KR20080079788A - Apparatus for treating substrate and method for controlling plasma density - Google Patents

Abstract

An apparatus for processing a substrate and a method for controlling plasma density are provided to improve the uniformity of plasma density distribution in an upper space in a process chamber corresponding to a substrate region by forming multi-layer-structured insulators. A plasma treatment process is performed in process chambers(100,200). A dielectric window(220) is installed on an upper portion of the process chambers. Multi-layer-structured insulators are provided at a central region of the dielectric window. An inductive coupling plasma antenna(300) is installed on an upper surface of the dielectric window. The inductive coupling plasma antenna forms an inductive electric field in the process chambers. The dielectric window includes a first insulator(222) and a second insulator(224). The first insulator is installed on an upper portion of the process chambers. A groove unit is formed at a central region of the first insulator. The second insulator is inserted into and fixed on the groove unit being formed on the first insulator.

Description

Substrate processing apparatus and control method of plasma density {APPARATUS FOR TREATING SUBSTRATE AND METHOD FOR CONTROLLING PLASMA DENSITY}

1 is a schematic configuration diagram showing an example of an inductively coupled plasma processing apparatus that is generally used in the prior art,

2 is a cross-sectional view showing an example of a substrate processing apparatus according to the present invention.

<Description of Symbols for Main Parts of Drawings>

100: upper processing chamber 110: substrate support member

200: lower processing chamber 220: dielectric window

222: first insulator 224: second insulator

300: inductively coupled plasma antenna 310: high frequency power

320: DC power supply member

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate processing apparatus and method, and more particularly, to a device for processing a substrate using plasma and a method for controlling density distribution of plasma.

In general, a plasma refers to an ionized gas state composed of ions, electrons, radicals, and the like, and a plasma is generated by a very high temperature, a strong electric field, or an RF electromagnetic field.

As plasma processing apparatuses, capacitively coupled plasma processing apparatuses, inductively coupled plasma processing apparatuses, and microwave plasma processing apparatuses are proposed according to plasma generation energy sources. have. Among them, inductively coupled plasma (ICP) processing apparatus has been widely used due to the advantages such as the generation of high density plasma at low pressure.

1 is a schematic diagram illustrating an example of an inductively coupled plasma processing apparatus that is generally used.

Referring to FIG. 1, an inductively coupled plasma processing apparatus 1 has a process chamber 10 that provides a space in which a plasma processing process is performed. In the process chamber 10, a substrate holder 20 for placing a substrate (for example, a wafer) W to be processed is installed, and an upper portion of the process chamber 10 is injected into the process chamber 10. Inductively Coupled Plasma Antenna 30 is installed to transmit RF power to generate plasma from the reactant gas.

As the inductively coupled plasma (ICP) antenna 30, as shown in FIG. 1, a planar spiral antenna is generally used. When high frequency power is applied to the inductively coupled plasma antenna 30 from the high frequency power source 40 connected to the center of the planar spiral antenna, current flowing along the coil of the antenna 30 generates a magnetic field in the space inside the process chamber 10. Form. The induction electric field is formed by this magnetic field, and the reaction gas supplied to the process chamber 10 obtains sufficient energy for ionization from the induction electric field to generate plasma.

However, in the inductively coupled plasma processing apparatus equipped with a planar spiral antenna, the intensity of the induction electric field is largest in the center portion of the antenna coil and has a distribution that decreases toward the periphery. As a result, the density of the inductively coupled plasma generated in the process chamber also has a nonuniform distribution that is high in the center portion and decreases toward the periphery.

In order to process a large area substrate of 300 mm or more, generation of a plasma having a uniform distribution in a space corresponding to at least the substrate area is required. However, as described above, the inductively coupled plasma processing apparatus equipped with the planar spiral antenna does not satisfy these requirements, and therefore, the etching depth of the wafer or the material film deposited on the wafer surface in the etching process or the deposition process using plasma, etc. There was a problem that the thickness and the properties depend on the position on the substrate.

Accordingly, it is an object of the present invention to provide a substrate processing apparatus and a control method of plasma density capable of generating a plasma having a uniform density distribution.

In order to achieve the above object, the substrate processing apparatus according to the present invention comprises: a processing chamber in which a plasma processing step is performed; A dielectric window provided above the processing chamber and having insulators having a multi-layer structure in a central region; And an inductively coupled plasma antenna installed on an upper surface of the dielectric window to form an induction electric field in the processing chamber.

A substrate processing apparatus according to the present invention having the above-described configuration, the dielectric window comprising: a first insulator provided at an upper portion of the processing chamber and having a groove portion formed in an upper surface central region; And a second insulator inserted into the groove portion formed in the first insulator.

According to one aspect of the invention, the first insulator is preferably provided with a dielectric of quartz material.

According to another aspect of the invention, the second insulator is preferably provided with a ceramic insulator.

According to an aspect of the present invention, it is preferable to further include a DC power supply member for applying a DC voltage to the inductively coupled plasma antenna to facilitate the discharge ignition (Ignition) of the plasma generated in the process chamber.

In order to achieve the above object, a plasma density control method according to the present invention includes a dielectric window having a dielectric material having a multi-layered insulator having a different material according to a region, thereby providing a density distribution of plasma generated under the dielectric window. It is characterized by controlling.

In the plasma density control method according to the present invention having the above-described characteristics, the insulator of the multilayer structure is preferably provided in the central region of the dielectric window.

Hereinafter, a substrate processing apparatus and a plasma density control method according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings. First, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible, even if shown on different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

(Example)

The substrate processing apparatus of this embodiment may be applied to various types of substrate processing apparatuses that form an induction magnetic field in the processing chamber and process the substrate by using the plasma generated thereby. Examples of such a substrate processing apparatus include an ashing apparatus for removing an unnecessary photoresist layer remaining on a substrate, a deposition apparatus for depositing a film quality on a substrate, or an etching apparatus for etching a substrate.

2 is a cross-sectional view showing an example of a substrate processing apparatus according to the present invention.

Referring to FIG. 2, the plasma processing apparatus according to the present invention has processing chambers 100 and 200 which provide a space in which a plasma processing process is performed. The processing chambers 100 and 200 include a lower processing chamber 100 in which a substrate processing process using plasma is performed, and an upper processing chamber 200 in which plasma to be provided to the lower processing chamber 100 is generated.

The substrate support member 110 that supports the substrate W is provided inside the lower processing chamber 100. As the substrate support member 110, an electrostatic chuck (ESC) that adsorbs and supports the substrate by electrostatic power may be used. Alternatively, a vacuum chuck (Vacuum Chuck) of fixing the substrate (W) to the substrate support member 110 by using a mechanical clamping method, and by adsorption support of the substrate by the vacuum pressure is supported by the substrate support member (110) May be used.

The substrate support member 110 may be installed to be movable in the vertical direction by the driving member 120. Since the substrate support member 110 is moved up and down by the driving member 120, the substrate W placed on the substrate support member 110 may be placed in a region showing a more uniform plasma density distribution.

The substrate supporting member 110 may be provided with a heating member 130 to heat the substrate W placed on the upper surface thereof to a process temperature, and various heating means such as a resistance heating element such as a coil may be used as the heating member 130. have.

The high frequency power supply 140 may be connected to the substrate support member 110, and a matcher 142 may be disposed between the substrate support member 110 and the high frequency power supply 140. The high frequency power supply 140 provides a bias voltage so that ions and radicals emitted from the plasma generated in the upper processing chamber 200 to be described later collide with the surface of the substrate W with sufficiently high energy.

An exhaust port 152 is formed in the bottom surface of the lower processing chamber 100. An exhaust line 154 is connected to the exhaust port 152, and an exhaust member 150, such as a vacuum pump, is provided on the exhaust line 154 to maintain the interior of the lower processing chamber 100 in a vacuum state.

An upper processing chamber 200 is provided above the lower processing chamber 100, and the upper processing chamber 200 generates plasma to be provided to the lower processing chamber 100.

A gas inlet 212 through which a reactive gas for generating plasma is introduced is formed on the sidewall of the upper processing chamber 200. A gas supply line 214 is connected to the gas inlet 212, and a reactive gas source 210 is connected to the gas supply line 214.

A dielectric window 220 is provided on the upper portion of the upper processing chamber 200 to transmit radio frequency (RF) power supplied from the high frequency power source 310 to the inductively coupled plasma antenna 300 to be described later. Is installed. The dielectric window 220 includes a first insulator 222 and a second insulator 224. The first insulator 222 is installed above the upper processing chamber 200, and the groove 223 is formed in the central region of the upper surface of the first insulator 222. The second insulator 224 is inserted into the groove 223 of the first insulator 222. The first insulator 222 may be made of a dielectric such as quartz glass, and the second insulator may be made of a ceramic insulator such as aluminum nitride having excellent insulating properties and heat dissipation efficiency.

An inductively coupled plasma (ICP) antenna 300 having a coil structure is installed on the top surface of the dielectric window 220. The inductively coupled plasma antenna 300 may be provided in a coil structure of a planar spiral. A high frequency power supply line 312 is connected to the inductively coupled plasma antenna 300. A high frequency power supply 310 for supplying RF (RF) power is connected to the high frequency power supply line 312, and a matcher 314 is installed between the high frequency power supply 310 and the inductively coupled plasma antenna 300. do.

A DC power supply line 322 is connected to the high frequency power supply line 312, and a DC power supply member 320 for applying a DC voltage to the inductively coupled plasma antenna 300 is connected to the DC power supply line 322. Can be electrically connected. In addition, a low pass filter (LPF) 324 may be disposed at a rear end of the DC power supply member 320 on the DC power supply line 322. The DC power supply member 320 applies a DC voltage to the inductively coupled plasma antenna 300 so that discharge ignition of plasma generated in the upper processing chamber 200 can be easily performed.

Referring to the process of processing the substrate using the substrate processing apparatus of the present invention having the configuration as described above are as follows.

First, RF power is applied from the high frequency power supply 310 to the inductively coupled plasma antenna 300. The magnetic field is formed in the inner space of the upper processing chamber 200 by the current flowing along the coil of the inductively coupled plasma antenna 300, and the induction electric field is formed by the change of the magnetic field over time. When the inductively coupled plasma antenna 300 has a planar spiral coil structure, the intensity of the induction electric field is largest in the center portion of the coil of the antenna 300 and has a distribution that decreases toward the periphery. At this time, the second insulator 224 made of aluminum nitride provided below the center portion of the inductively coupled plasma antenna 300 reduces the transmittance of RF power, and thus induces an electric field of uniform intensity at the center and the periphery of the antenna 300. To be formed. The reaction gas supplied to the upper processing chamber 200 through the gas inlet 212 obtains sufficient energy for ionization from the induction electric field to generate plasma. The generated plasma collides with the substrate W placed on the substrate supporting member 110 of the lower processing chamber 100 to process the substrate W.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

As described above, according to the present invention, the uniformity of the plasma density distribution can be improved in the upper space of the substrate in the processing chamber corresponding to the substrate region.

In addition, according to the present invention, it is possible to efficiently dissipate heat emitted from the inductively coupled plasma antenna.

Claims (7)

In the substrate processing apparatus, A processing chamber in which the plasma processing process is performed; A dielectric window provided above the processing chamber and having insulators having a multi-layer structure in a central region; An inductively coupled plasma antenna installed on an upper surface of the dielectric window to form an induction electric field in the processing chamber; Substrate processing apparatus comprising a. The method of claim 1, The dielectric window, A first insulator installed on an upper portion of the processing chamber and having a groove portion formed in an upper surface central region thereof; And a second insulator inserted into and formed in the groove portion formed in the first insulator. The method of claim 2, And the first insulator is made of a dielectric of quartz material. The method of claim 2, And the second insulator is formed of a ceramic insulator. The method according to any one of claims 1 to 4, And a direct current power supply member for applying a direct current voltage to the inductively coupled plasma antenna to facilitate discharge ignition of plasma generated in the processing chamber. In the method for controlling the density of the plasma, And controlling the density distribution of the plasma generated under the dielectric window by providing dielectric windows with insulators having a multi-layer structure having different materials according to regions. The method of claim 6, The insulator of the multilayer structure is provided in the central region of the dielectric window.

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