KR20090073327A - Apparatus for high density remote plasma processing - Google Patents

Abstract

A high density remote plasma processing unit is provided to maximize a size of an electric field secondly induced by a magnetic field by equalizing the direction of the current inducing the magnetic field. A remote plasma processing unit includes a process chamber, a plasma generator(110), and an oscillator(300). A substrate is received in a process chamber and is processed with the plasma. The plasma generator generates the plasma in the process chamber and supplies the plasma. The oscillator supplies the RF power as an energy source for generating the plasma. A plasma generator includes a tube(112) and a ferromagnetic core(114). A tube is connected to the upper part of the process chamber and has a space for generating the plasma inside. A ring type ferromagnetic core is installed to surround the outside of the tube.

Description

High Density Remote Plasma Processing Apparatus {Apparatus For High Density Remote Plasma Processing}

The present invention relates to a high-density remote plasma processing apparatus using a ferromagnetic material, and more particularly, includes a plasma generating unit integrally connected to a process chamber in which a plasma processing is performed on a predetermined substrate, and the plasma generating unit is laminated. It characterized in that it comprises a ferromagnetic core to be formed, and relates to a remote plasma processing apparatus having high efficiency since the generation of plasma is easy.

In general, a semiconductor chip manufacturing process or a flat panel display device such as a plasma display panel (PDP), a liquid crystal display (LCD), an organic light emitting diode (OLED), or the like. In the technical field in which fine patterns must be formed, such as in a manufacturing process, a plasma is generated using a plasma processing apparatus, and sputtering and chemical vapor deposition (CVD) are performed using the generated plasma. Various processes such as Vapor Deposition and Dry Etching are processed.

Plasma is a collection of ionized particles consisting of ion nuclei and free electrons in an electrically neutral state when a gaseous substance receives more energy, which refers to these ionized particles.

Representative types of devices that perform the process as described above using plasma include, for example, an inductively coupled plasma (ICP) generating device and a capacitively coupled plasma (CCP) according to a method of applying RF (Radio Frequency) power. : Capacitive Coupled Plasma) can be roughly classified into a generator. The former uses a method of converting a source material into a plasma by using an induction electric field induced by a single spiral RF antenna or a plurality of split electrode RF antennas. The method of generating a plasma using an RF electric field formed vertically between the electrodes by applying RF power to the parallel flat electrodes facing each other is used.

The CCP method has been widely used, but since this method has high ion energy accelerated perpendicularly to the substrate to be processed, there is a high possibility of damaging the substrate or the components inside the device due to ion shock, and the line width or selectivity. In addition to the difficulty of precisely controlling the pressure, there was a problem that can not be used in the tens of m Torr low pressure region.

On the other hand, the ICP method is capable of generating plasma relatively effectively even in the low pressure region of several tens of m Torr, and can obtain plasma of much higher density than the CCP method, and is treated in a susceptor serving as an electrode. Unlike the CCP method of placing a substrate, RF power contributing to plasma generation is applied to an antenna independent of the substrate to be processed, which has an advantage of independently controlling energy of ions incident on the substrate.

However, the conventional ICP method has a structure in which each induction coil constituting the antenna is connected in series, so that the amount of current flowing in each induction coil is constant, which makes it difficult to control the induction field distribution. The center of the process chamber has a high density of the plasma, while the portion near the inner wall has a low density of the plasma, it is extremely difficult to maintain the uniform density of the plasma in the process chamber.

In addition, the ICP method has an induction electric field which is lost to the upper part of the process chamber by the induction electric field used to generate the plasma in the process chamber among the induction electric fields generated by the magnetic field generated by the RF antenna, and a special magnetic shield means Since there is no leakage flux, it is necessary to supply high voltage and high current RF power in order to obtain an induction electric field of a predetermined intensity for plasma generation and maintenance. Therefore, sputtering of the inner wall of the process chamber by high energy ions and Components deteriorate, causing pollution, and the loss of RF power and the cost of RF power also increases.

In order to secure the shortcomings of the conventional ICP as described above, a remote plasma processing apparatus using a ferromagnetic material instead of a spiral antenna has recently been developed.

A ferromagnetic material is a substance (eg, iron, cobalt, nickel, or an alloy thereof) that adheres to a magnet. The atoms that make up the magnet are arranged irregularly in the absence of an external magnetic field. Although it does not have the same effect, it refers to a substance that magnetization remains even after the external magnetic field disappears after it is strongly magnetized in the direction of the magnetic field when a strong magnetic field is applied from the outside. In this case, each atom of the material can be equal to one magnet.

A remote plasma processing apparatus using a ferromagnetic material is a method of applying an RF power to a coil after winding an induction coil on a core made of a ferromagnetic material, and may be classified into an external type and an internal type according to an aspect in which the ferromagnetic core is installed in the device.

However, the remote plasma processing apparatus using the conventional ferromagnetic material also has a problem that the generation of plasma is not easy. In other words, the internal type is a structure in which the ferromagnetic core itself is completely included in the process chamber, so that even the induction coil wound around the core is located inside the process chamber, so that the impedance of the induction coil connected to the RF power is changed. This problem affects the matching state of RF power, which causes instability.

On the other hand, in the case of the external type, since the ferromagnetic core is installed in a separate structure above the process chamber, the matching state of the RF power as described above can be prevented from becoming unstable, but the plasma generation unit and the process are performed. Since the chambers are considerably spaced apart, it is disadvantageous for the ignition and maintenance of the plasma. As a result, it is difficult to expect a high plasma density.

Recently, the size of the substrate tends to be large, for example, 300 mm or more for cost reduction and yield improvement. Accordingly, the size of the remote plasma generator for processing large diameter substrates has also increased. However, a large-scale plasma generation device has a problem in that it is difficult to generate a uniform plasma in a large area because a method of arranging a plurality of conventional single ferromagnetic cores is used.

In addition, the remote plasma processing apparatus using a conventional ferromagnetic material requires a separate discharge initiation device, and in addition to the problem that an unstable plasma is generated at a high pressure, it is difficult to make an apparatus having a small plasma generation range. It is also difficult to generate a uniform plasma when applied to the.

The present invention has been made to solve the above-mentioned problems of the prior art, and an object thereof is to provide a remote plasma processing apparatus having high density and uniformity in plasma generation.

It is also an object of the present invention to provide a remote plasma processing apparatus that is easy to generate plasma even in a high pressure environment.

It is also an object of the present invention to provide a remote plasma processing apparatus that is easy to generate a uniform and highly efficient plasma irrespective of the substrate area.

In order to achieve the above object, the remote plasma processing apparatus according to the present invention includes a plasma generation unit which is integrally connected to a process chamber in which plasma processing is performed on a predetermined substrate, and the plasma generation unit includes a ferromagnetic core. It is characterized by including.

And, in order to achieve the object as described above, the remote plasma processing apparatus according to the present invention comprises a process chamber in which the substrate is placed plasma treatment; A plasma generator for generating and supplying plasma to the process chamber; And an oscillator for supplying RF power as an energy source required for plasma generation, wherein the plasma generator includes a tube that is integrally connected to an upper portion of the process chamber and has a space in which a plasma is generated. And it characterized in that it comprises a ring-shaped ferromagnetic core is installed to surround the outside of the tube.

The ferromagnetic core may be plural.

The tube may be a plurality, and a plurality of ferromagnetic cores may be installed in each of the tubes.

The plurality of ferromagnetic cores may be installed to be stacked in parallel in the longitudinal direction of the tube.

The ferromagnetic core may be wound with a coil connected to the oscillator.

As the current flows through the coil, plasma may be generated in the plasma generator by an electric field induced by a magnetic field formed on the ferromagnetic core.

A matching part for impedance matching may be installed between the ferromagnetic core and the oscillation part.

According to the present invention, by a parallel structure of stacking a plurality of cores formed of a ferromagnetic material and a configuration in which the direction of the coil wound around the core is the same, the secondary direction is induced by the magnetic field by making the direction of the current inducing the magnetic field the same. There is an effect that can maximize the size of the electric field.

In addition, according to the present invention, by maximizing the size of the induced electric field, there is an effect that can maximize the generation efficiency of the plasma in the device compared to the supplied RF power.

In addition, according to the present invention, there is an effect of increasing the density of the plasma in the process chamber and improving the uniformity.

In addition, according to the present invention, it is possible to provide a uniform and highly efficient plasma irrespective of the substrate area, which has the effect of easy processing of a large area substrate.

DETAILED DESCRIPTION The following detailed description of the invention refers to the accompanying drawings that show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It should be understood that the various embodiments of the present invention are different but need not be mutually exclusive. For example, certain shapes, structures, and characteristics described herein may be embodied in other embodiments without departing from the spirit and scope of the invention with respect to one embodiment. In addition, it is to be understood that the location or arrangement of individual components within each disclosed embodiment may be changed without departing from the spirit and scope of the invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention, if properly described, is defined only by the appended claims, along with the full range of equivalents to which such claims are entitled. Like reference numerals in the drawings refer to the same or similar functions throughout the several aspects.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention.

1 is a view schematically showing the overall configuration of a remote plasma processing apparatus 10 according to the present invention. As illustrated, the remote plasma processing apparatus 10 includes a plasma processing unit 100, a matching unit 200, and an oscillation unit 300.

First, the plasma processing unit 100 includes a plasma generation unit 110 for generating a plasma by an electric field, and a process chamber 120 in which an actual manufacturing process is performed by the plasma.

The plasma processing unit 100 generates plasma in the manufacture of a semiconductor chip or flat panel display, and performs various processing processes on silicon wafers and glasses such as sputtering, chemical vapor deposition, and dry etching.

The oscillator 300 serves to supply energy required for plasma generation by ionization of the gas supplied from the plasma generating unit 110 of the plasma processing unit 100, and the energy supplied at this time is microwave, radio frequency. Various types of energy, such as radio frequency (RF), may be used, but the following description will be limited to RF power.

The matching unit 200 is positioned between the plasma processing unit 100 and the oscillation unit 300 to match impedance so that appropriate RF power can be applied from the oscillation unit 300 to the plasma processing unit 100.

The configuration of the matching unit 200 and the oscillation unit 300 is well known in the field of an ICP-type plasma processing apparatus, such as the present invention, so a description thereof will be omitted herein.

2 and 3 are schematic perspective and detailed cross-sectional views showing the configuration of the plasma processing unit 100 according to an embodiment of the present invention, respectively.

As shown in FIG. 2 and FIG. 3, the plasma processing unit 100 may be composed of a plasma generating unit 110 and a process chamber 120, wherein the plasma generating unit 110 is a substrate to be processed (not shown). It is preferable that the plasma is located above the process chamber 120 so that the plasma can easily reach the substrate to be processed.

2 and 3, the plasma generating unit 110 includes a tube 112 that is integrally connected to an upper portion of the process chamber 120 and a ferromagnetic core that is formed around an outer circumference of the tube 112. 114 is preferably configured, and may further include an outer case (not shown) for receiving the tube 112 and the ferromagnetic core 114.

Tube 112 is a place where the plasma is generated by the ionization of the supplied gas, the upper side is closed and the lower side is opened so that the generated plasma can be efficiently moved to the process chamber 120, the upper side of the process chamber 120 The structure is formed integrally connected to the opening formed in the inner space, and the space is formed therein for generating the plasma, but is preferably manufactured in the form of a round cylinder, but modified to various shapes suitable for the shape of the ferromagnetic core 114 It may also be possible.

The ferromagnetic core 114 is a ring-shaped ferromagnetic material (eg, ferramagnetic, etc.) that provides a closed path of magnetic flux and induces an electric field that forms a magnetic field to ionize the gas, which is the outer side of the tube 112. A plurality is formed. 2 and 3, the number of ferromagnetic cores 112 is illustrated as four, but is not limited thereto. The number of ferromagnetic cores 112 may be usefully applied according to circumstances. In addition, the ferromagnetic core 114 may be formed in a circular ring shape, but is not limited thereto. The ferromagnetic core 114 may be formed around the outer side of the tube 112 to be deformed into various shapes to usefully close the magnetic flux. This may be possible.

According to the present invention, the ferromagnetic core 114 may be preferably formed in a structure that is stacked in the longitudinal direction of the tube 112 in parallel to each other, in this case, by the structure in which the ferromagnetic core 112 is laminated, It is possible to obtain a magnetic field having a large magnetic flux density relative to the power of the supplied RF, which has the advantage of inducing a high electric field.

In order for the ferromagnetic core 114 to form a magnetic field to induce an electric field, a portion of the ferromagnetic core 114 is wound with a coil 116 connected to the oscillator 120 to supply RF power. Here, the number of turns of the coil 116 may be appropriately adjusted to various times depending on the situation. At this time, the coil 116 is preferably wound around the respective ferromagnetic core 114 in the same direction, which is the direction of the electric field when the electric field is induced in the tube 112 is formed by the magnetized ferromagnetic core 112 This depends on the winding direction of the coil. Since the directions of the currents flowing through the coils 116 are all the same, as a result, the directions of the induced electric fields can also coincide with each other, thereby obtaining a maximized electric field. A process of inducing a maximized electric field and generating a plasma by the electric field will be described below with reference to the embodiment with reference to FIG. 3.

The process chamber 120 is a sealed reaction space in which various processes of processing a substrate to be processed using the plasma generated by the plasma generating unit 110 are performed, and a tube 112 is formed by forming a predetermined opening at an upper side thereof. It is integrally connected to the lower end of the gas inlet 122, the gas inlet 122 is a gas source that is the source of the plasma and a gas outlet 124 for exhausting the residual gas after the process may be formed.

In addition, a susceptor 126 may be formed in the process chamber 120 to allow a substrate to be placed on an upper surface thereof. The susceptor 126 may have a substrate disposed on the upper surface of the susceptor 126 facing the tube 112. It is desirable to be installed so that. The shape and size of the process chamber 120 may be configured and manufactured in various ways according to the type of substrate to be processed and the process to be performed. The susceptor 126 formed inside the process chamber 120 may also be described with reference to FIG. 2. Although formed as one, the number, shape, and specification of the susceptor 126 may be variously configured according to the type and process of the substrate to be processed.

4 is a cross-sectional view showing the configuration of the plasma generating unit 110 according to an embodiment of the present invention. A process of generating plasma by the electric field induced by the plasma generator 110 will be described with reference to FIG. 4.

As shown in the figure, a plurality of ferromagnetic cores 112 surrounding the tube 114 are stacked at predetermined intervals in the longitudinal direction of the tube 114 in parallel with each other, and the ferromagnetic cores 112 all have the same direction. As a result, the coil 116 connected to the oscillation unit 300 is wound. In this case, when RF power is applied to the coil 116, all the coils 116 have a current flowing in the same direction, and a magnetic field is formed by the current, and the ferromagnetic core 112 becomes magnetic by the magnetic field.

In general, the ferromagnetic material has a characteristic that the time-varying magnetic field 130 is formed by being strongly magnetized in the direction of the magnetic field when a strong magnetic field applied from the outside, the plurality of ferromagnetic cores 112 is a magnetic field generated by the current flowing in the same direction By forming a time-varying magnetic field 130 having the same directionality by the magnetization can be magnetized, in this case, since the ferromagnetic core 112 has a closed ring shape, the magnetic field is constrained along the same path as the shape of the ferromagnetic core 112 Can be.

According to the present invention, the coil 116 is wound around each of the ferromagnetic cores 112 stacked in parallel with each other at predetermined intervals, so that the plurality of ferromagnetic cores 112 have the time-varying magnetic field 130 in the same direction. ) Can be formed. In addition, as the plurality of ferromagnetic cores 112 form the time-varying magnetic field 130 in the same direction, the electric field 132 having the same directionality is induced for each ferromagnetic core 112 and compared with the RF power supplied inside the tube 114. There is an advantage that a maximized electric field 132 can be formed.

When the coil 116 is wound in the same direction for each of the plurality of ferromagnetic cores 112, the winding direction is not limited to a specific direction, but an electric field (that is, plasma) generated in the plasma generating unit 110 may be a process chamber ( It is preferable to select a direction in which the coil 116 is wound so as to face the substrate to be processed placed in 120.

On the other hand, in terms of improving the matching efficiency, one coil 116 winding all of the plurality of ferromagnetic cores 114 with one coil 116, that is, one coil 116 connecting the plurality of ferromagnetic cores 112 to the matching unit ( It is desirable to be connected in series with 20). However, one coil 116 is not necessarily limited to the form in which the matching unit 120 is connected in series. As shown in FIG. 5, a separate coil 116 is formed for each of the plurality of ferromagnetic cores 114. As a result, the plurality of coils 116 may be connected to the matching unit 120 in parallel.

The electric field 132 induced by the time-varying magnetic field 130 of the magnetized ferromagnetic core 112 causes the accelerated electrons (not shown) constituting the electric field 132 to collide with a neutral gas (not shown). Active species (protons) having an oxidizing power are generated and converted into a plasma state, which is a mixed gas of free electrons and active species, and the active species reach a substrate to be deposited on the susceptor 126 to deposit or etch. Will be performed.

6 is a perspective view schematically showing the configuration of a plasma processing unit 400 according to another embodiment of the present invention. As illustrated, a plurality of plasma generating units 110 may be provided on the process chamber 112 according to the area of the substrate to be processed or the number of substrates for one batch.

That is, the configuration shown in FIG. 6 may be referred to as a remote plasma processing apparatus that can be applied when processing a large area substrate. For example, unlike in the case of a semiconductor chip process, when the LCD and PDP manufacturing processes are performed in the process chamber 120, the process chamber 120 also needs to be large because the size of the substrate to be processed increases. There may be. In this case, as shown in FIG. 5, by distributing a plurality of plasma generating units 110 on the process chamber 120, a uniform plasma may be formed and maintained even in the large-area process chamber 120. .

In addition, when a plurality of susceptors 126 are installed inside the process chamber 120 to simultaneously process a plurality of substrates, the process chamber 120 should also be large in area, as shown in FIG. 6. By distributing a plurality of plasma generating units 110 on the process chamber 120, a uniform plasma may be formed and maintained even in the large-area process chamber 120. In this case, it is preferable to install the plurality of plasma generating units 110 in a structure opposite to the susceptor 126 installed in the process chamber 120, but is not necessarily limited thereto.

Although the present invention has been described by specific embodiments such as specific components and the like, but the embodiments and the drawings are provided to assist in a more general understanding of the present invention, the present invention is not limited to the above embodiments. For those skilled in the art, various modifications and variations can be made from such descriptions.

Therefore, the spirit of the present invention should not be limited to the embodiments described above, and all of the equivalents or equivalents of the claims, as well as the claims below, are included in the scope of the spirit of the present invention. I will say.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 schematically shows the overall configuration of a remote plasma processing apparatus according to the present invention.

Figure 2 is a perspective view schematically showing the configuration of a plasma processing unit according to an embodiment of the present invention.

3 is a cross-sectional view showing in detail the configuration of the plasma processing unit according to an embodiment of the present invention.

4 is a cross-sectional view showing a configuration of a plasma generating unit according to an embodiment of the present invention.

5 is a cross-sectional view showing a configuration of a plasma generating unit according to another embodiment of the present invention.

6 is a perspective view showing a configuration of a plasma processing unit according to another embodiment of the present invention.

<Brief description of the major reference numerals>

10: remote plasma processing device

100, 400: plasma processing unit

110: plasma generating unit

112: tube

114: ferromagnetic core

116: coil

120: process chamber

122: gas inlet

124: gas outlet

126: susceptor

130: time-varying magnetic field

132: electric field

200: matching unit

300: oscillation part

Claims (8)

And a plasma generating unit integrally connected to a process chamber in which plasma processing is performed on a predetermined substrate, wherein the plasma generating unit includes a ferromagnetic core. A process chamber in which a substrate is placed and plasma treated; A plasma generator for generating and supplying plasma to the process chamber; And Oscillator for supplying RF power as an energy source for plasma generation Including; The plasma generation unit A tube integrally connected with an upper portion of the process chamber and having a space in which a plasma is generated; And Ring-shaped ferromagnetic core installed to surround the outside of the tube Remote plasma processing apparatus comprising a. The method of claim 2, And a plurality of ferromagnetic cores. The method of claim 2, The plurality of tubes, the remote plasma processing apparatus, characterized in that a plurality of ferromagnetic core is provided in each of the tubes. The method according to claim 3 or 4, And the plurality of ferromagnetic cores are installed to be stacked in parallel in the longitudinal direction of the tube. The method of claim 2, And a coil connected to the oscillation unit is wound around the ferromagnetic core. The method of claim 6, The plasma is generated in the plasma generating unit by an electric field induced by a magnetic field formed on the ferromagnetic core as a current flows in the coil. The method of claim 2, And a matching unit for impedance matching between the ferromagnetic core and the oscillation unit.

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