KR101456549B1 - Plassma Enhanced Chemical Vapour Deposition Apparatus And Plassma Enhanced Chemical Vapour Deposition Method - Google Patents

Abstract

The present invention provides a plasma assisted chemical vapor deposition apparatus and method. The apparatus includes a vacuum chamber including a substrate holder for mounting a substrate, a dielectric tube mounted on a through hole formed in an upper surface of the vacuum chamber, a dielectric tube arranged to surround the dielectric tube, And an evaporation source for supplying metal vapor to the dielectric tube. The metal vapor passes through the plasma and is provided to the substrate to form a metal-nitride film or a metal-oxide film.

Description

[0001] Plasma Enhanced Chemical Vapor Deposition Apparatus and Plasma Assisted Chemical Vapor Deposition [

[0001] The present invention relates to a plasma assisted chemical vapor deposition apparatus, and more particularly, to a plasma assisted chemical vapor deposition apparatus, which is provided with a substrate through which a metal vapor and a plasma are formed, the metal vapor being activated by passing through the plasma, And a chemical vapor deposition apparatus provided on a substrate to form a thin film.

The GaN thin film is manufactured by a metal organic chemical vapor deposition (MOCVD) technique, a hydride vapor phase epitaxy (HVPE) technique, or a molecular beam epitaxy (MBE) technique.

 The MOCVD technique uses a metal organic precursor to process the 3-5 group material. The cost of the metal organic precursor is high and there is an impurity problem. And because the metal organic source is in a liquid state, there is a complexity of devices that require the use of bubblers. In addition, fine control is difficult. For example, the MOCVD technique for depositing a GaN thin film uses a metal organic precursor as a Ga source. In addition, the temperature of the substrate is very high, more than 1000 degrees centigrade.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a top-down large area plasma assisted chemical vapor deposition apparatus.

A plasma assisted chemical vapor deposition apparatus according to an embodiment of the present invention includes: a vacuum chamber including a substrate holder for mounting a substrate; A dielectric tube mounted at one end to the through hole formed in the upper surface of the vacuum chamber; A plasma generator arranged to surround the dielectric tube and generating plasma inside the dielectric tube by receiving RF power; And an evaporation source for providing metal vapor to the dielectric tube. The metal vapor is supplied to the substrate through the plasma to form a metal-nitride film or a metal-oxide film.

In one embodiment of the present invention, the evaporation source is an electromagnetic levitation coil spaced apart from the plasma generating portion and disposed to surround the dielectric tube at an upper portion of the plasma generating portion. And an alternating current source for providing alternating current power to the electromagnetic levitation coil, wherein the electromagnetic levitation coil is capable of electronically levitating and heating the metallic material within the dielectric tube to evaporate.

In one embodiment of the present invention, the evaporation source includes an auxiliary dielectric tube having an open end; An electromagnetic float coil disposed to surround the auxiliary dielectric tube; An alternating-current power supply for providing alternating-current power to the electromagnetic levitation coil; A connection pipe connecting one end of the auxiliary dielectric tube and the other end of the dielectric tube and including a curved portion; And a heating unit for heating the connection pipe. The electromagnetic lifting coil can evaporate the metallic material by heating and heating the metallic material inside the auxiliary dielectric tube. The metal vapor formed by evaporation of the metal material may be provided through the other end of the dielectric tube through the connection pipe.

In an embodiment of the present invention, the evaporation source includes an auxiliary container including an opening; An induction coil disposed to surround the auxiliary container; An AC power supply for supplying AC power to the induction coil; A connection pipe connecting the opening of the auxiliary container and the other end of the dielectric tube and including a curved portion; And a heating unit for heating the connection pipe. The induction coil evaporates the metallic material inside the auxiliary vessel. The metallic vapor formed by evaporation of the metallic material may be supplied through the other end of the dielectric tube through the coupling tube.

In one embodiment of the present invention, a first gas supply unit connected to the other end of the dielectric tube; And a second gas supply unit connected to a side surface of the vacuum chamber. The first gas supply part may provide a process gas, and the second gas supply part may provide an inert gas.

In one embodiment of the present invention, the metal-nitride film may be any one of GaN and InN, and the metal-oxide film may be any one of AlO and ZnO.

In an embodiment of the present invention, the plasma generating unit may be an antenna for generating an inductively coupled plasma wound around the dielectric tube, or an electrode for generating a capacitive coupling plasma around the dielectric tube.

According to an embodiment of the present invention, there is provided a plasma assisted chemical vapor deposition method comprising: evaporating a metal material to produce metal vapor; Providing said metal vapor within a dielectric tube; Providing a process gas inside the dielectric tube to form a plasma; And supplying the metal vapor and the plasma that have passed through the plasma to a substrate provided inside the vacuum chamber to form a metal-nitride film or a metal oxide film.

In one embodiment of the present invention, the step of generating the metal vapor may evaporate the metal material by an electromagnetic levitation method or a thermal evaporation method.

In one embodiment of the present invention, the method may further comprise the step of applying a bias RF power to a substrate holder to which the substrate is mounted to provide a self bias voltage.

 Since the present invention evaporates a metal source, only the metal source is heated to produce the metal vapor, so that the apparatus is simple and the possibility of mixing of impurities is low. Further, the metal vapor may be supplied to the substrate along with the plasma through the plasma generation region, so that the deposition temperature of the substrate may be unknown. Further, the substrate is disposed on the lower surface of the vacuum chamber, and the metal vapor and the plasma are provided at the upper part, which is structurally simple.

1 to 3 are views illustrating a plasma assisted chemical vapor deposition apparatus according to one embodiment of the present invention.
Fig. 4 is a perspective view illustrating the electromagnetic levitation coil of Fig. 1. Fig.

A typical thermal evaporation deposition apparatus includes a thermal evaporation source mounted on the lower surface of the chamber and a substrate mounted on the upper surface. Therefore, there is a mechanical difficulty that the substrate is mounted on the upper surface of the chamber.

Further, in a conventional plasma-assisted chemical vapor deposition apparatus, the plasma region where the inductively coupled plasma is formed and the gas supply region where the metal-containing gas is provided are different from each other, which limits a uniform thin film deposition. Further, when a thermal evaporation source is disposed on the lower surface of the chamber to provide the metal vapor, the inductively coupled plasma is disposed on the upper surface of the chamber to form a uniform thin film of a large area on the substrate disposed on the lower surface of the chamber It is difficult.

The present invention overcomes these problems by using a vaporization technique to vaporize a metal source, pass a metal vapor through a plasma to provide a substrate, the plasma forms an active species, And forming a thin film on the substrate while reacting.

A chemical vapor deposition apparatus according to an embodiment of the present invention can provide a substrate with a metal vapor and a plasma to form a thin film on a substrate. In order to allow the metal vapor to pass through the plasma region where the plasma is formed, the evaporation source may use an electromagnetic levitation method. Alternatively, the evaporation source may be provided in the plasma region through a heated connection tube having a curved portion of the vapor evaporated in the thermal evaporation source. The plasma region thus dissociates or excites the process gas to form the active species. Further, the metal vapor passing through the plasma region may be heated by the heated process gas or the plasma and transferred onto the substrate. In addition, the plasma can energize the substrate. Accordingly, the deposition temperature of the substrate can be reduced to 800 degrees Celsius or less.

In the case of a new material including metal (for example: GaN), a pure metal source is used instead of using a metal organic precursor as a metal (Ga) source. The pure metal source may be heated and evaporated by an electromagnetic levitation method or a thermal evaporation method to be used for synthesis of new materials. Accordingly, the impurity of the new material can be reduced, and composition control is easy.

The chemical vapor deposition method according to an embodiment of the present invention can synthesize a thin film of a new material, which is difficult to synthesize by an existing method, at a low temperature without impurities. This method can synthesize a metal-nitride film or a metal-oxide film. The metal-nitride film or the metal-oxide film can be applied to a solar cell, a photodiode having a wide wavelength, a semiconductor device, an LED device, and the like.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments disclosed herein are being provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. In the drawings, the components have been exaggerated for clarity. Like numbers refer to like elements throughout the specification.

1 is a view illustrating a plasma assisted chemical vapor deposition apparatus according to an embodiment of the present invention.

Fig. 4 is a perspective view illustrating the electromagnetic levitation coil of Fig. 1. Fig.

1 and 4, the plasma assisted chemical vapor deposition apparatus 100 includes a vacuum chamber 140 including a substrate holder 142 on which a substrate 144 is mounted, A plasma generator 150 disposed to surround the dielectric tube 110 and configured to generate plasma in the dielectric tube 110 by being supplied with RF power, And an evaporation source 120 for supplying metal vapor to the dielectric tube 110. The metal vapor is supplied to the substrate through the plasma to form a metal-nitride film or a metal-oxide film.

The vacuum chamber 140 may be a metal container including an upper plate 141. The vacuum chamber 140 is evacuated through an exhaust pump (not shown) connected to the exhaust line 148. The vacuum chamber 140 may have a symmetrical structure in the z-axis direction. The substrate holder 142 is mounted adjacent to the lower surface of the vacuum chamber 140 and can support the substrate 144 against gravity. The vacuum chamber 140 may have a cylindrical or rectangular cross-sectional shape. The substrate 144 may be a semiconductor substrate or a glass substrate.

The substrate holder 142 can mount and heat the substrate 142. The substrate 144 may be heated to about 800 degrees Celsius. In addition, a bias RF power supply 145 may be coupled to the substrate holder 142 to provide a self bias voltage to the substrate 144. The bias RF power source 145 may apply RF power to the substrate holder 142 through an impedance matching network 146 and a blocking capacitor. The bias RF power source 145 may control the energy of ions incident on the substrate 144.

One end of the dielectric tube 110 is coupled to the perimeter of the through hole 147 formed in the upper plate 141. The dielectric tube 110 extends in the z-axis direction. The dielectric tube 110 may be a quartz, alumina, or ceramic material. A first gas supply unit 162 may be connected to the other end of the dielectric tube 110. The first gas supply 162 may provide a first gas to the dielectric tube 110. The first gas may be a process gas such as oxygen or nitrogen. If the material deposited on the substrate 144 is a metal-nitride, the process gas may be nitrogen gas. If the material deposited on the substrate 144 is a metal-oxide, the process gas may be oxygen gas. A second gas supply unit 164 is mounted on a side surface or an upper surface of the vacuum chamber 140 and the second gas supply unit 164 may supply a second gas to the vacuum chamber. The second gas may be an inert gas such as argon. The inert gas can control the properties of the plasma and the properties of the thin film.

The plasma generating unit 150 may include an antenna 152 for generating an inductively coupled plasma and an RF power source 154 for supplying RF power to the antenna 152. An impedance matching network 155 may be disposed between the RF power supply 154 and the antenna 152. The frequency of the RF power supply 154 may be several MHz to several tens MHz. The antenna 152 generates an induced electromotive force in the dielectric tube 110, and the induced electromotive force can generate an inductively coupled plasma. The inductively coupled plasma may diffuse from the dielectric tube 110 toward the substrate. The inductively coupled plasma may transfer energy to the substrate 144 to reduce the formation temperature of the thin film on the substrate 144. The thin film formed on the substrate 144 may be polycrystalline or crystalline. The inductively coupled plasma may activate the process gas to produce active species. The active species produced in the inductively coupled plasma and the metal vapor may react on the substrate 144 to deposit a thin film.

The evaporation source 120 may provide the metal vapor to the dielectric tube 110. The evaporation source 120 includes an electromagnetic levitation coil 122 spaced from the antenna 152 and disposed to surround the dielectric tube 110 above the antenna 152, And an alternating current (AC) power supply 124 for providing the AC power. The electromagnetic lifting coil 122 can lift and heat the metal material 102 within the dielectric tube 110 by electromagnetic levitation.

The electromagnetic lifting coil 122 is wound on the upper portion of the dielectric tube 110 and the antenna 152 can be wound on the lower portion of the dielectric tube 110.

The electromagnetic lifting coil 122 includes an upper coil 122a and a lower coil 122b spaced apart from each other in the z axis direction and a connecting portion 122c connecting the upper coil 122a and the lower coil 122b . The direction of the current flowing in the upper coil 122a and the direction of the current flowing in the lower coil 122b may be opposite to each other. The upper coil may be two turns and the lower coil may be four turns so that the metal material 102 may be lifted at the interface between the upper coil 122a and the lower coil 122b . In addition, the metal material 102 may be heated by an induction electromotive force and evaporated to generate the metal vapor. The metal vapor may be heated by the plasma while moving to the lower end of the dielectric tube 110. Accordingly, the heated metal vapor, the process gas, the active species, and the plasma may be provided to the substrate 144 to form a thin film.

The AC power source 124 may supply power to the electromagnetic lifting coil 122. The frequency of the AC power supply 124 may be several tens of kHz to several hundreds of kHz.

Evaporation of the metallic material 102 by the electromagnetic levitation coil 122 can produce impure metal-free vapor. In addition, the amount of metal vapor to be evaporated by controlling the electric power applied to the electromagnetic lifting coil 122 can be adjusted. Accordingly, the composition and characteristics of the thin film can be easily controlled. Further, as the metal vapor passes through the plasma, the metal vapor is heated, and the deposition temperature of the substrate 144 can be reduced.

 The metal-nitride layer may be any one of GaN and InN, and the metal-oxide layer may be any one of AlO and ZnO.

2 is a view illustrating a plasma assisted chemical vapor deposition apparatus according to another embodiment of the present invention.

2, the plasma assisted chemical vapor deposition apparatus 200 includes a vacuum chamber 140 including a substrate holder 142 on which a substrate 144 is mounted, one end of which is formed on the upper surface of the vacuum chamber 140 A plasma generator 150 disposed to surround the dielectric tube 110 and generating plasma in the dielectric tube 110 by receiving RF power, a dielectric tube 110 mounted to the through hole 147, And an evaporation source 220 for supplying metal vapor to the dielectric tube 110. The metal vapor is supplied to the substrate through the plasma to form a metal-nitride film or a metal-oxide film.

The dielectric tube 110 may have a structure in which both ends are opened. One end of the vacuum chamber 140 may be connected to the through hole 147 formed in the upper plate 141 of the vacuum chamber 140 and the other end may be connected to the evaporation source 220.

A first gas supply unit 162 is disposed on the upper side of the dielectric tube 110. The first gas supply unit 162 supplies a process gas to the dielectric tube 162, and the antenna 152 discharges the process gas to form a plasma.

 The evaporation source 220 includes an auxiliary dielectric tube 221 having an open end, an electromagnetic lifting coil 222 disposed to surround the auxiliary dielectric tube 221, an alternating current (AC) A power source 224 and a coupling tube 225 connecting the one end of the auxiliary dielectric tube 221 and the other end of the dielectric tube 110 and including a curved portion 225a, And a heating unit 226 for heating the substrate.

The electromagnetic lifting coil 222 is configured to support and heat the metal material 102 inside the auxiliary dielectric tube 221 to evaporate the metal material 102 and to evaporate the metal material 102, The steam is supplied to the other end of the dielectric tube 110 through the coupling pipe 225.

The auxiliary dielectric tube 221 may extend in the z-axis direction. The auxiliary dielectric tube 221 may be a quartz, alumina, or ceramic material.

The electromagnetic lifting coil 222 may be disposed to surround the auxiliary dielectric tube 221. The electromagnetic lifting coil 222 includes an upper coil and a lower coil, and the direction of the current flowing in the upper coil and the direction of the current flowing in the lower coil may be opposite to each other. The electromagnetic lifting coil 222 can generate the metal vapor by levitating, heating, and evaporating the metal material 102 disposed within the auxiliary dielectric tube 221.

One end of the coupling pipe 225 is connected to one end of the auxiliary dielectric tube 221 and the other end of the coupling pipe 225 is connected to the other end of the dielectric tube 110. The connection pipe 225 may be formed of a metal material. The coupling pipe 225 may include a straight portion 225b and a curved portion 225a. The curved portion 225b may be provided in the z-axis direction of the auxiliary dielectric tube 221. Thus, if the metal material 102 fails to levitate in the auxiliary dielectric tube 221, the metallic material 102 may fall on the bottom surface of the auxiliary dielectric tube 221. Thus, the metal material 102 can be prevented from falling off the substrate 144. The curved portion 225a may be in a "U" shape. The inner diameter of the coupling tube 225 may be smaller than the inner diameter of the dielectric tube 110.

The connection pipe 225 is formed of a conductive material, and the heating unit 226 can heat the connection pipe 225. Accordingly, the metal vapor inside the connection pipe 225 can be transferred to the other end of the dielectric tube 110 without being deposited on the inner surface of the connection pipe 225. The heating unit 226 may include an induction heating coil and an induction heating AC power source 227 for supplying power to the induction heating coil. According to a modified embodiment of the present invention, the heating unit 226 can heat the connection pipe using a resistive material.

3 is a view illustrating a plasma assisted chemical vapor deposition apparatus according to another embodiment of the present invention.

Referring to FIG. 3, the plasma assisted chemical vapor deposition apparatus 300 includes a vacuum chamber 140 including a substrate holder 142 on which a substrate 144 is mounted, one end of which is formed on the upper surface of the vacuum chamber 140 A plasma generating unit 350 disposed to surround the dielectric tube 110 and generating RF plasma within the dielectric tube 110 by applying RF power to the dielectric tube 110, And an evaporation source 320 for supplying metal vapor to the dielectric tube 110. The metal vapor passes through the plasma and is supplied to the substrate 144 to form a metal-nitride film or a metal-oxide film.

The plasma generating unit 350 may include a cylindrical electrode 352 surrounding the dielectric tube 110 and an RF power source 354 supplying RF power to the electrode 352. An impedance matching network 355 may be disposed between the RF power source 354 and the electrode 352. The electrode 352 may generate a capacitive coupling plasma in the dielectric tube 110.

The evaporation source 320 includes an auxiliary container 321 including an opening portion, an induction coil 322 disposed to surround the auxiliary container 321, an AC power source 324 for providing AC power to the induction coil 322, A connecting pipe 325 connecting the opening 325 of the auxiliary container 321 and the other end of the dielectric tube 110 and including a curved portion 325a, (326). The induction coil 322 can heat and evaporate the metal material 329 in the auxiliary container 321. The metal vapor formed by evaporation of the metal material 329 may be supplied to the other end of the dielectric tube 110 through the connection pipe 325.

The auxiliary container 321 can receive the metallic material 329 in a solid state. The auxiliary container 321 may be a conductive material or a dielectric material. If the auxiliary container 321 is a conductive material, the induction coil 322 induces the auxiliary container 321 and the metallic material 329 to induce heating, and the metallic material 329 can be melted. On the other hand, the melting point of the auxiliary container 321 is higher than the melting point of the metallic material 329. Accordingly, the metal material 329 may evaporate to generate metal vapor.

If the auxiliary container 321 is a dielectric, the induction coil 321 may directly heat the metallic material 329 to melt the metallic material 329.

An opening 325 is formed on the upper surface of the auxiliary container 321. One end of the coupling tube 325 may be connected to the opening 325 and the other end of the coupling tube 325 may be connected to the other end of the dielectric tube 110. The metal vapor may be transmitted to the other end of the dielectric tube through the opening 325 and the connection tube 325.

The connection pipe 325 may be formed of a metal material. The connection pipe 325 may include a straight portion 325b and a curved portion 325a. The curved portion 325a may be installed in the z-axis direction of the auxiliary container 321. [ Accordingly, the auxiliary container 321 can stably store the metallic material 329. The curved portion 325a may be in a "U" shape.

The connection pipe 325 is formed of a conductive material, and the heating unit 326 can heat the connection pipe 325. Accordingly, the metal vapor inside the connection pipe 325 can be transferred to the other end of the dielectric tube 110 without being deposited on the inner side surface of the connection pipe 325. The heating unit 326 may include an induction heating coil and an induction heating AC power source 328 for supplying power to the induction heating coil.

According to a modified embodiment of the present invention, the heating unit 326 can heat the connection pipe 324 using a resistive material.

According to a modified embodiment of the present invention, the metal material can be heated through heat transfer to a resistive material.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, And all of the various forms of embodiments that can be practiced without departing from the technical spirit.

142: substrate holder
144: substrate
110: dielectric tube
150: Plasma generator
120: evaporation source

Claims (10)

delete A vacuum chamber including a substrate holder for mounting a substrate;
A dielectric tube mounted at one end to the through hole formed in the upper surface of the vacuum chamber;
A plasma generator arranged to surround the dielectric tube and generating plasma inside the dielectric tube by receiving RF power; And
And an evaporation source for providing metal vapor to the dielectric tube,
The metal vapor is supplied to the substrate through the plasma to form a metal-nitride film or a metal-oxide film,
The evaporation source comprises:
An electromagnetic levitation coil spaced apart from the plasma generating portion and disposed to surround the dielectric tube at an upper portion of the plasma generating portion; And
And an alternating current power source for providing alternating current power to the electromagnetic levitation coil,
Wherein the electromagnetic lifting coil is adapted to levitate and evaporate a metal material within the dielectric tube. A vacuum chamber including a substrate holder for mounting a substrate;
A dielectric tube mounted at one end to the through hole formed in the upper surface of the vacuum chamber;
A plasma generator arranged to surround the dielectric tube and generating plasma inside the dielectric tube by receiving RF power; And
And an evaporation source for providing metal vapor to the dielectric tube,
The metal vapor is supplied to the substrate through the plasma to form a metal-nitride film or a metal-oxide film,
The evaporation source comprises:
An auxiliary dielectric tube having an open end;
An electromagnetic float coil disposed to surround the auxiliary dielectric tube;
An alternating-current power supply for providing alternating-current power to the electromagnetic levitation coil;
A connection pipe connecting one end of the auxiliary dielectric tube and the other end of the dielectric tube and including a curved portion; And
And a heating unit for heating the connection pipe,
The electromagnetic lifting coil is configured to support and heat a metallic material inside the auxiliary dielectric tube to evaporate the metallic material,
And the metal vapor formed by evaporation of the metal material is provided through the other end of the dielectric tube through the connection pipe. A vacuum chamber including a substrate holder for mounting a substrate;
A dielectric tube mounted at one end to the through hole formed in the upper surface of the vacuum chamber;
A plasma generator arranged to surround the dielectric tube and generating plasma inside the dielectric tube by receiving RF power; And
And an evaporation source for providing metal vapor to the dielectric tube,
The metal vapor is supplied to the substrate through the plasma to form a metal-nitride film or a metal-oxide film,
The evaporation source comprises:
An auxiliary container including an opening;
An induction coil disposed to surround the auxiliary container;
An AC power supply for supplying AC power to the induction coil;
A connection pipe connecting the opening of the auxiliary container and the other end of the dielectric tube and including a curved portion; And
And a heating unit for heating the connection pipe,
Wherein the induction coil heats and evaporates a metal material in the auxiliary container,
Wherein the metal vapor formed by evaporation of the metal material is provided through the other end of the dielectric tube through the connection tube. 3. The method of claim 2,
A first gas supply unit connected to the other end of the dielectric tube; And
And a second gas supply unit connected to a side surface of the vacuum chamber,
The first gas supply part provides a process gas,
Wherein the second gas supply provides an inert gas. ≪ Desc / Clms Page number 13 > The method according to any one of claims 2 to 5,
Wherein the metal-nitride film is any one of GaN and InN,
Wherein the metal-oxide film is any one of AlO and ZnO. The method according to any one of claims 2 to 5,
Wherein the plasma generating unit is an antenna for generating an inductively coupled plasma wound around the dielectric tube, or an electrode for generating a capacitive coupling plasma around the dielectric tube. delete delete delete

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