Abstract:
Provided is an inductor. The inductor includes a first to a fourth conductive terminals formed in one direction within a semiconductor substrate, a first conductive line formed on one side of the semiconductor substrate and electrically connected to the second and third conductive terminals interiorly positioned among the first to fourth conductive terminals, a second conductive line formed on the one side of the semiconductor substrate and electrically connected to the first and fourth conductive terminals exteriorly positioned among the first to fourth conductive terminals, and a third conductive line formed on the other side of the semiconductor substrate and electrically connected to the first and third conductive terminals among the first to fourth conductive terminals.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This U.S. non-provisional patent application claims priority under 35 U.S.C. §119 of Korean Patent Application No. 10-2009-0124720, filed on Dec. 15, 2009, the entire contents of which are hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     The present invention disclosed herein relates to an inductor, and more particularly, to an inductor implementable on a semiconductor substrate. 
     An inductor is one of the most important components for an electric circuit with a resistor, a capacitor, a transistor and a power source. The inductor has a coil structure where copper or aluminum is wound many times as a screw form. The inductor suppresses a rapid change of a current by inducing the current in proportion to an amount of a current change. Herein, a ratio of counter electromotive force generated due to electromagnetic induction according to the change of the current flowing in a circuit is called an inductance (L). 
     Generally, the inductor is used for an Integrated Circuit (IC) and a Monolithic Microwave Integrated Circuit (MMIC) for communication. Particularly, a packaging technology for integrating many elements to a single chip is being developed with a recent advent of a technology related to a System on Chip (SoC). Accordingly, the inductor having a micro-structure and good characteristics is needed. Particularly, in the case of implementing the inductor on a single wafer, the inductor floated on a substrate is easily damaged by an external impact, has a low durability, and is difficult to be fabricated. 
     SUMMARY OF THE INVENTION 
     The present invention provides an inductor implemented on a small area with excellent characteristics. 
     Embodiments of the present invention provide inductors including a first to a fourth conductive terminals formed in one direction within a semiconductor substrate, a first conductive line formed on one side of the semiconductor substrate and electrically connected to the second and third conductive terminals interiorly positioned among the first to fourth conductive terminals, a second conductive line formed on the one side of the semiconductor substrate and electrically connected to the first and fourth conductive terminals exteriorly positioned among the first to fourth conductive terminals, and a third conductive line formed on the other side of the semiconductor substrate and electrically connected to the first and third conductive terminals among the first to fourth conductive terminals. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are included to provide a further understanding of the present invention, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present invention and, together with the description, serve to explain principles of the present invention. In the drawings: 
         FIG. 1  is a perspective view illustrating an inductor according to an embodiment of the present invention; 
         FIG. 2  is a cross-sectional view along a line of A-A′ of  FIG. 1 ; 
         FIG. 3  is a perspective view illustrating an inductor according to another embodiment of the present invention; 
         FIG. 4  is a cross-sectional view along a line of B-B′ of  FIG. 3 ; 
         FIG. 5  is a perspective view illustrating an inductor according to another embodiment of the present invention; 
         FIG. 6  is a perspective view illustrating an inductor according to another embodiment of the present invention; 
         FIG. 7  is a perspective view illustrating that upper and lower horizontal conductive units of the inductor of  FIG. 1  are formed as an arc shape; and 
         FIG. 8  is a perspective view illustrating that upper and lower horizontal conductive units of the inductor of  FIG. 3  are formed as an arc shape. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Preferred embodiments of the present invention will be described below in more detail with reference to the accompanying drawings 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. 
       FIG. 1  is a perspective view illustrating an inductor according to an embodiment of the present invention. 
     Referring to  FIG. 1 , an inductor  100  includes an input electrode unit  120 , an upper horizontal conductive unit  130 , first to fourth vertical conductive units  140 A to  140 D, first and second lower horizontal conductive units  150 A and  150 B, and an output electrode unit  160 . 
     The first vertical conductive unit  140 A is connected to the upper horizontal conductive unit  130  and the first lower horizontal conductive unit  150 A through a via hole of a substrate  110 . The second vertical conductive unit  140 B is connected to the input electrode unit  120  and the second lower horizontal conductive unit  150 B through the via hole of the substrate  110 . The third vertical conductive unit  140 C is connected to the upper horizontal conductive unit  130  and the second lower horizontal conductive unit  150 B through the via hole of the substrate  110 . The fourth vertical conductive unit  140 D is connected to the output electrode  160  and the second lower horizontal conductive unit  150 B through the via hole of the substrate  110 . The first to fourth vertical conductive units  140 A to  140 D provide one coil structure by connecting the upper horizontal conductive unit  130  to the first or second lower horizontal conductive unit  150 A or  150 B. 
     The substrate  110  directly contacts the first to fourth vertical conductive units  140 A to  140 D, the upper horizontal conductive unit  130 , and the first and second lower horizontal conductive units  150 A and  150 B. Accordingly, it is preferable that the substrate  110  has insulative characteristics. In the embodiment of the present invention, the substrate  110  may be formed with high resistant silicon. For another instance, the substrate  110  may have the insulative characteristics by performing an insulation process on its surface. The substrate  110  includes a plurality of via holes, and each via hole vertically penetrates a body of the substrate  110 . 
     The input electrode unit  120  and the output electrode unit  160  connect the inductor to a circuit on the same or an external substrate. In the embodiment of the present invention, the input electrode unit  120  and the output electrode unit  160  are exposed to an upper surface of the substrate  100 . However, as another example, the input electrode unit  120  and the output electrode unit  160  may be connected to a lower circuit through the via hole passing through the substrate  110 . The input electrode unit  120  and the output electrode unit  160  may be also exposed to the upper surface and a lower surface respectively. 
     The upper horizontal conductive unit  130  is formed on the upper surface of the substrate  110 . The first and second lower horizontal conductive units  150 A and  150 B are formed on the lower surface of the substrate  110 . The upper horizontal conductive unit  130 , the first and second lower horizontal conductive units  150 A and  150 B may be formed in a method of plating or deposition. For instance, in the case of the plating, the upper horizontal conductive unit  130 , the first and second lower horizontal conductive units  150 A and  150 B may be formed with copper (Cu) or gold (Au). 
     The upper horizontal conductive unit  130 , the first and second lower horizontal conductive units  150 A and  150 B are connected to the first to fourth vertical conductive units  140 A to  140 D to form a conductive path. 
     For instance, one end of the upper horizontal conductive unit  130  is connected to one end of the first lower horizontal conductive unit  150 A through the first vertical conductive unit  140 A. The other end of the lower horizontal conductive unit  150 A is connected to the fourth vertical conductive unit  140 D to form the conductive path. Also, the other end of the upper horizontal conductive unit  130  is connected to one end of the second lower horizontal conductive unit  150 B through the third vertical conductive unit  140 C. The other end of the second lower horizontal conductive unit  150 B is connected to the second vertical conductive unit  140 B to form the conductive path. 
     In the embodiment of the present invention, lengths of the first lower horizontal conductive unit  150 A and the second lower horizontal conductive unit  150 B are different from each other. This is for minimizing an area where the inductor  100  is formed on the substrate  110 . That is, by positioning the second lower horizontal conductive unit  150 B at an inner side of the first lower horizontal conductive unit  150 A, the area where the inductor is formed may be minimized. 
     For instance, referring to  FIG. 1 , it is assumed that the first to fourth vertical conductive units  140 A to  140 D penetrate the body of the substrate  110  in a row. In this case, the first lower conductive unit  150 A connects the first and fourth vertical conductive units  140 A and  140 D separated from each other to form the conductive path. Also, the second lower conductive unit  150 B connects the second and third vertical conductive units  140 B and  140 C adjacent to each other to form the conductive path. Accordingly, the lengths of the first and second lower horizontal conductive units  150 A and  150 B may be different from each other. 
     The first to fourth vertical conductive units  140 A to  140 D are formed within the via hole of the substrate  110 . The first vertical conductive unit  140 A connects the upper horizontal conductive unit  130  and the first lower horizontal conductive unit  150 A to form the conductive unit. The second vertical conductive unit  140 B connects the second lower horizontal conductive unit  150 B and the input electrode  120  to form the conductive path. The third vertical conductive unit  140 C connects the upper horizontal conductive unit  130  and the second lower horizontal conductive unit  150 B to form the conductive path. The fourth vertical conductive unit  140 D connects the first lower horizontal conductive unit  150 A and the output electrode  160  to form the conductive path. 
     The first to fourth vertical conductive units  140 A to  140 D may be formed in the method of plating or deposition. In the case of the method of plating, the first to fourth vertical conductive units  140 A to  140 D may be formed with the copper (Cu) or the gold (Au). 
     In the embodiment of the present invention, the first to fourth vertical conductive units  140 A and  140 D may be arranged in a row at regular intervals. This is for minimizing the area where the inductor  100  is formed on the substrate  110 . That is, by using the first to fourth vertical conductive units  140 A and  140 D arranged in a row, the inductor  100  may be formed using small size of the substrate. 
     Meanwhile, in the embodiment of the present invention, the inductor  100  may be fabricated in various methods. For instance, the upper horizontal conductive unit  130  and the input and output electrodes  120  and  160  are formed on the upper surface of the substrate firstly. Thereafter, the plurality of via holes are formed in the body of the substrate  110 . Thereafter, by filling the via holes with conductive material, the first to fourth vertical conducive units  140 A to  140 D are formed. After the first to fourth vertical conducive units  140 A to  140 D are formed, the first and second lower horizontal conductive unit  150 A and  150 B are formed on the lower surface of the substrate  110 . 
       FIG. 2  is a cross-sectional view along a line of A-A′ of  FIG. 1 . 
     Referring to  FIG. 2 , the upper horizontal conductive unit  130  and the input and output electrodes  120  and  130  are formed at the same layer on the substrate  110 . Also, the first to fourth vertical conducive units  140 A to  140 D are arranged in a row at regular intervals along the line of A-A′. 
     The first vertical conductive unit  140 A penetrates the body of the substrate  110  and connects the upper horizontal conductive unit  130  and the first lower horizontal conductive unit  150 A. The second vertical conductive unit  140 B penetrates the body of the substrate  110  and connects the input electrode unit  120  and the second lower horizontal conductive unit  150 B. The third vertical conductive unit  140 C penetrates the body of the substrate  110  and connects the upper horizontal conductive unit  130  and the second lower horizontal conductive unit  150 B. The fourth vertical conductive unit  140 D penetrates the body of the substrate  110  and connects the output electrode  160  and the first lower horizontal conductive unit  150 A. 
       FIG. 3  is a perspective view illustrating an inductor according to another embodiment of the present invention. A structure of an inductor  200  of  FIG. 3  is similar to that of the inductor  100  of  FIG. 1 . Accordingly, differences between them will be described in detail below. 
     Referring to  FIG. 3 , the inductor  200  includes a substrate  210 , an input electrode unit  220 , an upper horizontal conductive unit  230 , first to fourth vertical conductive units  240 A to  240 D, first and second lower horizontal conductive units  250 A and  250 B, and an output electrode unit  260 . Unlike the inductor  100  of  FIG. 1 , the input and output electrode units  220  and  260  and the upper horizontal conductive unit  230  are positioned at different layers. This will be described more clearly referring to  FIG. 4  below. 
       FIG. 4  is a cross-sectional view along a line of B-B′ of  FIG. 3 . 
     Referring to  FIG. 4 , the inductor  200  further includes an insulating layer  211  unlike the inductor  100  of  FIG. 1 . The upper horizontal conductive unit  230  and the input and output electrodes  220  and  260  are formed at different layers. 
     In detail, the insulating layer  211  is formed on the substrate  210 . The upper horizontal conductive layer  230  is formed within the insulating layer  211 , and the input and output electrode units  220  and  260  are formed on the insulating layer  211 . Accordingly, the upper horizontal conductive unit  230  and the input and output electrode units  220  and  260  are electrically separated from each other by the insulating layer  211 . Also, since the insulating layer  211  serves as a protection layer, the upper horizontal conductive layer  230  may be protected. 
     Meanwhile, in the other embodiment of the present invention, the insulating layer  211  includes material having insulative characteristics. For instance, the insulating layer  211  may be TEOS/BPSG. For another example, the insulating layer  211  may have a structure of SiO 2 /SOG/SiO 2 . 
       FIG. 5  is a perspective view illustrating an inductor according to another embodiment of the present invention. An inductor  300  of  FIG. 5  has a structure repeating the structure of the inductor  100  of  FIG. 1  several times. Therefore, differences between them will be described in detail. 
     Referring to  FIG. 5 , the inductor  300  includes a substrate  310 , an input electrode unit  320 , first and second upper horizontal conductive units  330 A and  330 B, a connection conductive unit  331 , first to eighth vertical conductive units  340 A and  340 H, first to fourth lower horizontal conductive units  350 A to  350 D, and an output electrode unit  360 . 
     In detail, the first and second upper horizontal conductive units  330 A and  330 B and the first to fourth lower horizontal conducive units  350 A to  350 D are formed on an upper surface and a lower surface of the substrate  310  respectively. in this case, the structures of the first and second upper horizontal conducive units  330 A and  330 B and the structures of the first to fourth lower horizontal conductive units  350 A to  350 D are repeated structures of the upper horizontal conductive unit  130  and the first and second lower horizontal conductive units  150 A and  150 B respectively. 
     However, the inductor  300  of  FIG. 5  further includes the connection conductive unit  331  for connecting the first upper horizontal conductive unit  330 A and the second upper horizontal conducive unit  330 B in series. The connection conductive unit  331  is formed in the same method of forming the first and second upper horizontal conductive units  330 A and  330 B. Also, the connection conductive unit  331  is positioned at the same layer with the first and second upper horizontal conductive units  330 A and  330 B. 
     The first to eighth vertical conductive units  340 A to  340 H are formed within the via hole of the substrate  310 . For instance, the first to fourth vertical conductive units  340 A to  340 D arranged in a row and the fifth to eighth vertical conductive units  340 E to  340 H parallel to them are formed at the substrate  310 . 
     The first to eighth vertical conductive units  340 A to  340 H connect the first and second upper horizontal conductive units  330 A and  330 B to the first to fourth lower horizontal conductive units  350 A to  350 D to form the conductive path. Also, the second and sixth vertical conductive units  340 B and  340 F are connected to each other by the connection conductive unit  331  to form the conductive path. 
       FIG. 6  is a perspective view illustrating an inductor according to another embodiment of the present invention. An inductor  400  of  FIG. 6  has a structure repeating the structure of the inductor  200  of  FIG. 3  several times. Therefore, the structure of the inductor  400  of  FIG. 6  is similar to that of the inductors  200  and  300  of  FIGS. 3 and 5 . Accordingly, differences between them will be described in detail below. 
     The inductor  400  of  FIG. 6  includes a connection conductive unit  431  for connecting the upper horizontal conductive unit  230  of  FIG. 3  in series like the inductor  300  of  FIG. 5 . However, unlike the connection conductive unit  331  of FIG.  5 , the connection conductive unit  431  of  FIG. 6  is positioned at a different layer from the first and second upper horizontal conductive units  430 A and  430 B. That is, referring to  FIG. 6 , the connection conductive unit  431  is positioned at the same layer with the input and output electrode units  420  and  460 . This indicates that the connection conductive unit  431  is electrically separated from the first and second upper horizontal conductive units  430 A and  430 B by the insulating layer. This is similar to the above-description for  FIG. 3 , and thus detailed explanations are omitted. 
     Meanwhile, in another embodiment of the present invention, the upper and lower horizontal conductive units may be formed as an arc shape. For instance,  FIG. 7  is a perspective view illustrating that the upper and lower horizontal conductive units of the inductor of  FIG. 1  are formed as the arc shape. For another example,  FIG. 8  is a perspective view illustrating that the upper and lower horizontal conductive units of the inductor of  FIG. 3  are formed as the arc shape. In this case, cross-sections of the inductors of  FIGS. 7 and 8  are similar to  FIGS. 2 and 4 . 
     According to the present invention, the inductor can be implemented on a small-sized semiconductor substrate. Further, the inductor has an excellent durability against an external impact. 
     The above-disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments, which fall within the true spirit and scope of the present invention. Thus, to the maximum extent allowed by law, the scope of the present invention is to be determined by the broadest permissible interpretation of the following claims and their equivalents, and shall not be restricted or limited by the foregoing detailed description.