CN100442507C - Symmetrical inductance element - Google Patents

Abstract

The invention discloses a symmetrical inductance element, which comprises: first and second winding portions and a coupling portion are symmetrical to each other. Each winding part comprises a first semi-circle lead layer, a second semi-circle lead layer and a third semi-circle lead layer which are concentrically arranged from inside to outside. Each of the half-turn conductive layers has a first end and a second end, wherein the first ends of the first half-turn conductive layers are coupled to each other. The coupling portion includes: a first pair and a second pair of connection layers. The first pair of connecting layers are connected with the first ends of the second and third half-coil wire layers of the two winding parts in a staggered manner. The second pair of connecting layers are connected with the second ends of the first and second half-circle lead layers of the two winding parts in a staggered manner. The adjacent half-circle-shaped conducting wire layers in each winding part have a wire distance, and the wire distance on the outer side is larger than the wire distance on the opposite inner side. The symmetrical inductance element provided by the invention can reduce the parasitic capacitance effect and increase the available frequency range of the inductance element when the differential signal is operated.

Description

Symmetrical inductive element

technical field

The present invention relates to a semiconductor device, and more particularly to a symmetrical inductive element with differential operation.

Background technique

Many digital and analog components and circuits have been successfully used in semiconductor integrated circuits. The above components include passive components such as resistors, capacitors or inductors. A typical semiconductor integrated circuit includes a silicon substrate. More than one dielectric layer is disposed on the base, and more than one metal layer is disposed in the dielectric layer. These metal layers can be used to form on-chip components, such as on-chip inductors, through current semiconductor process technology.

Traditionally, on-chip inductors are formed on a substrate and used in radio frequency band IC designs. Please refer to FIG. 1 , wherein FIG. 1 shows a schematic plan view of a known on-chip inductor with a planar spiral structure. The on-chip inductor is formed in an insulating layer 104 above a substrate 100, which includes a spiral metal layer 103 and an interconnection structure. The spiral metal layer 103 is embedded in the insulating layer 104 . The interconnection structure includes conductive plugs 105 and 109 embedded in an underlying insulating layer (not shown), a metal layer 107 and a metal layer 111 embedded in an insulating layer 104 . The spiral metal layer 103 forms a current path through the conductive plugs 105 and 109 and the metal layers 107 and 111 to be electrically connected to the external or internal circuits of the chip.

The advantage of the planar spiral inductor is that it can increase the integration level of the circuit by reducing the number of circuit components built outside the chip and the required complex interconnection. Furthermore, the planar spiral inductor can avoid the parasitic effect produced by the bond pad or the bond wire between the on-chip circuit and the off-chip circuit.

The aforementioned planar spiral inductor has a low quality factor (Q value) and a large area. In order to further improve the Q value of the inductor and reduce the area, it is proposed to increase the thickness of the spiral metal layer 103 and reduce the trace space S between the inner circle and the outer circle of the spiral metal layer 103 .

However, more and more wireless communication designs use differential circuits to reduce common mode noise, and the inductors used in the above differential circuits need to be symmetrical to prevent common mode noise. That is, the inductor has the same structure viewed from any end point. The planar spiral inductor in Figure 1 is not symmetrical, and it cannot effectively isolate noise if it is applied to a differential circuit.

Contents of the invention

In view of this, the present invention provides a symmetrical inductance element to prevent generation of common mode noise. At the same time, the available frequency range of the inductance element is increased by changing the pitch of the coil in the inductor.

According to the above objective, the present invention provides a symmetrical inductance element, comprising: an insulating layer, a first winding portion, a second winding portion, and a coupling portion. The insulating layer is disposed on the base. The first winding part and the second winding part are symmetrically arranged in the insulating layer. Each winding part includes a first semi-circular wire layer, a second semi-circular wire layer and a third semi-circular wire layer concentrically arranged from inside to outside. Each semi-circular wire layer has a first end and a second end, wherein the first ends of the first semi-circular wire layers are coupled to each other. The coupling part is disposed in the insulating layer between the first winding part and the second winding part, and includes: a first pair of connecting layers and a second pair of connecting layers. The first pair of connection layers are alternately connected to the first ends of the second semi-circular conductor layer and the third semi-circular conductor layer of the two winding parts. The second pair of connecting layers is alternately connected to the second ends of the first semi-circular conductor layer and the second semi-circular conductor layer of the two winding parts. There is a line distance between adjacent half-circle wire layers in each winding part, and the line distance on the outer side is larger than the line space on the inner side.

According to the above purpose, the present invention provides a symmetrical inductive element, which includes an insulating layer, a plurality of semi-circular wire layers, at least one first pair of connection layers and at least one second pair of connection layers, and the two adjacent There is a line distance between the semi-circular wire layers, and the line space on the outer side is larger than the line space on the inner side. In addition, a plurality of semi-circular conductor layers are concentrically arranged in the insulating layer from inside to outside, and each semi-circular conductor layer has a first end and a second end, wherein the two semi-circular conductor layers located at the innermost The first ends are coupled to each other. A first pair of connection layers connects the first ends of the plurality of semi-circular wire layers, and a second pair of connection layers connects the second ends of the plurality of semi-circular wire layers.

According to the above purpose, the present invention provides a symmetrical inductance element, including an insulating layer, a first winding part, a second winding part and two semi-circular wire layers, wherein the first winding part is placed in the insulating layer , has a plurality of wire layers, and the second winding part is placed in the insulating layer, and is symmetrical to the first winding part, and has a plurality of wire layers. In addition, there is a wire distance between the two semi-circular wire layers and the adjacent winding portion, and the wire distance is greater than the wire distance between the two adjacent wire layers in the winding portion. The two semi-circular wire layers are placed in the insulating layer, and are respectively located outside the first winding part and the second winding part, and are electrically connected to the first winding part and the second winding part respectively. line department.

The symmetrical inductance element provided by the present invention can reduce the parasitic capacitance effect and increase the usable frequency range of the inductance element when the differential signal is operated.

Description of drawings

FIG. 1 is a schematic plan view of a known on-chip inductor with a planar spiral structure.

FIG. 2 is a schematic plan view illustrating a three-turn symmetrical inductor element according to an embodiment of the present invention.

FIG. 3 is a schematic plan view illustrating a four-turn symmetrical inductor element according to an embodiment of the present invention.

FIG. 4 is a schematic plan view illustrating a four-turn symmetrical inductor element according to an embodiment of the present invention.

FIG. 5 is a schematic plan view illustrating a four-turn symmetrical inductor element according to an embodiment of the present invention.

Detailed ways

A schematic plan view of a three-turn symmetrical inductance element according to an embodiment of the present invention will be described below with reference to FIG. 2 . The symmetrical inductance element includes: an insulating layer 210 , a first winding portion and a second winding portion, and a coupling portion. The insulating layer 210 is disposed on a substrate 200 . The substrate 200 includes a silicon substrate or other known semiconductor substrates. The substrate 200 may include various elements, such as transistors, resistors and other commonly used semiconductor elements. Furthermore, the substrate 200 may also include other conductive layers (eg, copper, aluminum or alloys thereof) and insulating layers (eg, silicon oxide layer, silicon nitride layer or low dielectric material layer). In order to simplify the drawing, only a flat base is shown here. In addition, the insulating layer 210 can be a single layer of low dielectric material layer or a multilayer dielectric structure. In this embodiment, the insulating layer 210 may include a silicon oxide layer, a silicon nitride layer or a low dielectric material layer.

The first winding portion is disposed in the insulating layer 210 and located on a first side of the dotted line 2 . The first winding portion includes a first semicircular wire layer 201 , a second semicircular conductive layer 203 and a third semicircular conductive layer 205 arranged concentrically from inside to outside. The second winding portion is disposed in the insulating layer 210 and located on a second side of the dotted line 2 opposite to the first side. The second winding portion includes a first semi-circular wire layer 202 , a second semi-circular wire layer 204 and a third semi-circular wire layer 206 arranged concentrically from inside to outside. The second winding part is symmetrical to the first winding part with the dotted line 2 as the axis of symmetry.

The first wire winding part and the second wire winding part can form a substantially circular, rectangular, hexagonal, octagonal or polygonal shape. Here, to simplify the diagram, an octagon is used as an example for illustration. Furthermore, the material of the first winding part and the second winding part can be made of copper, aluminum or alloys thereof. In this embodiment, the first semi-circular wire layer 201, the second semi-circular conductive layer 203, and the third semi-circular conductive layer 205 of the first winding part are the same as the first semi-circular conductive layer 205 of the second winding part. The wire layer 202 , the second semi-circular wire layer 204 and the third semi-circular wire layer 206 may have the same wire width W. As shown in FIG.

Each semicircular wire layer has a first end 10 and a second end 20 . In this embodiment, the first end 10 of the first semi-circular wire layer 201 of the first winding part is coupled to the first end 10 of the first semi-circular wire layer 202 of the second winding part. Furthermore, the second ends 20 of the third half-circle wire layers 205 and 206 of the first winding part and the second winding part have a lateral extension part 30 and 40, which are used as signal input/output ends for to input differential signals.

In this embodiment, in order to maintain the geometric symmetry of the inductance element, the coupling part is disposed in the insulating layer 210 between the first winding part and the second winding part, which includes a first pair of connecting layers and The second pair of connection layers. The first pair of connecting layers alternately connects the first ends 10 of the second semicircular conductor layers 203 and 204 and the third semicircular conductor layers 205 and 206 of the two winding parts. Moreover, the second pair of connecting layers interdigitately connects the second ends 20 of the first semi-circular conductor layers 201 and 202 and the second semicircular conductor layers 203 and 204 of the two winding parts. For example, the first pair of connection layers includes an upper jumper layer 215 coupled to the first ends 10 of the second semi-circular wire layer 203 and the third semi-circular wire layer 206, and a lower jumper layer 217 coupled to the first end 10 of the second semi-circular wire layer 206. The first end 10 of the second semi-circular wire layer 204 and the third semi-circular wire layer 205 . The second pair of connection layers includes an upper jumper layer 213 coupled to the second end 20 of the first semi-circular conductor layer 201 and the second semi-circular conductor layer 204, and a lower jumper layer 211 coupled to the first semi-circular conductor layer 204. The wire layer 202 and the second end 20 of the second semicircular wire layer 203 .

Generally speaking, since the adjacent metal winding layers (winding) in the single-ended signal operation (single-ended signal operation) inductance element will pass the signal of the same phase, there is no need to consider the parasitic between adjacent metal winding layers. Capacitive effect (parasitic capacitance effect). Therefore, the wire spacing between the metal winding layers must be reduced as much as possible to improve the performance of the inductance element. However, unlike inductive elements operated with single-ended signals, adjacent winding layers in an inductive element operated with differential signals will pass signals with a phase difference of 180 degrees, so the parasitic capacitance between adjacent metal winding layers needs to be considered Effect, especially the parasitic capacitance effect generated between the outermost metal winding layers. When the parasitic capacitance between the outermost metal winding layers increases, the peak Q-factor frequency (peak Q-factor frequency) will drop and increase the inductance value deviation (inductance value deviation), thereby limiting the usable frequency range of the inductive component.

Therefore, in the symmetrical inductive element of this embodiment, there is a pitch between adjacent semi-circular wire layers in each winding portion, and at least one relatively outer pitch is greater than at least one relatively inner pitch. For example, the line distance S2 between the second semicircular conductor layers 203 and 204 and the third semicircular conductor layers 205 and 206 is greater than that between the second semicircular conductor layers 203 and 204 and the first semicircular conductor layer The line distance S1 between 201 and 202 (ie, S2>S1). In this way, according to the symmetrical inductive element of the present invention, since the outermost line spacing S2 is increased, the parasitic capacitance effect can be reduced when the symmetrical inductive element operates with differential signals, and the usable frequency range of the inductive element can be increased.

The four-turn symmetrical inductance element of other embodiments of the present invention will be described below with reference to FIG. 3 , wherein the components that are the same as those in FIG. 2 use the same reference numerals and their descriptions are omitted. In FIG. 3 , the first winding part and the second winding part further include fourth semi-circular wire layers 207 and 208 , which are respectively located outside the third semi-circular conductive layers 205 and 206 . Likewise, the fourth semicircular wire layers 207 and 208 may have the same wire width W. As shown in FIG. Moreover, the coupling portion further includes a third pair of connecting layers, which interdigitately connect the second ends 20 of the third semi-circular wire layers 205 and 206 and the fourth semi-circular wire layers 207 and 208 of the two winding portions. For example, the third pair of connection layers includes an upper jumper layer 219 coupled to the second end 20 of the third semi-circular wire layer 205 and the fourth semi-circular wire layer 208, and a lower jumper layer 221 coupled to the second end 20 of the fourth semi-circular wire layer 208. The second end 20 of the third semicircular wire layer 206 and the fourth semicircular conductive layer 207 . Furthermore, the first end 10 of the fourth half-circle-shaped wire layer 207 and 208 of the first winding part and the second winding part has a lateral extension part 30 and 40, which is used as a signal input/output end, for to input differential signals.

In this embodiment, the line spacing gradually increases from the inside to the outside. For example, the distance S3 between the third semicircular conductor layers 205 and 206 and the fourth semicircular conductor layers 207 and 208 is greater than that between the second semicircular conductor layers 203 and 204 and the third semicircular conductor layer Line distance S2 between 205 and 206 . Furthermore, the line spacing S2 between the second semicircular conductor layers 203 and 204 and the third semicircular conductor layers 205 and 206 is larger than the second semicircular conductor layers 203 and 204 and the first semicircular conductor layer 201 and the line distance S1 between 202 (ie, S3>S2>S1).

In other embodiments, the line distance S3 may be substantially the same as the line distance S2 and larger than the line distance S1 (ie, S3 = S2 > S1 ), as shown in FIG. 4 . Also, in other embodiments, the line distance S2 may be substantially the same as the line distance S1 and smaller than the line distance S3 (ie, S3>S2=S1), as shown in FIG. 5 . In this way, since the outermost adjacent winding layer has the largest pitch, the symmetrical inductance element can reduce the parasitic capacitance effect and increase the usable frequency range of the inductance element when the differential signal operation is performed. In addition, those skilled in the art can easily understand that the present invention also has the same advantages when applied to other symmetrical inductance elements with more than four turns.

The above description is only a preferred embodiment of the present invention, but it is not intended to limit the scope of the present invention. Any person familiar with this technology can make further improvements on this basis without departing from the spirit and scope of the present invention. Improvements and changes, so the protection scope of the present invention should be defined by the claims of the present application.

A brief description of the symbols in the drawings is as follows:

100: base

103: Spiral metal layer

104: insulation layer

105, 109: Conductive plug

107, 111: metal layer

S: line spacing

2: dotted line

10: First end

20: Second End

30, 40: Lateral extension

200: base

201, 202: the first semi-circular wire layer

203, 204: the second semi-circular wire layer

205, 206: the third semi-circular wire layer

207, 208: the fourth semi-circular wire layer

210: insulating layer

211, 217, 221: lower bridging layer

213, 215, 219: upper bridging layer

S1, S2, S3: line spacing

W: line width

Claims (10)

1. symmetrical inductance element, described symmetrical inductance element comprises:

Insulating barrier is arranged in the substrate; It is characterized in that,

First winding section and second winding section, be symmetrically set in this insulating barrier, each winding section comprises the first half-turn shape conductor layer, the second half-turn shape conductor layer and the 3rd half-turn shape conductor layer of concentric arrangement from inside to outside, and each half-turn shape conductor layer has one first end and one second end, and described first end of the wherein said first half-turn shape conductor layer couples mutually; And

Couplings is arranged in this insulating barrier between this first winding section and this second winding section, comprising:

First pair of articulamentum is cross-linked this second half-turn shape conductor layer of two winding sections and described first end of the 3rd half-turn shape conductor layer; And

Second pair of articulamentum is cross-linked described second end of this first half-turn shape conductor layers of two winding sections and this second half figure conductor layers;

Wherein have line-spacing between the adjacent described half-turn shape conductor layer in each described winding section, and the line-spacing that is positioned at the outside is greater than being positioned at inboard line-spacing.

2. symmetrical inductance element according to claim 1, it is characterized in that, described first winding section and second winding section comprise that more the 4th half-turn shape conductor layer is positioned at the outside of the 3rd half-turn shape conductor layer, and this couplings more comprises the 3rd pair of articulamentum, is cross-linked the 3rd half-turn shape conductor layer of two winding sections and described second end of the 4 half figure conductor layer.

3. symmetrical inductance element according to claim 2, it is characterized in that, line-spacing between the 4th half-turn shape conductor layer and the 3rd half-turn shape conductor layer is same as the line-spacing between the 3rd half-turn shape conductor layer and this second half-turn shape conductor layer, and greater than the line-spacing between this second half figure conductor layer and this first half-turn shape conductor layer.

4. symmetrical inductance element according to claim 2, it is characterized in that, line-spacing between this first half-turn shape conductor layer and this second half-turn shape conductor layer is same as the line-spacing between the 3 half figure conductor layer and this second half-turn shape conductor layer, and less than the line-spacing between the 4 half figure conductor layer and the 3 half figure conductor layer.

5. symmetrical inductance element, described symmetrical inductance element comprises:

Insulating barrier; It is characterized in that,

A plurality of half-turn shape conductor layers, concentric arrangement is in this insulating barrier from inside to outside for it, and each half-turn shape conductor layer has first end and second end, described first end that wherein is positioned at two and half the most inboard figure conductor layers couples mutually;

At least one first pair of articulamentum connects described first end of described a plurality of half-turn shape conductor layers; And

At least one second pair of articulamentum connects described second end of described a plurality of half-turn shape conductor layers;

Have line-spacing between wherein adjacent two these half-turn shape conductor layers, and the line-spacing outside being positioned at is greater than being positioned at inboard line-spacing.

6. symmetrical inductance element, described symmetrical inductance element comprises:

Insulating barrier; It is characterized in that,

First winding section, it places in this insulating barrier, and has a plurality of conductor layers;

Second winding section, it places in this insulating barrier, and is symmetrical in this first winding section, and has a plurality of conductor layers; And

Two half-turn shape conductor layers, it is arranged in this insulating barrier, and lays respectively at the outside of this first winding section and this second winding section, and wherein these two half-turn shape conductor layers are electrically connected at this first winding section and this second winding section respectively;

Wherein have line-spacing between these two half-turn shape conductor layers and the winding section that is adjacent, and this line-spacing is greater than the line-spacing between two adjacent in this winding section these conductor layers.

7. symmetrical inductance element according to claim 6, it is characterized in that, each winding section comprises the first half-turn shape conductor layer, the second half-turn shape conductor layer and the 3rd half-turn shape conductor layer of concentric arrangement from inside to outside, and each half-turn shape conductor layer has first end and second end, and described first end of the wherein said first half-turn shape conductor layer couples mutually.

8. symmetrical inductance element according to claim 7 is characterized in that it more comprises couplings, be arranged in this insulating barrier between this first winding section and this second winding section, and this couplings comprises:

First pair of articulamentum is cross-linked this second half-turn shape conductor layer of two winding sections and described first end of the 3rd half-turn shape conductor layer; And

Second pair of articulamentum is cross-linked this first half-turn shape conductor layer of two winding sections and described second end of this second half-turn shape conductor layer.

9. symmetrical inductance element according to claim 8 is characterized in that, this first pair of articulamentum and second pair of articulamentum include the cross-over connection layer and reach cross-over connection layer down.

10. symmetrical inductance element according to claim 7, it is characterized in that, described first winding section and second winding section comprise that more the 4th half-turn shape conductor layer is positioned at the outside of the 3 half figure conductor layer, and this couplings more comprises the 3rd pair of articulamentum, is cross-linked the 3rd half-turn shape conductor layer of two winding sections and described second end of the 4th half-turn shape conductor layer.

Images