KR20050118488A - Tunable inductor and method of manufacturing the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tunable inductor and a method of manufacturing the same. A tunable inductor and a method of manufacturing the same are connected to each other. When the first and second electrodes are adjusted according to the voltage so that the inductance value is changed and used as a matching element with the tunable capacitor, a tunable inductor capable of matching in a wider frequency band and a method of manufacturing the same are provided. Presented.

Description

Tunable inductor and method of manufacturing the same

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tunable inductor and a method of manufacturing the same, and in particular, joining the first and second inductors having the first and second electrodes formed thereon, and applying the microelectromechanical system (MEMS) switch concept The present invention relates to a tunable inductor and a method of manufacturing the same in which an inductance value is changed by adjusting an interval of an electrode according to a voltage to be changed.

As a matching element used to match a signal of a high frequency band in an RF transmission line and deliver optimal power to a receiver, a series circuit of an inductor and a capacitor as shown in FIG. 1. Alternatively, a parallel circuit is used. Their inductance and capacitance are designed to match the desired frequency. The inductor used was a single metal layer or a structure of two stacked metal layers.

By the way, the frequency used in the current mobile phone or PCS is different because the bandwidth used, if you use a fixed inductance and capacitance is only one frequency band can not be used universally.

Disclosure of Invention An object of the present invention is to provide a tunable inductor and a method of manufacturing the same, which can be appropriately matched as necessary in various frequency bands by allowing inductance values to vary according to a frequency band used.

Another object of the present invention is to provide a tunable inductor and a method of manufacturing the same, which can implement various inductance values according to an applied voltage by implementing electrodes on upper and lower inductors using a MEMS switch concept. .

In the tunable inductor according to the present invention, the electrodes of the second inductor are connected to each other by bonding the first and second inductors having the first and second electrodes formed thereon, and applying a voltage to the electrodes of the first inductor. To adjust the inductance value.

The first inductor may include a semiconductor substrate, a copper layer formed in a spiral shape on the semiconductor substrate and insulated by an insulating film, a diffusion barrier layer formed on the copper layer, and an electrode formed on a predetermined region above the diffusion barrier layer. Include.

The second inductor is formed on a semiconductor substrate, a copper layer formed in a spiral form on the semiconductor substrate and insulated by an insulating film, a first diffusion barrier layer formed on the copper layer, and an upper portion of the first diffusion barrier layer. And a conductive layer having a predetermined portion etched to a predetermined thickness, a second diffusion barrier layer formed on the conductive layer, and an electrode formed on a predetermined region above the second diffusion barrier layer.

The first inductor and the second inductor are bonded to each other, and the etched portion of the second inductor is filled with air.

A method of manufacturing a tunable inductor according to the present invention includes forming a first insulating film on a first semiconductor substrate, filling the first copper layer after patterning the first insulating film, and forming the first copper layer. Forming a first diffusion barrier over the first insulating layer, forming a first polysilicon layer over the first diffusion barrier, and then patterning the first electrode to form a first electrode; Forming an insulating film, embedding a second copper layer after patterning the second insulating film, forming a second diffusion barrier layer on the second insulating film on which the second copper layer is formed, Forming a second polysilicon layer on the diffusion barrier layer and patterning the predetermined region of the second polysilicon layer to a predetermined thickness; and forming a third polysilicon layer on the second polysilicon layer. Forming a diffusion barrier layer, forming a third polysilicon layer on the third diffusion barrier layer, and then patterning a second electrode to form a second electrode, and the first semiconductor substrate having the first copper layer and the first electrode formed thereon And bonding the second semiconductor substrate on which the second copper layer and the second electrode are formed.

The first and second insulating layers are patterned in a spiral form.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention;

FIG. 2 is a schematic diagram of a tunable inductor using a MEMS switch according to the present invention, in which first and second electrodes are respectively formed on first and second inductors, and then bonded and applied thereto. The spacing of the electrodes is adjusted according to the voltage so that the inductance value is changed.

Referring to the first inductor forming process, the first insulator 12 is formed on the first semiconductor substrate 11, and then, the first inductor is formed by a lithography process and an etching process using a mask for forming a spiral inductor. The insulating film 12 is patterned. After forming the first copper layer 13 over the entire structure including the patterned first insulating film 12, the first copper layer 13 is polished to expose the first insulating film 12 to form a first inductor. . The first polysilicon film 15 is formed after the first diffusion barrier 14 is formed over the entire structure. Then, the first polysilicon film 15 is patterned to form an horn electrode.

Referring to the process of forming the second inductor, after forming the second insulating layer 17 on the second semiconductor substrate 16, the second inductor may be a lithography process and an etching process using a mask for forming a spiral inductor. The insulating film 17 is patterned. After forming the second copper layer 18 over the entire structure including the patterned second insulating layer 17, the second insulating layer 17 is polished to expose the second inductor. A second diffusion barrier film 19 is formed over the entire structure, and a second polysilicon film 20 is formed over the entire structure. After etching a predetermined portion of the second polysilicon film 20 so that the second polysilicon film 20 remains at a predetermined thickness, a third diffusion barrier 21 is formed on the entire structure. The third polysilicon layer 22 is formed on the third diffusion barrier layer 21 and then patterned to form an electrode.

As described above, the first inductor and the second inductor having the electrodes formed thereon are bonded to each other, and at this time, the second polysilicon layer 20 is patterned so that the joined portion is filled with air.

In the inductor according to the present invention configured as described above, when a bias is applied to an electrode formed of the first polysilicon film 15, a charge is generated, and electrostatic force is applied to the first copper layer 13 and the first electrode. It is made between the two copper layers 18, and the electrodes of the second inductor move by the static electricity to be adjacent to or in contact with the electrodes of the first inductor. Thus, the inductance value is adjusted according to the spacing of the electrodes to implement a tunable inductor.

As described above, in accordance with the present invention, the first and second inductors having the first and second electrodes formed thereon are bonded to each other, and the electrode spacing is adjusted according to the applied voltage using a MEMS (Micro ElectroMechanical System) switch concept to inductance. By configuring the tunable inductor so that the value changes, if it is used as a matching element with the tunable capacitor, it can be matched in a wider frequency band and can be used in various products.

1 is a circuit diagram of a matching element composed of a series circuit of an inductor and a capacitor.

2 is a cross-sectional view of a tunable inductor according to the present invention.

<Explanation of symbols for the main parts of the drawings>

11 first semiconductor substrate 12 first insulating film

13 first copper layer 14 first diffusion barrier film

15: first polysilicon film 16: second semiconductor substrate

17 second insulating film 18 second copper layer

19: 2nd diffusion prevention film 20: 2nd polysilicon film

21: third diffusion barrier film 22: third polysilicon film

Claims (6)

A tunable in which an electrode of the second inductor is moved by adjusting the first and second inductors having the first and second electrodes formed thereon and applying a voltage to the electrodes of the first inductor to adjust the inductance value. Inductor. The method of claim 1, wherein the first inductor Semiconductor substrates; A copper layer formed in a spiral shape on the semiconductor substrate and insulated by an insulating film; A diffusion barrier formed on the copper layer; And Tunable inductor including an electrode formed in a predetermined region on the diffusion barrier. The method of claim 1, wherein the second inductor Semiconductor substrates; A copper layer formed in a spiral shape on the semiconductor substrate and insulated by an insulating film; A first diffusion barrier layer formed on the copper layer; A conductive layer formed on the first diffusion barrier layer and having a predetermined portion etched to a predetermined thickness; A second diffusion barrier layer formed on the conductive layer; And A tunable inductor including an electrode formed on a predetermined region above the second diffusion barrier. The tunable inductor of claim 1, wherein the first inductor and the second inductor are bonded to each other, and an etched portion of the second inductor is filled with air. Forming a first insulating film on the first semiconductor substrate; Embedding a first copper layer after patterning the first insulating film; Forming a first diffusion barrier over the first insulating layer on which the first copper layer is formed; Forming a first electrode by forming a first polysilicon layer on the first diffusion barrier layer and then patterning the first electrode; Forming a second insulating film on the second semiconductor substrate; Embedding a second copper layer after patterning the second insulating film; Forming a second diffusion barrier layer on the second insulating layer on which the second copper layer is formed; Forming a second polysilicon layer on the second diffusion barrier layer and patterning the predetermined region of the second polysilicon layer to have a predetermined thickness; Forming a third diffusion barrier over the second polysilicon layer; Forming a second electrode by forming and then patterning a third polysilicon layer on the third diffusion barrier layer; And And bonding the first semiconductor substrate on which the first copper layer and the first electrode are formed, and the second semiconductor substrate on which the second copper layer and the second electrode are formed. The method of claim 5, wherein the first and second insulating layers are patterned in a spiral form.