Abstract:
A suspended type nanowire array and a manufacturing method thereof may be provided. More particularly, an array including a suspended type nanowire having two kinds of nanowires stacked thereon and a manufacturing method thereof may be provided. The suspended type nanowire array includes: a substrate; a suspended type nanowire which is suspended above the substrate and comprises a first nanowire, an insulating member, and a second nanowire which are sequentially stacked; a first electrode portion which is electrically connected to the first nanowire; and a second electrode portion which is electrically connected to the second nanowire.

Description:
BACKGROUND 
       [0001]    Field 
         [0002]    This disclosure relates to a suspended type nanowire array and a manufacturing method thereof, and more particularly to an array including a suspended type nanowire having two kinds of nanowires stacked thereon and a manufacturing method thereof. 
         [0003]    Description of the Related Art 
         [0004]    A nanowire has particular characteristics which cannot be discovered in a macroscopic world due to its very small size. By using these particular characteristics, hyperfine and high performance electronic devices can be manufactured. 
         [0005]    Some of the hyperfine and high performance electronic devices require nanowires heated to a high temperature for their operations. 
         [0006]    Korean Registered Patent Publication No. 10-1403406 (hereinafter, referred to as a conventional technology) discloses a method for manufacturing a gas sensor and a temperature sensor which are based on a suspended type carbon nanowire. 
         [0007]    The conventional technology is related to a method in which a micro-sized wire made by a semiconductor process is thermally decomposed at a high temperature, so that a carbon electrode and a suspended type carbon nanowire are integrally formed. Through this conventional technology, it is possible to manufacture a gas sensor which detects a gas concentration by stacking a particular material (gas detection material) on the carbon nanowire or a temperature sensor which detects a temperature by measuring a resistance value of the carbon nanowire. 
         [0008]    The conventional technology relates to a method for forming carbon nanowires instead of nanowires made of various materials. Since it is impossible to heat the carbon nanowire at a high temperature, the conventional technology cannot be applied to an electronic device which requires the nanowire heated to high temperature. 
         [0009]    Also, when the nanowire is heated at a high temperature, the nanowire is transformed by the high temperature, so that the nanowire itself may be damaged. Therefore, there is a requirement for a technology for preventing the nanowire itself from being damaged. 
       SUMMARY 
       [0010]    One embodiment is a suspended type nanowire array comprising: a substrate; a suspended type nanowire which is suspended above the substrate and comprises a first nanowire, an insulating member, and a second nanowire which are sequentially stacked; a first electrode portion which is electrically connected to the first nanowire; and a second electrode portion which is electrically connected to the second nanowire. 
         [0011]    A length of the insulating member is less than a length of the first nanowire, and a length of the second nanowire is the same as or is less than the length of the insulating member. 
         [0012]    The first nanowire is a heat radiator. 
         [0013]    A plurality of the suspended type nanowires are provided. Two adjacent suspended type nanowires among the plurality of suspended type nanowires are disposed apart from each other at a predetermined distance. A duty ratio between the two first nanowires of the two suspended type nanowires is greater than 2.5%. 
         [0014]    Materials of the first nanowire and the second nanowire are a metal or a metal oxide. The material of the first nanowire is different from the material of the second nanowire. 
         [0015]    The insulating member is an insulating wire. The insulating wire covers an entire top surface and a portion of a side of the first nanowire. The second nanowire is disposed on a top surface of the insulating wire. 
         [0016]    The insulating member is an insulating thin film. 
         [0017]    A plurality of the suspended type nanowires are provided. The suspended type nanowire array further includes a first suspended type electrode which is disposed on the first nanowires of the plurality of suspended type nanowires; and a second suspended type electrode which is disposed on the second nanowires of the plurality of suspended type nanowires. 
         [0018]    One end of each of the first nanowires is connected to the first electrode portion. The second electrode portion comprises a first electrode and a second electrode which are electrically connected through the second nanowires and the second suspended type electrode. 
         [0019]    The first electrode portion comprises a first electrode connected to one end of the first nanowire and a second electrode connected to the other end of the first nanowire. The second electrode portion comprises a first electrode and a second electrode which are electrically connected through the second nanowire. 
         [0020]    Each of the first electrode of the second electrode portion and the second electrode of the second electrode portion includes an extension electrode which is disposed on the second nanowire and is suspended above the substrate. 
         [0021]    The substrate comprises protrusions on which the first electrode of the first electrode portion, the second electrode of the first electrode portion, the first electrode of the second electrode portion, and the second electrode of the second electrode portion are disposed respectively. 
         [0022]    Another embodiment is a method for manufacturing a suspended type nanowire array. The method includes: forming a nanowire such that a first nanowire is formed on a predetermined number of protrusions of a nanograting substrate by using a photolithographic technique or a shadow mask technique, and an insulating member and a second nanowire are sequentially deposited on the first nanowire by using the photolithographic technique or the shadow mask technique; forming an electrode such that a first electrode portion which is electrically connected to the first nanowires and a second electrode portion which is electrically connected to the second nanowires are formed by using a patterning technique or the shadow mask technique; and etching the nanograting substrate by a predetermined thickness from a top surface to a bottom surface thereof. 
         [0023]    In the forming an electrode, a first docking electrode is formed on the first nanowires, a second docking electrode is formed on the second nanowires, one end of each of the first nanowires is connected to the first electrode portion, and an extension electrode extending from the second electrode portion is formed on the second nanowires. 
         [0024]    In the forming an electrode, one end of each of the first nanowires is connected to a first electrode of the first electrode portion, and the other end of each of the first nanowires is connected to a second electrode of the first electrode portion, and an extension electrode extending from the second electrode portion is formed on the second nanowires. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]      FIG. 1  is a perspective view of a suspended type nanowire array according to a first embodiment of the present invention; 
           [0026]      FIG. 2  is a side view of the suspended type nanowire array shown in  FIG. 1 ; 
           [0027]      FIG. 3  is a cross sectional view taken along line A-A′ shown in  FIG. 1   
           [0028]      FIG. 4  is a cross sectional view of a suspended type nanowire  100 ′, i.e., a modified example of a suspended type nanowire  100  shown in  FIG. 3 ; 
           [0029]      FIG. 5  is a view for describing a temperature difference due to a predetermined interval between a plurality of the suspended type nanowires  100  shown in  FIG. 1 ; 
           [0030]      FIG. 6  shows a relative temperature distribution according to a duty ratio between the plurality of the suspended type nanowires  100  shown in  FIG. 1  and a relative temperature distribution according to a duty ratio between typical substrate attachment type nanowires; 
           [0031]      FIGS. 7, 8, 9, 10, and 11  are views for describing a method for manufacturing the suspended type nanowire array according to the first embodiment of the present invention shown in  FIG. 1 ; 
           [0032]      FIG. 12  is a perspective view of a suspended type nanowire array according to a second embodiment of the present invention; and 
           [0033]      FIG. 13  is an actual electron microscope photograph showing the suspended type nanowire  100  shown in  FIG. 1 or 12 . 
       
    
    
     DETAILED DESCRIPTION 
       [0034]    The embodiment of the present invention can be variously transformed, and the scope of the present invention is not limited to the following embodiment. The shapes and sizes of the components in the drawings may be exaggerated for clarity of the description. It is noted that the same reference numerals are used to denote the same elements throughout the drawings. In the following description of the present invention, the detailed description of known functions and configurations incorporated herein is omitted when it may make the subject matter of the present invention unclear. 
         [0035]    Hereinafter, a suspended type nanowire array according to an embodiment of the present invention and a manufacturing method thereof will be described with reference to the accompanying drawings. 
       First Embodiment 
       [0036]      FIG. 1  is a perspective view of a suspended type nanowire array according to a first embodiment of the present invention.  FIG. 2  is a side view of the suspended type nanowire array shown in  FIG. 1 .  FIG. 3  is a cross sectional view taken along line A-A′ shown in  FIG. 1 . 
         [0037]    Referring to  FIGS. 1 to 3 , the suspended type nanowire array (or suspension type nanowire array) according to the first embodiment of the present invention may include a substrate  10 , a suspended type nanowire  100 , a first electrode portion  300 , a second electrode portion  500 , and suspended type electrode portion  700 . 
         [0038]    The suspended type nanowire  100 , the first electrode portion  300 , the second electrode portion  500 , and the suspended type electrode portion  700  are disposed on the substrate  10 . 
         [0039]    The substrate  10  includes a top surface  10   a  and a protrusion  10   b.    
         [0040]    The suspended type nanowire  100  and the suspended type electrode portion  700  may be disposed on the top surface  10   a  of the substrate  10 . Specifically, the suspended type nanowire  100  and the suspended type electrode portion  700  may be disposed apart from the top surface  10   a  of the substrate  10  at a predetermined distance. 
         [0041]    The protrusion  10   b  may be disposed on the top surface  10   a . Here, the protrusion  10   b  may be made of a material the same as that of the substrate  10  and may extend from the top surface  10   a.    
         [0042]    A plurality of the protrusions  10   b  may be disposed on the top surface  10   a . The plurality of protrusions  10   ba ,  10   bb ,  10   bc , and  10   bd  may be arranged in a line. The plurality of protrusions  10   ba ,  10   bb ,  10   bc , and  10   bd  arranged in a line may be disposed apart from each other at a predetermined interval. 
         [0043]    The first electrode portion  300  and the second electrode portion  500  may be disposed on the plurality of protrusions  10   ba ,  10   bb ,  10   bc , and  10   bd , respectively. Specifically, as shown in the drawing, when four protrusions  10   ba ,  10   bb ,  10   bc , and  10   bd  are provided, a second electrode  500   b  of the second electrode portion  500  may be disposed on a first protrusion  10   ba , a second electrode  300   b  of the first electrode portion  300  may be disposed on a second protrusion  10   bb , a first electrode  300   a  of the first electrode portion  300  may be disposed on a third protrusion  10   bc , and a first electrode  500   a  of the second electrode portion  500  may be disposed on a fourth protrusion  10   bd.    
         [0044]    While the plurality of protrusions  10   b  are shown in the drawing, one protrusion  10   b  may be provided. Also, the first electrode portion  300  and the second electrode portion  500  may be disposed on one protrusion  10   b  and are apart from each other. 
         [0045]    The suspended type nanowire  100  is suspended above the substrate  10 . The suspended type nanowire  100  is disposed apart from the top surface  10   a  of the substrate  10  at a predetermined distance. When the suspended type nanowire  100  is suspended above the substrate  10 , heat which is transferred (lost) to the substrate  10  by conduction is minimized, so that it is possible to maximize the energy efficiency of the suspended type nanowire  100  and to reduce the possibility that the structure of the suspended type nanowire  100  is damaged by deformation of the substrate due to the high temperature of the suspended type nanowire  100 . 
         [0046]    The suspended type nanowire  100  includes a first nanowire  110 , an insulating member  130 , and a second nanowire  150 . 
         [0047]    One end of the first nanowire  110  is connected to the first electrode portion  300 , and the other end of the first nanowire  110  is disposed apart from the substrate  10  at a predetermined interval. In this case, the first nanowire  110  is not cut in spite of expanding by the heat. That is, resistance to stress of the first nanowire  110  can be improved. If the one and the other ends of the first nanowire  110  are fixed, the first nanowire  110  may be cut by internal stress when the first nanowire  110  thermally expands. However, when the other end of the first nanowire  110  is not fixed to the first electrode portion  300  and is disposed apart from the substrate  10  at a predetermined interval, the first nanowire  110  is able to freely expand or contract, so that the first nanowire  110  is not cut by the internal stress. 
         [0048]    The suspended type electrode portion  700  is disposed on the first nanowire  110 . A first suspended type electrode  700   a  of the suspended type electrode portion  700  is disposed on the other end of the first nanowire  110 . 
         [0049]    The first nanowire  110  may be a metal or a metal oxide. When the first nanowire  110  is a metal, a higher temperature can be obtained by a low power consumption. This is caused by thermal isolation of the first nanowire  110  made of a metallic material. The thermal isolation means that the electron mobility of the metal-made first nanowire  110  is reduced by the scattering due to a very narrow moving path, so that thermal conductivity is reduced. 
         [0050]    The second nanowire  150  is disposed on the first nanowire  110 . One end of the second nanowire  150  is connected to the second electrode portion  500 . As mentioned, when the one end of the second nanowire  150  is connected to the second electrode portion  500  and the other end of the second nanowire  150  is not connected to the second electrode portion  500 , the second nanowire  150  is not cut in spite of expanding by the heat. That is, for the same reason as that of the above-described first nanowire  110 , resistance to stress of the second nanowire  150  can be improved. 
         [0051]    The length of the second nanowire  150  may be less than that of the first nanowire  110 . The width of the second nanowire  150  may be greater than that of the first nanowire  110 . 
         [0052]    Extension electrodes  510   a  and  510   b  of the second electrode portion  500  may be disposed on the second nanowire  150 . The extension electrodes  510   a  and  510   b  of the second electrode portion  500  may be disposed on one end of the second nanowire  150 . 
         [0053]    The suspended type electrode portion  700  may be disposed on the second nanowire  150 . A second suspended type electrode  700   b  of the suspended type electrode portion  700  may be disposed on the other end of the second nanowire  150 . 
         [0054]    The second nanowire  150  may be a metal or a metal oxide. When the second nanowire  150  is a metal, a higher temperature can be obtained by a low power consumption. This is caused by thermal isolation of the second nanowire  150  made of a metallic material. The thermal isolation means that the electron mobility of the metal-made second nanowire  150  is reduced by the scattering due to a very narrow moving path, so that thermal conductivity is reduced. 
         [0055]    The material of the second nanowire  150  may be different from that of the first nanowire  110 . For example, the material of the first nanowire  110  may be a metallic material such as Pt, and the material of the second nanowire  150  may be a metal oxide such as a tin oxide (SnO 2 ). Here, when the material of the first nanowire  110  is Pt and the material of the second nanowire  150  is tin oxide (SnO 2 ), the suspended type nanowire array according to the first embodiment of the present invention can be used as a gas sensor. 
         [0056]    The insulating member  130  is disposed between the first nanowire  110  and the second nanowire  150 . 
         [0057]    The insulating member  130  is disposed on the first nanowire  110 , and the second nanowire  150  is disposed on the insulating member  130 . While the first nanowire  110  and the second nanowire  150  are electrically insulated from each other by the insulating member  130 , the insulating member  130  is able to thermally conduct heat radiated from the first nanowire  110  to the second nanowire  150  or conduct heat radiated from the second nanowire  150  to the first nanowire  110 . 
         [0058]    The insulating member  130  may have, as shown in  FIG. 3 , a shape of a wire. That is, the insulating member  130  may be an insulating wire. The length of the insulating member  130  may be less than that of the first nanowire  110  and may be the same as that of the second nanowire  150 . Also, the length of the insulating member  130  may be less than that of the first nanowire  110  and may be greater than that of the second nanowire  150 . 
         [0059]    The insulating member  130  may cover an upper portion of the first nanowire  110 . In other words, the insulating wire  130  may be disposed on the entire top surface and a portion of the side of the first nanowire  110 . Also, the second nanowire  150  may be disposed on the top surface of the insulating wire  130 . 
         [0060]    The first nanowire  110  may be a nano heat radiator which radiates heat. When the first nanowire  110  radiates heat, the heat radiated from the first nanowire  110  is conducted to the second nanowire  150  through the insulating wire  130 . Therefore, the second nanowire  150  may be heated to a high temperature by the first nanowire  110 . Meanwhile, contrary to this, the second nanowire  150  may be a nano heat radiator which radiates heat, and the first nanowire  110  may be heated to a high temperature by the second nanowire  150 . 
         [0061]    Meanwhile, the insulating member  130  may have a thin film shape. This will be described in detail with reference to  FIG. 4 . 
         [0062]      FIG. 4  is a cross sectional view of a suspended type nanowire  100 ′, i.e., a modified example of the suspended type nanowire  100  shown in  FIG. 3 . 
         [0063]    Referring to  FIG. 4 , the suspended type nanowire  100 ′ includes the first nanowire  110 , an insulating member  130 ′, and the second nanowire  150 . The first nanowire  110  and the second nanowire  150  are the same as the first nanowire  110  and the second nanowire  150  shown in  FIG. 3 . 
         [0064]    The insulating member  130 ′ has a structure different from that of the insulating member  130  shown in  FIG. 3 . 
         [0065]    The insulating member  130 ′ may be an insulating thin film. The insulating thin film  130 ′ may be disposed between a plurality of the first nanowires  110  and a plurality of the second nanowires  150 . 
         [0066]    The insulating thin film  130 ′ may have a predetermined thickness and may include a first convex portion which is upwardly convex and a second convex portion which is downwardly convex. The first convex portion is disposed on the first nanowire  110 , and the second convex portion may be disposed between two adjacent first nanowires  110 . The insulating thin film  130 ′ provides electrical insulation not only between the first nanowire  110  and the second nanowire  150  but also between the first nanowire  110  and another second nanowire  150  located diagonally with respect to the first nanowire  110 . Therefore, the suspended type nanowire array can be more stably driven. 
         [0067]    Referring back to  FIGS. 1 to 3 , a plurality of the above-described suspended type nanowires  100  may be provided. The plurality of suspended type nanowires  100  may be disposed apart from each other at a predetermined interval. Here, it means that the predetermined interval between the two adjacent nanowires  100  is less an interval in which a temperature of one suspended type nanowire is affected by the temperature of another suspended type nanowire. This will be described in more detail with reference to  FIGS. 5 and 6 . 
         [0068]      FIG. 5  is a view for describing a temperature difference due to a predetermined interval between the plurality of suspended type nanowires  100  shown in  FIG. 1 . 
         [0069]    A case where a temperature of one first nanowire  110  is not affected by the temperature of another adjacent first nanowire is shown in (a) of  FIG. 5 . A case where a temperature of one first nanowire  110  is affected by the temperature of another adjacent first nanowire is shown in (b) of  FIG. 5 . In (a) and (b) of  FIG. 5 , it is assumed that the first nanowires  110  are all heated to the same temperature. 
         [0070]    Referring to (a) and (b) of  FIG. 5 , when a predetermined interval between the two adjacent first nanowires  110  is, as shown in (b) of  FIG. 5 , less than an interval in which a temperature of one first nanowire is affected by the temperature of another first nanowire, a temperature higher than the temperature of (a) of  FIG. 5  can be obtained. This is based on a phenomenon in which the heat radiated from each of the first nanowires  110  are constructed and overlapped. 
         [0071]      FIG. 6  shows a relative temperature distribution according to a duty ratio between the plurality of suspended type nanowires  100  shown in  FIG. 1  and a relative temperature distribution according to a duty ratio between typical substrate attachment type nanowires. 
         [0072]    In  FIG. 6 , the ten first nanowires  110  shown in  FIG. 1  are used and the ten first nanowires  110  are assumed to consume the same amount of power. The material of the first nanowire  110  is palladium, and the width of the first nanowire  110  is 50 nm. 
         [0073]    For reference,  FIG. 6  shows a temperature distribution of the cross-section formed by cutting the first nanowire  110  shown in  FIG. 1 . Only the ambient temperatures of the first nanowire  110  are distinguished by colors. 
         [0074]    When a sum of the width of the first nanowire  110  and the interval between the two adjacent first nanowires  110  is assumed to be 100%, the duty ratio shown in  FIG. 6  means a ratio of the width of the first nanowire  110  to the sum. The duty ratio of 50% means that the width of the first nanowire  110  is the same as the interval between the two adjacent first nanowires  110 . The duty ratio of 10% means that when the width of the first nanowire  110  is 50 nm, the interval between the two adjacent first nanowires  110  is 450 mm. 
         [0075]    Referring to  FIG. 6 , it can be found that the relative temperature distribution of the suspended type nanowires is higher than the relative temperature distribution of the substrate attachment type nanowires. It can be also found that when the duty ratio between the first nanowires is greater than 2.5%, a temperature of one first nanowire is affected by the temperature of another adjacent first nanowire. 
         [0076]    Referring back to  FIGS. 1 to 3 , the plurality of suspended type nanowires  100  may be divided into a first group G 1  and a second group G 2 . Each of the first and the second groups G 1  and G 2  may include at least one suspended type nanowire  100 . 
         [0077]    One end of the first nanowire  110  of each of the suspended type nanowires  100  included in the first group G 1  is connected to the first electrode  300   a  of the first electrode portion  300 . The other end of the first nanowire  110  is suspended above the substrate  10 . 
         [0078]    One end of the first nanowire  110  of each of the suspended type nanowires  100  included in the second group G 2  is connected to the second electrode  300   b  of the first electrode portion  300 . The other end of the first nanowire  110  is suspended above the substrate  10 . 
         [0079]    The first suspended type electrode  700   a  disposed on the other end of the first nanowire  110  of each of all of the suspended type nanowires  100 . The first nanowires  110  of the suspended type nanowires  100  included in the first group G 1  may be electrically connected to the first nanowires  110  of the suspended type nanowires  100  included in the second group G 2  by the first suspended type electrode  700   a . A current which is input through the first electrode  300   a  of the first electrode portion  300  may sequentially flow into the second electrode  300   b  of the first electrode portion  300  through the first nanowires  110  of the suspended type nanowires  100  included in the first group G 1 , the first suspended type electrode  700   a , and the first nanowires  110  of the suspended type nanowires  100  included in the second group G 2 . 
         [0080]    Meanwhile, one end of the second nanowire  150  of each of the suspended type nanowires  100  included in the first group G 1  is electrically connected to the first electrode  500   a  of the second electrode portion  500 . The other end of the second nanowire  150  is suspended above the substrate  10 . 
         [0081]    Here, the one end of the second nanowire  150  may be electrically connected to the first electrode  500   a  of the second electrode portion  500  through the extension electrode  510   a  of the first electrode  500   a  of the second electrode portion  500 . One end of the extension electrode  510   a  is connected to the first electrode  500   a , and the other end of the extension electrode  510   a  is disposed on one end of the second nanowire  150  of each of the suspended type nanowires  100  included in the first group G 1 . 
         [0082]    One end of the second nanowire  150  of each of the suspended type nanowires  100  included in the second group G 2  is electrically connected to the second electrode  500   b  of the second electrode portion  500 . The other end of the second nanowire  150  is suspended above the substrate  10 . 
         [0083]    Here, the one end of the second nanowire  150  may be electrically connected to the second electrode  500   b  of the second electrode portion  500  through the extension electrode  510   b  of the second electrode  500   b  of the second electrode portion  500 . One end of the extension electrode  510   b  is connected to the second electrode  500   b , and the other end of the extension electrode  510   b  is disposed on one end of the second nanowire  150  of each of the suspended type nanowires  100  included in the second group G 2 . 
         [0084]    The second suspended type electrode  700   b  disposed on the other end of the second nanowire  150  of each of all of the suspended type nanowires  100 . The second nanowire  150  of the suspended type nanowires  100  included in the first group G 1  may be electrically connected to the second nanowire  150  of the suspended type nanowires  100  included in the second group G 2  by the second suspended type electrode  700   b . A current which is input through the first electrode  500   a  of the second electrode portion  500  may sequentially flow into the second electrode  500   b  of the second electrode portion  500  through the second nanowires  150  of the suspended type nanowires  100  included in the first group G 1 , the second suspended type electrode  700   b , and the second nanowires  150  of the suspended type nanowires  100  included in the second group G 2 . 
         [0085]    As such, in the suspended type nanowire  100 , since the insulating member  130  is located between the first nanowire  110  and the second nanowire  150 , the first nanowire  110  and the second nanowire  150  can have mutually independent electrical paths. 
         [0086]    The first electrode portion  300  may be disposed on the protrusion  10   b  of the substrate  10  and may include the first electrode  300   a  and the second electrode  300   b.    
         [0087]    The first electrode  300   a  may be disposed on the third protrusion  10   bc  among the first to the fourth protrusions  10   ba ,  10   bb ,  10   bc , and  10   bd  arranged in a line. The second electrode  300   b  may be disposed on the second protrusion  10   bb.    
         [0088]    The first electrode  300   a  may be a positive (+) electrode and the second electrode  300   b  may be a negative (−) electrode. Contrary to this, the first electrode  300   a  may be a negative (−) electrode and the second electrode  300   b  may be a positive (+) electrode. 
         [0089]    The first electrode  300   a  is connected to one end of the first nanowire  110  of the suspended type nanowire  100  included in the first group G 1 . Here, one side of the first electrode  300   a  may be connected to one end of the first nanowire  110 . 
         [0090]    The second electrode  300   b  is connected to one end of the first nanowire  110  of the suspended type nanowire  100  included in the second group G 2 . Here, one side of the second electrode  300   b  may be connected to one end of the first nanowire  110 . 
         [0091]    The second electrode portion  500  may be disposed on the protrusion  10   b  of the substrate  10  and may include the first electrode  500   a  and the second electrode  500   b.    
         [0092]    The first electrode  500   a  may be disposed on the fourth protrusion  10   bd  among the first to the fourth protrusions  10   ba ,  10   bb ,  10   bc , and  10   bd  arranged in a line. The second electrode  500   b  may be disposed on the first protrusion  10   ba.    
         [0093]    The first electrode  500   a  may be a positive (+) electrode and the second electrode  500   b  may be a negative (−) electrode. Contrary to this, the first electrode  500   a  may be a negative (−) electrode and the second electrode  500   b  may be a positive (+) electrode. 
         [0094]    The first electrode  500   a  is electrically connected to one end of the second nanowire  150  of the suspended type nanowire  100  included in the first group G 1 . Here, first electrode  500   a  may include the extension electrode  510   a  which is connected to one end of the second nanowire  150 . One end of the extension electrode  510   a  may be connected to the first electrode  500   a , and the other end of the extension electrode  510   a  may be connected to one end of the second nanowire  150  by being disposed on one end of the second nanowire  150 . The extension electrode  510   a  may be made of a material the same as that of the first electrode  500   a , together with the first electrode  500   a . Since the extension electrode  510   a  is suspended above the substrate  10 , the extension electrode  510   a  can be designated as a suspended type electrode of the first electrode  500   a.    
         [0095]    The second electrode  500   b  is electrically connected to one end of the second nanowire  150  of the suspended type nanowire  100  included in the second group G 2 . Here, second electrode  500   b  may include the extension electrode  510   b  which is connected to one end of the second nanowire  150 . One end of the extension electrode  510   b  may be connected to the second electrode  500   b , and the other end of the extension electrode  510   b  may be connected to one end of the second nanowire  150  by being disposed on one end of the second nanowire  150 . The extension electrode  510   b  may be made of a material the same as that of the second electrode  500   b , together with the second electrode  500   b . Since the extension electrode  510   b  is suspended above the substrate  10 , the extension electrode  510   b  can be designated as a suspended type electrode of the second electrode  500   b.    
         [0096]    The suspended type electrode portion  700  may be disposed on the suspended type nanowires  100  and may include the first suspended type electrode  700   a  and the second suspended type electrode  700   b.    
         [0097]    Since the suspended type electrode portion  700  is disposed on the suspended type nanowires  100 , the suspended type electrode portion  700  is suspended above the substrate  10 . 
         [0098]    Each of the first suspended type electrode  700   a  and the second suspended type electrode  700   b  may have a flat plate shape which extends in a direction perpendicular to a longitudinal direction of the suspended type nanowire  100 . 
         [0099]    The first suspended type electrode  700   a  is connected to the other end of the first nanowire  110  by being disposed on the other end of the first nanowire  110  of each of all of the suspended type nanowires  100 . 
         [0100]    The second suspended type electrode  700   b  is connected to the other end of the second nanowire  150  by being disposed on the other end of the second nanowire  150  of each of all of the suspended type nanowires  100 . 
         [0101]      FIGS. 7 to 11  are views for describing a method for manufacturing the suspended type nanowire array according to the first embodiment of the present invention shown in  FIG. 1 . 
         [0102]    Referring to  FIG. 7 , the first nanowire  110  is formed on a nanograting substrate  10 A by using a photolithographic technique. 
         [0103]    The photolithographic technique corresponds to a general photolithographic technique which is used in a semiconductor process. 
         [0104]    The first nanowire  110  is formed on a predetermined number of protrusions  11  of the nanograting substrate  10 A by using the photolithographic technique. By using a shadowing effect of the protrusion  11 , the wire-shaped first nanowire  110  can be easily formed by simple deposition or oblique deposition. 
         [0105]      FIG. 8  is a cross-sectional TEM image showing the first nanowire  110  formed on the nanograting substrate  10 A by oblique deposition. Referring to  FIG. 8 , the first nanowire is disposed on the protrusion of the nanograting substrate. The first nanowire may be disposed on the top surface of the protrusion and on the upper portion of the side of the protrusion by oblique deposition. 
         [0106]    All of future patterning processes can be more simplified by using a shadow mask instead of photolithography. 
         [0107]    Next, referring to  FIG. 9 , the insulating member  130  and the second nanowire  150  are sequentially deposited on the first nanowire  110  by using the photolithographic technique. Specifically, the insulating member  130  is formed on the entire top surface and a portion of the side of the first nanowire  110  by using the photolithographic technique, and then the second nanowire  150  is formed on the insulating member  130 . Also, in the formation of the second nanowire  150 , the second nanowire  150  is not intended to be directly connected to the first nanowire  110 . 
         [0108]    The method for forming the insulating member  130  and the second nanowire  150  uses simple deposition or oblique deposition. Therefore, it is possible to manufacture nanowires made of various materials if necessary. 
         [0109]    Next, referring to  FIG. 10 , the first electrode portion  300  which is electrically connected to the first nanowire  110 , the second electrode portion  500  which is electrically connected to the second nanowire  150 , and the docking electrode portion  700  are formed by using a patterning technique or a shadow mask technique. 
         [0110]    Here, it is desirable that the docking electrode portion  700  to be suspended for a stress resistant structure should be manufactured to have a sufficiently small width, so that the material located at the lower portion of the docking electrode portion  700  is intended to be removed by isotropic etching. 
         [0111]    Since the first electrode portion  300 , the second electrode portion  500 , and the docking electrode portion  700  are formed by using a patterning technique or a shadow mask technique, there is an advantage in that the suspended type nanowire array arranged simultaneously with the manufacture thereof can be immediately used in the manufacture of a device without a separate additional process. Meanwhile, the conventional substrate attachment type nanowire is manufactured by an existing common chemical synthesis, it is complicated to transfer the substrate attachment type nanowire to a substrate which is used to manufacture the device. However, the manufacturing method according to the embodiment of the present invention does not include the above-mentioned complicate process. 
         [0112]    Lastly, the nanograting substrate  10 A shown in  FIG. 10  is etched by a predetermined thickness from the top surface to the bottom surface, so that the substrate  10  including the top surface  10   a  and the protrusion  10   b  is, as shown in  FIG. 11 , formed. 
         [0113]    The etching method may include a chemical etching method. Since the first nanowire  110  has a sufficiently small width, a slight isotropic etching which inevitably exists is enough to completely remove the material located at the lower portion of the first nanowire  110 . 
         [0114]    The first electrode portion  300 , the second electrode portion  500 , and the docking electrode portion  700  function as a mask during the etching process. Therefore, a separate patterning process is not required. The docking electrode portion  700  is suspended by etching the nanograting substrate  10 A. 
         [0115]    Through the manufacturing method shown in  FIGS. 7 to 11 , it is possible to manufacture the suspended type nanowire array with a highly advanced structure only by using a semiconductor process technology. Therefore, the manufacturing method has a high productivity, so that the suspended type nanowire array can be mass-produced and manufactured by a batch process. 
         [0116]    Also, due to the characteristics of the nanograting-based nanowire manufacturing method using simple deposition, nanowires made of various materials can be used in a variety of electronic devices requiring operations at high temperature. 
         [0117]    Also, hundreds and thousands of the completely arranged suspended type nanowires are used, so that measured detection signals are leveled and high reliability is obtained. 
         [0118]    Also, the length or area of the suspended type nanowire array is precisely controlled in a unit of several micrometers. 
       Second Embodiment 
       [0119]      FIG. 12  is a perspective view of a suspended type nanowire array according to a second embodiment of the present invention. 
         [0120]    Referring to  FIG. 12 , the suspended type nanowire array according to the second embodiment of the present invention may include a substrate  10 ′, the suspended type nanowire  100 , a first electrode portion  300 ′, a second electrode portion  500 ′. 
         [0121]    The suspended type nanowire array according to the second embodiment is different from the suspended type nanowire array according to the first embodiment shown in  FIG. 1  in that suspended type nanowire array according to the second embodiment does not include the suspended type electrode portion  700  shown in  FIG. 1 . Additionally, there are also differences in the structure of the substrate  10 ′, the position of the first electrode portion  300 ′, and the position of the second electrode portion  500 ′. 
         [0122]    The substrate  10 ′ includes a top surface  10   a ′ and the first to the fourth protrusions  10   ba ′,  10   bb ′,  10   bc ′, and  10   bd ′ disposed on the top surface  10   a′.    
         [0123]    The first protrusion  10   ba ′ and the second protrusion  10   bb ′ are disposed on one side of the top surface  10   a ′ in a line. The third protrusion  10   bc ′ and the fourth protrusion  10   bd ′ are disposed on the other side of the top surface  10   a ′ in a line. The second protrusion  10   bb ′ and the third protrusion  10   bc ′ are disposed opposite to each other. Here, while  FIG. 12  shows that the first protrusion  10   ba ′ and the fourth protrusion  10   bd ′ are not disposed opposite to each other, the first protrusion  10   ba ′ and the fourth protrusion  10   bd ′ are not limited to this. The first protrusion  10   ba ′ and the fourth protrusion  10   bd ′ may be also disposed opposite to each other. 
         [0124]    The first electrode portion  300 ′ includes a first electrode  300   a ′ and a second electrode  300   b′.    
         [0125]    The first electrode  300   a ′ is disposed on the third protrusion  10   bc ′, and the second electrode  300   b ′ is disposed on the second protrusion  10   bb′.    
         [0126]    The first electrode  300   a ′ is connected to one end of the first nanowire  110  of the suspended type nanowire  100 , and the second electrode  300   b ′ is connected to the other end of the first nanowire  110  of the suspended type nanowire  100 . The suspended type nanowire  100  can be suspended above the substrate  10 ′ by the first electrode  300   a ′ and the second electrode  300   b′.    
         [0127]    The first electrode  300   a ′ may be a positive (+) electrode and the second electrode  300   b ′ may be a negative (−) electrode, and vice versa. 
         [0128]    The second electrode portion  500 ′ includes a first electrode  500   a ′ and a second electrode  500   b′.    
         [0129]    The first electrode  500   a ′ is disposed on the fourth protrusion  10   bd ′, and the second electrode  500   b ′ is disposed on the first protrusion  10   ba′.    
         [0130]    The first electrode  500   a ′ is electrically connected to one end of the second nanowire  150  of the suspended type nanowire  100 , and the second electrode  500   b ′ is electrically connected to the other end of the second nanowire  150  of the suspended type nanowire  100 . 
         [0131]    The first electrode  500   a ′ may include an extension electrode  510   a ′ which is electrically connected to one end of the second nanowire  150  of the suspended type nanowire  100 . One end of the extension electrode  510   a ′ may be connected to the first electrode  500   a ′, and the other end of the extension electrode  510   a ′ may be connected to the second nanowire  150  by being disposed on one end of the second nanowire  150  of the suspended type nanowire  100 . 
         [0132]    The second electrode  500   b ′ may include an extension electrode  510   b ′ which is electrically connected to the other end of the second nanowire  150  of the suspended type nanowire  100 . One end of the extension electrode  510   b ′ may be connected to the second electrode  500   b ′, and the other end of the extension electrode  510   b ′ may be connected to the second nanowire  150  by being disposed on the other end of the second nanowire  150  of the suspended type nanowire  100 . 
         [0133]    The first electrode  500   a ′ may be a positive (+) electrode and the second electrode  500   b ′ may be a negative (−) electrode, and vice versa. 
         [0134]    The suspended type nanowire  100  of the suspended type nanowire array according to the second embodiment has the same structure as that of the suspended type nanowire  100  of the suspended type nanowire array according to the first embodiment shown in  FIG. 1 . However, the connection structure to the first electrode portion  300 ′ of the second embodiment is different from that of the first embodiment. 
         [0135]    Specifically, one end of the suspended type nanowire  100  of the suspended type nanowire array according to the second embodiment is connected to the first electrode  300   a ′ of the first electrode portion  300 ′, and the other end of the suspended type nanowire  100  of the suspended type nanowire array according to the second embodiment is connected to the second electrode  300   b ′ of the first electrode portion  300 ′. 
         [0136]    In the structure of the suspended type nanowire array according to the second embodiment, the same parts as the structure of the suspended type nanowire array according to the first embodiment can provide the same technical effect as that of the suspended type nanowire array according to the first embodiment. 
         [0137]      FIG. 13  is an actual electron microscope photograph showing the suspended type nanowire  100  shown in  FIG. 1 or 12 . 
         [0138]    While the embodiment of the present invention has been described with reference to the accompanying drawings, these are just examples and do not limit the present invention. Further, the present invention may be changed and modified in various ways, without departing from the essential features of the present invention, by those skilled in the art. For example, the components described in detail in the embodiments of the present invention may be modified.