KR20150073641A - Electro Plating Machine for Controlling Voltage and Current Density and Electro Plating Method thereby - Google Patents

Abstract

The present invention relates to an electroplating device and a method thereof capable of controlling voltage and current density. In an electroplating device having a plating bath in which a substrate is received, an anode facing a plated surface of the substrate and to which plating metal is connected, and a cathode connected to the substrate to form an electric field between the anode and the substrate, the electroplating device according to the present invention comprises: a power supply part for applying voltage to the substrate; a variable resistance part serially connected to the power supply part; a bypass part connected to the variable resistance part and the substrate in parallel; and a control part connected to the power supply part, the variable resistance part, and the bypass part to control the voltage and the current density applied to the substrate. Accordingly, the present invention can perform a high quality plating process by simultaneously controlling the voltage and the current density for an optimal plating process when the electroplating process is performed.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electroplating apparatus capable of controlling voltage and current density,

The present invention relates to an electroplating apparatus and method thereof, and is capable of performing a high-quality plating process by simultaneously controlling voltage and current density.

The electroplating process is capable of obtaining a high-quality thin film at a low cost, and has a simple method and mass production capability.

In general, it is widely used to form various metal thin films to prevent rust on the surface of the product or to increase the added value. It is also widely used in the fields of MEMS / NEMS and semiconductor devices.

This is because, as compared with other thin film forming techniques, the materials can be efficiently used, the deposition rate is fast, and the thin film can be formed thick, so that research groups and related industries are continuously researching and developing.

It is important to control the uniformity, physical properties, and surface state of the thin film in such a plating process. Particularly, it is important to prevent bubbles and pinhole defects. In order to alleviate the bubbles and pinhole defects, pulse plating, ), Development of plating solution, and so on.

However, such a method is difficult to set because of the difficulty in setting process conditions, and there are still a lot of unfinished parts. Therefore, the electroplating process is carried out at a low current density by a conventional defect prevention method.

To do this, the process is generally performed by using a constant current or constant voltage control of the power supply. If both currents are set too low, the voltage becomes too low to make the process difficult.

However, in the case of a micro-area plating process, if the voltage is lowered to lower the current density, the plating process may not proceed because the threshold voltage is not exceeded, and there is a case where the characteristics of the plating material are changed or the thin film is not formed at all .

In the case of constant current control, plating thickness can be easily predicted when a certain area is plated. However, when a high voltage is applied, it may cause destruction of a thin film or a device. When a low voltage is applied, The required threshold voltage can not be exceeded and the plating may hardly proceed.

In particular, in the case of plating an alloy, since the composition of the alloy is plated differently depending on the voltage, there is a problem that it is very difficult to form an alloy of a desired composition by an existing method.

In the case of constant voltage control, the process can proceed by setting a voltage at which the plating proceeds well. However, when the reaction region of the electrode is constant, the current density may vary in various ways depending on the area of the object to be plated. In most cases, the voltage can be adjusted according to the current flowing. However, in the case of micro-area plating, there is a limit to lower the voltage to lower the current density. When a high current density is formed, A problem of destruction of the thin film may occur.

A conventional cathode current control system for wafer electroplating is disclosed in Korean Patent Laid-Open Publication No. 2001-0024154 by a method of connecting individual resistors to a plurality of plating jig electrodes for current control during the plating process .

In the prior art, Korean Patent Laid-Open Publication No. 10-2005-0062227 entitled "Electroplating Apparatus ", a negative electrode is formed by a plurality of contacts on a semiconductor substrate to be plated and a variable resistor is connected to the negative electrode, And the amount of current flowing between the contact points is adjusted to achieve uniform plating speed.

However, in the conventional method as described above, the process is carried out with emphasis on the current density control by connecting the resistors in series or parallel in most circuits. However, since the voltage control is not performed, the various problems described above are still not solved have.

Disclosure of the Invention The present invention has been made to solve the above problems and provides a plating apparatus and method for simultaneously controlling a voltage and a current density capable of simultaneously setting a voltage and a current density capable of performing an optimal plating process in an electroplating process .

In order to accomplish the above object, the present invention provides a plating apparatus comprising: a plating vessel for receiving a substrate; an anode disposed opposite to a surface to be plated of the substrate and connected with a plating metal; and a predetermined electric field between the anode and the substrate And a negative electrode connected to the substrate so as to be formed on the substrate, the electroplating apparatus comprising: a power supply unit for applying a voltage to the substrate; a variable resistance unit connected in series to the power supply unit; And a control unit connected to the power supply unit, the variable resistor unit, and the bypass unit, and connected to the anode to control a reaction area of the anode to control voltage and current density applied to the substrate The present invention relates to an electroplating apparatus capable of controlling a voltage and a current density, and an electroplating method thereof.

In addition, it is preferable that a plurality of the plating metals are formed, a voltage is applied to the substrate through each of the plating metals, and the bypass portion is connected to each of the plating metals.

Preferably, the electroplating apparatus capable of controlling the voltage and the current density further includes a current measuring unit for measuring a current density of the substrate, wherein the variable resistance unit includes a general resistance, a shunt resistor, and an electron And measuring a current flowing through each of the anodes by measuring a potential difference across both ends of the variable resistor section in the current measuring section connected to one of the controllable variable resistors in series and measuring the current density of the substrate desirable.

Here, it is preferable that the current measuring unit measures the current density of the substrate by measuring an electric current flowing through each anode by attaching an ammeter capable of communicating with the outside, and based on the measured current density value, It is preferable to automatically control the set value of the power supply unit or automatically control the current density of the substrate in accordance with the reaction area of the anode and the plating area of the body to be plated.

The bypass unit may include an electronically controllable electric circuit composed of a transistor, an inductor, a capacitor and a resistor, an electronically controllable IC-type current control circuit, an electronically controlled variable resistor, a variable resistor with an electronically controlled motor, , A constant voltage circuit, and a constant current circuit.

According to the present invention, it is possible to simultaneously control a voltage and a current density at which an optimal plating process can be performed in the electroplating process, thereby achieving a high-quality plating process.

Further, the present invention can control the voltage as well as the current density at the same time, so that the voltage applied to the plating liquid can be fixed and the current density can be controlled even if the reaction area or the plating area of the anode changes during the plating process, Can be formed.

In addition, by controlling the reaction area of the anode, the voltage and current density applied to the substrate can be set to a value desired by the user. This method is suitable for element plating with a very small area, There is no problem of thin film breakdown and it is possible to overcome the occurrence of redundancy due to the excessive current density that may occur in the simple constant voltage control.

Therefore, high-quality plating process can be performed and it is expected that the ripple effects will be great.

1 is a schematic view of an electroplating apparatus capable of controlling voltage and current density according to the present invention;
2 is a schematic diagram according to an embodiment of the present invention;

The present invention relates to an electroplating apparatus and method thereof, and is capable of performing a high-quality plating process by simultaneously controlling voltage and current density.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. 1 is a configuration diagram of an electroplating apparatus capable of controlling voltage and current density according to the present invention.

As shown in the drawings, an electroplating apparatus capable of controlling voltage and current density according to an embodiment of the present invention includes a plating vessel for receiving a substrate, an anode disposed opposite to a surface to be plated of the substrate, And a cathode connected to the substrate such that a predetermined electric field is formed between the anode and the substrate, the plating apparatus comprising: a power supply unit for applying a voltage to a substrate; a variable resistance unit connected in series to the power supply unit; A bypass unit connected in parallel to the variable resistance unit and the substrate, a bypass unit connected to the power supply unit, the variable resistance unit, and the bypass unit, and connected to the anode to control a reaction area of the anode, And a control unit for controlling the current density.

The present invention relates to a conventional plating apparatus, which comprises a power supply unit for applying a voltage to a substrate to be plated, a variable resistor unit connected in series to the power supply unit to control the voltage constantly by varying the resistance, A control unit for automatically controlling the power supply unit, the variable resistor unit, and the bypass unit, and the control unit connected to the anode to automatically control the reaction area.

That is, the present invention provides a method of controlling the current density by controlling the current density of the substrate by controlling the reaction area of the anode and making the substrate and the resistor connect in series (variable resistance portion) and parallel connection (bypass portion) , The voltage applied to the substrate can be kept constant at a desired set value, and the current density can be controlled according to the resistance.

First, the power supply unit applies a voltage to the substrate, and DC, AC power, pulse power, or the like is used.

The variable resistor unit is connected to the power supply unit in series to control the voltage applied to the substrate to be constant, and is also connected to the substrate in series.

Here, the variable resistance portion is formed of a general resistance, a shunt resistance, or an electronically controllable variable resistor, and the current density of the substrate is measured by measuring a potential difference flowing across both ends of the variable resistance portion, The voltage density and the current density applied to the substrate can be changed in real time by using the variable resistance portion.

The bypass unit is connected to the variable resistor unit and the substrate in parallel to control the current density of the substrate. The bypass unit electrically controls an electronic circuit including a transistor, an inductor, a capacitor and a resistor, A potentiometer IC type current control circuit, an electronically controlled variable resistor, a variable resistor with an electronically controlled motor, an electronically controlled potentiometer, a constant voltage circuit, and a constant current circuit.

That is, when a voltage is applied from the power supply unit, the voltage and current are distributed to the substrate and the bypass unit, and thus the voltage and the current density applied to the substrate are controlled by the user, As shown in FIG.

More specifically, the current density of the substrate flows differently depending on the resistance ratio between the bypass portion and the substrate. For example, if the resistance of the plating liquid and the substrate is the same as the resistance of the bypass portion, the voltage applied from the power supply portion is equally applied to the substrate and the bypass portion, and the current is distributed in a 1: 1 flow. At this time, the applied voltage does not change even if the resistance value of the bypass portion is adjusted, and when the resistance value of the bypass portion is adjusted, the current applied to the substrate is controlled according to the ratio of the resistance.

The current flowing through the substrate may be monitored and utilized by a current measuring unit, for example, a microcontroller, an ammeter, etc., and the bypass unit may be built in the power supply unit.

Further, the present invention controls the current density of the substrate by controlling the current flowing through the substrate by controlling the resistance of the substrate itself by changing the reaction area of the anode. As shown in FIG. 1, the reaction area of the anode can be controlled by adjusting the area of the anode contained in the plating solution, and the control unit (microcontroller) connected to the anode can automatically control the depth of the anode to be immersed in the plating solution .

The power supply unit, the variable resistor unit, the bypass unit, and the anode are connected to a control unit (microcontroller) to control each part according to the current density measured by the substrate, adjust the reaction area of the resistor and the anode, So that the current density can be automatically controlled.

Therefore, the present invention is capable of precisely controlling the voltage and current density of the substrate, and is more suitable for element plating having a small area. There is no problem of element and thin film breakage due to excessive voltage generated in simple constant current control, It is possible to minimize the occurrence of defects due to the excessive current density that can occur, and thus it is possible to perform a plating process of high quality.

According to another aspect of the present invention, there is provided a plasma display panel including a plurality of plating metals formed on a substrate, a plurality of plating metals formed on the plating metals, And the like. That is, the current density of the substrate can be controlled by controlling the reaction area of the anode.

The plated metal refers to a metal to be plated on a surface to be plated of the substrate. A plurality of plated metals may be formed of a plurality of plated metals of the same kind, or various types of plated metals may be formed.

In order to form a plurality of plating metals of the same kind, when a plating layer having a different thickness or density at a specific position on the surface to be plated of the substrate is to be formed into a single or multiple layers, the reaction area of the anode connected to the plating metal The number of modules) to control the voltage and current density.

The formation of a plurality of different types of plating metal is intended to form other kinds of plating layers at specific positions on the surface to be plated of the substrate or to form different types of plating layers for each layer when the plating layers are multilayer, So that the voltage and current density are controlled by the anode connected to the plating metal, respectively.

And the bypass portion is connected to the plating metal to control the current density of the substrate corresponding to each region.

Further, the current flowing through the substrate corresponding to each of the plated metals is measured by the current measuring section, and a potential difference across both ends of the variable resistance section formed by any one of the general-purpose resistor, the shunt resistor and the electronically controllable variable resistor connected in series to the respective anodes And measuring a current flowing through each of the anodes to measure a current density of the substrate.

The current measuring unit measures an electric current flowing through each of the anodes by attaching an ammeter capable of communicating with the outside, thereby measuring the current density of the substrate.

The current density measured by the current measuring unit is automatically controlled through the control unit according to the set value of the power supply unit, the reaction area of the anode, or the plating area of the material to be plated, So that a plating layer of a different composition is formed in the plating liquid. The plating layer of the other composition may be formed as a single layer or a multilayer.

That is, a constant voltage is always applied by adjusting the set value of the power supply unit from the current density measured on the substrate, or the voltage applied to the substrate is kept fixed and the current density can be controlled.

Generally, in the case of constant-voltage plating, the process can proceed by setting a voltage value at which the plating proceeds well. However, when the reaction region of the electrode is constant, the current density may vary according to the plating area of the plated body. In most cases, the voltage can be adjusted according to the current flowing. However, in the case of micro-area plating, there is a limit to lower the voltage in order to lower the current density. When a high current density is formed, A problem of destruction of the thin film may occur.

Accordingly, it is possible to control not only the voltage but also the current density, so that the voltage applied to the plating liquid can be fixed and the current density can be controlled even if the reaction area or plating area of the anode changes during the plating process, Can be formed.

Hereinafter, the operation of the present invention will be described in detail.

the substrate on which the seed metal is deposited is accommodated in the plating bath and electroplating is performed.

First, a voltage is applied to the substrate through the power supply unit, and the current flowing toward the substrate is measured while the constant-voltage plating is being performed. At this time, the resistance by the variable resistance portion is set to a constant value for maintaining the constant voltage, and the current flowing through the substrate is measured accordingly.

Here, if the voltage value is not the set voltage value, the voltage value of the power supply unit can be adjusted through the variable resistance unit connected in series to the power supply unit. This is to ensure that a constant voltage is always applied to the substrate in accordance with the parameters generated in the plating process, such as the reaction area of the anode being changed or the plating area being changed, although the voltage supplied from the power supply unit is constant. That is, it is intended to carry out the constant voltage plating.

When the reaction area of the anode or the plating area of the substrate increases or decreases, the current flowing to the substrate changes, and when the current density deviates from the set current density value, the current density of the substrate is controlled through the bypass section connected in parallel to the variable resistance section and the substrate .

The voltage and current density applied to the semiconductor substrate are controlled through the power supply unit, the variable resistor unit, and the connected control unit (microcontroller) of the bypass unit based on the measured current density value.

FIG. 2 is a schematic diagram according to an embodiment of the present invention (FIG. 2 (a) - a simple schematic diagram for FIG. 1, FIGS. 2 (b), 2 (c) A variable resistor R1 and a substrate Load R2 are connected in series and a bypass circuit R3 is connected in parallel with the power supply V, It can be seen that they are connected. That is, in the electroplating apparatus, the voltage and the current density can be simultaneously controlled by connecting the resistance to the substrate in parallel with the series.

The potential difference (V1-V2) across the variable resistor (R1) is measured with a voltmeter, and the current flowing through the substrate is measured with an ammeter.

First, a voltage of 1 V was applied from the power supply unit, the resistance R1 in the variable resistance unit was set to 5 OMEGA, and the current was measured at 0.1 A. In this case, the potential difference between the both ends of the variable resistance portion was 0.5 V. When the resistance R2 of the substrate was 10 OMEGA, the measured current value was 0.05 A, the resistance R3 of the bypass portion was 10 OMEGA, Respectively.

In this case, when the plating area is doubled (R2 is 5 ?, 0.1 A) (FIG. 2 (c)), the voltage applied to the substrate even when the plating area is doubled by adjusting the variable resistor R1 to 3.5? Is maintained at 0.5 V, and the current density can also be kept constant by adjusting the resistance R3 of the bypass portion to 11.6 ?. That is, the voltage and current density flowing through the substrate R2 can always be kept constant despite the increase in the plating area.

In addition, if the plating area of the substrate is constant but the reaction area of the anode is increased by changing the number of anode modules, the current density of the substrate increases and in this case, the thickness of the plating layer increases. The reaction area of the anode may be increased.

The control of the variable resistance unit and the bypass unit and the control of the reaction area of the anode can be automatically controlled by the micro controller, and the current density of the substrate can be controlled by the microcontroller So that the user can promptly cope with a change in reaction conditions such as a sudden change in plating area and the like.

Claims (12)

An anode connected to the plating metal and a cathode connected to the substrate so that a predetermined electric field is formed between the anode and the substrate; The electroplating apparatus according to claim 1,
A power supply unit for applying a voltage to the substrate;
A variable resistor connected in series to the power supply;
A bypass unit connected in parallel to the variable resistor unit and the substrate;
And a control unit connected to the power supply unit, the variable resistance unit, and the bypass unit, and controlling the voltage and current density applied to the substrate by controlling the reaction area of the anode by being connected to the anode. Which can control the voltage and the current density. The plating method according to claim 1,
Wherein a plurality of electrodes are formed on the substrate and a voltage is applied to the substrate through each of the plating metals, and the bypass unit is connected to each of the plating metals. The electroplating apparatus according to claim 2, wherein the electroplating apparatus capable of controlling the voltage and the current density comprises:
And a current measuring unit for measuring a current density of the substrate is further formed. The variable resistance unit according to claim 3, wherein the variable resistance unit is formed by connecting one of a universal resistance, a shunt resistor, and an electronically controllable variable resistor to each anode in series, and measuring a potential difference across the variable resistance unit in the current measurement unit And measuring a current flowing through each of the positive electrodes to measure a current density of the substrate, wherein the voltage and the current density can be controlled. The apparatus of claim 3, wherein the current measuring unit comprises:
And an ammeter capable of communicating with the outside is attached to measure the current flowing through each of the anodes, thereby measuring the current density of the substrate. 4. The method of claim 3, wherein, based on the measured current density value,
Wherein an electric current density of the substrate is automatically controlled according to a setting value of the power supply unit or a plating area of a plating target of a plating target. The apparatus according to claim 1,
Electronically controllable electronic circuits consisting of transistors, inductors, capacitors and resistors, electronically controlled IC-type current control circuits, electronically controlled variable resistors, variable resistors with electronically controlled motors, electronically controlled potentiometers, constant voltage circuits and constant current circuits Wherein the voltage and the current density of the electroplating apparatus are controlled so that the voltage and the current density can be controlled. An electroplating method for plating a plating metal connected to an anode on a surface to be plated of a substrate,
A first step of applying a voltage to the substrate through the power supply unit;
A second step of measuring a current density of the substrate through a current measuring unit;
A third step of controlling a voltage value of the power supply unit through a variable resistance unit connected in series to the power supply unit;
A fourth step of controlling a current density of the substrate through the variable resistor and a bypass connected in parallel to the substrate;
And controlling a voltage and a current density to be applied to the substrate through the control unit connected to the power supply unit, the variable resistor unit, and the bypass unit based on the measurement current density value. An electroplating method capable of controlling current density. The plasma display apparatus according to claim 8, wherein the plating metal is formed in a plurality of layers, a voltage is applied to the substrate through each plating metal, and the bypass portion is connected to each of the plating metals to control a current density of the substrate Wherein the voltage and current density can be controlled. The variable resistance unit according to claim 9, wherein the variable resistance unit is formed by connecting one of a general resistance, a shunt resistance, and an electronically controllable variable resistance to each anode in series, and measures a potential difference across both ends of the variable resistance unit in the current measurement unit And measuring a current flowing through each of the positive electrodes to measure a current density of the substrate. The apparatus of claim 9, wherein the current measuring unit comprises:
A method of electroplating capable of controlling voltage and current density, characterized by measuring an electric current flowing through each anode by attaching an ammeter capable of communicating with the outside, thereby measuring the current density of the substrate. 10. The method of claim 9, wherein based on the measured current density value,
Wherein the current density of the substrate is automatically controlled according to a setting value of the power supply unit or a plating area of a plating target of a plating target.

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