CN106206553A - A kind of three-dimensional spiral inductor based on silicon via-hole array - Google Patents

Abstract

The invention discloses a three-dimensional spiral inductor based on a through-silicon hole array, which comprises: a top layer, a middle layer and a bottom layer, and the through-silicon holes on the middle layer are arranged into a square matrix of N×N (N≥5), The metal pillars in the hole are connected with the top metal interconnection on the top layer and the bottom metal interconnection on the bottom layer to form a series path, which is a three-dimensional spiral structure in the vertical plane (that is, a three-dimensional spiral inductor ), in use, the current flows from one plate of the three-dimensional spiral inductor to the other plate, except for the metal post in the center, the current will pass through each metal post in turn, because the inductance value of each TSV is equal to its The sum of its own self-inductance and the mutual inductance of adjacent TSVs, the total inductance of the three-dimensional spiral inductor is equal to the superposition of the self-inductance and mutual inductance values of all TSVs in the array, so the three-dimensional spiral inductor of the present invention can Dramatically improve the quality and inductance value of integrated inductors.

Description

A 3D Spiral Inductor Based on TSV Array

technical field

The invention relates to an inductor, in particular to a three-dimensional spiral inductor based on a through-silicon via (TSV) array, and belongs to the field of integrated inductors oriented to radio frequency/microwave integrated circuits.

Background technique

As one of the three major passive devices, inductors are an important part of various circuits in modern communication systems. They are widely used in analog, analog-digital hybrid, radio frequency and microwave integrated circuits. It also has the functions of screening signals, filtering noise, stabilizing current and suppressing electromagnetic wave interference.

The most common usage of inductors in circuits is to form LC filter circuits together with capacitors.

At present, there are two types of inductors: discrete inductors and integrated inductors. Individual discrete inductors are generally large in size, which is not conducive to monolithic integration and system miniaturization; inductors made by integrated circuit manufacturing processes are generally made by The metal spiral is etched on the surface of the silicon substrate. The inductance value of this type of inductor is very small, which limits the use of the inductor in integrated circuits. However, there is an increasing need for high-performance, large-value integrated inductors.

Through Silicon Via (TSV) is a three-dimensional structure that penetrates the silicon substrate, which can effectively improve the integration of circuits and the quality and performance of circuit systems. and manufacturing offers new methods.

Contents of the invention

The purpose of the present invention is to provide a three-dimensional spiral inductor based on a through-silicon via array, which has the advantages of small area, high integration, large inductance, and high quality factor.

In order to achieve the above object, the present invention adopts the following technical solutions:

A three-dimensional spiral inductor based on a through-silicon via array, comprising: a top layer, an intermediate layer and a bottom layer, characterized in that,

The aforementioned intermediate layer is a semiconductor substrate layer (201), made of silicon material, etched with a number of through-silicon holes penetrating the upper and lower surfaces, all of which have the same diameter, and the aforementioned through-silicon holes are arranged in an N× A square matrix of N, the aforementioned N≥5, the row spacing and column spacing between all TSVs are equal, the aforementioned TSVs are filled with metal pillars (203) equal in height to the TSVs, and the aforementioned metal pillars (203) ) and the inner wall of the TSV is also filled with an insulating layer (202);

The aforementioned top layer is the top layer dielectric layer (101), which is made of insulating material, and the top layer metal interconnection line (102), the top layer first plate metal interconnection line (103) and the top layer second plate metal interconnection line are made in it. line(104);

The aforementioned bottom layer is the bottom dielectric layer (301), which is made of insulating material, and the bottom metal interconnection line (302) is made therein;

After the above-mentioned top layer, middle layer and bottom layer are sequentially combined, the top-layer metal interconnection line (102), the metal column (203) and the bottom-layer metal interconnection line (302) are connected together to form an uninterrupted series path, the aforementioned series path What is formed in the vertical plane is a three-dimensional spiral structure, and the aforementioned three-dimensional spiral structure constitutes a three-dimensional spiral inductor; the first metal interconnection line (103) of the aforementioned top layer and the second plate metal interconnection line (104) of the top layer are used as The lead-out electrodes of the two pole plates of the three-dimensional spiral inductor; when in use, the current flows from one pole plate of the three-dimensional spiral inductor to the other pole plate, except for the metal column (203) at the center, the current will pass through each Metal posts (203).

The aforementioned three-dimensional spiral inductor based on the through-silicon hole array is characterized in that the insulating materials used to make the aforementioned top dielectric layer (101), bottom dielectric layer (301) and insulating layer (202) are silicon dioxide, silicon nitride or silicon oxynitride.

The aforementioned three-dimensional spiral inductor based on the TSV array is characterized in that the material used to make the aforementioned metal pillar (203) is copper or aluminum.

The aforementioned three-dimensional spiral inductor based on a through-silicon hole array is characterized in that the aforementioned top-layer metal interconnection (102), the top-level first plate metal interconnection (103), and the top-level second plate metal interconnection are made (104) and the underlying metal interconnection (302) are made of copper or aluminum.

The benefit of the present invention lies in that in the three-dimensional spiral inductor based on the TSV array of the present invention, the TSVs in the semiconductor substrate layer are arranged in an N×N square matrix (N≥5), and the TSVs in the TSVs The metal column (203) of the top layer metal interconnection line (102) and the bottom layer metal interconnection line (302) are connected together to form a series path, and the series path is a three-dimensional spiral structure in the vertical plane (that is, a three-dimensional spiral inductor device), in use, the current flows from one plate of the three-dimensional spiral inductor to the other plate, except for the metal column in the center, the current will pass through each metal column in turn, because the inductance value of each TSV is different Equal to the sum of its own self-inductance and the mutual inductance of adjacent TSVs, the total inductance of the three-dimensional spiral inductor is equal to the superposition of the self-inductance and mutual inductance values of all TSVs in the array, so the three-dimensional spiral inductor of the present invention The inductor can greatly improve the quality and inductance value of the integrated inductor, so that it can well meet the requirements of the increasingly developed modern communication system for the integrated inductor.

Description of drawings

Fig. 1 is the plan view of the top dielectric layer of three-dimensional spiral inductor of the present invention;

Fig. 2 is the top view of the semiconductor substrate layer of the three-dimensional spiral inductor of the present invention;

Fig. 3 is the top view of the bottom dielectric layer of the three-dimensional spiral inductor of the present invention;

Fig. 4 is a perspective view after stacking the top dielectric layer, the semiconductor substrate layer and the bottom dielectric layer;

Fig. 5 is the A-A ' sectional view of the three-dimensional spiral inductor in Fig. 4;

Fig. 6 is the B-B' sectional view of the three-dimensional spiral inductor in Fig. 4;

Fig. 7 is the C-C ' sectional view of the three-dimensional spiral inductor in Fig. 4;

Fig. 8 is the graph that the inductance value (L value) of the three-dimensional spiral inductor of the present invention changes with the inductance area;

Fig. 9 is a graph showing the variation of the inductance quality factor (Q value) with the inductance area of the three-dimensional spiral inductor of the present invention.

The meanings of reference signs in the figure: 101-top dielectric layer, 102-top metal interconnection, 103-top first plate metal interconnection, 104-top second plate metal interconnection, 201-semiconductor lining Bottom layer, 202—insulation layer, 203—metal pillar, 301—bottom dielectric layer, 302—bottom metal interconnection line.

detailed description

The present invention will be specifically introduced below in conjunction with the accompanying drawings and specific embodiments.

1. The structure of three-dimensional spiral inductor

The structure of the three-dimensional spiral inductor based on the through-silicon hole array of the present invention includes: a top layer, a middle layer and a bottom layer.

1. Top floor

Referring to FIG. 1 , the top layer is a top dielectric layer 101, which is made of insulating material, and a top metal interconnection 102, a top first plate metal interconnection 103 and a top second plate metal interconnection 104 are fabricated therein.

The insulating material used for making the top dielectric layer 101 is silicon dioxide, silicon nitride or silicon oxynitride.

The material used to make the top metal interconnection 102 , the top first plate metal interconnection 103 and the top second plate metal interconnection 104 is copper or aluminum.

2. Middle layer

Referring to Fig. 2, the middle layer is a semiconductor substrate layer 201, which is made of silicon material, and a number of TSVs penetrating the upper and lower surfaces are etched on it, all TSVs have the same diameter, and the TSVs are arranged in an N× A square matrix of N, N≥5, the row spacing and column spacing between all TSVs are equal, the TSVs are filled with metal pillars 203 equal in height to the TSVs, and the metal pillars 203 are in contact with the inner walls of the TSVs An insulating layer 202 is also filled therebetween.

The insulating material used for making the insulating layer 202 is silicon dioxide, silicon nitride or silicon oxynitride.

The material used to make the metal post 203 is copper or aluminum.

3. Bottom layer

Referring to FIG. 3 , the bottom layer is a bottom dielectric layer 301 made of insulating material, and a bottom metal interconnection line 302 is fabricated therein.

The insulating material used to make the underlying dielectric layer 301 is silicon dioxide, silicon nitride or silicon oxynitride.

The material used to make the bottom metal interconnection line 302 is copper or aluminum.

Referring to Fig. 4, Fig. 5, Fig. 6 and Fig. 7, after the top layer, the middle layer and the bottom layer are sequentially combined, the top layer metal interconnection lines 102, the metal pillars 203 and the bottom layer metal interconnection lines 302 are connected together to form a different Discontinuous series path, what this series path forms in the vertical plane is a three-dimensional spiral structure, and this three-dimensional spiral structure promptly constitutes a three-dimensional spiral inductor; wherein the first metal interconnection line 103 of the top layer and the second plate metal of the top layer The interconnection wire 104 serves as the lead-out electrodes of the two plates of the three-dimensional spiral inductor.

When in use, the current flows from one pole plate to the other pole plate of the three-dimensional spiral inductor, and the current will pass through each metal pole 203 in turn except the central metal pole 203 .

Since the inductance of each TSV is equal to the sum of its own self-inductance and the mutual inductance of adjacent TSVs, the total inductance of the three-dimensional spiral inductor is equal to the self-inductance and mutual inductance of all TSVs in the array. superposition, so the three-dimensional spiral inductor of the present invention can greatly improve the quality and inductance value of the integrated inductor, so that it can well meet the requirements of the increasingly developed modern communication system for the integrated inductor.

2. Performance testing of three-dimensional spiral inductors

1. The inductance value of the inductor

Fig. 8 is a graph showing the variation of the inductance value (L value) with the inductance area of the three-dimensional spiral inductor of the present invention.

It can be seen from Figure 8:

(1) The inductance value of the three-dimensional spiral inductor of the present invention and the ordinary planar inductor all increases with the increase of the inductance area, and under the same situation of the inductance area, the inductance value of the three-dimensional spiral inductor of the present invention is about ordinary 3.2 times the inductance value of the planar inductor;

(2) When the inductance area is 50um×50um, the inductance density per unit area of the inductance value of the three-dimensional spiral inductor of the present invention is about 304nH/mm ² , which is far greater than the inductance per unit area of the inductance value of ordinary planar inductors Density (only 93nH/mm ² );

2. The quality factor of the inductor

Fig. 9 is a graph showing the variation of the inductance quality factor (Q value) with the inductance area of the three-dimensional spiral inductor of the present invention.

It can be seen from Figure 9 that:

(1) In the frequency range of 0 to 20 GHz, the quality factor of the three-dimensional spiral inductor of the present invention is between 15 and 25, which is far superior to that of ordinary planar inductors of the same size;

(2) The quality factor of the three-dimensional spiral inductor of the present invention varies with frequency, and the peak is located near 6 GHz, and the peak frequency is higher than the quality factor of ordinary planar inductors.

It can be seen that the three-dimensional spiral inductor based on the through-silicon via (TSV) array of the present invention greatly improves the quality and inductance value of the integrated inductor, and is more suitable for integrated circuits, especially in radio frequency/microwave/millimeter wave circuits .

It should be noted that the above embodiments do not limit the present invention in any form, and all technical solutions obtained by means of equivalent replacement or equivalent transformation fall within the protection scope of the present invention.

Claims (4)

1. a three-dimensional spiral inductor based on silicon via-hole array, including: top layer, intermediate layer and bottom, it is characterised in that

Described top layer is top layer dielectric layer (101), adopts and is made from an insulative material, make in it have top-level metallic interconnection line (102), Top layer the first pole plate metal interconnecting wires (103) and top layer the second pole plate metal interconnecting wires (104)；

Described intermediate layer is semiconductor substrate layer (201), uses silicon materials to make, it is etched with several through upper and lower surfaces Silicon through hole, the diameter of all silicon through holes is the most equal, and described silicon arrays of openings becomes the square matrix of a N × N, described N >=5, Line space and column pitch between all silicon through holes are the most equal, are filled with the metal column contour with silicon through hole in described silicon through hole (203), insulating barrier (202) it is also filled with between described metal column (203) and the inwall of silicon through hole；

Described bottom is underlying dielectric layer (301), adopts and is made from an insulative material, and making in it has underlying metal interconnection line (302)；

After described top layer, intermediate layer and bottom combine successively, top-level metallic interconnection line (102), metal column (203) and underlying metal Interconnection line (302) links together, and forms a continual tandem paths, and described tandem paths is formed in perpendicular Be a three-dimensional spiral structure, described three-dimensional spiral structure i.e. constitutes a three-dimensional spiral inductor；Described top layer the first gold medal Belong to interconnection line (103) and top layer the second pole plate metal interconnecting wires (104) the drawing of two pole plates as this three-dimensional spiral inductor Go out electrode；During use, electric current flows to another pole plate from three-dimensional spiral inductor pole plate, except being positioned at the metal at center Outward, electric current will pass sequentially through each metal column (203) to post (203).

Three-dimensional spiral inductor based on silicon via-hole array the most according to claim 1, it is characterised in that make described top The insulant that layer dielectric layer (101), underlying dielectric layer (301) and insulating barrier (202) use is silicon dioxide, silicon nitride or nitrogen Silicon oxide.

Three-dimensional spiral inductor based on silicon via-hole array the most according to claim 1, it is characterised in that make described gold The material that genus post (203) uses is copper or aluminum.

Three-dimensional spiral inductor based on silicon via-hole array the most according to claim 3, it is characterised in that make described top Layer metal interconnecting wires (102), top layer the first pole plate metal interconnecting wires (103), top layer the second pole plate metal interconnecting wires (104) and the end The material that layer metal interconnecting wires (302) uses is copper or aluminum.