CN116110696A

CN116110696A - Ultra-high coupling full-symmetrical transformer based on TSV

Info

Publication number: CN116110696A
Application number: CN202310046643.9A
Authority: CN
Inventors: 王凤娟; 邓悦; 余宁梅; 杨媛; 尹湘坤; 朱樟明
Original assignee: Xian University of Technology
Current assignee: Xian University of Technology
Priority date: 2023-01-31
Filing date: 2023-01-31
Publication date: 2023-05-12

Abstract

The invention discloses an ultra-high coupling full-symmetrical transformer based on TSV, and the primary coil and the secondary coil of the 1:1 transformer provided by the invention are completely symmetrical in structure, and can be used for differential circuits to inhibit common mode noise. The invention adopts the silicon through holes to form a vertical structure, each metal layer of the primary coil and the secondary coil is connected through the silicon through holes to realize a mode of up-down alternation, compared with a two-dimensional transformer, the compact structure reduces the occupied area by half, realizes a longer coupling path in the same occupied area, and enhances the coupling between the primary winding and the secondary winding. Because the primary coil and the secondary coil are mutually surrounded, magnetic flux generated by the primary coil passes through the secondary coil as much as possible, magnetic leakage is small, and an ultrahigh coupling coefficient larger than 0.970 is formed.

Description

Ultra-high coupling full-symmetrical transformer based on TSV

Technical Field

The invention belongs to the technical field of passive electronic devices, and relates to an ultra-high coupling full-symmetrical transformer based on TSV.

Background

Transformers are critical passive devices in many Radio Frequency Integrated Circuit (RFIC) applications and have been widely used in the design of filters, balun, couplers, voltage controlled oscillators and power amplifiers. The traditional two-dimensional sheet transformer is of a planar or laminated structure, and has the problems of low coupling coefficient, large occupied chip area and the like. In recent years, with the development of through silicon via technology, three-dimensional transformers based on TSVs start to be in a brand-new angle, two dimensions are changed into three dimensions by increasing TSVs in the vertical direction, the occupied area of the transformers can be effectively reduced, the coupling coefficient is improved, the bottleneck faced in the design of the two-dimensional transformers is solved, and meanwhile, the three-dimensional transformers become a great advantage in the future radio frequency integrated circuit design. However, three-dimensional transformers based on TSVs have not been proposed by researchers so far and have the characteristics of miniaturization, high coupling and full symmetry.

Disclosure of Invention

The invention aims to provide an ultra-high coupling full-symmetrical transformer based on TSV, which solves the problems of low coupling coefficient, large occupied chip area and difficult integration with a differential circuit of the existing three-dimensional transformer.

The technical scheme adopted by the invention is that the ultra-high coupling full-symmetrical three-dimensional transformer based on TSV comprises a primary coil structure and a secondary coil which are symmetrically arranged; the primary coil and the secondary coil are formed by connecting a metal layer, a contact hole and a Through Silicon Via (TSV); each section of metal layer of the primary coil and each section of metal layer of the secondary coil are connected through two contact holes and one through silicon via hole to form a mode of up-down alternation; the primary coil and the secondary coil are wound from outside to inside.

The invention is also characterized in that:

the primary coil is provided with a Port _p1 、Port _p2 Two ports, the secondary coil is provided with ports _s1 、Port _s2 Two ports, port when the transformer works _p2 And Port _s2 Grounded, port _p1 And Port _s1 Respectively as an input port and an output port of the transformer.

The metal layers and the contact holes in the primary coil and the secondary coil are made of copper or aluminum.

The through silicon via TSV includes a metal pillar and an insulating layer.

In the TSV, the metal column is a copper column or an aluminum column; the insulating layer material is one of silicon dioxide, silicon nitride or silicon oxynitride.

The invention has the beneficial effects that the primary coil and the secondary coil of the 1:1 transformer designed by the invention are completely symmetrical in structure, and can be used for differential circuits to inhibit common mode noise. The invention adopts the silicon through holes to form a vertical structure, each metal layer of the primary coil and the secondary coil is connected through the silicon through holes to realize a mode of up-down alternation, compared with a two-dimensional transformer, the compact structure reduces the occupied area by half, realizes a longer coupling path in the same occupied area, and enhances the coupling between the primary winding and the secondary winding. Because the primary coil and the secondary coil are mutually surrounded and all are wound from the outermost layer to the center, magnetic flux generated by the primary coil passes through the secondary coil as much as possible, magnetic leakage is small, and an ultrahigh coupling coefficient larger than 0.970 is formed. In addition, the self-resonance frequency and the quality factor are greatly improved, the frequency range in which the transformer can work is enlarged, and the performance of the transformer is improved. Therefore, the designed 1:1 transformer structure meets the requirements of miniaturization, high coupling and full symmetry.

Drawings

FIG. 1 is a schematic diagram of a 1:1 transformer of the ultra-high coupling fully symmetric transformer based on TSV of the present invention;

FIG. 2 is a top view of a 1:1 transformer of the ultra-high coupling fully symmetric transformer based on TSV of the present invention;

fig. 3 is a simulation diagram of the coupling coefficient of a 1:1 transformer of the ultra-high coupling full-symmetrical transformer based on TSV.

Detailed Description

The invention will be described in detail below with reference to the drawings and the detailed description.

The ultra-high coupling holohedral symmetry three-dimensional transformer based on TSV comprises a top dielectric layer, a middle silicon substrate layer and a bottom dielectric layer. As shown in fig. 1 and 2, a metal layer P is formed in the top dielectric layer ₁ 、P ₃ 、P ₅ 、S ₆ 、S ₈ 、S ₁₀ And contact withHole C ₁ 、C ₄ 、C ₅ 、C ₈ 、C ₉ 、C ₁₂ 、C ₁₃ 、C ₁₆ 。

TSV with through silicon vias fabricated in intermediate silicon substrate layer ₁ 、TSV ₂ 、TSV ₃ 、TSV ₄ 、TSV ₅ 、TSV ₆ 、TSV ₇ And TSV (through silicon via) ₈ The eight through silicon vias are completely consistent in structure, and metal columns and insulating layers are sequentially manufactured from inside to outside.

Metal layers P are respectively arranged in the bottom dielectric layer ₂ 、P ₄ 、S ₇ 、S ₉ And contact hole C ₂ 、C ₃ 、C ₆ 、C ₇ 、C ₁₀ 、C ₁₁ 、C ₁₄ 、C ₁₅ 。

Metal layer P ₁ Contact hole C ₁ TSV (through silicon Via) ₁ Contact hole C ₂ Metal layer P ₂ Contact hole C ₃ TSV (through silicon Via) ₂ Contact hole C ₄ Metal layer P ₃ Contact hole C ₅ TSV (through silicon Via) ₃ Contact hole C ₆ Metal layer P ₄ Contact hole C ₇ TSV (through silicon Via) ₄ Contact hole C ₈ Metal layer P ₅ The primary coils of the 1:1 transformers are connected in turn.

Metal layer S ₆ Contact hole C ₉ TSV (through silicon Via) ₅ Contact hole C ₁₀ Metal layer S ₇ Contact hole C ₁₁ TSV (through silicon Via) ₆ Contact hole C ₁₂ Metal layer S ₈ Contact hole C ₁₃ TSV (through silicon Via) ₇ Contact hole C ₁₄ Metal layer S ₉ Contact hole C ₁₅ TSV (through silicon Via) ₈ Contact hole C ₁₆ Metal layer S ₁₀ The secondary coils of the 1:1 transformers are connected in turn. P (P) ₁ The metal layer is terminated by Port _p1 Port, P ₅ The metal layer is terminated by Port _p2 Port S ₆ The metal layer is terminated by Port _s1 Port S ₁₀ The metal layer is terminated by Port _s2 A port.

Each section of metal layer of the primary coil and each section of metal layer of the secondary coil are connected through two contact holes and one silicon through hole to form a mode of up-down alternation, the primary coil and the secondary coil are completely symmetrical and are wound from the outermost layer to the center, the coupling path can be increased by adopting the structure, magnetic flux generated by the primary coil can pass through the secondary coil as much as possible, magnetic leakage is small, and the two have the advantage of promoting the ultra-high coupling coefficient of the structure.

The primary coil of the transformer is provided with a Port _p1 、Port _p2 Two ports, the secondary coil of the transformer is provided with ports _s1 、Port _s2 Two ports, port when the transformer works _p2 And Port _s2 Grounded, port _p1 And Port _s1 As an input/output port of the transformer.

The top dielectric layer and the bottom dielectric layer are made of one of insulating material silicon dioxide, silicon nitride or silicon oxynitride, and in the embodiment, silicon dioxide is adopted;

the metal filled in the through silicon via is copper or aluminum, and copper is used for filling in the embodiment;

the insulating layer of the through silicon via uses one of silicon dioxide, silicon nitride or silicon oxynitride, and in this embodiment, silicon dioxide is used;

metal layer P ₁ 、P ₂ 、P ₃ 、P ₄ 、P ₅ 、S ₆ 、S ₇ 、S ₈ 、S ₉ 、S ₁₀ And contact hole C ₁ 、C ₂ 、C ₃ 、C ₄ 、C ₅ 、C ₆ 、C ₇ 、C ₈ 、C ₉ 、C ₁₀ 、C ₁₁ 、C ₁₂ 、C ₁₃ 、C ₁₄ 、C ₁₅ 、C ₁₆ The material used is copper or aluminum, copper being used in this example.

In order to test the performance of the proposed 1:1 transformer, the transformer was modeled and simulated using electromagnetic simulation software HFSS, resulting in a coupling coefficient of 0-40 GHz, as shown in FIG. 3, from which it can be seen that the proposed 1:1 transformer has a coupling coefficient greater than 0.970. Metal layer width of the modelThe height of the through silicon via is 80 mu m, the length of the whole model is 110 mu m, the width is 90 mu m, the height is 88 mu m, and the occupied area is 0.0099mm ² The integration level is improved, and the requirements of miniaturization, high coupling and full symmetry are met.

Claims

1. Ultra-high coupling full-symmetrical three-dimensional transformer based on TSV, its characterized in that: the device comprises a primary coil structure and a secondary coil which are symmetrically arranged; the primary coil and the secondary coil are formed by connecting a metal layer, a contact hole and a TSV (through silicon via); each section of metal layer of the primary coil and each section of metal layer of the secondary coil are connected through two contact holes and one through silicon via hole to form a mode of up-down alternation; the primary coil and the secondary coil are wound from outside to inside.

2. The ultra-high coupling fully symmetrical three-dimensional transformer based on TSV according to claim 1, characterized in that: the primary coil is provided with a Port _p1 、Port _p2 Two ports, the secondary coil is provided with ports _s1 、Port _s2 Two ports, port when the transformer works _p2 And Port _s2 Grounded, port _p1 And Port _s1 Respectively as an input port and an output port of the transformer.

3. The ultra-high coupling fully symmetrical three-dimensional transformer based on TSV according to claim 1, characterized in that: and the metal layers in the primary coil and the secondary coil and the contact holes are made of copper or aluminum.

4. The ultra-high coupling fully symmetrical three-dimensional transformer based on TSV according to claim 1, characterized in that: the through silicon via TSV includes a metal pillar and an insulating layer.

5. The ultra-high coupling fully symmetric three-dimensional transformer based on TSV according to claim 4 characterized in that: in the TSV, the metal column is a copper column or an aluminum column; the insulating layer material is one of silicon dioxide, silicon nitride or silicon oxynitride.