Patent Publication Number: US-8980736-B2

Title: Semiconductor devices and methods of manufacturing the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is a divisional of U.S. patent application Ser. No. 13/760,597, filed on Feb. 6, 2013 (published as U.S. Patent Application Publication No. 2013/0248956 A1); which claims priority from Korean Patent Application No. 10-2012-0028339, filed on Mar. 20, 2012, in the Korean Intellectual Property Office (KIPO), the entire contents of both of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     1. Technical Field 
     Example embodiments of the inventive concept may relate to semiconductor devices and/or methods of forming the same. Example embodiments of the inventive concept also may relate to semiconductor devices including vertical channel transistors and/or methods of forming the same. 
     2. Description of Related Art 
     Semiconductor devices have been used in various electronic industries because of small size, multi-function and/or low manufacture cost thereof. The semiconductor devices may include semiconductor memory devices storing data, semiconductor logic devices processing operations of logical data, and hybrid semiconductor devices having both the function of the semiconductor memory devices and the function of the semiconductor logic devices. 
     As the electronic industries are highly developed, the semiconductor devices are increasingly integrated. Thus, it is more and more difficult to realize semiconductor devices by occurrence of various problems such as a process margin reduction of a photolithography process defining fine patterns. Additionally, high speed semiconductor devices have been demanded with the development of the electronic industries. Thus, various researches have been conducted for satisfying the demands of high integration and/or high speed of the semiconductor devices. 
     SUMMARY 
     Example embodiments of the inventive concept may provide semiconductor devices capable of being highly integrated. 
     Example embodiments of the inventive concept also may provide methods of manufacturing the semiconductor devices. 
     In some example embodiments, a semiconductor device may comprise active patterns of pillar-shapes on a substrate and spaced apart from each other in one direction; a gate electrode extending in the one direction and overlapped with sidewalls of the active patterns; a gate insulating layer between the gate electrode and the active patterns; bit lines connected to bottom surfaces of respective active patterns; and/or capacitors connected to top surfaces of the respective active patterns. Each of the active patterns may have no p-type/n-type (PN) junctions. 
     In some example embodiments, each of the active patterns may have a width greater than or equal to about 5 nm and less than or equal to about 30 nm. 
     In some example embodiments, each of the active patterns may be fully doped with dopants of one conductivity type. 
     In some example embodiments, each of the active patterns may comprise a channel region corresponding to the gate electrode; a first region between the channel region and a respective bit line; and/or a second region between the channel region and a respective capacitor. 
     In some example embodiments, the channel region, the first region, and the second region may be doped with dopants of a same conductivity type. 
     In some example embodiments, a method of manufacturing a semiconductor device may comprise forming active patterns of pillar-shapes upward protruding from a substrate, the active patterns fully doped with dopants of one conductivity type; forming a gate electrode extending in one direction, the gate electrode overlapped with sidewalls of the active patterns; and/or forming a gate insulating layer between the gate electrode and the active patterns. 
     In some example embodiments, forming the active patterns may comprise etching a substrate to form the active patterns having a width greater than or equal to about 5 nm and less than or equal to about 30 nm. 
     In some example embodiments, the method may further comprise, before forming the active patterns, etching a substrate to form a trench; filling a lower part of the trench with a conductive material to form a bit line; and/or filling an upper part of the trench with an insulating material to form a mask on the bit line. The gate electrode may cross over the bit line. 
     In some example embodiments, forming the gate insulating layer may comprise etching the substrate to form a trench extending in the one direction; and/or conformally forming the gate insulating layer on the active patterns exposed by the trench. 
     In some example embodiments, forming the trench may comprise forming a first part of the trench extending in the one direction; and/or forming a second part of the trench extending from the first part of the trench to at least a portion of a sidewall of a respective active pattern. 
     In some example embodiments, forming the gate electrode may comprise filling a part of the trench having the gate insulating layer with a conductive material to form the gate electrode; and/or forming a mask filling the trench on the gate electrode. 
     In some example embodiments, the method may further comprise forming capacitors on top surfaces of respective active patterns. 
     In some example embodiments, a semiconductor device may comprise a substrate; active patterns on the substrate that are spaced apart from each other; gate insulating layers at least partially around respective active patterns; and/or a gate electrode configured to contact the gate insulating layers. The active patterns may include no p-type/n-type (PN) junctions. 
     In some example embodiments, each of the active patterns may have a width greater than or equal to about 5 nm and less than or equal to about 30 nm. 
     In some example embodiments, each of the active patterns may be doped with dopants of a same conductivity type. 
     In some example embodiments, the semiconductor device may further comprise bit lines connected to bottom surfaces of the respective active patterns. 
     In some example embodiments, the semiconductor device may further comprise capacitors connected to top surfaces of the respective active patterns. 
     In some example embodiments, the semiconductor device may further comprise bit lines connected to the respective active patterns; and/or capacitors connected to the respective active patterns. 
     In some example embodiments, each of the active patterns may comprise a channel region corresponding to the gate electrode; a first region between the channel region and a respective bit line; and/or a second region between the channel region and a respective capacitor. 
     In some example embodiments, the channel region, the first region, and the second region may be doped with dopants of a same conductivity type. 
     In some example embodiments, a semiconductor device may comprise a substrate; active patterns on the substrate that are spaced apart from each other; a gate electrode configured to overlap sidewalls of the active patterns; and/or gate insulating layers between the gate electrode and respective active patterns. The active patterns may be doped with dopants of a same conductivity type. 
     In some example embodiments, each of the active patterns may have a width greater than or equal to about 5 nm and less than or equal to about 30 nm. 
     In some example embodiments, each of the active patterns may be fully doped with the dopants of the same conductivity type. 
     In some example embodiments, the semiconductor device may further comprise bit lines connected to bottom surfaces of the respective active patterns. 
     In some example embodiments, the semiconductor device may further comprise capacitors connected to top surfaces of the respective active patterns. 
     In some example embodiments, the semiconductor device may further comprise bit lines connected to the respective active patterns; and/or capacitors connected to the respective active patterns. 
     In some example embodiments, each of the active patterns may comprise a channel region corresponding to the gate electrode; a first region between the channel region and a respective bit line; and/or a second region between the channel region and a respective capacitor. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and/or other aspects and advantages will become more apparent and more readily appreciated from the following detailed description of example embodiments, taken in conjunction with the accompanying drawings, in which: 
         FIG. 1A  is a plan view illustrating a semiconductor device according to some example embodiments of the inventive concept; 
         FIGS. 1B and 1C  are cross-sectional views illustrating a semiconductor device according to some example embodiments of the inventive concept; 
         FIGS. 2A ,  3 A,  4 A, and  5 A are plan views illustrating a method of manufacturing a semiconductor device according to some example embodiments of the inventive concept; 
         FIGS. 2B ,  3 B,  4 B, and  5 B are cross-sectional views illustrating a method of manufacturing a semiconductor device according to some example embodiments of the inventive concept; 
         FIGS. 2C ,  3 C,  4 C, and  5 C are cross-sectional views a method of manufacturing a semiconductor device according to some example embodiments of the inventive concept; 
         FIGS. 6A and 6B  are cross-sectional views to explain a method of operating a semiconductor device according to some example embodiments of the inventive concept; 
         FIG. 7A  is a schematic block diagram illustrating an example of memory cards including semiconductor devices according to some example embodiments of the inventive concept; and 
         FIG. 7B  is a schematic block diagram illustrating an example of systems including semiconductor devices according to some example embodiments of the inventive concept. 
     
    
    
     DETAILED DESCRIPTION 
     Example embodiments will now be described more fully with reference to the accompanying drawings. Embodiments, however, may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these example embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope to those skilled in the art. In the drawings, the thicknesses of layers and regions may be exaggerated for clarity. 
     It will be understood that when an element is referred to as being “on,” “connected to,” “electrically connected to,” or “coupled to” to another component, it may be directly on, connected to, electrically connected to, or coupled to the other component or intervening components may be present. In contrast, when a component is referred to as being “directly on,” “directly connected to,” “directly electrically connected to,” or “directly coupled to” another component, there are no intervening components present. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     It will be understood that although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers, and/or sections, these elements, components, regions, layers, and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, and/or section from another element, component, region, layer, and/or section. For example, a first element, component, region, layer, and/or section could be termed a second element, component, region, layer, and/or section without departing from the teachings of example embodiments. 
     Spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper,” and the like may be used herein for ease of description to describe the relationship of one component and/or feature to another component and/or feature, or other component(s) and/or feature(s), as illustrated in the drawings. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. 
     The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes,” and/or “including,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     Example embodiments may be described herein with reference to cross-sectional illustrations that are schematic illustrations of idealized example embodiments (and intermediate structures). As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, example embodiments should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, an implanted region illustrated as a rectangle will typically have rounded or curved features and/or a gradient of implant concentration at its edges rather than a binary change from implanted to non-implanted region. Likewise, a buried region formed by implantation may result in some implantation in the region between the buried region and the surface through which the implantation takes place. Thus, the regions illustrated in the figures are schematic in nature, their shapes are not intended to illustrate the actual shape of a region of a device, and their shapes are not intended to limit the scope of the example embodiments. 
     Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein. 
     Reference will now be made to example embodiments, which are illustrated in the accompanying drawings, wherein like reference numerals may refer to like components throughout. 
       FIG. 1A  is a plan view illustrating a semiconductor device according to some example embodiments of the inventive concept.  FIG. 1B  is a cross-sectional view taken along a line A-A′ of  FIG. 1A , and  FIG. 1C  is a cross-sectional view taken along a line B-B′ of  FIG. 1A . 
     Referring to  FIGS. 1A ,  1 B, and  1 C, a semiconductor device may include a bit line  108  formed in a substrate  100 , a vertical channel transistor TR, and a capacitor CAP. 
     The substrate  100  may include a device isolation pattern  102  and active patterns  104  defined by the device isolation pattern  102 . The active patterns  104  may include lower patterns  103   b  extending in a first direction D 1  and parallel to each other, and upper patterns  103   a  upward extending from the lower patterns  103   b , respectively. The upper pattern  103   a  may have a pillar-shape. In some example embodiments, a plurality of the upper patterns  103   a  may be disposed on one lower pattern  103   b  and be spaced apart from each other the first direction D 1 . A plurality of the lower patterns  103   b  may be spaced apart from each other a second direction D 2 , such that the upper patterns  103   a  on the plurality of the lower patterns  103   b  may be spaced apart from each other in the first and second directions D 1  and D 2 . 
     According to some example embodiments of the inventive concept, the upper pattern  103   a  of the active pattern  104  may have a width W within a range of several nanometers (nm) to several tens of nanometers in the first direction. The upper pattern  103   a  may have the width W of about 30 nm or less. The vertical channel transistor TR may have a profitable characteristic as the width W becomes smaller. 
     For example, if a horizontal cross section of the upper pattern  103   a  has a quadrangular shape, the width W may be a length of a side of the quadrangular shape parallel to the first direction D 1 . In some example embodiments, if the horizontal cross section of the upper patterns  103   a  has a circular shape, the width W may be a diameter of the circular shape. 
     Since the upper pattern  103   a  has the width W within the range of several nanometers to several tens of nanometers, a channel region in the upper pattern  103   a  may be fully depleted when the vertical channel transistor TR is turned off. 
     According to some example embodiments of the inventive concept, each of the upper patterns  103   a  of the active patterns  104  may be doped in whole with dopants of one conductivity type. 
     The bit line  108  may extend in the first direction D 1  in the substrate  100 . The bit line  108  is disposed under the vertical channel transistor TR, such that it may be defined as a buried bit line. The bit line  108  may include at least one of tungsten, tungsten nitride, and titanium nitride. 
     In some example embodiments, the semiconductor device may further include a bit line mask  110  disposed on the bit line  108 . The bit line mask  110  may have substantially the same width as that of a top surface of the bit line  108 , and the bit line mask  110  may extend in substantially the same direction as the extending direction of the bit line  108 . The bit line mask  110  may include an insulating material such as nitride, oxide, and/or oxynitride. 
     The bit line  108  may be provided in plural. The plurality of bit lines  108  may be parallel to each other. According to some example embodiments of the inventive concept, the plurality of bit lines  108  may be in contact with the lower patterns  103   b  of the active patterns  104 , respectively. The plurality of bit lines  108  may be parallel with the lower patterns  103   b.    
     The vertical channel transistor TR may include a gate electrode  116 , a gate insulating layer  114 , and a channel region  104   c.    
     The gate electrode  116  may be disposed to be adjacent to the upper patterns  103   a  of the active patterns  104 . In some example embodiments, the gate electrode  116  may connect the upper patterns  103   a  of the active patterns  104  which are arranged in the second direction D 2  to constitute one column. The gate electrode  116  may include at least one of tungsten, tungsten nitride, and titanium nitride. 
     In some example embodiments, the gate electrode  116  may include a first portion  116   a  extending in the second direction D 2 , and second portions  116   b  extending from the first portion  116   a  in the first direction D 1 . Each of the second portions  116   b  of the gate electrode  116  may surround at least a portion of each of the upper patterns  103   a  constituting the one column. The first portion  116   a  may be spaced apart from the bit line  108  and cross over the bit line  108 . The first portion  116   a  may be disposed to be parallel to the one column at a side of the upper patterns  103   a  constituting the one column. The second portion  116   b  may be spaced apart from the capacitor CAP. 
     In some example embodiments, the gate electrode  116  and the bit line  108  may be spaced apart from each other by a first region  104   a  of the upper pattern  103   a  of the active pattern  104 . The gate electrode  116  and the capacitor CAP may be spaced apart from each other by a second region  104   b  of the upper pattern  103   a  of the active pattern  104 . The channel region  104   c  of the vertical channel transistor TR may be disposed between the first and second regions  104   a  and  104   b . The channel region  104   c  and the first and second regions  104   a  and  104   b  may include dopants of the same conductivity type. Thus, the vertical channel transistor TR has no p-type/n-type (PN) junction. In other words, the vertical channel transistor TR may be a junctionless transistor. 
     According to some example embodiments of the inventive concept, the vertical channel transistor TR may include a gate mask  118  disposed on the gate electrode  116 . The gate mask  118  may surround at least a portion of the second region  104   b  of the upper pattern  103   a  of the active pattern  104 . The gate mask  118  may include an insulating material such as nitride, oxide, and/or oxynitride. Meanwhile, the gate electrode  116  and the gate mask  118  may be in contact with at least a portion of the bit line mask  110 . 
     The gate insulating layer  114  may be disposed between the gate electrode  116  and the upper pattern  103   a  of the active pattern  104 . Additionally, the gate insulating layer  114  may extend between the gate mask  118  and the upper pattern  103   a  of the active pattern  104 . The gate insulating layer  114  may include silicon oxide and/or a high-k dielectric oxide. 
     The capacitor CAP may be disposed on the second region  104   b  of the upper pattern  103   a  of the active pattern  104 . The capacitor CAP may be in contact with the second region  104   b . The capacitor CAP may be provided in plural, and the plurality of capacitors CAP may be connected to top surfaces of the upper patterns  103   a , respectively. The capacitor CAP may include a lower electrode  120 , a dielectric layer (not shown), and an upper electrode (not shown). In some example embodiments, the lower electrode  120  may have a cylindrical shape. However, example embodiments of the inventive concept are not limited thereto. 
     As described above, the vertical channel transistor TR does not have junctions between the channel region  104   c  and the first and second regions  104   a  and  104   b . In other words, the vertical channel transistor TR may be the junctionless transistor. Thus, a gate induced drain leakage (GIDL) may be reduced to suppress a floating body phenomenon of the channel region  104   c . Additionally, the channel region  104   c  of the vertical channel transistor TR may have the width W of about 30 nm or less, so that the channel region  104   c  may be easily fully depleted to reduce a voltage applied to the gate electrode  116 . 
     Hereinafter, a method of manufacturing a semiconductor device will be described. 
       FIGS. 2A ,  3 A,  4 A, and  5 A are plan views illustrating a method of manufacturing a semiconductor device according to some example embodiments of the inventive concept.  FIGS. 2B ,  3 B,  4 B, and  5 B are cross-sectional views illustrating a method of manufacturing a semiconductor device according to some example embodiments of the inventive concept.  FIGS. 2C ,  3 C,  4 C, and  5 C are cross-sectional views a method of manufacturing a semiconductor device according to some example embodiments of the inventive concept.  FIGS. 2B and 2C  are cross-sectional views taken along a line A-A′ and a line B-B′ of  FIG. 2A , respectively.  FIGS. 3B and 3C  are cross-sectional views taken along a line A-A′ and a line B-B′ of  FIG. 3A , respectively.  FIGS. 4B and 4C  are cross-sectional views taken along a line A-A′ and a line B-B′ of  FIG. 4A , respectively.  FIGS. 5B and 5C  are cross-sectional views taken along a line A-A′ and a line B-B′ of  FIG. 5A , respectively. 
     Referring to  FIGS. 2A ,  2 B, and  2 C, a bit line  108  and a device isolation pattern  102  may be formed in a substrate  100 . 
     The substrate  100  may be etched to form a first trench  106  extending in a first direction D 1 . The first trench  106  may be provided in plural. The plurality of the first trenches  106  may be parallel to each other. The plurality of the first trenches  106  may be spaced apart from each other in a second direction D 2  perpendicular to the first direction D 1 . 
     A lower part of the first trench  106  may be filled with a conductive material, thereby forming a bit line  108 . An upper part of the first trench  106  may be filled with an insulating material, thereby forming a bit line mask  110  on the bit line  108 . 
     The substrate  100  may be etched to form an active pattern  104  including a lower pattern  103   b  and an upper pattern  103   a . The lower pattern  103   b  may extend in the first direction D 1 , and the upper pattern  103   a  may have a pillar-shape upward protruding from the lower pattern  103   b . A plurality of the upper patterns  103   a  may be formed on a single lower pattern  103   b . The upper patterns  103   a  on the single lower pattern  103   b  may be spaced apart from each other in the first direction D 1 . Additionally, the lower pattern  103   b  may be formed in plural. In other words, the active pattern  104  may be formed in plural. The lower patterns  103   b  may be parallel to each other. The upper patterns  103   a  on the lower patterns  103   b  may be arranged in the first and second directions D 1  and D 2  and be spaced apart from each other. 
     In some example embodiments, an entire substrate  100  may be doped with dopants of one conductivity type. In some example embodiments, the substrate  100  may be doped with dopants of a first conductivity type, and the active pattern  104  may be doped with dopants of a second conductivity type different from the first conductivity type. The entire active pattern  104  may be doped with dopants of one conductivity type, so that the active pattern has no junction. In other words, the junctionless active pattern  104  may be formed. 
     Even though the junction does not exist in the active pattern  104 , a vertical channel transistor TR completed in a subsequent process may function as a switching element according to a voltage applied to a gate electrode  116  thereof. Thus, the method of manufacturing the semiconductor device may not require an ion implantation process for forming conventional source/drain regions. As a result, the method of manufacturing the semiconductor device may be simple. 
     In some example embodiments, the upper pattern  103   a  of the active pattern  104  may have a width W within a range of several nanometers to several tens of nanometers. For example, the upper pattern  103   a  may have the width within a range of about 5 nm to about 30 nm. 
     The device isolation pattern  102  may be formed to fill a space between the active patterns  104 . The device isolation pattern  102  may include an insulating material such as oxide, nitride, and/or oxynitride. After the device isolation pattern  102  is formed, a polishing process may be performed until top surfaces of the active patterns  104  (i.e., top surfaces of the upper patterns  103   a ) are exposed. 
     Referring to  FIGS. 3A ,  3 B, and  3 C, the bit line mask  110 , the active pattern  104  and the device isolation pattern  102  may be etched to form a second trench  112 . 
     The second trench  112  may include a first part  112   a  extending in the second direction D 2  and a second part  112   b  connected to the first part  112   a . The second part  112   b  of the second trench  112  may extend in the first direction D 1  and expose at least a portion of the upper pattern  103   a  of the active pattern  104 . A depth of the second trench  112  may be smaller than a depth of the first trench  106 . 
     The second trench  112  may be formed in plural. The first parts  112   a  of the second trenches  112  may be parallel to each other and be spaced apart from each other in the first direction D 1 . 
     Referring to  FIGS. 4A ,  4 B, and  4 C, a gate insulating layer  114  may be formed along surfaces of the active patterns  104  exposed by the second trenches  112 . The gate insulating layer  114  may not completely fill the second trenches  112 . 
     For example, if the active patterns  104  may include silicon, the exposed active patterns  104  may be thermally oxidized to form the gate insulating layer  114  including a silicon oxide. In some example embodiments, the gate insulating layer  114  may be conformally formed along a surface profile of the exposed active patterns  104  by a deposition process. 
     Referring to  FIGS. 5A ,  5 B, and  5 C, a gate electrode  116  and a gate mask  118  may be sequentially formed in the second trench  112  in which the gate insulating layer  114  is formed. 
     The gate electrode  116  may be formed by filling a part of the second trench  112  with a conductive material. The conductive material may include at least one of tungsten, titanium nitride, and tungsten nitride. The conductive material may fill a lower part of the second trench  112 . 
     The gate electrode  116  may include a first portion  116   a  extending in the second direction D 2  and a second portion  116   b  extending from the first portion  116   a  in the first direction D 1 . The second portion  116   b  may surround at least a portion of the upper pattern  103   a  of the active pattern  104 . 
     An upper part of the second trench  112  may be filled with an insulating material, thereby forming the gate mask  118  on the gate electrode  116 . 
     Referring to  FIGS. 1A ,  1 B, and  1 C again, the capacitor CAP may be formed on the upper pattern  103   a  of the active pattern  104 . Even though not illustrated in detail in the drawings, after the lower electrode  120  of the capacitor CAP is formed on the upper pattern  103   a  of the active pattern  104 , the dielectric layer and the upper electrode of the capacitor CAP may be sequentially formed on the lower electrode  120  of the capacitor CAP. 
     Hereinafter, a method of operating the semiconductor device according to some example embodiments will be described with reference to the drawings. 
       FIG. 6A  is a cross-sectional view for explaining an on-operation of a transistor of the semiconductor device according to some example embodiments of the inventive concept, and  FIG. 6B  is a cross-sectional view for explaining an off-operation of a transistor of the semiconductor device according to some example embodiments of the inventive concept. 
     Referring to  FIGS. 6A and 6B , the transistor of the semiconductor device may be the vertical channel transistor TR described with reference to  FIG. 1B . Hereinafter, for example, the active pattern  104  of the vertical channel transistor TR may be fully doped with n-type dopants. 
     Referring to  FIG. 6A , if a voltage Vg greater than 0 V (zero volts) is applied to the gate electrode  116  of the vertical channel transistor TR, the channel region  104   c  may be accumulated, so that the first region  104   a  is connected to the second region  104   b . Thus, the vertical channel transistor TR is turned on. Since the upper pattern  103   a  of the active pattern  104  has the width W of several tens of nanometers, the entire channel region  104   c  may be accumulated. Thus, an on-current of the vertical channel transistor TR may increase, so that efficiency of the vertical channel transistor TR may increase. 
     Referring to  FIG. 6B , if a voltage Vg less than 0 V (zero volts) is applied to the gate electrode  116  of the vertical channel transistor TR, the channel region  104   c  may be depleted to insulate the first region  104   a  from the second region  104   b . Thus, the vertical channel transistor TR is turned off. 
     Even though not shown in detail in the drawings, if the active pattern  104  of the vertical channel transistor TR is doped with p-type dopants, the operation of the vertical channel transistor TR may be operated by methods opposite to the methods described with reference to  FIGS. 6A and 6B . 
       FIG. 7A  is a schematic block diagram illustrating an example of memory cards including semiconductor devices according to some example embodiments of the inventive concept. 
     Referring to  FIG. 7A , the semiconductor device according to some example embodiments of the inventive concept may be applied to a memory card  300 . For example, the memory card  300  may include a memory controller  320  that controls data communication between a host HOST and a memory device  310 . A static random-access memory (SRAM) device  322  may be used as an operation memory of a central processing unit (CPU)  324 . A host interface (I/F) unit  326  may be configured to include a data communication protocol between the memory card  300  and the host HOST. An error check and correction (ECC) block  328  may detect and correct errors of data which are read out from the memory device  310 . A memory interface (I/F) unit  330  may interface the memory device  310 . The CPU  324  controls overall operations of the memory controller  320 . 
     When the memory device  310  applied to the memory card  300  includes the semiconductor device according to some example embodiments of the inventive concept, the PN junction interface may not exist at source/drain regions. Thus, the GIDL may be reduced to suppress the floating body phenomenon of the channel region. 
       FIG. 7B  is a schematic block diagram illustrating an example of systems including semiconductor devices according to some example embodiments of the inventive concept. 
     Referring to  FIG. 7B , an information processing system  400  may include the semiconductor device according to some example embodiments of the inventive concept. The information processing system  400  may include a mobile device or a computer. For example, the information processing system  400  may include a modem  420 , a CPU  430 , a random-access memory (RAM)  440 , and a user interface (I/F) unit  450  that are electrically connected to a memory system  410  through a system bus  460 . The memory system  410  may store data processed by the CPU  430  or data inputted from an external device. The memory system  410  may include a memory device  414  and a memory controller  412 . The memory system  410  may be substantially the same as the memory card  300  described with reference to  FIG. 7A . The information processing system  400  may be realized as a memory card, a solid state disk (SSD) device, a camera image sensor and another type of application chipset. For example, the memory system  410  may consist of the SSD device. In this case, the information processing system  400  may stably and reliably store massive data. 
     According to some example embodiments of the inventive concept, the channel region may not be distinguished from source/drain regions, so that the vertical channel transistor has no junction. Thus, the GIDL may be reduced and the floating body phenomenon of the channel region may be prevented. As a result, performance of the vertical channel transistor may be improved. 
     While example embodiments have been particularly shown and described, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.