KR20070029356A - Plasma generation apparatus for making radical effectively - Google Patents

Abstract

A plasma generation apparatus for generating a radical is provided to prevent a thin film of a PECVD(Plasma Enhanced Chemical Vapor Deposition) device from being damaged due to an ion impact by filtering a high energy ion. A plasma generation apparatus for generating a radical includes a chamber(110), a substrate installation unit(120), an RF electrode(130), a first RF power unit(170), a first matcher(174), an insulation plate(150), a ground electrode(160), and a gas supply unit(180). The chamber(110) defines a reaction region. The substrate installation unit(120) is installed on the inside of the chamber(110). The RF electrode(130) is installed on an upper part of the substrate installation unit(120), and is insulated from the chamber(110). The first RF power unit(170) is connected to the RF electrode(130). The first matcher(174) matches an impedance between the first RF power unit(170) and the RF electrode(130). The insulation plate(150) is installed between the RF electrode(130) and the substrate installation unit(120). The conductive ground electrode(160) is installed on an upper part of the insulation plate(150), and has a plurality of second penetration units connected to a first penetration unit. The gas supply unit(180) provides a fuel material to an upper part of the ground electrode(160).

Description

Plasma generation apparatus for making radical effectively

1 is a schematic configuration diagram of a general PECVD equipment

2 is a schematic structural diagram of a plasma generating apparatus according to an embodiment of the present invention;

3 is a plan view showing a part of an insulating plate and a ground electrode;

4 is a schematic configuration diagram of a plasma generator in which a second RF power source is connected to a susceptor;

* Explanation of symbols for main parts of drawings *

100: plasma generator 110: chamber

112: chamber lead 120: susceptor

122: susceptor support 130: RF electrode

132: insulation member 134: O-ring

140: gas distribution plate 142: buffer space

150: insulating plate 151: first through portion

152: locking jaw 156: support member

160: ground electrode 161: second through part

170: first RF power supply 172: feeder

174: first matcher 176: second RF power supply

178: second hooker 180: gas inlet pipe

182: flange 190: exhaust port

The present invention provides a plasma for manufacturing a display device or a semiconductor device such as a liquid crystal display (LCD), a field emission display (FED), an organic light emitting diode device (OLED), etc. The present invention relates to a plasma generating apparatus for processing a glass or a wafer (hereinafter, referred to as a substrate) by using a.

FIG. 1 schematically illustrates a general configuration of a Plasma Enhanced Chemical Vapor Deposition (PECVD) apparatus for converting a raw material into a plasma state and then depositing a thin film on a substrate using the plasma generator as an example.

In this regard, the PECVD apparatus 10 includes a chamber 11 defining a constant reaction region, a susceptor 12 positioned inside the chamber 11 and having a substrate 30 disposed on an upper surface thereof, and the susceptor 12. Gas distribution plate 13 for injecting the raw material to the upper portion of), the RF electrode 15 located on the upper portion of the gas distribution plate 13, the gas inlet connected to the central portion of the RF electrode 15 A pipe 16 and an exhaust port 19 formed at the bottom of the chamber 11 to exhaust residual gas is included.

The RF electrode 15 is connected to the RF power source 17, and a matcher 18 for matching impedance is provided between the RF power source 17 and the RF electrode 15.

The susceptor 12 is supported by the susceptor support 12a, and a driving device (not shown) is connected to the susceptor support 12a to move the susceptor 12 up and down.

The gas distribution plate 13 has a peripheral portion thereof coupled to the RF electrode 15 to form a buffer space 14 between the RF electrode 15, and the gas distribution plate 13 and the RF electrode 15 are usually Both are in an electrically connected state because they are made of anodized aluminum.

The chamber 11 is normally grounded, and the gas distribution plate 13 and the RF electrode 15 are insulated from the chamber 11 using the insulating member 20.

Looking at the process of generating a plasma in the PECVD apparatus 10 having such a configuration as follows.

First, a process atmosphere is formed in the chamber 11 through vacuum pumping, and then the raw material is injected into the upper portion of the susceptor 12 through the gas inlet pipe 16 and the gas distribution plate 13. At the same time, RF power is applied to the RF electrode 15. The RF power is transmitted to the gas distribution plate 13 electrically connected to the RF electrode 15, and the RF power delivered to the gas distribution plate 13 is grounded susceptor. The RF electric field is generated between (12) and the electrons in the raw material are accelerated by the generated RF electric field to collide with the neutral gas.

Due to the collision, the raw material is in a plasma state, which is a mixture of electrons and ions, and even when it is not dissociated into ions, active species in an excited state are generated due to collision energy.

Since the rate of dissociation of the raw material into the plasma state is very low, such as 10 ^-5 to 10 ^-6 , the density of the active species in the neutral state is much higher even though plasma is generated. Is used.

However, when plasma is generated in the PECVD apparatus 10, a sheath is generated between the plasma and the substrate. Sheath is a phenomenon caused by the difference in mobility between electrons and ions at the interface between the plasma and the surrounding material, and a kind of built-in electric field is formed between the electrons reaching the interface first and the cations on the plasma surface. It serves to maintain the plasma bulk (bulk) density metastable.

However, sheaths not only play this positive role but also accelerate the cations trapped in the sheath, which can cause ion bombardment to deteriorate the product or generate unnecessary particles. In the thin film deposition process, the deposited thin film is damaged.

Meanwhile, instead of grounding the susceptor 12 in the configuration of FIG. 1, it may be used as an etcher for selectively etching the substrate 30 by connecting to a second RF power source. Since it is difficult to control properly, there is a problem that the porous soft thin film is not suitable for etching without thin film damage.

An object of the present invention is to provide a plasma generating apparatus capable of precise etching process while improving film quality by minimizing ion impact by appropriately controlling ion energy and electron energy in a PECVD apparatus or an etchant.

The present invention to achieve the above object, a chamber defining a reaction zone; A substrate setter installed in the chamber; An RF electrode installed on the substrate mounting means and insulated from the chamber; A first RF power source connected to the RF electrode; A first matcher for matching an impedance between the first RF power supply and the RF electrode; An insulating plate disposed between the RF electrode and the substrate mounting means and having a plurality of first through portions; A conductive ground electrode provided on the insulating plate and having a plurality of second through parts communicating with the first through part; It provides a plasma generating device including a gas supply means for supplying a raw material to the upper portion of the ground electrode.

At this time, the ground electrode preferably has a thickness of 0.1㎛ 10mm or less.

In addition, the ground electrode may be formed by coating the upper portion of the insulating plate, in this case it is preferably made of indium tin oxide (ITO) or aluminum.

Preferably, the diameter of the first through part is smaller than the diameter of the second through part, and in this case, the first through part preferably has a diameter of 1 mm to 10 mm smaller than the second through part.

A second RF power source may be connected to the substrate mounting unit, and a second mediator for impedance matching may be connected between the second RF power source and the substrate mounting unit.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a cross-sectional view of a plasma generating apparatus 100 according to an embodiment of the present invention. Referring to this, a chamber 110 defining a reaction space and a chamber 30 are located inside the chamber 110. A gas distribution plate 140 and a gas distribution plate 140 coupled to the susceptor 120, the RF electrode 130 positioned on the susceptor 120, and a lower portion of the RF electrode 130 and having a plurality of injection holes. ) And a gas inlet pipe 180 for supplying a raw material to the buffer space 142 between the RF electrode 130.

 The RF power source 170 is connected to the RF electrode 130 through a feed line 172. The feed line is connected to a flange 182 penetrating the center of the RF electrode 130 to connect the gas inlet pipe 180. 172 is connected. A matcher 174 for matching impedance is installed between the RF power supply 170 and the RF electrode 130.

The RF electrode 130 connected to the gas distribution plate 140 and the RF power source 170 is made of a material such as aluminum and is electrically connected to each other, and is connected to the chamber 110 grounded using the insulating member 132. It must be insulated.

In the plasma generating apparatus of the present invention, a space between the RF electrode 130 and the susceptor 120, more specifically, a space between the gas distribution plate 140 and the susceptor 120 electrically connected to the RF electrode 130. It is characterized in that the insulating plate 150 is installed on the ground electrode 160 on the upper portion of the insulating plate 150.

The insulating plate 150 is made of an insulator such as ceramic, and has a plurality of first through parts 151 formed in a base material of a flat plate shape, and supports the fixing member 156 fixed to the inner wall of the chamber 110. Mounted on top

Insulation plate 150 should have the appropriate rigidity because it must be able to withstand the weight of the ground electrode 160 mounted on its own weight and the top.

The ground electrode 160 is formed by forming a second through portion 161 communicating with the first through portion 151 on a conductive flat plate base material, or coating a conductive metal on the insulating plate 150 to a predetermined thickness. It may be formed by.

It is preferable to use aluminum, an aluminum alloy, or anodized aluminum as the conductive plate base material, and in the case of coating, coating is performed using aluminum or indium tin oxide (ITO).

Since the ground electrode 160 is supported by the lower insulating plate 150, it is not necessary to be too thick, and preferably 0.1 µm or more and 10 mm or less.

Regardless of the type, the ground electrode 160 should be grounded. However, since the chamber 110 is in a ground state, the ground electrode 160 is preferably electrically connected to the chamber 110.

In this way, by installing the ground electrode 160 and the insulating plate 150 to horizontally divide the inside of the chamber, the inside of the chamber is the upper region (I, hereinafter 'generating region') of the ground electrode 160 where plasma is generated, Ions and active species generated in the generation region (I) are divided into regions (II, hereinafter referred to as 'reaction regions') in which they diffuse and react with the substrate 30.

That is, RF power supplied from the RF power source 170 is applied to the RF electrode 130 and then transferred to the lower surface of the gas distribution plate 140, and a generation region between the gas distribution plate 140 and the ground electrode 160 is provided. In (I), a vertical RF electric field is formed.

In the RF electric field, electrons are accelerated to collide with a neutral gas to generate ions and active species, and the ions and active species thus generated are diffused into the reaction region (II) below through the first and second through parts 151 and 161.

However, since the ions generated in the generation region (I) are often trapped in the plasma interface or the sheath around the first and second through portions 151 and 161 or collide with the neutral gas, they are converted into neutral particles. Not only is the rate of diffusion into the reaction region (II) through (151, 161) low but also the energy of ions is often significantly reduced even though passing through the first and second through parts (151, 161).

On the other hand, since the active species is electrically neutral, the active species smoothly diffuses through the first and second through portions 151 and 161 to the lower reaction region (II). In the reaction region (II), the density of plasma is very low. Compared with), the rate of extinction of active species by recombination is low, resulting in long residence time.

Therefore, in the reaction region (II), the density of active species is higher than that of the conventional plasma generator, so that the deposition rate is faster, and the energy and density of the ions are lower. .

The interval between the RF electrode 130 and the ground electrode 160 in the generation region I above the ground electrode 160 is within 5 mm to 100 mm. More specifically, the interval between the gas distribution plate 140 and the ground electrode 160 is configured within 5mm to 100mm.

In order to effectively confine the plasma generated in the generation region (I), to maintain a plasma of an appropriate density, and to form an active species, the interval can be appropriately adjusted within the above range.

In addition, the interval of the reaction region (II) between the ground electrode 160 and the susceptor 120 is selected from the range of 10mm to 200mm or less, and the uniformity of the thin film deposited on the substrate and the activity diffused in the reaction region (II). The distribution of species is chosen at a uniform location.

On the other hand, the second through portion 161 of the ground electrode 160 is preferably larger in diameter than the first through portion 151 of the insulating plate 150, so when viewed from the top as shown in FIG. A portion of the insulating plate 150 and the first through part 151 are exposed to the inside of the through part 161.

This is to prevent the thin film, which is inevitably deposited on the ground electrode 160, from being peeled off and diffused downward to contaminate the substrate 30. That is, when the second through part 161 has a larger diameter than the first through part 151, a part of the insulating plate 150 is exposed to the inside of the second through part 161 to form a step 152. Particles separated from the ground electrode 160 are accumulated in the step 152 so that the particles do not flow downward.

As such, the insulating plate 150 not only supports the ground electrode 160 but also prevents contamination due to particles, thereby increasing the reproducibility of the device.

Meanwhile, the ions generated in the generation region (I) flow into the reaction region (II) except that they are trapped in the sheath or collided with the neutral gas and converted into neutral particles. Thus, the ions are used to etch the substrate 30. It may be.

In order to use this for etching, it is preferable to connect the second RF power source 176 to the susceptor 120 as shown in FIG. 4 to control the incident direction and energy of the ions.

In the plasma generating apparatus according to an embodiment of the present invention, since high energy ions are filtered in the process of ions diffused into the reaction region (II), they are suitable for etching porous soft thin films.

In particular, a thin film (eg, SiOC, etc.) having a dielectric constant of 3 or less has a problem in that a thin film damage is too large due to high energy ions when using a conventional etching apparatus. Such thin film damage can be prevented.

On the other hand, the plasma generating apparatus of the present invention is not limited to a semiconductor manufacturing apparatus or a flat panel display apparatus, and can be used to manufacture thin films such as carbon nanotubes (CNT), and in particular, to deposit low temperature poly silicon (LTPS) thin films. It can be usefully applied.

According to the plasma generating apparatus of the present invention, by filtering high energy ions, in the case of PECVD, thin film damage due to ion bombardment can be prevented to obtain excellent film quality, and the loss of active species due to recombination can be reduced to increase the thin film deposition rate. have.

In addition, the high energy ions are filtered in the etching apparatus, so that the soft thin film can be precisely etched without damage.

Claims (7)

A chamber defining a reaction zone; A substrate setter installed in the chamber; An RF electrode installed on the substrate mounting means and insulated from the chamber; A first RF power source connected to the RF electrode; A first matcher for matching an impedance between the first RF power supply and the RF electrode; An insulating plate disposed between the RF electrode and the substrate mounting means and having a plurality of first through portions; A conductive ground electrode provided on the insulating plate and having a plurality of second through parts communicating with the first through part; Gas supply means for supplying a raw material to the ground electrode Plasma generator comprising a The method of claim 1, The ground electrode has a plasma generator having a thickness of 0.1㎛ more than 10mm The method of claim 1, The ground electrode is formed on the plasma coating is formed on the upper plate The method of claim 3, The ground electrode is a plasma generator made of indium tin oxide (ITO) or aluminum The method of claim 1, The diameter of the first through portion is smaller than the diameter of the plasma generating device of the second through portion The method of claim 5, The first through portion has a diameter of 1mm to 10mm smaller than the second through portion plasma generating apparatus The method of claim 1, A second RF power source is connected to the substrate mounting unit, and a plasma generating device is connected between the second RF power source and the substrate mounting unit to a second matcher for impedance matching.

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