KR20110092965A - Apparatus of facing target sputtering and method for synthesizning crystalline silicon thin films at lower temperature using the same - Google Patents

Abstract

PURPOSE: A target facing sputtering device and a low temperature crystalline silicon thin film combining method using the same are provided to place a substrate in the lower part of a plasma area between a first target and a second target, thereby suppressing collision between the substrate and high energy particles which are generated during a process for depositing a thin film. CONSTITUTION: A gas supply unit(110) supplies a gas to a chamber(100). An inductively coupled plasma coil is arranged on a plasma area between a first target(130a) and a second target(130b). A substrate(150) is arranged in the lower part of the plasma area between the first target and the second target. A first RF power supply source(162) applies potentials to first and second targets. A second RF power supply source(164) applies potentials to the inductively coupled plasma coil.

Description

Opposite target sputtering apparatus and low temperature crystalline silicon thin film synthesis method using the same

The present invention relates to an opposing target sputtering apparatus and a method for synthesizing a low temperature crystalline silicon thin film using the same.

Physical vapor deposition (PVD), which deposits a thin film in a semiconductor device manufacturing process, vacuums particles of the same material (Al, Ti, TiW, W, Ti, TiN, Co, Ni, etc.) as a thin film to be produced. Among them, a process method for depositing on a semiconductor substrate by various physical methods, and is mainly used as a method for forming a metal film and an alloy film. Here, the deposition method may be sputtering or spin coating.

1 is a block diagram of a conventional stuffing device.

As shown in FIG. 1, the conventional conventional sputtering apparatus 10 includes a chamber 15, a substrate support 12 installed inside the chamber 15, and a target 11 installed to face the substrate support 12. It is configured to include). Here, the Ar gas is filled as the plasma gas in the chamber 15, and the semiconductor substrate 13 is disposed on the substrate support 12.

In the action of the sputtering apparatus 10, when a negative voltage is applied to the target 11, which is a cathode, by the power supply device 14, the electrons generated by the discharge collide with Ar gas, thereby causing Ar + ions to be discharged. Will be generated. As a result, plasma is formed. This plasma is maintained near the surface of the target 11 by the magnetic field generating means, thereby generating more electrons. The generated electrons again produce Ar + ions, so the glow discharge is maintained.

In addition, electrons move to the substrate 13 which is an anode, and Ar + ions move to the target 11 which is a cathode and collide with the target 11. When Ar + ions collide with the target 11, the sputtered particles protrude from the target 11 and the secondary electrons protrude from the target 11. Secondary electrons are used to maintain the glow discharge, and the sputtered particles protruding from the target 11 are moved to the substrate 13 to form a thin film layer on the substrate 13.

However, as described above, in the conventional sputtering method in which the substrate 13 is located opposite to the target 11, negative ions enter the substrate 13 and impinge on the thin film, resulting in damage to the substrate and poor crystallinity. There is a problem that a thin film layer is formed.

Therefore, there is a need to improve this to form a thin film layer having good crystallinity without damaging the substrate.

One embodiment of the present invention is to position the substrate at the bottom of the plasma region between the first and the second target, thereby preventing damage of the deposited thin film by maximally suppress the substrate collision of the high-energy particles generated during thin film deposition It is an object of the present invention to provide an opposing target sputtering apparatus capable of producing a high density plasma by reducing and constraining the plasma by the formed magnetic field.

In addition, by placing an inductively coupled plasma coil on top of the plasma region between the first and second targets so that the gas supplied from the gas supply part passes, the high density plasma is generated and the degree of dissociation of the supplied hydrogen gas is increased. It is an object of the present invention to provide an opposing target sputtering apparatus for enhancing the crystallinity of a thin film deposited on the substrate.

As a technical means for achieving the above-described technical problem, the opposed target sputtering apparatus according to an embodiment of the present invention, the gas supply unit for supplying gas to the chamber, the first and second targets disposed to face each other, and the gas supply unit An inductively coupled plasma coil disposed above the plasma region between the first and second targets so that the gas supplied from the substrate passes therethrough, a substrate disposed below the plasma region between the first and second targets, and the first and second targets And a second RF power source connected to the magnet disposed on one side of the first RF power source for applying a potential to the first and second targets and a second RF power source for applying the potential to the inductively coupled plasma coil.

In addition, the opposing target sputtering apparatus according to an embodiment of the present invention comprises a gas supply unit for supplying gas to the chamber, the first and second targets disposed to face each other, the closed loop form of the gas supplied from the gas supply unit An inductively coupled plasma coil disposed above the plasma region between the first and second targets, a substrate disposed below the plasma region between the first and second targets, and disposed behind the first and second targets And a second RF power source connected to the magnet for applying a potential to the first and second targets and a second RF power source for applying the potential to the inductively coupled plasma coil.

According to the above-described problem solving means of the present invention, the position of the substrate to be disposed at the bottom of the plasma region between the first and second target, deposited by suppressing the substrate collision of the high-energy particles generated during thin film deposition as much as possible High density plasma can be generated by reducing damage to the thin film and confining the plasma by the formed magnetic field.

In addition, according to the above-described problem solving means of the present invention, by placing an inductively coupled plasma coil on the upper end of the plasma region between the first and the second target so that the gas supplied from the gas supply unit, it is possible to generate a high-density plasma and At the same time, the degree of dissociation of the supplied hydrogen gas may be increased to increase the crystallinity of the thin film deposited on the substrate.

1 is a block diagram of a conventional stuffing device.
2 is a block diagram of a counter target sputtering apparatus according to an embodiment of the present invention.
3 is a graph showing an increase in the concentration of hydrogen excited in the plasma as the power supplied to the inductively coupled plasma coil in the counter target sputtering apparatus increases.
4 and 5 are graphs showing the crystallinity of the thin film layer as the power supplied to the inductively coupled plasma coil increases in the counter target sputtering apparatus.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is "connected" to another part, this includes not only "directly connected" but also "electrically connected" with another element in between. . In addition, when a part is said to "include" a certain component, which means that it may further include other components, except to exclude other components unless otherwise stated.

2 is a block diagram of a counter target sputtering apparatus according to an embodiment of the present invention.

As shown in FIG. 2, the facing target sputtering apparatus of the present embodiment includes a chamber 100, a gas supply 110, an inductively coupled plasma (ICP) 120, first and The second targets 130a and 130b, the magnets 140a and 140b, the substrate 150, the first RF power source 162 and the second RF power source 164 are included.

The gas supply unit 110 supplies a gas to the chamber 100. Here, the gas supply unit 110 may supply a plasma gas (hereinafter, “gas”) such as Ar, SiH 4, H 2, and O 2 to the inside of the chamber 100. The supplied gas passes through the inductively coupled plasma coil 120.

The inductively coupled plasma coil 120 is disposed above the plasma region 1 between the first and second targets 130a and 130b to allow the gas supplied from the gas supply unit 110 to pass therethrough. Here, a potential is applied to the inductively coupled plasma coil 120 by the second RF power source 164, and the density of the gas passing through the inductively coupled plasma coil 120 is increased by the applied potential.

For example, in the case of H2 in the supplied gas, the degree of dissociation increases while passing through the inductively coupled plasma coil 120, and a high density plasma is formed in the plasma region 1 between the first and second targets 130a and 130b. Generated to enable rapid growth of the thin film.

More specifically, when a gas having a high density while passing through the inductively coupled plasma coil 120 is supplied between the first and second targets 130a and 130b, ions or electrons reciprocate between the targets 130a and 130b. High-density plasma is generated and high deposition rate is obtained even when oxygen gas having a lower ionization rate than Ar gas is used as the supply gas.

Therefore, even when depositing a thin film using oxygen gas, that is, reactive sputtering, it is possible to implement a high deposition rate. Of course, the inductively coupled plasma coils 120 may be arranged in plural in other embodiments.

The first and second targets 130a and 130b are disposed to face each other, and include, for example, cobalt (Co), nickel (Ni), titanium (Ti), tungsten (W), aluminum (Al), and the like. Can be configured. When a potential is applied to the first and second targets 130a and 130b by the first RF power source 162, local discharge may be formed between the first and second targets 130a and 130b.

That is, ionization of the gas passing through the inductively coupled plasma coil 120 between the first and second targets 130a and 130b is promoted, and a plasma in a discharge form is generated between the first and second targets 130a and 130b. Can be. The plasma may include electrons, anions, cations, and the like, where the electrons serve to ionize the supplied gas.

In addition, magnets 140a and 140b are disposed on one side of the first and second targets 130a and 130b to be connected to the first RF power source 162, and the first and second targets 130a and 130b are connected to the first RF power source 162. The potential may be supplied to the second targets 130a and 130b. At this time, the magnets 140a and 140b are disposed behind the targets 130a and 130b so that the magnetic fields are vertically distributed on the surfaces of the targets 130a and 130b so that potentials may be applied to the first and second targets 130a and 130b. have.

At this time, each of the magnets 140a and 140b may include a plurality of magnets based on the same axis as shown, but this is only an example and the present invention is not limited thereto. For example, each of the magnets 140a and 140b may include only one magnet in the form of a disc.

In addition, in the case of including a plurality of magnets, the polarity of the inner magnet connected to the first RF power source 162 and the polarity of the outer magnet surrounding the inner magnet is set differently, but unlike the same It can be set to have polarity.

The magnetic fields generated by the magnets 140a and 140b mounted on the rear surfaces of the first and second targets 130a and 130b may be applied in a direction perpendicular to the surfaces of the targets 130a and 130b. That is, if the magnetic field applied from the first target 130a is the N pole, the magnetic field generated from the second target 130b is the S pole, so that the target is a high-speed sputter of all materials without being magnetic or nonmagnetic. May be possible. In addition, the above-described first and second targets 130a and 130b may be movable so that the intensity of the magnetic field between the first and second targets 130a and 130b may be adjusted.

Meanwhile, the substrate 150 is disposed below the plasma region 1 between the first and second targets 130a and 130b. Since the arrangement of the substrate 150 is configured to be spaced apart from the plasma region 1, collision of the substrate 150 of particles having high energy generated during sputtering can be suppressed as much as possible. That is, collision of the substrate 150 of particles having high energy due to electrons as well as negative ions can be eliminated. Accordingly, damage to the substrate 150 can be prevented, and a thin film layer having very good crystallinity can be produced.

More specifically, in the case of the conventional sputtering method in which the substrate 150 faces the target, an anion impinges on the substrate 150 and is deposited, and thus a good thin film layer cannot be formed.

In addition, electrons may be constrained by a leakage magnetic field formed on the target surface to increase the ionization rate of the gas in the vicinity of the target, thereby forming a high-density plasma. The impingement to the substrate 150 with high energy corresponding to the voltage applied to the target without being trapped by the leakage magnetic field formed in the dam caused damage to the deposited thin film.

Accordingly, in the exemplary embodiment of the present invention, the magnets 140a and 140b are disposed on the rear surfaces of the first and second targets 130a and 130b, and the position of the substrate 150 is positioned between the first and second targets 130a and 130b. In order to reduce the damage to the thin film layer by being disposed at the bottom of the plasma region 1, the collision of the substrates 150 having the high energy generated during thin film deposition is suppressed to the maximum.

Meanwhile, the first RF power source 162 is connected to the magnets 140a and 140b disposed on one side of the first and second targets 130a and 130b to apply a potential to the first and second targets. The second RF power source 164 applies a potential to the inductively coupled plasma coil 120. For example, the frequency of power supplied from the first RF power source 162 and the second RF power source 164 may be 13.56 MHz or more. In this case, as the power supplied from the second RF power source 164 to the inductively coupled plasma coil 120 is increased, the density of the gas supplied to the chamber 100 may be increased to generate a high density plasma.

3 is a graph showing an increase in the concentration of hydrogen excited in the plasma as the power supplied to the inductively coupled plasma coil in the counter target sputtering apparatus according to an embodiment of the present invention.

3, the relative intensity of the hydrogen concentration excited in the plasma as the power supplied to the inductively coupled plasma coil 120 from the second RF power source 164 increases. It can be seen that) increases. Thus, as described above, a high density plasma can be generated in the plasma region 1 between the first and second targets 130a and 130b. Accordingly, a good thin film layer can be formed, a graph of which is shown in FIG. 4 below.

4 and 5 are graphs showing the crystallinity of the thin film layer as the power supplied to the inductively coupled plasma coil without a separate substrate heating in the counter target sputtering apparatus according to an embodiment of the present invention.

As shown in FIG. 4, it can be seen that as the power supplied from the second RF power source 164 to the inductively coupled plasma coil 120 is increased, the amorphous phase is changed into a good crystalline phase. Specifically, as the power supplied to the inductively coupled plasma coil 120 changes from 0W to 200W, 300W, 400W, 500W, the Raman Shift changes from about 480 cm ^{- 1} to about 520 cm ^{- 1} . Able to know.

In addition, as shown in FIGS. 5A and 5B, the Laban shift is about 480 cm ⁻¹ , 510 cm ⁻¹ , and 520 cm ⁻¹ , respectively, about 59% when the power supplied is 400W. In contrast to the crystallinity of (Christallinity), it can be seen that the crystallization rate of about 63% when the power supplied is 500W.

Therefore, high density plasma is generated through the inductively coupled plasma coil 120 disposed above the plasma region 1 between the first and second targets 130a and 130b to allow the gas supplied from the gas supply unit 110 to pass therethrough. As a result, it can be confirmed that the crystallinity of the thin film deposited on the substrate 150 can be increased.

The foregoing description of the present invention is intended for illustration, and it will be understood by those skilled in the art that the present invention may be easily modified in other specific forms without changing the technical spirit or essential features of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present invention is shown by the following claims rather than the above description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. do.

100: chamber 110: gas supply
120: inductively coupled plasma coils 130a, 130b: first and second targets
140a and 140b: Magnet 150: Substrate
162: first RF power source 164: second RF power source

Claims (5)

In the opposite target sputtering apparatus,
A gas supply unit supplying gas to the chamber,
An inductively coupled plasma coil disposed above the plasma region between the first and second targets so that the gas supplied from the gas supply part passes;
A substrate disposed at a lower end of the plasma region between the first and second targets,
A first RF power source connected to a magnet disposed on one side of the first and second targets to apply a potential to the first and second targets;
And a second RF power source for applying a potential to the inductively coupled plasma coil. The method of claim 1,
The inductively coupled plasma coil is opposed target sputtering apparatus, characterized in that configured in the form. The method of claim 1,
And the magnet is disposed on a rear surface of the first and second targets. The method of claim 1,
And the first and second targets are disposed to face each other. In the opposite target sputtering apparatus,
A gas supply unit supplying gas to the chamber,
First and second targets disposed to face each other,
An inductively coupled plasma coil configured in a closed loop shape and disposed above the plasma region between the first and second targets so that the gas supplied from the gas supply part passes;
A substrate disposed at a lower end of the plasma region between the first and second targets,
A magnet disposed on a rear surface of the first and second targets,
A first RF power source connected to the magnet to apply a potential to the first and second targets;
And a second RF power source for applying a potential to the inductively coupled plasma coil.

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