embodiment, and this cross-sectional structure corresponds to an area similar to the area illustrated in  FIG. 11 . As illustrated in  FIG. 46 , the thickness of the slit SHE 1  and the thickness of the slit SHE 2  in the above-described embodiments may be different. 
     In addition, the positions of the slits SHE 1  and SHE 2  in the Y direction may be mutually displaced. The slits SHE 1  and SHE 2  may have any shapes or dispositions, if the adjacent slits SHE 1  and SHE 2  are, at least, coupled by the support pillar HR disposed in the gap portion GP 2 . Similarly, the slits SHE 1  and SHE 2  in the fourth embodiment may have any shapes or dispositions, if the adjacent slits SHE 1  and SHE 2  are, at least, coupled by the contact C 4  disposed in the gap portion GP 2 . Further, in the above-described embodiments, insofar as each of the slits SHE 1  and SHE 2  divides at least all of the stacked conductive layers  25 , each of the slits SHE 1  and SHE 2  may also divide some of the conductive layers corresponding to the word lines WL. 
     In the present specification, the slit SHE 1  is defined as the “slit SHE 1  provided to extend in the X direction”. However, the slit SHE 1  may be divided by the memory pillar MP, and may have a discontinuous structure. For example, when the memory pillar MP and slit SHE 1  overlap, the slits SHE 1  (insulator members) divided by the memory pillar MP may be disposed to extend across the memory pillar MP in the X direction. 
     In the above-described embodiments, the case was exemplarily described in which, in the hookup area HA, the end portions of the word lines WL 0  to WL 11  are provided in a stepped shape of three rows, the stepped shape including two steps in the Y direction and a plurality of steps in the X direction. However, the embodiments are not limited to this. The number of steps formed in the Y direction in the end portions of the stacked word lines WL may be freely selected. Specifically, in the semiconductor memory device  1 , the end portions of the word lines WL in the hookup area HA may be designed in a stepped shape of a freely selected number of rows. 
     In the above-described embodiments, the case was exemplarily described in which the semiconductor memory device  1  is configured such that circuitry such as the sense amplifier module  16  is provided below the memory cell array  10 . However, the embodiments are not limited to this. For example, the semiconductor memory device  1  may be configured such that the memory cell array  10  and sense amplifier module  16  are formed above the semiconductor substrate  20 . Further, the semiconductor memory device  1  may be configured such that a chip provided with the sense amplifier module  16  or the like and a chip provided with the memory cell array  10  are bonded together. 
     In the above-described embodiments, the configuration was described in which the word lines WL and select gate line SGS are adjacent and the word lines WL and select gate lines SGD are adjacent. However, the embodiments are not limited to this. For example, a dummy word line corresponding to a dummy transistor may be provided between the uppermost word line WL and the select gate lines SGD. Similarly, a dummy word line may be provided between the lowermost word line WL and the select gate line SGS. Further, a conductive layer near a joint portion of pillars coupled in the Z direction may be used as a dummy word line. 
     The drawings used in the descriptions of the above embodiments illustrate the case in which the support pillar HR and contact C 4  have taper shapes. However, the embodiments are not limited to this. For example, the support pillar HR and contact C 4  may have inverse taper shapes, or may shapes with bulging intermediate portions. Similarly, the slit SLT and slit SHE may have inverse taper shapes, or may have shapes with bulging intermediate portions. Besides, in the above-described embodiments, the case was exemplarily described in which the cross-sectional shape of each of the support pillar HR, contact C 4  and memory pillar MP is circular. However, this cross-sectional shape may be elliptic, or may be a freely designed shape. 
     In the above-described embodiments, the case was exemplarily described in which the semiconductor layer  31  and conductive layer  21  are electrically connected via the bottom portion of the memory pillar MP. However, the embodiments are not limited to this. The semiconductor layer  31  and conductive layer  21  may be electrically connected via a side surface of the memory pillar MP. In this case, a part of the stacked film  32  formed in a side surface portion of the memory pillar MP is removed, and a structure is formed in which the semiconductor layer  31  and conductive layer  21  are in contact with each other via the removed part. In addition, the stacked film  32  in each memory pillar MP may be configured such that the insulator film  34  and tunnel insulator film  33  are successively formed in the memory hole. The block insulator film  35  may be formed on peripheries of the conductive layers  23  to  25  including the side-surface side of the insulator film  34 , when the replacement process of the stacked interconnects is executed. 
     In the present specification, the term “connection” means an electrical connection, and does not exclude, for example, a connection with another element being interposed. In addition, the expression “electrically connected” may also mean “electrically connected via an insulator” if the same operation as “electrically connected” is enabled. The expression “successively provided” means the formation by the same manufacturing step. No boundary is formed in a successively provided part in a certain constituent element. The expression “successively provided” has the same meaning as a continuous film from a first portion to a second portion in a certain film or layer. 
     In the present specification, the term “columnar shape” means a structure provided in a hole formed in a manufacturing step of the semiconductor memory device  1 . A structure formed in each of the memory hole LMH and UMH may be referred to as “pillar”. Specifically, in the first embodiment, the memory pillar MP has such a structure that a pillar corresponding to the memory hole UMH is formed on a pillar corresponding to the memory hole LMH. 
     In the present specification, the term “outside diameter” means a diameter of a constituent element in a cross section parallel to the surface of the semiconductor substrate  20 . In addition, the term “outside diameter” is measured by using, for example, an outermost peripheral member among members in a hole, which are used to form a constituent element that is a target of measurement. For example, when an outside diameter of the contact C 4  and an outside diameter of the support pillar HR are compared, the outside diameters of constituent elements included in the same cross section are compared. 
     While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.