Patent Publication Number: US-9425238-B2

Title: Semiconductor device and method for fabricating the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a division of U.S. patent application Ser. No. 12/982,122 filed on Dec. 30, 2010, which claims priority of Korean Patent Application No. 10-2010-0068245, filed on Jul. 15, 2010. The disclosure of each of the foregoing applications is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     Exemplary embodiments of the present invention relate to semiconductor device fabrication technology, and more particularly, to a semiconductor device having a resistive memory and a method for fabricating the same. 
     Extensive research is being conducted on next-generation memory devices that can replace dynamic random access memory (DRAM) devices and flash memory devices. Examples of the next-generation memory devices include resistive memory (ReRAM) devices. The resistive memory devices provide good characteristics at low fabrication costs. In particular, the resistive memory devices are esteemed as high-capacity memory devices because they have a very simple stacked structure of metal-insulator-metal. 
     A stacked structure, including a plurality of crossbar type memory arrays, is especially esteemed as a structure for a high-capacity memory device using a resistive memory device. 
     However, implementing a high-capacity memory device by stacking a plurality of memory arrays requires interconnections and contacts for connecting the memory array of each layer to peripheral circuits such as a driver and a sense amplifier (SA) formed on a substrate. These interconnections and contacts increase the size of a semiconductor device and degrade the operation characteristics. 
     Specifically, in order to form the contacts for connecting the memory array of each layer to the peripheral circuits, a separate space for the contacts should be prepared at the center or the edge of the memory array of each layer, thus increasing the size of the semiconductor device. Also, the structure of interconnections for connection of the contacts formed in a plurality of layers is complicated and the space occupied for forming the interconnections is increased, thus further increasing the size of the semiconductor device. 
     Also, as a design rule decreases, the critical dimension of an interconnection decreases, thus increasing the resistance of the interconnection. The increase in the resistance of the interconnection may cause a loading resistance to be connected to the resistive memory device, thus making it difficult to accurately control the resistive memory device formed in each layer. 
     SUMMARY OF THE INVENTION 
     Exemplary embodiments of the present invention are directed to a semiconductor device and a method for fabricating the same, which can reduce the size of a high-capacity memory device. 
     In accordance with an exemplary embodiment of the present invention, a semiconductor device includes a plurality of memory blocks including a transistor region and a memory region, wherein a variable resistance layer of the memory region acts as a gate insulating layer in the transistor region. The memory blocks may be stacked on a substrate including a predetermined structure, and an interlayer dielectric may be inserted between the memory blocks. 
     The variable resistance layer and the gate insulating layer may be connected to each other, or may be disconnected from each other. 
     The memory region may include a plurality of first conductive lines disposed on an interlayer dielectric under the variable resistance layer, and a plurality of second conductive lines disposed on the variable resistance layer crossing over the first conductive lines. 
     The transistor region may include a plurality of gate electrodes disposed on an interlayer dielectric under the gate insulating layer, a channel layer disposed on the gate insulating layer to overlap the gate electrodes, and a plurality of source electrodes and drain electrodes disposed on the channel layer to overlap a portion of the gate electrodes. The channel layer may include an oxide layer or a silicon layer. The oxide layer may include at least one material selected from the group consisting of an indium oxide layer, a zirconium oxide layer, a gallium oxide layer, and a tin oxide layer. The variable resistance layer may include an oxide layer, and the oxide layer may include a plurality of oxygen vacancies. 
     In accordance with another exemplary embodiment of the present invention, a semiconductor device includes a plurality of memory blocks including a transistor region and a memory region, wherein a variable resistance layer of the memory region has a sequential stack structure of a first insulating layer and a second insulating layer, the first insulating layer acts as a gate insulating layer in the transistor region, and the second insulating layer acts as a channel layer in the transistor region. The memory blocks may be stacked on a substrate including a predetermined structure, and an interlayer dielectric may be inserted between the memory blocks. 
     The first insulating layer and the gate insulating layer may be connected to each other, or may be disconnected from each other. The second insulating layer and the channel layer may be connected to each other, or may be disconnected from each other. 
     The memory region may include a plurality of first conductive lines disposed on an interlayer dielectric under the first insulating layer, and a plurality of second conductive lines disposed on the second insulating layer crossing over the first conductive lines. 
     The transistor region may include a plurality of gate electrodes disposed on an interlayer dielectric under the gate insulating layer, and a plurality of source electrodes and drain electrodes disposed on the channel layer to overlap a portion of the gate electrodes. The first insulating layer and the second insulating layer may include an oxide layer, and the oxide layer may include a plurality of oxygen vacancies. The second insulating layer may include at least one material selected from the group consisting of an indium oxide layer, a zirconium oxide layer, a gallium oxide layer, and a tin oxide layer. 
     In accordance with still another exemplary embodiment of the present invention, a semiconductor device includes a transistor, and a memory cell, wherein a variable resistance layer of the memory cell is the same material and on the same plane as a gate insulating layer of the transistor. 
     In accordance with yet another exemplary embodiment of the present invention, a method for fabricating a semiconductor device includes forming an interlayer dielectric defining a transistor region and a memory region forming a plurality of gate electrodes on the interlayer dielectric in the transistor region and forming a plurality of first conductive lines on the interlayer dielectric in the memory region, forming a first insulating layer on the interlayer dielectric, forming a second insulating layer on the first insulating layer, forming a first electrode and a second electrode on the second insulating layer in the transistor region to overlap a portion of the gate electrode and forming a plurality of second conductive lines crossing over the first conductive lines in the memory region, and applying a bias voltage to the first and second conductive lines to perform a conductive path forming process. 
     The method may further include exposing the first insulating layer of the memory region by selectively etching the second insulating layer, after the forming of the second insulating layer. 
     The method may further include dividing the second insulating layer of the transistor region and the second insulating layer of the memory region by selectively etching the second insulating layer, after the forming of the second insulating layer. 
     The method may further include dividing the first insulating layer of the transistor region and the first insulating layer of the memory region by selectively etching the first insulating layer, after the forming of the second insulating layer. 
     The first insulating layer and the second insulating layer may include an oxide layer, and the oxide layer may include a plurality of oxygen vacancies. The second insulating layer may include at least one material selected from the group consisting of an indium oxide layer, a zirconium oxide layer, a gallium oxide layer, and a tin oxide layer. 
     In accordance with still another exemplary embodiment of the present invention, a method for fabricating a semiconductor device includes forming a variable resistance layer in a memory region of a memory block, and forming a gate insulating layer in a transistor region of the memory block, wherein the variable resistance layer and the gate insulating layer are simultaneously formed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a perspective view illustrating a semiconductor device in accordance with a first exemplary embodiment of the present invention. 
         FIG. 1B  is a partial perspective view illustrating one memory block in accordance with the first exemplary embodiment of the present invention. 
         FIG. 1C  shows cross-sectional views taken along lines A-A′ and B-B′ of  FIG. 1B . 
         FIG. 2A  is a perspective view illustrating a semiconductor device in accordance with a second exemplary embodiment of the present invention. 
         FIG. 2B  is a partial perspective view illustrating one memory block in accordance with the second exemplary embodiment of the present invention. 
         FIG. 2C  shows cross-sectional views taken along lines A-A′ and B-B′ of  FIG. 2B . 
         FIG. 3A  is a perspective view illustrating a semiconductor device in accordance with a third exemplary embodiment of the present invention. 
         FIG. 3B  is a partial perspective view illustrating one memory block in accordance with the third exemplary embodiment of the present invention. 
         FIG. 3C  shows cross-sectional views taken along lines A-A′ and B-B′ of  FIG. 3B . 
         FIGS. 4A to 4D  are perspective views illustrating a method for fabricating a semiconductor device in accordance with an exemplary embodiment of the present invention. 
     
    
    
     DESCRIPTION OF SPECIFIC EMBODIMENTS 
     Exemplary embodiments of the present invention will be described below in more detail with reference to the accompanying drawings. The present invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. Throughout the disclosure, like reference numerals refer to like parts throughout the various figures and embodiments of the present invention. 
     The drawings are not necessarily to scale and in some instances, proportions may have been exaggerated in order to clearly illustrate features of the embodiments. When a first layer is referred to as being “on” a second layer or “on” a substrate, it not only refers to a case where the first layer is formed directly on the second layer or the substrate, but also a case where a third layer exists between the first layer and the second layer or the substrate. 
     The present invention provides a semiconductor device and a method for fabricating the same, which can effectively reduce the size of a high-capacity memory device. To this end, the present invention provides a semiconductor device integrating a peripheral circuit and a resistive memory device in which a plurality of memory blocks are stacked and each memory block has a crossbar type array structure. Herein, the peripheral circuit includes a driver for driving the resistive memory device and a sense amplifier (SA) for detecting stored data. As is well known in the art, a peripheral circuit such as a sense amplifier includes a plurality of transistors and is configured with a combination thereof. 
     Hereinafter, for convenience in description, a description will be given of exemplary embodiments in which a semiconductor device has a stack structure of three memory blocks. However, the present invention is not limited thereto. That is, in other exemplary embodiments, a semiconductor device may have a stack structure with less than or more than three memory blocks. 
       FIGS. 1A to 1C  are views illustrating a semiconductor device in accordance with a first exemplary embodiment of the present invention.  FIG. 1A  is a perspective view illustrating a semiconductor device in accordance with a first exemplary embodiment of the present invention.  FIG. 1B  is a partial perspective view illustrating one memory block in accordance with the first exemplary embodiment of the present invention.  FIG. 1C  shows cross-sectional views taken along lines A-A′ and B-B′ of  FIG. 1B . 
     Referring to  FIGS. 1A to 1C , a semiconductor device in accordance with the first exemplary embodiment of the present invention includes a substrate  101  having a predetermined structure formed therein, a plurality of memory blocks  102  stacked on the substrate  101 , and a passivation layer  103  formed on the top layer. 
     The substrate  101  may include various semiconductor devices such as a power device, a high voltage device, a display driver IC (DDI) device, and a bipolar-CMOS-DMOS (BCD) device. 
     Each of the memory blocks  102  has a transistor region where a peripheral circuit is formed, and a memory region where a resistive memory device is formed. In the first exemplary embodiment of the present invention, a variable resistance layer  13 A of the memory region acts as a gate insulating layer  13 B in the transistor region. That is, the variable resistance layer  13 A and the gate insulating layer  13 B are simultaneously formed of the same material and are disposed on the same plane. As illustrated in  FIG. 1B , the variable resistance layer  13 A may be connected to the gate insulating layer  13 B. Although not illustrated in the drawings, in other embodiments, the variable resistance layer  13 A and the gate insulating layer  13 B may not be connected to each other. 
     The memory region includes an interlayer dielectric  11 , a plurality of first conductive lines  12 A formed on the interlayer dielectric  11  to act as a bottom electrode (BE), a variable resistance layer  13 A formed on the interlayer dielectric  11  to contact the first conductive lines  12 A, and a plurality of second conductive lines  15 A formed on the variable resistance layer  13 A to act as a top electrode (TE). The second conductive lines  15 A are arranged so that they cross over the first conductive lines  12 A. That is, a resistive memory device formed in the memory region has a crossbar type array structure where the variable resistance layer  13 A is disposed between the crossing first and second conductive lines  12 A and  15 A. 
     The transistor region includes an interlayer dielectric  11 , a plurality of gate electrodes  12 B formed on the interlayer dielectric  11 , a gate insulating layer  13 B formed on the interlayer dielectric  11  to contact the gate electrodes  12 B, a channel layer  14  formed on the gate insulating layer  13 B to overlap the gate electrodes  12 B, and first electrodes (or drain electrodes)  15 B and second electrodes (or source electrodes)  15 C formed on the channel layer  14  to overlap a portion of corresponding gate electrodes  12 B. Herein, the first electrodes  15 B may be connected to corresponding second conductive lines  15 A of the memory region. 
     The variable resistance layer  13 A of the memory region extends to the transistor region to act as the gate insulating layer  13 B. Therefore, the variable resistance layer  13 A of the memory region and the gate insulating layer  13 B of the transistor region may be formed of the same material. Also, the variable resistance layer  13 A and the gate insulating layer  13 B are simultaneously formed through the same process, and are disposed on the same plane. Also, the variable resistance layer  13 A and the gate insulating layer  13 B have a thickness of approximately 1 nm to approximately 100 nm. 
     The variable resistance layer  13 A may be an oxide layer including a plurality of oxygen vacancies. Herein, the oxygen vacancies serve to change the resistance of the variable resistance layer  13 A. Specifically, the variable resistance layer  13 A has a conductive path created by the oxygen vacancies through a conductive path forming process that rearranges the oxygen vacancies by applying a high voltage to the first conductive line  12 A and the second conductive line  15 A. Whether or not an operation voltage (lower than the high voltage applied in the conductive path forming process) is applied to the first conductive line  12 A and the second conductive line  15 A determines whether or not the conductive path connects the first conductive line  12 A and the second conductive line  15 A. In this manner, the resistance of the variable resistance layer  13 A may be changed and the change may be used to store data. 
     Since the variable resistance layer  13 A and the gate insulating layer  13 B are formed of the same material, the gate insulating layer  13 B also includes a plurality of oxygen vacancies. Even when the gate insulating layer  13 B includes a plurality of oxygen vacancies, because the conductive path by the oxygen vacancies is not created through the conductive path forming process, it does not have variable resistance characteristics like the variable resistance layer  13 A. Thus, the gate insulating layer  13 B has insulating characteristics even though it includes oxygen vacancies like the variable resistance layer  13 A formed of the same material. 
     The variable resistance layer  13   a  may include at least one material selected from the group consisting of silicon (Si) oxide, aluminum (Al) oxide, hafnium (Hf) oxide, zirconium (Zr) oxide, lanthanum (La) oxide, titanium (Ti) oxide, niobium (Nb) oxide, tantalum (Ta) oxide, nickel (Ni) oxide, strontium-titanium (SrTi) oxide, barium-titanium (BaTi) oxide, and barium-strontium (BaSr) oxide. 
     The first conductive line  12 A and the gate electrode  12 B disposed on the same plane may include the same material. Also, the first conductive line  12 A and the gate electrode  12 B may be simultaneously formed through the same process. 
     Herein, the first conductive line  12 A, the gate electrode  12 B, the second conductive line  15 A, the first electrode  15 B, and the second electrode  15 C may be a metallic layer. The metallic layer may include tungsten (W), tantalum (Ta), platinum (Pt), titanium nitride (TiN), or tantalum nitride (TaN). 
     The channel layer  14  of the transistor region may have a thickness of approximately 1 nm to approximately 100 nm, and may include a silicon layer or an oxide layer. Herein, the silicon layer may include a polysilicon (poly Si) layer. Also, the oxide layer may include at least one material selected from the group consisting of indium oxide (In 2 O 3 ), zirconium oxide (ZnO), gallium oxide (Ga 2 O 3 ), and tin oxide (SnO 2 ). The oxide layer for the channel layer  14  has semiconductor characteristics due to its atomic bond (e.g., metal-oxygen bond). Also, it is know that the oxide layer has a wide band gap and a high carrier mobility. For reference, the wide band gap means a band gap of more than 3.5 eV. 
     In the semiconductor device in accordance with the first exemplary embodiment of the present invention, the memory device and the peripheral circuit are integrated in one memory block  102 . Accordingly, the present invention does not require a separate interconnection and contact for connecting the peripheral circuit and the memory device. Therefore, the present invention can provide a high-capacity memory device having a reduced chip size. Also, the present invention can simplify the fabrication process of a high-capacity memory device. 
     Conventionally, a peripheral circuit for a memory device is formed on the substrate  101 . However, the present invention does not need to form a peripheral circuit for a memory device on the substrate  101 . Thus, various semiconductor devices can be formed in a space typically used for a peripheral circuit and for interconnections and contacts. Accordingly, an embedded system with a high-capacity memory device can be constructed with a reduced chip size. 
       FIGS. 2A to 2C  are views illustrating a semiconductor device in accordance with a second exemplary embodiment of the present invention.  FIG. 2A  is a perspective view illustrating a semiconductor device in accordance with the second exemplary embodiment of the present invention.  FIG. 2B  is a partial perspective view illustrating one memory block in accordance with the second exemplary embodiment of the present invention.  FIG. 2C  shows cross-sectional views taken along lines A-A′ and B-B′ of  FIG. 2B . 
     Hereinafter, for convenience in description, like reference numerals are used to denote like elements throughout the first and second exemplary embodiments of the present invention. 
     Referring to  FIGS. 2A to 2C , a semiconductor device in accordance with the second exemplary embodiment of the present invention includes a substrate  201  having a predetermined structure formed therein, a plurality of memory blocks  202  stacked on the substrate  201 , and a passivation layer  203  formed on the top layer. 
     The memory block  202  has a transistor region where a peripheral circuit is formed, and a memory region where a resistive memory device is formed. In the second exemplary embodiment of the present invention, a variable resistance layer  23  of the memory region acts as a gate insulating layer  21 B and a channel layer  22 B in the transistor region. Specifically, the variable resistance layer  23  has a sequential stack of a first oxide layer  21 A and a second oxide layer  22 A, wherein the first oxide layer  21 A acts as the gate insulating layer  21 B in the transistor region and the second oxide layer  22 A acts as the channel layer  22 B in the transistor region. That is, the first oxide layer  21 A and the gate insulating layer  21 B are simultaneously formed of the same material and are disposed on the same plane. As illustrated in the drawings, the first oxide layer  21 A may be connected to the gate insulating layer  21 B. Also, the second oxide layer  22 A and the channel layer  22 B are simultaneously formed of the same material and are disposed on the same plane. As illustrated in the drawings, the second oxide layer  22 A may be connected to the channel layer  22 B. 
     The memory region includes an interlayer dielectric  11 , a plurality of first conductive lines  12 A formed on the interlayer dielectric  11  to act as a bottom electrode (BE), a first oxide layer  21 A formed on the interlayer dielectric  11  to contact the first conductive lines  12 A, a second oxide layer  22 A formed on the first oxide layer  21 A, and a plurality of second conductive lines  15 A formed on the second oxide layer  22 A to act as a top electrode (TE). The second conductive lines  15 A are arranged so that they cross over the first conductive lines  12 A. That is, a resistive memory device formed in the memory region has a crossbar type array structure where the variable resistance layer  23  is disposed between the crossing first and second conductive lines  12 A and  15 A. 
     The transistor region includes an interlayer dielectric  11 , a plurality of gate electrodes  12 B formed on the interlayer dielectric  11 , a gate insulating layer  21 B formed on the interlayer dielectric  11  to contact the gate electrodes  12 B, a channel layer  22 B formed on the gate insulating layer  21 B to overlap the gate electrodes  12 B, and first electrodes (or drain electrodes)  15 B and second electrodes (or source electrodes)  15 C formed on the channel layer  22 B to overlap a portion of corresponding gate electrodes  12 B. Herein, the first electrodes  15 B may be connected to corresponding second conductive lines  15 A of the memory region. 
     The first oxide layer  21 A acting as the variable resistance layer  23  in the memory region extends to the transistor region to act as the gate insulating layer  21 B. Therefore, the first oxide layer  21 A and the gate insulating layer  21 B may be formed of the same material. Also, the first oxide layer  21 A and the gate insulating layer  21 B are simultaneously formed through the same process, and are disposed on the same plane. Also, the first oxide layer  21 A and the gate insulating layer  21 B have a thickness of approximately 1 nm to approximately 100 nm. 
     The second oxide layer  22 A acting as the variable resistance layer  23  in the memory region extends to the transistor region to act as the channel layer  22 B. Therefore, the second oxide layer  22 A and the channel layer  22 B may be formed of the same material. Also, the second oxide layer  22 A and the channel layer  22 B are simultaneously formed through the same process, and are disposed on the same plane. Also, the second oxide layer  22 A and the channel layer  22 B have a thickness of approximately 1 nm to approximately 100 nm. 
     The first oxide layer  21 A and the second oxide layer  22 A acting as the variable resistance layer  23  may include a plurality of oxygen vacancies. Herein, the oxygen vacancies serve to change the resistance of the variable resistance layer  23 . Specifically, the variable resistance layer  23  has a conductive path created by the oxygen vacancies through a conductive path forming process that rearranges the oxygen vacancies by applying a high voltage to the first conductive line  12 A and the second conductive line  15 A. Whether or not an operation voltage (lower than the high voltage applied in the conductive path forming process) is applied to the first conductive line  12 A and the second conductive line  15 A determines whether or not the conductive path connects the first conductive line  12 A and the second conductive line  15 A. In this manner, the resistance of the variable resistance layer  23  may be changed and the change may be used to store data. 
     Since the gate insulating layer  21 B and the channel layer  22 B are formed of the same materials as the first oxide layer  21 A and the second oxide layer  22 A, respectively, they also may include a plurality of oxygen vacancies. However, even though the gate insulating layer  21 B and the channel layer  22 B include a plurality of oxygen vacancies, they do not have variable resistance characteristics like the variable resistance layer  23 . The gate insulating layer  21 B and the channel layer  22 B do not have variable resistance characteristics because the conductive path forming process is not performed on the oxygen vacancies in the transistor region, and thus, a conductive path is not created in the transistor region. Thus, the gate insulating layer  21 B and the channel layer  22 B maintain their own physical properties even though they are formed of the same material as the variable resistance layer  23 , and therefore include oxygen vacancies. That is, the gate insulating layer  21 B has insulating characteristics even though it includes oxygen vacancies; and the channel layer  22 B has semiconductor characteristics even though it includes oxygen vacancies. 
     The gate insulating layer  21 B and the first oxide layer  21 A may include at least one material selected from the group consisting of silicon (Si) oxide, aluminum (Al) oxide, hafnium (Hf) oxide, zirconium (Zr) oxide, lanthanum (La) oxide, titanium (Ti) oxide, niobium (Nb) oxide, tantalum (Ta) oxide, nickel (Ni) oxide, strontium-titanium (SrTi) oxide, barium-titanium (BaTi) oxide, and barium-strontium (BaSr) oxide. 
     The channel layer  22 B and the second oxide layer  22 A may include at least one material selected from the group consisting of indium oxide (In 2 O 3 ), zirconium oxide (ZnO), gallium oxide (Ga 2 O 3 ), and tin oxide (SnO 2 ). 
     In the semiconductor device in accordance with the second exemplary embodiment of the present invention, the variable resistance layer  23  of the memory region extends to the transistor region to act as the gate insulating layer  21 A and the channel layer  22 B. Accordingly, the second exemplary embodiment of the present invention can simplify the fabrication process and the structure of the semiconductor device. 
       FIGS. 3A to 3C  are views illustrating a semiconductor device in accordance with a third exemplary embodiment of the present invention.  FIG. 3A  is a perspective view illustrating a semiconductor device in accordance with the third exemplary embodiment of the present invention.  FIG. 3B  is a partial perspective view illustrating one memory block in accordance with the third exemplary embodiment of the present invention.  FIG. 3C  shows cross-sectional views taken along lines A-A′ and B-B′ of  FIG. 3B . 
     Hereinafter, for convenience in description, like reference numerals are used to denote like elements throughout the second and third embodiments of the present invention. 
     As illustrated in  FIGS. 3A to 3C , a semiconductor device in accordance with the third exemplary embodiment of the present invention is similar to the semiconductor device in accordance with the second exemplary embodiment of the present invention. 
     As shown in  FIGS. 3A to 3C , the channel layer  22 B in the transistor region is disconnected from the second oxide layer  22 A acting as a variable resistance layer  23  in the memory region. Although the second oxide layer  22 A and the channel layer  22 B are disconnected from each other, they are simultaneously formed of the same material and are disposed on the same plane. 
     Although not illustrated in the drawings, the first oxide layer  21 A and the gate insulating layer  21 B may be disconnected from each other as well. Where the first oxide layer  21 A and the gate insulating layer  21 B are disconnected from each other, they still may be simultaneously formed of the same material and disposed on the same plane. 
       FIGS. 4A to 4D  are perspective views illustrating a method for fabricating a semiconductor device in accordance with an exemplary embodiment of the present invention. 
     Herein, as an example, a description will be given of a method for fabricating a semiconductor device having the structure in accordance with the second exemplary embodiment of the present invention. From this description, similar methods for fabricating other exemplary embodiments should be understood. 
     Referring to  FIG. 4A , an interlayer dielectric  31 , having a transistor region and a memory region, is selectively etched to form a first recess pattern  32  in the memory region and form a second recess pattern  33  in the transistor region. 
     Referring to  FIG. 4B , a conductive layer is deposited on the interlayer dielectric  31  to fill the first and second recess patterns  32  and  33 . After the deposition of the conductive layer, a planarization process may be performed to expose the interlayer dielectric  31 . The planarization process may be performed through a chemical mechanical polishing (CMP) process. 
     Through the above process, first conductive lines  34 A filling the first recess pattern  32  and acting as bottom electrodes are formed in the memory region. Also, gate electrodes  34 B filling the second recess pattern  33  are formed in the transistor region. Herein, the first conductive lines  34 A and the gate electrodes  34 B may include a metallic layer. The metallic layer may include tungsten (W), tantalum (Ta), platinum (Pt), titanium nitride (TiN), or tantalum nitride (TaN). 
     Referring to  FIG. 4C , a first insulating layer  35  is formed over the interlayer dielectric  31  including the first conductive lines  34 A and the gate electrodes  34 B. Herein, the first insulating layer  35  acts as a variable resistance layer in the memory region, and acts as a gate insulating layer in the transistor region. 
     The first insulating layer  35  may include an oxide layer including oxygen vacancies. Specifically, the first insulating layer may be formed of at least one material selected from the group consisting of silicon (Si) oxide, aluminum (Al) oxide, hafnium (Hf) oxide, zirconium (Zr) oxide, lanthanum (La) oxide, titanium (Ti) oxide, niobium (Nb) oxide, tantalum (Ta) oxide, nickel (Ni) oxide, strontium-titanium (SrTi) oxide, barium-titanium (BaTi) oxide, and barium-strontium (BaSr) oxide. 
     A second insulating layer  36  is formed on the first insulating layer  35 . Herein, the second insulating layer  36  acts as a variable resistance layer in the memory region in combination with the first insulating layer  35 , and acts as a channel layer in the transistor region. 
     The second insulating layer  36  may include an oxide layer that contains oxygen vacancies and semiconductor characteristics. Specifically, the second insulating layer  36  may be formed of at least one material selected from the group consisting of indium oxide (In 2 O 3 ), zirconium oxide (ZnO), gallium oxide (Ga 2 O 3 ), and tin oxide (SnO 2 ). 
     After the second insulating layer  36  is formed, the second insulating layer  36  may be selectively etched to expose the first insulating layer  35  in the memory region, thereby forming the structure in accordance with the first exemplary embodiment of the present invention. After the second insulating layer  36  is selectively etched, the first insulating layer  35  may be selectively etched to divide the first insulating layer  35  of the transistor region and the first insulating layer  35  of the memory region. 
     Alternatively, after the second insulating layer  36  is formed, the second insulating layer  36  may be selectively etched to divide the second insulating layer  36  of the transistor region and the second insulating layer  36  of the memory region, thereby forming the structure in accordance with the third exemplary embodiment of the present invention. Herein, after the second insulating layer  36  is selectively etched, the first insulating layer  35  may be selectively etched to divide the first insulating layer  35  of the transistor region and the first insulating layer  35  of the memory region. 
     Referring to  FIG. 4D , a conductive layer is deposited on the second insulating layer  36  and the conductive layer is selectively etched to form at least one second conductive line  37 A acting as a top electrode of the memory region. While the second conductive line  37 A, crossing over the first conductive lines  34 A, is formed, a first electrode  37 B and a second electrode  37 C, acting as a source electrode and a drain electrode, are formed in the transistor region. 
     Herein, the second conductive line  37 A, the first electrode  37 B, and the second electrode  37 C may include a metallic layer. The metallic layer may include tungsten (W), tantalum (Ta), platinum (Pt), titanium nitride (TiN), or tantalum nitride (TaN). 
     A high voltage is applied to the first conductive line  34 A and the second conductive line  37 A to perform a conductive path forming process that creates a conductive path using oxygen vacancies in the first and second insulating layers  35  and  36  formed in the memory region. 
     One memory block can be completed by the above processes. The above processes may be repeated to stack memory blocks on the substrate, thereby completing a semiconductor device with a high-capacity memory device. 
     As described above, the present invention integrates a memory region and a transistor region, which is used to drive the memory device, in one memory block. Accordingly, the present invention does not require a separate interconnection and contact for connecting the peripheral circuit and the memory device. Therefore, the present invention can implement a high-capacity memory device with a reduced chip size. 
     While the present invention has been described with respect to the specific embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.