JPH04237106A - Integrated inductance element and integrated transformer - Google Patents

Abstract

PURPOSE:To reduce the occupation area on the plane surface in parallel with a substrate by a method wherein a helical concentrated constant inductance element is formed in such a manner that it is positioned within the plane surface, which is not in parallel with the substrate, using a plurality of layers of metal film and through hole. CONSTITUTION:An insulating film 3 and a metal film 2 are alternately laminated on a semiconductor substrate 1. Two helical concentrated constant inductance elements 5 are formed in such a manner that they are positioned in the plane surface, which is not in parallel with the substrate 1, using a plurality of layers of metal film 2 and through holes 4, they are connected with each other and, are double wound. Also, two helical-shaped concentrated constant inductance elements 2 are arranged in a non-connected manner, and a transformer is formed by having them magnetically coupled with each other. As the inductance elements 5 are formed on the plane surface which is not in parallel with the substrate 1, a plurality of inductance elements 5 can be brought close with each other. As a result, a magnetically coupled circuit, having a small occupation area and magnetically coupled, can be formed easily.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to lumped inductance elements used in monolithic microwave integrated circuits.

0002

[Prior Art] Monolithic microwave integrated circuit (MM)
IC) is constructed by combining active elements, transmission lines, and passive elements such as LCR on a semiconductor substrate. For passive elements, lumped constant elements can be used in circuits whose size is sufficiently small relative to the wavelength, and the circuit can be made more compact than distributed constant elements. FIG. 1 shows a conventional lumped constant inductance element.

0003

[Problems to be Solved by the Invention] However, in the conventional inductance element, the coil 12 is constructed on a plane parallel to the substrate 11 as shown in FIG. It had the disadvantage of being large. Furthermore, it has been difficult to construct a circuit that magnetically couples a plurality of inductance elements, such as a transformer.

SUMMARY OF THE INVENTION An object of the present invention is to provide an integrated inductance element and an integrated transformer that occupy a small area and can easily constitute a magnetically coupled circuit.

[0005]

[Means for Solving the Problems] In order to overcome the above problems, the present invention has the following configuration. In other words, in a multilayer integrated circuit in which insulating films and metal films are alternately stacked on a semiconductor substrate, through holes are provided in the insulating films, and metal films of different layers are interconnected, the metal films of multiple layers and the through holes are stacked alternately on a semiconductor substrate. A spiral lumped inductance element is configured to be located in a plane that is not parallel to the substrate. This makes it possible to dramatically reduce the area occupied on a plane parallel to the substrate. Moreover, it becomes easy to magnetically couple a plurality of unconnected inductance elements.

[0006]

[Examples] Examples will be explained in detail below. FIG. 1 shows a first embodiment of the invention. Insulating film 3 on semiconductor substrate 1
and metal films 2 are alternately laminated, two spiral lumped inductance elements are constructed so as to be located in a plane that is not parallel to the substrate by the plurality of layers of metal films and through holes 4, and they are connected to each other. It is then rolled twice. In this way, the occupied area can be dramatically reduced to about the width of the wiring, compared to the conventional method. Furthermore, even if the number of turns is increased, the increase in the occupied area is extremely small compared to the conventional case.

FIG. 2 shows a second embodiment of the invention. This is a transformer 6 in which two two-turn spiral lumped constant inductance elements 5 are arranged without being connected in a plane that is not parallel to the substrate 1 and are magnetically coupled to each other. Since the inductance elements 5 are formed in a plane that is not parallel to the substrate 1, a plurality of inductance elements can be brought very close to each other, and magnetic mutual coupling becomes easy. Further, in this figure, a magnetic material (for example, ferrite oxide) 7 is stacked on the third layer and crossed with an inductance element to obtain a large inductance. In terms of the IC manufacturing process, it is much easier to stack the magnetic material on the interlayer insulating film parallel to the substrate than to form the magnetic material perpendicular to the substrate. Of course, even if there is no magnetic material 7, or if all the insulating films are made of magnetic material, it operates as a transformer.

FIG. 3 shows a third embodiment of the present invention. 1st
Annular outer inductance element 5 with layer wiring and fifth layer wiring
a, a ring-shaped inner inductance element 5b is formed by the second layer wiring and the fourth layer wiring, and these are magnetically coupled to each other. The third layer is laminated with magnetic material. The distance between the two inductance elements 5a and 5b is determined by the thickness of the interlayer insulating film in the direction perpendicular to the substrate, but can be configured to be close to each other in the direction parallel to the substrate 1, so that magnetic mutual coupling is prevented. It's easy.

[0009]

As described above, according to the present invention, the area occupied by lumped constant inductance elements used in integrated circuits can be dramatically reduced. Further, it becomes easy to form a transformer in which a plurality of inductance elements are magnetically coupled to each other in an integrated circuit.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view showing an embodiment in which an integrated inductance element is formed according to the present invention.

FIG. 2 is a schematic perspective view showing an embodiment of an integrated transformer according to the present invention.

FIG. 3 is a schematic perspective view showing another embodiment of an integrated transformer according to the present invention.

FIG. 4 is a schematic perspective view showing an example of a conventional inductance element.

[Explanation of symbols]

1 Semiconductor substrate 2 Metal film 3 Insulating film 4 Through hole 5, 5a, 5b Inductance element 6 Transformer 7 Magnetic material

Claims (4)

[Claims] [Claim 1] n layers (n is 4 or more) laminated on a substrate
J (J≦n+1) conductor layers are disposed above and below each insulating film and separated from each other by the insulating film, and a through hole is provided in the insulating film at a desired position to connect the different layers. In a multilayer integrated circuit in which conductor layers are interconnected, the J
m conductor strips are arranged in parallel on conductor layers, and the lowest layer (first
One end of the k-th (k is 1 to m) conductor wire in the uppermost layer (layer J) and one end of the k-th conductor wire in the uppermost layer (J layer) are connected to each other through the through hole, and The other end of the k-th conductor wire and one end of the k-th conductor wire of the second layer are connected to each other through the through hole, and one end of the J conductor wire is then connected to the other end of the k-th conductor wire through the through hole. m spiral conductor wire rings are formed by connecting through holes, and one end of the adjacent spiral conductor wire rings is connected by a conductor wire layer laminated on the same insulating layer to form one conductor wire ring. is formed. An integrated inductance element characterized by: [Claim 2] n layers (n is 4 or more) laminated on a substrate
J (J≦n+1) conductor layers are disposed above and below each insulating film and separated from each other by the insulating film, and a through hole is provided in the insulating film at a desired position to connect the different layers. In a multilayer integrated circuit in which conductor layers are interconnected, the J
Two conductor wires are arranged in parallel on each conductor layer, one end of the first conductor wire in the bottom layer (first layer) and the second conductor wire in the top layer (J layer) of the two conductor wires. One end of the first conductor wire in the uppermost layer and one end of the first conductor wire in the second layer are connected to each other through the through hole. Then, sequentially, one ends of the J conductor wires are connected to each other through the through hole, and the same connection is made for the second conductor wire among the two conductor wires, so that the two conductor wires are connected. 1. An integrated transformer characterized in that a spiral conductor wire is formed, and the two spiral conductor wires are magnetically coupled to each other. 3. The integrated inductance according to claim 1, wherein part or all of the plurality of insulating layers are made of a magnetic material. 4. The integrated transformer according to claim 2, wherein part or all of the plurality of insulating layers are made of a magnetic material.