KR100230360B1 - Induced coupling type plasma apparatus - Google Patents

Abstract

An inductively coupled plasma forming apparatus using high frequency is disclosed. An inductively coupled plasma forming apparatus according to the present invention includes a high frequency generator for generating a high frequency, a coil wound around the etching chamber of the plasma etching apparatus and supplied with high frequency from the high frequency generator, And a DC supplying means for supplying a DC current to the coil so that a magnetic field circulating in a predetermined direction around the coil can be formed.

Description

Inductively Coupled Plasma Forming Device

FIG. 1 schematically illustrates a conventional plasma forming apparatus applied to an inductively coupled plasma (ICP) etching apparatus.

FIG. 2 shows a secondary induced electric field in the etching chamber when high frequency power is applied to the etching chamber using a conventional plasma forming apparatus.

FIG. 3 shows a second-order induced electric field formed in the etching chamber when the high-frequency power is high.

FIG. 4 shows the magnetic field formed in the circular coil when a DC current is applied to the circular coil for generating the ICP.

FIG. 5 schematically shows a configuration of an inductively coupled plasma forming apparatus according to a preferred embodiment of the present invention.

DESCRIPTION OF THE REFERENCE NUMERALS

112: high frequency generator 114: coil

116: matching network 120: DC supply means

V _DC : DC voltage supply L: Inductor

C: Capacitor

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma forming apparatus and, more particularly, to an inductively coupled plasma (hereinafter referred to as " plasma generating apparatus ") having a configuration capable of suppressing plasma generation by a capacitively coupled mode Forming apparatus.

As patterns of semiconductor devices are integrated, processing of patterns having an etching selectivity ratio and a high aspect ratio is becoming more important. Recently, a technique related to dry etching using plasma in the process of manufacturing semiconductor devices has been developed. Particularly, efforts to put inductively coupled plasma (hereinafter referred to as "ICP") as a plasma source capable of generating a low-pressure and high-density plasma,

FIG. 1 is a schematic view of a conventional plasma forming apparatus applied to an ICP etching apparatus.

Referring to FIG. 1, a conventional plasma forming apparatus includes a high frequency generator 12 for generating a high frequency, a high frequency generator 12 for generating high frequency waves by a high frequency generated from the high frequency generator 12 by being wound around the etching chamber 10, And a matching network 16 connected between the high frequency generator 12 and the ICP type coil 14 to match the impedance in the plasma forming apparatus. The ICP type coil 14, .

In the conventional plasma forming apparatus configured as described above, the RF power generated by the high frequency generator 12 is supplied to the etching chamber 10 through the coil wound once or several times around the etching chamber 10 . The second-induced electric field is formed in the etching chamber 10 by the applied high-frequency power.

FIG. 2 is a view showing an aspect of a secondary induced electric field formed in the etching chamber 10 when a high frequency power is applied to the etching chamber 10 using a plasma forming apparatus as described with reference to FIG. 1 1 shows a cross section of the etching chamber 10 shown in FIG. 1 cut in a direction in which the coil 14 is wound.

2, when applying a high frequency power into the etching chamber 10 through the coil 14 using a conventional plasma forming apparatus, generally within the etching chamber 10 An induction electric field in the inductively coupled mode, that is, a secondary electric field 22 is formed in the opposite direction to the primary electric field 20, and electrons are accelerated in the etching chamber 10 by the secondary electric field 22 .

However, in the case of using the above conventional plasma forming apparatus, electrons are not accelerated only by the secondary electric field in the ICP type etching apparatus. That is, when the high frequency power is high, since the voltage applied to the coil is high, the direction of the electric field formed in the etching chamber is different from the direction shown in the second figure.

FIG. 3 is a diagram showing the shape of a secondary induction electric field formed in the etching chamber 10 when the high-frequency power is high, and shows a cross section in the same direction as the direction shown in FIG.

3, when a relatively high frequency power is applied to the etching chamber 10 through the coil 14 using a conventional plasma forming apparatus, the voltage applied to the coil 14 In the etching chamber 10, in addition to the secondary electric field 22 as described with reference to FIG. 2, a CC mode in the etching chamber 10 toward the inner wall of the etching chamber 10 in the radial direction, The electrons in the etching chamber 10 are accelerated toward the inner wall of the etching chamber 10 along the direction of the electric field 32 in the CC mode.

As described above, since the electric field of the CC mode is formed in the etching chamber in the etching apparatus using the conventional plasma forming apparatus, not only the plasma generation efficiency is lowered but also the electrons and ions accelerated in the radial direction toward the inner wall of the etching chamber This results in the inner wall of the etch chamber being sputtered. Therefore, this causes a cause of contamination and particle generation in the semiconductor manufacturing facility and the semiconductor device to be processed, resulting in the life or shortening of the facility.

Therefore, an object of the present invention is to provide an induction-competition type plasma forming apparatus capable of minimizing the influence of an electric field of the CC mode which may occur in a plasma etching apparatus even when a relatively high RF power is applied.

In order to attain the above object, the present invention provides an inductively coupled plasma forming apparatus using a high frequency, comprising: a high frequency generator for generating a high frequency; a coil wound around the etching chamber of the plasma etching apparatus and supplied with high frequency from the high frequency generator; A matching network connected between the high frequency generator and the coil to match the impedances, a direct current supply unit for supplying a direct current to the coils so that a magnetic field circulating in a predetermined direction around the coils can be formed, And an inductively coupled plasma generating device for generating an inductively coupled plasma.

Preferably, the DC supply means includes a DC voltage supply, an inductor, and a capacitor.

According to the present invention, even when a relatively high RF power is applied, the influence of the electric field of the CC mode which can occur in the plasma etching apparatus is minimized, thereby eliminating the contamination source of the semiconductor manufacturing facility and the semiconductor device, have.

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

In general, according to Ampere's law,

The curvature of the magnetic vector H can be expressed by the product of the current J and the displacement current 1dD / 1dt. According to the above equation, when the current J flows around the conductor, a magnetic field B is formed around the conductor. The magnitude of the magnetic field B thus formed can be expressed as follows.

Where μ ₀ is the magnetic permeability in vacuum, I is the current flowing through the conductor, and r is the distance from the conductor.

When a DC current is applied to a circular coil for generating an ICP by using the above-described principle, a magnetic field that circulates in a constant direction around the coil can be obtained.

FIG. 4 shows a magnetic field B formed in the circular coil 50 when a DC current is applied to the circular coil 50 for generating ICP.

If the above-described principle is applied to the plasma forming apparatus, the influence of the electric field of the CC mode formed in the etching chamber can be minimized.

FIG. 5 schematically shows a configuration of a plasma forming apparatus according to a preferred embodiment of the present invention. In the plasma forming apparatus according to the present invention, a high frequency and a direct current are used together to form a magnetic field in the etching chamber.

5, a plasma forming apparatus according to the present invention includes a high frequency generator 112 for generating a high frequency, and a high frequency generator 112 which is wound in the horizontal direction outside the etching chamber of the etching apparatus, A matching network 116 which is connected between the high frequency generator 112 and the coil 114 to match the impedance in the plasma forming apparatus, And a DC supply means 120 for supplying a DC current to the coil 114 so that a magnetic field circulating in a predetermined direction around the coil 114 can be formed. The direct current supplying means 120 is constituted by a direct current voltage supply V _DC and is configured to prevent the high frequency RF generated from the high frequency generator 112 from flowing back to the direct current voltage supply V _DC It is preferable to further include an inductor L and a capacitor C. The direct current supplying means 120 may be connected directly to the coil 114 to supply the direct current to the coil 114. Alternatively, the direct current supplying means 120 may be connected to an external coil (not shown) The DC current may be supplied to the coil 114 through the DC link.

In the inductively coupled plasma generating apparatus according to the present invention, a magnetic field circulating in a predetermined direction is formed around a coil wound on the outside of the etching apparatus, so that a magnetic field is formed by DC supply from the inner wall of the etching chamber. Therefore, electrons or ions radially accelerated toward the inner wall of the etching chamber, as in the case of the conventional plasma forming apparatus, are not affected by the law of Lorentz's force near the inner wall of the etching chamber to reach the inner wall of the etching chamber And returns to the inside of the etching chamber.

Therefore, according to the present invention, the inner wall of the etching chamber is not damaged by sputtering, thereby reducing the contamination degree of the semiconductor manufacturing facility and the semiconductor element, and facilitating maintenance of the equipment.

Although the ICP etching chamber is described as an etching chamber of the etching apparatus using plasma in the above embodiments, the present invention is not limited to this, and the present invention is not limited thereto, and the etching chamber of the TCP (Transformer Coupled Plasma) type or the helicon wave plasma It can also be applied to chambers.

It is apparent that the present invention is not limited to the above embodiments and that many modifications can be made by those skilled in the art within the technical scope of the present invention.

Claims (2)

An inductively coupled plasma generating apparatus using a high frequency, comprising: a high frequency generator for generating a high frequency; a coil wound around the etching chamber of the plasma etching apparatus and supplied with a high frequency from the high frequency generator; And a direct current supplying means for supplying a direct current to the coil so that a magnetic field circulating in a predetermined direction around the coil can be formed, Type plasma forming apparatus. The inductively coupled plasma forming apparatus according to claim 1, wherein the direct current supplying means includes a DC voltage supply, an inductor, and a capacitor.