KR100218676B1 - Spiral inductor structure - Google Patents

Abstract

The present invention relates to a structure of a spiral inductor. In a spiral inductor formed of a multilayer metal wiring of two or more layers, a first metal wiring among the two selected metal wirings is arranged in a spiral form, The inductance and the self resonant frequency can be increased by disposing the second metal interconnection in the form of a spiral and by arranging the second metal interconnection in the form of a spiral so that the second metal interconnection is located between the patterns of the first metal interconnection, And parasitic capacitance can be reduced. Further, in a spiral inductor formed of three or more multilayer metal wirings, the first metal wiring among the three selected metal wirings is arranged in a straight line, and the second metal wiring and the third metal wiring are formed in a spiral form It is possible to increase the inductance by forming the number of revolutions twice or more in the same area.

Description

Structure of the spiral inductor

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a spiral inductor, and particularly to a structure of a spiral inductor having a large inductance and small area and excellent performance.

Although attempts have been made to implement an inductor on a silicon substrate by using a conventional integrated circuit manufacturing method, a large loss of electromagnetic wave due to conductivity of the silicon substrate is large, and a large inductance is generated due to the resistance of the metal line and the parasitic component of the substrate. It is difficult to realize a spiral inductor having excellent performance.

The structure of a conventional spiral inductor will now be described with reference to FIGS. 1 and 2. FIG. Figs. 1 and 2 show a stereo diagram and a layout of a conventional spiral inductor. Fig. A spiral inductor is a spiral inductor having a circular or rectangular shape.

1A and 1B are a three-dimensional view and a layout view of a spiral inductor using a conventional air bridge process. The first metal wires 11 are spirally arranged and the air bridge metal 12 is configured as an inductor center terminal using an air bridge process.

2A and 2B are a three-dimensional view and a layout view of a spiral inductor using a conventional via process. The first metal interconnection 21 is linearly arranged on the inductor center terminal and the first contact 23 is formed in the selected region. And a second metal wiring 22 is spirally arranged on the first contact 23.

The inductance of a spiral inductor is determined by the number of turns of the inductor, the innerdiameter, and the width of the metal wiring. The inductance of the spiral inductor is sensitive to the number of turns. In order to reduce the parasitic resistance, which is one of the problems of the spiral inductor, the width of the metal wiring must be designed to be wide. Therefore, a large area is required as the number of turns increases. Therefore, the area occupied by the spiral inductor in the IC chip is increasing, and the importance of the spiral inductor having a large inductance and small area and excellent performance is increasing.

In order to manufacture a spiral inductor which is applied to a monolithic radio frequency (RF) IC having a large inductance and small area and high performance, a number of turns of at least two times the same area is laid out The present invention provides a structure of a spiral inductor.

It is another object of the present invention to provide a structure of a high-performance spiral inductor capable of increasing the self-resonant frequency by reducing the parasitic capacitance of a multilayer metal substrate.

In order to achieve the above object, a structure of a spiral inductor according to a first embodiment of the present invention is a multi-layered spiral inductor using an integrated circuit manufacturing process having two or more metal wirings, wherein at least two metal The wiring lines are arranged so as to overlap in the same spiral manner with the insulating film sandwiched therebetween, or between the patterns of each other, and the respective metal wirings are arranged to be electrically connected by the contacts.

According to another aspect of the present invention, there is provided a multi-layered spiral inductor using an integrated circuit manufacturing process having three or more metal wirings, A second metal interconnection disposed on the first metal interconnection with the insulating film interposed therebetween and connected to the first metal interconnection through a first contact, and a second metal interconnection disposed on the second metal interconnection, And a third metal interconnection arranged so as to be connected to the second metal interconnection through a second contact with an insulating film interposed therebetween, in order to realize a maximum spiral rotation speed, the third metal interconnection is rotated 1 to 4 times And the third metal interconnection is connected to the third metal interconnection via the fourth contact after the second metal interconnection is rotated 1 to 4 times , And the third metal interconnection is rotated 1 to 4 times, and then connected to the second metal interconnection through the fifth contact and finally connected to the first metal interconnection.

FIGS. 1A and 1B are a three-dimensional view and layout of a spiral inductor using a conventional air bridge process. FIG.

FIGS. 2A and 2B are three-dimensional views and layouts of a spiral inductor using a conventional via process. FIG.

Figs. 3A and 3B are a three-dimensional view and a layout view of a spiral inductor according to the present invention; Fig.

FIGS. 4A and 4B are a three-dimensional view and a layout view of a spiral inductor according to the first embodiment of the present invention; FIG.

5A and 5B are a three-dimensional view and a layout view of a spiral inductor according to a second embodiment of the present invention.

DESCRIPTION OF THE REFERENCE NUMERALS

11, 21, 31, 41, 51: first metal wiring 12: air bridge metal

22, 32, 42, 52: second metal wiring 23, 33, 43, 53:

54: third metal wiring 55: second contact

56: third contact 57: fourth contact

The present invention will be described in detail with reference to the accompanying drawings.

FIG. 3A is a three-dimensional view of the spiral inductor according to the present invention, and FIG. 3B is a layout view of the spiral inductor. A spiral inductor in which the first metal interconnection 31 is rotated in the counterclockwise direction is disposed, and then the first contact 33 is disposed in the selected region. After the first contact 33 is disposed, the second metal wiring 32 is rotated counterclockwise so as to overlap with the first metal wiring 31 on the first metal wiring 31 to form a spiral inductor do. Such a structure can lay out a turn number twice or more in the same area as the conventional structure, so that it can have a large inductance. When this arrangement method is implemented as a multilayer metallization, various types of spiral inductors can be formed. For example, when a five-layer multilayer wiring process is performed with the structure proposed in the present invention, the second metal wiring and the third metal wiring of five layers, the third metal wiring and the fourth metal wiring, the fourth metal wiring, The first metal interconnection and the fourth metal interconnection, the first metal interconnection and the fifth metal interconnection, the second metal interconnection and the fourth metal interconnection, the first metal interconnection and the third metal interconnection, The second metal interconnection, the fifth metal interconnection, the third metal interconnection, and the fifth metal interconnection.

4A and 4B are a perspective view and a layout diagram of a spiral inductor according to a first embodiment of the present invention, similar to the method described in FIGS. 3A and 3B. However, the parasitic capacitance between the multi- Is a structure for increasing the self resonance frequency (f _wo ). The first metal interconnection 41 is rotated in the counterclockwise direction, and then the first inductor 43 is disposed. After the first contact 43 is disposed, the second metal wiring 42 is spirally arranged on the upper part between the spaces where the first metal wiring 41 passes. When this method is applied to a multilayer metallization, various types of spiral inductors can be formed. Such a structure can reduce the area of a flat plate capacitor between metal wirings.

5A and 5B are a perspective view and a layout view of a spiral inductor according to a second embodiment of the present invention, which is another method capable of laying out a large number of turns on the same area. After the first metal interconnection 51 is arranged linearly in the center of the inductor, the first contact 53 is arranged. A spiral inductor in the form of a second counter-clockwise rotation of the second metal interconnection 52 is disposed above the disposed first contact 53. After the second metal interconnection 52 is disposed, a plurality of contacts 55, 56, 57 are disposed. The third metal interconnection 54 is also rotated in a counterclockwise direction in a selected area above the plurality of contacts 55, 56 and 57 to form a spiral inductor. Here, the second metal interconnection 52 is helically arranged from the first contact 53 to the region where the second contact 55 is to be formed, and is arranged spirally from the third contact 56 to the fourth via hole 57 . At this time, the second contact 55 and the third contact 56 should not be shorted. In this way, the second metal interconnection 52 is formed up to the n-th contact. The third metal interconnection 54 is located on top of the second metal interconnection 52 and spirally arranged from the second contact 55 to the third contact 56. The third metal interconnection 54 is disposed spirally from the fourth contact, . At this time, the third contact and the fourth contact should not be short-circuited. In this way, the third metal interconnection 54 is spirally formed up to the n-th contact. Various structures of the spiral inductor can be formed by implementing such a structure in a multi-layer metal wiring of three or more layers. For example, when a six-layer multilayer wiring process is performed with such a structure, the first metal interconnection, the second metal interconnection and the third metal interconnection, the third metal interconnection, the fourth metal interconnection and the fifth metal interconnection, The fifth metal interconnection, the fifth metal interconnection, the fifth metal interconnection, and the sixth metal interconnection. The first metal interconnection, the fifth metal interconnection, the sixth metal interconnection, the first metal interconnection, Metal wiring, third metal wiring and fourth metal wiring, second metal wiring and fifth metal wiring, sixth metal wiring, second metal wiring and fourth metal wiring and fifth metal wiring, third metal wiring and fifth metal Wiring and the sixth metal interconnection. Such a structure can lay out a turn number twice or more in the same area as the conventional structure, so that it can have a large inductance.

As described above, according to the present invention, it is possible to increase the inductance and increase the self-resonant frequency by reducing the parasitic capacitance because the number of turns of the spiral inductor can be increased by two or more times. When a high-performance spiral inductor is fabricated on a silicon substrate by applying the structure according to the present invention, a low noise amplifier (LNA) having a frequency range of 1 to 2 GHz, a Personal Communication System (PCS) silicon RF ICs can be realized, and furthermore, there is an excellent effect of integrating digital ICs, analog ICs, and RF ICs in the same chip.

Claims (2)

In a multilayered spiral inductor using an integrated circuit manufacturing process having two or more metal wirings, at least two metal wirings of the multilayered metal wirings are overlapped in the same spiral manner with an insulating film sandwiched therebetween, or disposed between patterns of each other, And the metal wiring is arranged to be electrically connected by the contact. A multi-layered spiral inductor using an integrated circuit manufacturing process having three or more metal wirings, comprising: a first metal wiring arranged in a straight line among three selected metal wirings; and a second metal wiring disposed on the first metal wiring with an insulating film interposed therebetween A second metal interconnection arranged to be connected to the first metal interconnection through a first contact and a second metal interconnection arranged to be connected to the second metal interconnection via an insulating film on the second metal interconnection, The third metal wiring is connected to the second metal wiring through the third contact after rotating the third metal wiring 1 to 4 times and the second metal wiring is connected to the first metal wiring through the first metal wiring, To 4 times, and then connected to the third metal interconnection through the fourth contact, and after rotating the third metal interconnection 1 to 4 times, the second metal interconnection After the connection with the wiring structure of the finally RY barrels inductor, characterized in that formed it is connected to the first metal wiring.