JPH06267745A - High-frequency semiconductor integrated circuit device - Google Patents

Abstract

(57) [Abstract] [Purpose] To alleviate the limitation on the amount of current that can flow in the spiral inductor used in the matching circuit portion of the high frequency element in the high frequency semiconductor integrated circuit device. [Structure] The conductor 3 is embedded in the groove of the semiconductor substrate 1 at the intersection of the lines forming the spiral inductor. The line 2 and the conductor 3 embedded in the groove are crossed three-dimensionally. [Effect] Since the conductor 3 embedded in the semiconductor substrate 1 is used instead of the air bridge used conventionally, the amount of current is adjusted by adjusting the embedded amount of the conductor 3 and changing the cross-sectional area of the conductor 3. Can be relaxed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spiral inductor used in a high frequency semiconductor integrated circuit device.

[0002]

2. Description of the Related Art FIG. 11 is a plan view showing the structure of a conventional spiral inductor formed using an air bridge, and FIG. 12 is a sectional view taken along the line VII-VII in FIG. In the figure, 51 is a semiconductor substrate, 52 is a line formed of a conductor on the semiconductor substrate 51, a hatched portion indicated by 52a is a thin portion corresponding to an intersecting portion of the line 52, and a dotted line indicated by 53. The portion surrounded by is the portion of the air bridge that is lifted so that the lines 52 and 52a are not in electrical contact with each other at the intersecting portion of the line 52. The line 52 constitutes a one-turn spiral inductor.

Conventionally, a spiral inductor used for a matching circuit portion of a high frequency element (for example, a GaAs integrated circuit for a high power amplifier) is formed on a semiconductor substrate 51, and a line is wound inward in a spiral shape. An air bridge 53 is used to prevent the lines 52 and 52a from electrically contacting each other at an intersecting portion in order to draw out a lead wire from the end portion on the wound side.

When operating this high frequency element, it is necessary to pass a direct current of several hundred mA or more through the inductor. However, due to the manufacturing process, the air bridge 53 cannot be made too high, and therefore the line 52 needs to have the thinned portion 52a at the intersection thereof.

[0005]

Since the conventional high-frequency semiconductor integrated circuit device is configured as described above, the amount of current that can flow in the spiral inductor of the high-frequency semiconductor integrated circuit device is in the line 52a immediately below the air bridge 53. There were problems such as limitation depending on the cross-sectional area.

The present invention has been made to solve the above problems, and an object thereof is to alleviate the limitation on the amount of current that can flow in the spiral inductor.

[0007]

A high frequency semiconductor integrated circuit device according to a first invention comprises a substrate having a groove on one main surface,
A spiral inductor having a line formed on the substrate, wherein a part of the line is arranged in the groove,
It is characterized in that it is formed below the one main surface of the substrate.

A high frequency semiconductor integrated circuit device according to a second aspect of the present invention is the high frequency semiconductor integrated circuit device according to the first aspect of the present invention, wherein the part of the line disposed in the groove is substantially the entire spiral inductor. It is characterized by including.

A high frequency semiconductor integrated circuit device according to a third aspect of the present invention comprises a spiral inductor formed of spiral parallel reciprocating lines formed in one main surface of a substrate.

[0010]

The spiral inductor according to the first invention is
A part of it is arranged in the groove, and the spiral inductor can be configured without forming an air bridge by bringing the intersection of the spiral inductor into the part arranged in the groove. By adjusting the depth, it is possible to increase the cross-sectional area of the line of the spiral inductor at the crossing portion, so that the restriction on the amount of current that can flow can be relaxed.

Since the spiral inductor according to the second invention is formed almost entirely in the groove of the semiconductor substrate, for example, the upper portion of the region where the spiral inductor is formed is filled with an insulator so as to have the same height as the surface of the substrate. Other elements can be formed in that region by
High integration of the high frequency semiconductor integrated circuit device can be achieved.

Since the spiral inductor according to the third aspect of the invention is composed of spiral parallel reciprocating lines, the spiral inductor can be formed without forming intersecting portions, and the spiral inductor can be formed without using an air bridge. Can be configured. In addition, since it is composed of spiral reciprocating parallel lines, a long line can be formed on the substrate with a small occupied area.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. 1 is a plan view showing the structure of a spiral inductor of a high frequency semiconductor integrated circuit device according to a first embodiment of the present invention. In FIG. 1, reference numeral 1 is a semiconductor substrate, 2 is a line formed on the semiconductor substrate 1 to form a spiral inductor, and 3 is a conductor embedded in the semiconductor substrate 1 to connect the line 2 of the spiral inductor and a line 6 to the outside. ,
Reference numeral 5 is a through hole that connects the line 2 and the conductor 3.

FIG. 2 is a sectional view of the spiral inductor shown in FIG. 1 taken along the line II. In the figure, reference numeral 4 is an insulator formed on a conductor for filling the groove of the semiconductor substrate 1 to make it flat, and the same reference numerals as those in FIG. 1 indicate the same portions as those of FIG. As can be seen from FIG. 2, the conductor 3 embedded in the semiconductor substrate 1 can adjust the cross-sectional area of the conductor 3 relatively easily by adjusting the embedding depth and the embedding amount. Since the cross-sectional area of the conductor 3 can be made large, the amount of current flowing through the spiral inductor can be increased.

Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a plan view showing the structure of the spiral inductor of the high frequency semiconductor integrated circuit device according to the second embodiment of the present invention. In FIG. 3, 11 is a semiconductor substrate, 12
Is a line forming a spiral inductor formed on the semiconductor substrate 11, and 13 is a line 12 of the spiral inductor.
And a conductor embedded in the semiconductor substrate 11 for connecting the line 16 to the outside and a through hole 15 connecting the line 12 and the line 16 to the conductor 13. The high frequency semiconductor integrated circuit device shown in FIG. 3 is different from the high frequency semiconductor integrated circuit device of the first embodiment in the number of turns of the spiral inductor. As can be seen from FIG. 3, there are three intersecting points, but the conductor 13 to be embedded may be one, and the groove for that may be formed only one, so that the spiral inductor can be efficiently formed. This effect increases as the number of turns of the spiral inductor increases.

Next, a third embodiment of the present invention will be described with reference to the drawings. FIG. 4 is a plan view showing the structure of the spiral inductor of the high frequency semiconductor integrated circuit device according to the third embodiment of the present invention. In FIG. 4, reference numeral 21 denotes a semiconductor substrate, 22
Is a line which is formed in the groove of the semiconductor substrate 21 and constitutes a spiral inductor, 23 and 26 are lines which are connected to the line 22 which constitutes a spiral inductor, and 25 is a through hole which connects the line 22 and the lines 23 and 26. Is.

FIG. 5 is a sectional view taken along line II-II of the spiral inductor shown in FIG. In the figure, reference numeral 24 is an insulator formed on a conductor for filling the groove of the semiconductor substrate 1 to make it flat, and the same reference numerals as those in FIG. 4 denote the same portions as those in FIG. As can be seen from FIG. 5, the line 22 embedded in the semiconductor substrate 21 can adjust the cross-sectional area of the line 22 relatively easily by adjusting the embedded depth and the embedded amount. Therefore, since the cross-sectional area of the line 22 can be increased, the amount of current flowing through the spiral inductor can be increased. Further, as shown in FIG. 4, since the line 22 forming the spiral inductor is embedded, it is possible to form other elements, lines, etc. in the region above it.

FIG. 6 is a plan view showing a state in which an MIM (Metal-Insulator-Metal) capacitor is actually formed on the embedded spiral inductor. In FIG. 6, 31 is a semiconductor substrate, 32 is a line formed in a groove of the semiconductor substrate 31 to form a spiral inductor, 38 is a line connected to the line 32 forming a spiral inductor by a through hole 38, and 35 is M formed in the region above the line 32 forming the spiral inductor
The upper electrode of the IM capacitor. Reference numeral 39 is a line drawn from the lower electrode of the MIM capacitor, and 40 is a through hole connecting the lower electrode of the MIM capacitor and the line 32. As shown in the figure, since the line 32 forming the spiral inductor is embedded in the groove, MI is formed in the same region on the semiconductor substrate 31 as the spiral inductor.
The M capacitor can be configured, and the integration degree of the device can be improved.

FIG. 7 is a sectional view of the high frequency semiconductor integrated circuit device shown in FIG. 6, taken along the line IV-IV. In FIG. 7, 33 is a lower electrode of the MIM capacitor, 34 is an insulating layer of the MIM capacitor formed between the lower electrode 33 and the upper electrode 35, and 37 is a groove in which the line 32 is formed on the line 32. It is an insulator for filling the semiconductor substrate 31 with a flat main surface, and the same reference numerals as those in FIG. 6 denote the same parts as those in FIG. It can be seen from FIG. 7 that the lower electrode 33 and the line 32 are connected by the through hole 40. The signal output from the spiral inductor is input to the lower electrode 33 of the MIM capacitor composed of the electrodes 33 and 35 and the insulating layer 34 through the through hole 40.

FIG. 8 is a sectional view of the high frequency semiconductor integrated circuit device shown in FIG. In FIG. 8, the same reference numerals as those shown in FIGS. 6 and 7 denote the same reference numerals in FIGS.
Shows the same part as. Line 32 and line 38 from FIG.
It can be seen that and are connected by the through hole 36.
The signal input from line 38 passes through line 32 and MI
It is output from the line 39 through the lower electrode 33 of the M capacitor.

As described above, other elements such as MIM capacitors can be formed in the space of the semiconductor substrate 31 opened above the spiral inductor, and if the layout of the spiral inductor is devised, the high frequency semiconductor integrated circuit device can be manufactured. It is possible to reduce the chip area. However, since the MIM capacitor is formed where the lower electrode 33 of the MIM capacitor and the line 32 overlap,
It is necessary to use the insulator 37 that can mitigate the effect. In addition, it is necessary to carry out the design including the influence of this capacitor.

Next, a fourth embodiment of the present invention will be described with reference to the drawings. FIG. 9 is a plan view showing the structure of the spiral inductor of the high frequency semiconductor integrated circuit device according to the fourth embodiment of the present invention. In FIG. 9, 41 is a semiconductor substrate, 42
Is a line which is formed on the semiconductor substrate 1 and constitutes a spiral inductor. Here, the spiral inductor is a one-stroke pattern formed so as to wind the reciprocating line in a spiral shape. Therefore, a thin and long line can be easily formed on the semiconductor substrate 41 with a small occupied area, and the degree of integration can be improved.

FIG. 10 is a sectional view of the spiral inductor shown in FIG. 9, taken along the line VI-VI. In the figure, the same reference numerals as those in FIG. 9 indicate the same parts as those in FIG. As can be seen from FIG. 10, the line 42 formed on the semiconductor substrate 41 is formed only on the main surface of the semiconductor substrate 41 and does not require an air bridge.

In each of the above embodiments, the rectangular spiral inductor has been described, but a circular spiral inductor may be used, and the same effect as that of the above embodiments can be obtained.

Further, in each of the above-described embodiments, it is necessary to pay attention to the relationship between the used frequency and the line length when performing layout, as in the conventional case.

[0026]

As described above, according to the high-frequency semiconductor integrated circuit device of the present invention as set forth in claim 1, the substrate having the groove on the one main surface and the spiral inductor having the line formed on the substrate are provided, Since a part of the line is arranged in the groove and is formed below one main surface of the substrate, it is not necessary to use an air bridge as in the conventional case, and a line forming a spiral inductor. It becomes easier to increase the cross-sectional area of, and there is an effect that the restriction on the amount of current that can flow in the spiral inductor can be relaxed.

According to the high frequency semiconductor integrated circuit device of the second aspect of the present invention, since part of the line disposed in the groove is configured to include substantially the entire spiral inductor, the spiral inductor Since elements and the like can be formed on the upper semiconductor substrate and the degree of integration can be improved, the effect that the area of the chip on which the circuit of the high-frequency semiconductor integrated circuit device is formed can be reduced can be obtained. is there.

According to the high frequency semiconductor integrated circuit device of the third aspect of the present invention, since it is provided with the spiral inductor composed of spiral parallel reciprocating lines formed in one main surface of the substrate, the conventional high frequency semiconductor integrated circuit device is constituted. As described above, it is easy to increase the cross-sectional area of the line forming the spiral inductor without using the air bridge, and there is an effect that the restriction on the amount of current that can flow in the spiral inductor can be relaxed.

[Brief description of drawings]

FIG. 1 is a plan view showing the structure of a spiral inductor of a high frequency semiconductor integrated circuit device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the spiral inductor shown in FIG. 1 taken along the line I-I.

FIG. 3 is a plan view showing the structure of a spiral inductor of a high frequency semiconductor integrated circuit device according to a second embodiment of the present invention.

FIG. 4 is a plan view showing a structure of a spiral inductor of a high frequency semiconductor integrated circuit device according to a third embodiment of the present invention.

5 is a cross-sectional view of the spiral inductor shown in FIG. 4, taken along the line II-II.

FIG. 6 is a plan view showing a configuration of a combination of a spiral inductor and an MIM capacitor of a high frequency semiconductor integrated circuit device according to a third embodiment of the present invention.

7 is a cross-sectional view taken along the line IV-IV of the spiral inductor shown in FIG.

FIG. 8 is a cross-sectional view of the spiral inductor shown in FIG. 6, taken along the line VV.

FIG. 9 is a plan view showing the structure of a spiral inductor of a high frequency semiconductor integrated circuit device according to a fourth embodiment of the present invention.

10 is a VI-VI of the spiral inductor shown in FIG.
FIG.

FIG. 11 is a plan view showing a configuration of a spiral inductor of a conventional high frequency semiconductor integrated circuit device.

12 is a VII of the spiral inductor shown in FIG.
-VII is a cross-sectional view taken along the arrow.

[Explanation of symbols]

 1, 21, 31, 41, 51 Semiconductor substrate 2, 22, 32, 42, 52 Line 3, 13 Conductor 4, 24, 37 Insulator 5, 15, 25, 36 Through hole 53 Air bridge

Claims (3)

[Claims] 1. A substrate having a groove on its one main surface, and a spiral inductor having a line formed on the substrate, wherein a part of the line is disposed in the groove, and the one side of the substrate is provided. A high-frequency semiconductor integrated circuit device, which is formed below a main surface. 2. The high frequency semiconductor integrated circuit device according to claim 1, wherein the part of the line disposed in the groove includes substantially the entire spiral inductor. 3. A high frequency semiconductor integrated circuit device comprising a spiral inductor formed of a spiral parallel reciprocating line formed in one main surface of a substrate.