KR100354967B1 - Large area and high density plasma generating apparatus - Google Patents

Abstract

In order to provide a device capable of generating a large-area plasma having a uniform density distribution under a low injection gas pressure, the present invention provides a plasma generating apparatus for generating a large-scale plasma, wherein the large-scale plasma is generated. chamber; And a plurality of high-density plasma generators formed annularly on the sidewall of the main chamber.

Description

LARGE AREA AND HIGH DENSITY PLASMA GENERATING APPARATUS}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma generating apparatus for generating a plasma, and more particularly, to a plasma generating apparatus for generating a plasma having a large effective area capable of processing a large sample and a uniform and high density distribution.

In the technical field in which fine patterns such as semiconductor devices or flat panel displays are to be formed, it is common to use a plasma etching process that generates and uses plasma. Recently, in order to achieve cost reduction and improved throughput, the size of wafers for semiconductor devices and substrates for flat panel displays tends to be larger than 300 mm, thereby generating plasma for processing such large wafers or substrates. The specification of devices is also increasing.

Conventional plasma sources include diodes, microwaves, radio frequency waves, and the like. However, the diode system is not suitable for processing fine patterns because of the difficulty in controlling high voltages and requiring high pressure gas pressure. In addition, according to the Electron Cyclotron Resonance (ECR) method, which is a kind of microwave method, there is an advantage of generating a high density plasma even under low pressure, but it is difficult to uniformly form a plasma distribution. The disadvantage is even more pronounced as the size of the plasma increases. According to the helicon wave method, which has a very high plasma generation efficiency, the energy of the electric field and the magnetic field is combined and excited to generate a plasma having a high density and a uniform distribution in a small plasma, but still a large scale Generating a plasma has the disadvantage that the density distribution is not uniform.

Recently, researches for generating a large-area plasma using a helicon wave method or an inductively coupled plasma generator are known. However, according to the above-described inductively coupled plasma generator, in order to increase the size of the plasma, the size of the helical antenna must be increased. In this case, the inductance is increased so that the high frequency of the plasma power source is matched. Has a problem that becomes difficult.

In addition, recently, apparatuses for generating a large-scale plasma by installing a plurality of small plasma generating sources capable of generating the small-scale high-density plasma as described above have been introduced, but many small-scale plasma generating sources used in such apparatuses have been introduced. Most of them are sensitive to the pressure of the injected gas, and the density of plasma generated from each device is greatly different from each other, and the overall density of the plasma is uneven, and the plasma containing the electron beam component having a large energy is transferred to the main chamber. The direct supply has a problem of damaging a sample such as a wafer or a substrate.

The present invention has been made to solve the problems of the prior art, and to provide a device capable of generating a large-scale plasma having a uniform density distribution under a low injection gas pressure.

1 is a schematic plan view of a plasma generating apparatus according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along line AA ′ of FIG. 1.

3 is a cross-sectional view taken along line BB ′ of FIG. 2.

4 is a diagram illustrating an intensity distribution of a magnetic field of the plasma generating device of FIG. 1.

* Explanation of the symbols of the main parts of the drawings

102: main chamber 104: plasma generating source

106: inductive antenna 108: gas inlet

110: chuck 112: sample

114: induction coil 116: magnet

In order to achieve the above object, the present invention provides a plasma generating apparatus for generating a large-scale plasma, comprising: a main chamber in which the large-scale plasma is generated; And a plurality of high-density plasma generators formed annularly on the sidewall of the main chamber.

Embodiments of the present invention will now be described with reference to the accompanying drawings.

Referring first to FIG. 1, FIG. 1 is a schematic plan view of a plasma generating apparatus according to an embodiment of the present invention. As shown, the plasma generating apparatus 100 of the present invention, the main chamber 102 in which a large-scale plasma is formed, and the annular surface forming the same plane as the main chamber 102 on the side wall of the main chamber 102 It includes a plurality of plasma generating source 104 installed. The plurality of plasma generators 104 may be provided as shown in FIG. 6, but the number may be increased to eight, twelve, sixteen, etc. according to the sizes of the main chamber 102 and the plasma generator 104. Can be.

The plasma generator 104 may generate a small scale high density plasma, and may use a conventional plasma generator having an axial magnetic field, such as a small helicon plasma source. The small plasma generator 104 will be described in detail later with reference to FIG. 3. In addition, in this specification, since the size of the plasma supplied by each plasma generating source 104 is relatively small compared to the size of the plasma generated in the main chamber 102, only the expression of large scale or small scale is used. It should be noted that the expression large or small is relative and is not absolutely distinguished by a certain number.

Referring back to FIG. 1, in the plasma generation apparatus 100 according to the present invention, a density distribution of plasma generated from the plurality of plasma generating sources 104 and supplied to the main chamber 102 may be obtained in the main chamber. In order to be uniform regardless of the position of the inside, an inductive antenna 106 is further formed on the plasma generating apparatus 100. In the conventional induction coupling plasma generating source, the number of turns of the antenna has to be increased in order to apply high energy, but in this case, high frequency matching becomes very difficult as described above. However, according to the present invention, the number of turns of the inductive antenna 106 need not be large. This is because the function of the inductive antenna 106 is to supply auxiliary energy to increase the uniformity of the generated plasma unlike the conventional case. Therefore, as the number of the plasma generators 104 increases, the function of the inductive antenna 106 may be unnecessary, and when the fewer plasma generators 104 are used, the inductive antenna 106 may be used. Uniform density distribution can be achieved by increasing the number of turns of.

Referring now to Figures 2 and 3, the structure of the plasma generator 100 according to the present invention will be described in more detail. FIG. 2 is a cross-sectional view taken along line AA ′ of FIG. 1. As shown, a main chamber 102 is formed in the center and a chuck 110 for placing a sample 112 such as a wafer or a substrate is formed therein. A small plasma generator 104 is mounted around the main chamber 102, and a gas for generating plasma from the outside is supplied through the gas injection hole 108. The plasma generated from the small-scale plasma generator 104 is supplied to the main chamber 102 by the injection pressure of the gas and the magnetic pressure by the magnetic field distribution. The plurality of small-scale plasma generators 104 used in the plasma generator 104 include a magnetic field. The distribution of the magnetic field by the magnet 116 (see FIG. 3) used in this case is described in detail later. Align to the minimum inside of.

Referring now to FIG. 3, FIG. 3 is a cross-sectional view taken along line B-B ′ of FIG. 2. In FIG. 3, only one of the plurality of plasma generating sources 104 is illustrated and the rest thereof are omitted in order to describe the structure of the plasma generating source 104 in more detail. As shown, the plasma generating source 104 preferably includes an axial magnetic field capable of obtaining high plasma generating efficiency and high plasma density, and a representative example thereof may be a helicon plasma source. That is, the induction coil 114 is installed under the axial magnetic field formed by the external electromagnet 116 to plasma the gas supplied from the gas inlet 108.

According to a preferred embodiment of the present invention, the direction of the electromagnet is adjusted so that the magnetic field (expressed by N and S) generated by the electromagnet 116 is alternately formed with the magnetic field by the induction coil of the adjacent plasma generating source. The "N" and "S" shown in FIG. 3 and the arrows shown inside the main chamber 102 show the direction of the magnetic field formed by the electromagnet coil adjusted in this way. In this way, a magnetic field distribution as shown in FIG. 4 can be formed. In addition, when the electromagnet 116 is formed of two solenoid coils, the plasma may be easily moved to the main chamber 102 by controlling the difference in current from the induction coil 114.

FIG. 4 is a diagram illustrating the intensity of the magnetic field of the plasma generating device of FIG. 1. As shown, it can be seen that the intensity of the magnetic field gradually decreases from the region in which the induction coil 114 is installed to the center of the main chamber 102 (that is, the "well" of the magnetic field is formed). Plasma generated from the plasma generation source 104 is injected into the main chamber 102 by the distribution of the magnetic field as shown, and the large-scale plasma (shown in a cloud shape) formed in this way is the main chamber 102. It does not react with the inner wall and is trapped in the "well" of the magnetic field. Therefore, it is possible to ensure the stability of the large-scale plasma formed and collected from a plurality of sources 104, respectively, and to accelerate all the generated plasma toward the chuck 110 to effectively process the sample 112 In addition, it is possible to effectively prevent the contamination of the plasma remaining inside the main chamber (102).

As described above, since the plasma generating apparatus of the present invention has a large scale, uniform and stable characteristics, it can be applied to the microstructure processing as shown in FIG. 2, and the sample chuck is removed and the aperture is removed. The large current ion beam can also be extracted by installing).

According to the present invention, a large number of uniform plasma can be generated regardless of the pressure of the injection gas by a plurality of plasma generating sources formed on the same plane as the main chamber, and stable by a well of the magnetic field by the plurality of plasma generating sources. Can be retained. The plasma generating apparatus according to the present invention can be applied to equipment for processing large diameter wafers or flat panel displays, and can also be applied to large-scale large current ion beam generation sources.

Although the technical idea of the present invention has been described in detail according to the above preferred embodiment, it should be noted that the above-described embodiment is for the purpose of description and not of limitation.

Claims (7)

In the plasma generating apparatus for generating a large-scale plasma, A main chamber in which the large-scale plasma is generated; And Plasma generating apparatus comprising a plurality of high-density plasma generating sources attached to the side wall of the main chamber annularly to generate the plasma itself and inject into the main chamber. The method of claim 1, Inductive antenna formed in a spiral shape on top of the main chamber Plasma generator further comprising. The method of claim 1, And the intensity of the magnetic field in the regions of the plurality of plasma generation sources is stronger than that of the magnetic field inside the main chamber. The method according to claim 1 or 2, And the plurality of plasma generating sources are high density plasma generating sources including an axial magnetic field. The method of claim 4, wherein And a direction of the magnetic field formed by each of the plurality of plasma generating sources is opposite to the direction of the magnetic field formed by the adjacent plasma generating sources. The method of claim 1, And a sample chuck for forming a microstructure under the main chamber. The method of claim 1, And an ion beam extractor for extracting an ion beam from the plasma under the main chamber.