JPH0661058A - Semiconductor integrated circuit device - Google Patents

Abstract

PURPOSE:To miniaturize a semiconductor integrated circuit device, by forming an inductor of a transmission circuit element formed in a semiconductor integrated circuit device or the like, in the structure wherein high inductance can be obtained in a minute area. CONSTITUTION:Two or more layers of ring type conductive wiring films 3a, 3b, 3c having notches are laminated on the surface of a semiconductor substrate 2, via interlayer insulating films 4a, 4b, 4c. The adjacent conductive wiring films are connected in series at the notched parts by using connection wirings 5a, 5b so as to have the same rotation direction. Thereby an inductor 1 is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inductor and a semiconductor integrated circuit device using the inductor. More specifically, the present invention relates to an inductor and a semiconductor integrated circuit device in which the structure of the inductor is three-dimensionally formed to reduce the area.

[0002]

2. Description of the Related Art Conventionally, as a high frequency semiconductor integrated circuit device, a high frequency field effect transistor (hereinafter referred to as FET) is formed on a semiconductor substrate, and a monolithic microwave having an inductor and a capacitor formed on the substrate. An integrated circuit device (hereinafter referred to as MMIC) is used.

In this MMIC, of the transmission circuit elements formed on the surface of the substrate, the inductor has a structure as shown in FIG. In FIG. 5, gallium arsenide (GaA
The inductor 21 is manufactured by forming the conductive wiring film 23 made of Ti / Au in a spiral shape on the semiconductor substrate 22 made of s) or the like.

[0004]

In order to increase the inductance of the above inductor 21, the number of spiral turns must be increased. However, when the number of turns is increased, the conductive wiring film becomes longer toward the outer periphery, and the semiconductor substrate 22
It occupies a large surface area. Therefore, MMI
It becomes difficult to reduce the size of C, and accordingly it becomes difficult to reduce the cost.

It is an object of the present invention to solve the above problems and to provide a structure of an inductor capable of obtaining a high inductance in a small area, and to provide a miniaturized semiconductor integrated circuit device.

[0006]

The inductor of the present invention comprises:
On the substrate, two or more layers of ring-shaped conductive wiring films partially having a cutout are laminated with an interlayer insulating film interposed therebetween, and the conductive wiring films adjacent to each other are connected at the cutout so that they are in the same rotation direction. It is characterized by being connected in series by wiring.

A semiconductor integrated circuit device of the present invention is a semiconductor integrated circuit device comprising an active element formed on a semiconductor substrate and a transmission circuit element including an inductor formed on the surface of the substrate. At least one inductor formed is the inductor according to claim 1.

[0008]

According to the present invention, the inductor is formed by stacking the ring-shaped conductive wiring films on the surface of the substrate through the interlayer insulating film and connecting the conductive wiring films of the respective layers in series. An inductor can be formed with the area of the conductive wiring film of
An inductor can be formed with a small area. Moreover, the conductive wiring film forming the coil and the interlayer insulating film between them can be formed thin, and any number of layers can be formed according to a desired inductor, and an inductor having a large inductance in a small area can be formed.

[0009]

The present invention will be described below with reference to the drawings. 1 is a cross-sectional explanatory view showing an inductor portion of a transmission circuit element which is an embodiment of the present invention, FIG. 2 is a perspective explanatory view schematically showing a three-dimensional arrangement of the inductor portion of FIG. 1, and FIG. 4 is a plan layout view showing a main part of a high-frequency amplifier circuit including the inductor of FIG. 4, and FIG. 4 is an equivalent circuit diagram of FIG.

The structure of the inductor 1 which is a constituent element of the semiconductor integrated circuit device of the present invention will be described with reference to FIGS.
For example, the first conductive wiring film 3a made of Ti / Au is formed on the semiconductor substrate 2 made of gallium arsenide (GaAs).
However, it has a rectangular loop shape that is partially cut by the evaporation or sputtering method and the photolithography process.
It is formed of a band-shaped film having a thickness of ˜2 μm. The first interlayer insulating film 4a made of a SiO ₂ film or a SiN film is formed on the surface by a CVD method or a sputtering method.
It is formed with a thickness of ˜1 μm. On the surface of the first interlayer insulating film 4a, the second conductive wiring film 3 is formed similarly to the first layer.
b and the second interlayer insulating film 4b are formed. One end of each of the first and second conductive wiring films 3a and 3b is a first connection wiring 5 made of Ti / Pt / Au.
It is electrically connected by a. First connection wiring 5
a is formed by etching a part of the first interlayer insulating film 4a to form a contact hole before forming the second conductive wiring film 3b, and depositing the same metal material as the conductive wiring film on the surface by sputtering or sputtering. It is formed by Further, similarly, a third conductive wiring film 3c and a third interlayer insulating film 4c are formed on the second interlayer insulating film. At this time, the other end of the second conductive wiring film and one end of the third conductive wiring film 3c immediately above the second conductive wiring film are formed in the same manner as the above-mentioned first connecting wiring 5a. It is electrically connected by 5b. Further, the third interlayer insulating film 4
A contact hole is formed in a part of c, and the electrode wiring 6 is formed on the surface thereof so that it can be electrically connected to another element. The conductive wiring films are connected in series by connecting wirings at the above-mentioned notches so that the adjacent conductive wiring films have the same rotation direction to form a coil.

The inductor 1 constructed as above is
As shown in FIG. 2, the end portions of the first to third conductive wiring films are connected in series and are formed as a laminated body of conductive wiring films extending in the direction perpendicular to the surface of the semiconductor substrate 2. . Therefore, the number of turns of the coil can be increased even if the area occupied by the inductor 1 on the semiconductor substrate 2 is small. Furthermore, when changing the specifications of the inductor, it is possible to obtain the desired inductance relatively simply by changing the number of conductive wiring films to be stacked.
It can be set freely in more than one layer.

Next, an MMIC having the above-described inductor will be described with reference to FIGS. In the MMIC, active elements such as FETs and diodes are formed on a semiconductor substrate, and transmission circuit elements such as inductors and capacitors are formed on the surface of the substrate.

As shown in FIGS. 3 and 4, an MMIC microwave F used in a low noise microwave amplifier or the like.
In the main part around ET, the gate electrode 8 of the amplification FET 7 is electrically connected to the first terminal 9 through the inductor 10, and the drain electrode 11 is electrically connected to the second terminal 12 through the inductor 13. Connected, the source electrode 14 is the ground side terminal
It is configured to be electrically connected to 15 through an inductor 16. As shown in the equivalent circuit diagram of FIG. 4, capacitors 17 and 18 for cutting direct current are connected to the input side and the output side of the first and second terminals 9 and 12, respectively, and an inductor 19 is further provided. , 20 through 1st respectively
Bias terminal 21 and second bias terminal 22 are formed so that a DC bias can be supplied.

In this amplifier circuit, the inductors 10, 13 and 16 are arranged in a smaller area than the conventional one, so that the entire circuit is miniaturized.

In this embodiment, an example in which rectangular loop-shaped conductive wiring films are laminated is shown, but the present invention is not limited to this shape, and circular loop-shaped conductive wiring films may be laminated. Any shape coil can be formed by photolithography process.

[0016]

According to the present invention, since the inductor is formed by laminating the conductive wiring film in the coil portion in the direction perpendicular to the surface of the substrate, the area is changed even if the number of turns is increased. In addition, high inductance can be obtained in a small area.

Further, a high frequency element such as an FET is formed on a semiconductor substrate, and an inductor formed on the surface of the substrate is formed by the inductor of the present invention, whereby a monolithic microwave integrated circuit device having a small chip area can be formed. . Furthermore, as a result of the smaller element area, the wiring connecting the elements becomes shorter, mutual interference and noise generation in the wiring that tends to occur in the microwave band can be suppressed, and a monolithic microwave integrated circuit device with high characteristics can be obtained. be able to.

Further, with the miniaturization of the device, it is possible to cope with the recent miniaturization of electronic equipment and to contribute to cost reduction.

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view showing an inductor portion which is an embodiment of the present invention.

FIG. 2 is a perspective view schematically showing a coil portion of the inductor shown in FIG.

FIG. 3 is a plan layout view showing a main part of a high frequency amplifier circuit.

FIG. 4 is an equivalent circuit diagram of FIG.

FIG. 5 is an explanatory plan view showing a conventional inductor.

[Explanation of symbols]

 1 Inductor 2 Semiconductor substrate 3a First conductive wiring film 3b Second conductive wiring film 3c Third conductive wiring film 4a First interlayer insulating film 4b Second interlayer insulating film 4c Third interlayer insulating film 5a First Connection wiring 5b Second connection wiring

Claims (2)

[Claims] 1. A ring-shaped conductive wiring film having a notch in a part thereof is laminated on a substrate by two or more layers via an interlayer insulating film, and the conductive wiring films adjacent to each other have the same rotation direction. An inductor which is connected in series by connection wiring at the cutout portion. 2. A semiconductor integrated circuit device comprising an active element formed on a semiconductor substrate and a transmission circuit element including an inductor formed on the surface of the substrate, wherein at least one inductor formed on the surface of the substrate. Is the inductor according to claim 1, wherein the semiconductor integrated circuit device is a semiconductor integrated circuit device.