KR20180080983A - Parts for plasma processing apparatus having tungsten oxide bulk - Google Patents

Abstract

Suggested are a component for a plasma device made of bulk tungsten oxide and a manufacturing method thereof, capable of having excellent corrosion resistance to plasma, securing the uniformity of plasma distribution, increasing electric conductivity and thermal conductivity, and making a simple structure. The present invention comprises: a chamber forming a reaction space for plasma processing; and a component located in the chamber to contact plasma. The component is bulk tungsten oxide having corrosion resistance to plasma and having a volume resistivity of 10^3-10^(-6) Ω·cm.

Description

TECHNICAL FIELD [0001] The present invention relates to a component for a plasma device comprising a tungsten oxide bulk,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a component for a plasma apparatus, and more particularly, to a component for a plasma apparatus made of a tungsten oxide bulk having high corrosion resistance against plasma.

In the plasma processing apparatus, an upper electrode and a lower electrode are disposed in a chamber, and a substrate such as a semiconductor wafer or a glass substrate is mounted on the lower electrode, and electric power is applied between both electrodes. Electrons accelerated by an electric field between the electrodes, electrons emitted from the electrodes, or heated electrons collide with molecules of the process gas to generate a plasma of the process gas. Active species such as radicals and ions in the plasma are subjected to desired microfabrication, for example etching, on the substrate surface. 2. Description of the Related Art Recently, design rules for the production of microelectronic devices and the like are becoming finer and, in particular, plasma etching is required to have higher dimensional accuracy. In such a plasma processing apparatus, components such as an edge ring, a focus ring, and a shower head influenced by plasma are built in.

In the case of the above-mentioned edge ring, as the power increases, the central part becomes the maximum on the substrate and the edge part becomes the lowest by the wavelength effect where the standing wave is formed and the skin effect where the electric field concentrates on the central part on the electrode surface. The nonuniformity is increased. If the plasma distribution is uneven on the substrate, the plasma treatment is not constant and the quality of the fine electronic device is deteriorated. Korean Patent Laid-Open No. 2009-0101129 attempts to provide uniformity of plasma distribution by placing a dielectric between the susceptor and the edge portion. However, the above-mentioned patent has a complicated structure, and it is difficult to precisely design between the dielectric and the edge portion.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a component for a plasma apparatus, which is excellent in corrosion resistance against plasma, ensures uniformity of plasma distribution, improves electric conductivity and thermal conductivity, and has a simple structure of a tungsten oxide bulk.

SUMMARY OF THE INVENTION [0006] An object of the present invention is to provide a plasma processing apparatus comprising a chamber for forming a reaction space for plasma processing, and a component disposed inside the chamber and contacting the plasma, the plasma processing apparatus comprising: And the tungsten oxide has a volume resistivity of 10 ³ to 10 ^-6 Ω · cm.

In the apparatus of the present invention, the tungsten oxide bulk may be any compound based on tungsten and oxygen. The tungsten oxide bulk may be single phase or complex phase. Said single phase may comprise a stoichiometric phase of tungsten and oxygen and a non-stoichiometric phase deviating from said stoichiometric composition. The single phase or complex phase may include a solid solution added with impurities in the single phase or the composite phase.

In a preferred apparatus of the present invention, the part may be any one selected from an edge ring, a focus ring or a shower head. The part is an edge ring that presses the edge of the substrate held in the susceptor, and the distribution of the plasma can extend beyond the edge of the substrate. The part may have a critical thickness of 0.3 mm. The part may be a sintered bulk. The part may be a physical or chemical vapor deposited bulk.

According to the component for a plasma apparatus made of the tungsten oxide bulk of the present invention, by using a component including tungsten oxide which is excellent in plasma corrosion resistance and imparted with electrical conductivity, it is excellent in corrosion resistance to plasma and ensures uniformity of plasma distribution And the structure is simple.

1 and 2 are views schematically showing a plasma processing apparatus equipped with a plasma part according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments described below can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. The embodiments of the present invention are provided to enable those skilled in the art to more fully understand the present invention.

An embodiment of the present invention proposes a component for a plasma device (hereinafter referred to as a plasma component) which is excellent in corrosion resistance against plasma, ensures uniformity of plasma distribution, and has a simple structure by using a tungsten oxide bulk. Such a plasma processing apparatus includes components such as an edge ring, a focus ring, and a shower head that are affected by a plasma. Here, an edge ring will be described as an example. To this end, a plasma component will be specifically described with reference to the edge ring of the present invention, and a method for manufacturing the plasma component will be described in detail.

In the embodiment of the present invention, the term " bulk " refers to a form in which a plasma component is formed without intervention of a parent material. If there is intervention of the base material, the base material is coated or bonded with tungsten oxide. In other words, the bulk of the present invention excludes coating or bonding of tungsten oxide to the base material. The reason for applying the bulk is to utilize the characteristics of the bulk only by excluding the influence of the base material from the viewpoint of corrosion resistance.

1 and 2 are views schematically showing a plasma processing apparatus equipped with a plasma part according to an embodiment of the present invention. The present invention can be applied to a plasma processing apparatus having various structures in addition to the structure of the apparatus proposed within the scope of the present invention.

1 and 2, the treatment apparatus of the present invention comprises a chamber 10, a susceptor 20, a showerhead 30, and an edge ring 40. Here, the susceptor 20, the showerhead 30, the edge ring 40, and the like are the plasma components AP affected by the plasma. The chamber 10 defines a reaction space, and the susceptor 20 mounts the substrate 50 on its upper surface and moves up and down. In some cases, the susceptor 20 may be stationary and not move, but here, the case of vertically moving is taken as an example. The showerhead 30 is located above the susceptor 20 and injects the process gas into the substrate 50. The showerhead 30 is connected through a gas supply pipe 12 to the chamber 10 to introduce the process gas from the outside. The showerhead 30 has a buffer space 31 for uniformly diffusing the process gas introduced through the gas supply pipe 12 into the showerhead 30 before being injected into the showerhead 30 and a nozzle unit 32 composed of a number of through holes, . The edge ring 40 is mounted on the inner wall of the chamber 10 and is located above the ring support 41.

An RF power supply 16, which supplies RF power for generation of plasma, is connected to the plasma electrode or the antenna outside the chamber 10. As shown, a plasma electrode is integrally formed with the showerhead 30, and an RF power source 16 (not shown) is connected to the gas supply pipe 12 so that the RF power is applied to the center of the electrode. Can be connected. A separate RF power source is also applied to the susceptor 20 in order to control the energy of the plasma incident on the substrate 50. Although not shown, the susceptor 20 may include a heater for preheating or heating the substrate 50, a lift pin for mounting the substrate 50, and the like.

When the substrate 50 is placed on the susceptor 20, the susceptor 20 is raised to the position of the plasma treatment process. The edge ring 40 rises together while squeezing the edge of the substrate 50. When the susceptor 20 is raised to place the substrate 50 in the process position, the process gas is injected through the showerhead 30, and RF power is applied to convert the process gas into a plasma reactive species having strong reactivity . The active paper substrate 50 may be subjected to a deposition process, an etching process, and the like, and the process gas may be discharged at a constant flow rate through the exhaust port 14 during the process. After the treatment process is performed for a predetermined period of time, the residual gas is discharged to the discharge port (14). Subsequently, the susceptor 20 is lowered and the substrate 50 is taken out from the chamber 10 to the outside.

The tungsten oxide (WO) according to an embodiment of the present invention includes WO ₃ and the like, and refers to all compounds having a base of tungsten and oxygen. The tungsten oxide of the present invention may be either single phase or complex phase. Wherein the single phase of tungsten oxide comprises both a stoichiometric phase of tungsten and oxygen and a non-stoichiometric phase deviating from the stoichiometric composition, and the composite phase is, for example, the tungsten and oxygen- ) Is a mixture of at least two of the tungsten oxide compounds in a predetermined ratio. In addition, the tungsten oxide of the present invention includes both impurities added to the single phase or the composite phase of the tungsten oxide to form a solid solution or impurities which are inevitably added in the process of producing tungsten oxide.

Hereinafter, the influence of plasma around the edge ring 40 among the plasma components AP will be examined. When the electric power for forming the plasma is increased, the central part of the substrate 50 becomes the maximum and the edge becomes the lowest by the wavelength effect in which the standing wave is formed in the chamber 10 and the skin effect where the electric field concentrates at the central part in the electrode surface. , The distribution of the plasma on the substrate 50 becomes uneven. If the plasma distribution on the substrate 50 is nonuniform, the plasma treatment is not constant and the quality of the fine electronic device is deteriorated. Herein, the plasma distribution refers to a state in which plasma is applied on the substrate 50 and the tungsten oxide edge ring 40, and the distribution is the plasma density at each point of the substrate 50 and the tungsten oxide edge ring 40, And is related to the straightness toward the substrate 50.

The difference in volume resistivity with the tungsten oxide edge ring 40 at the edge ED of the substrate 50 greatly affects the plasma distribution uniformity. Here, the uniformity refers to the degree of change of the plasma distribution. If the uniformity is small, the plasma distribution abruptly changes, and if the uniformity is large, the plasma distribution changes slowly. For this purpose, it is preferable that the volume resistivity of the tungsten oxide edge ring 40 is similar to or lower than the volume resistivity of the substrate 50. In this case, the plasma distribution extends beyond the edge of the substrate 50 to the tungsten oxide edge ring 40, so that the edge of the substrate 50 has a relatively high uniformity. This uniformity means that the plasma density and the straightness toward the substrate 50 are excellent. In the drawing, the state of leaving the edge of the substrate 50 is represented by the edge ED.

The volume resistivity of the tungsten oxide edge ring 40 according to the embodiment of the present invention is similar to or smaller than that of the substrate 50, which can be explained from the following viewpoints. If the volume resistivity of the tungsten oxide edge ring 40 is similar to or smaller than the substrate 50, the plasma distribution extends beyond the edge of the substrate 50 to the tungsten oxide edge ring 40. The volume resistivity of the tungsten oxide edge ring 40 of the present invention extends from the edge of the substrate to the tungsten oxide edge ring 40 so that the plasma distribution over the entire substrate 50 is uniform . This volume resistivity can be defined as the expansion of the tungsten oxide edge ring 40 beyond the edge of the substrate 50.

Volume resistivity of 10 ³ to 10 of the tungsten oxide edge ring 40 of the present invention ^{- 6} Ω · cm is based on the technical idea for making uniform the plasma distribution in the edge of the substrate 50. Accordingly, the volume resistivity can not be obtained through simple repetitive experiments without considering the technical idea. In the foregoing, the relationship between the volume resistivity of the tungsten oxide edge ring 40 and the substrate 50 is described by taking the edge ring as an example. However, in the case of other parts such as a shower head, the volume resistivity of tungsten oxide is the same in terms of improving plasma corrosion resistance.

On the other hand, the plasma corrosion resistance is influenced by the density (g / cm 3) of the component. That is, the plasma corrosion resistance increases as the density of the plasma component increases. The density of WO ₃ in the tungsten oxide (WO) of the present invention is 7.16 g / cm 3, 3.12 g / cm 3 of silicon carbide (SiC) and 3.95 g (g) of alumina (Al ₂ O ₃ ) / Cm < 3 >). Accordingly, the tungsten oxide bulk of the present invention has higher corrosion resistance to plasma than conventional silicon carbide and alumina.

The plasma part AP including the edge ring 40 according to the embodiment of the present invention has a critical thickness. The reasons are as follows. First, when the edge ring 40 is initially mounted on the etching equipment, the surface of the edge ring 40 is collinear with the surface of the substrate 50. Substrate 50 is replaced for each subsequent etch process, but edge ring 40 remains the same. As such an etching process is repeated, a step is generated between the surface of the substrate 50 and the surface of the edge ring 40, and the step is continuously increased.

Second, the aspect ratio of the etch pattern has been increasing steadily as the device has been miniaturized. For etching corresponding to this aspect ratio, the plasma power must be increased. Plasma etching involves chemical etching by chemical reaction and physical etching by physical ion collision. However, as the plasma power increases, the intensity of the physical etching becomes relatively larger than the chemical etching, and becomes overwhelming at a predetermined power or higher. This makes it more difficult to maintain the corrosion resistance of the edge ring 40.

Thirdly, when the step between the surface of the substrate 50 and the surface of the edge ring 40 is spread beyond a predetermined thickness, the direction of the active ions pushed toward the edge of the substrate 50 is shifted from the direction perpendicular to the surface of the substrate 50 It gradually changes in an oblique direction. Etching patterns such as etching holes or trenches are also formed on the substrate 50 in the oblique direction by the etching ions in the oblique direction. Misalignment occurs in the oblique direction from the pattern of the underlying layer of the cornea, thereby reducing the yield of the device. Therefore, the minimum etch thickness limit to allow the misalignment to be tolerated and the minimum etch thickness limit to maintain the productivity of the device by etching the largest number of substrates 50 should be established.

Considering the reasons explained above, the thickness for general corrosion resistance should be 0.3mm or more. This thickness is called the critical thickness. Of course, the thickness of the plasma made of the tungsten oxide bulk is usually within 3 mm, but more thickness can be applied if necessary. This is because the thickness of the plasma part AP requires a critical thickness which is the minimum thickness for corrosion resistance. The critical thickness is designed in consideration of the technical idea of the present invention, and can not be obtained by repeated experiments of the plasma part (AP).

Hereinafter, a method of manufacturing a bulk-shaped plasma part (AP) including tungsten oxide (WO) will be described. The tungsten oxide plasma part (AP) is fabricated by sintering and deposition, such as physical or chemical vapor deposition, and itself becomes a bulk-type part. In addition, physical or chemical vapor deposition utilizes a source material to produce tungsten oxide plasma parts (AP), which can be distinguished from other methods (e.g., sintering). The methods presented herein are merely illustrative of appropriate examples for each, and thus include other methods within the scope of the present invention.

<Tungsten oxide plasma part (AP) by sintering>

The sintering is performed by sintering the tungsten oxide powder in an air atmosphere, an oxygen gas atmosphere, or an inert gas atmosphere. The inert gas may be any known inert gas, preferably argon, nitrogen, or the like. The tungsten oxide plasma component produced by sintering is a sintered body in a bulk form.

<Tungsten oxide plasma parts (AP) by physical or chemical vapor deposition>

The chemical vapor deposition is a process in which a tungsten source and an oxygen source are reacted and deposited on a base material under a predetermined condition to grow the base material, and then the base material is removed. For example, WF ₆ as a tungsten precursor, oxygen (O ₂ ) or ozone (O ₃ ) as an oxygen precursor can be deposited at a deposition temperature of 500 to 1500 ° C. using a chemical vapor deposition apparatus have. In physical vapor deposition, a tungsten target is sputtered with an inert gas such as Ar and a gas such as oxygen (O ₂ ) or ozone (O ₃ ) is injected to cause the tungsten oxide to be synthesized and grown on the base material, The target itself is made of tungsten oxide, and the tungsten oxide is grown on the base material by sputtering, and the base material is removed. The tungsten oxide component produced by such physical or chemical vapor deposition is in the bulk form described above.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but many variations and modifications may be made without departing from the spirit and scope of the invention. It is possible.

10; Chamber 12; Gas supply pipe
20; A susceptor 30; Shower head
40; Edge ring 41; Ring support
50; Substrate AP; Plasma parts

Claims (10)

A chamber forming a reaction space for plasma processing:
And a component located within the chamber and in contact with the plasma,
The component is formed of tungsten oxide in the bulk plasma corrosion resistance, the tungsten oxide is the volume resistivity of 10 ³ to 10 ^- parts for a plasma device consisting of tungsten oxide, characterized in that the bulk having ⁶ Ω · cm. The component of claim 1, wherein the tungsten oxide bulk is a compound based on tungsten and oxygen. The component of claim 1, wherein the tungsten oxide bulk is a single phase or a composite phase. 4. The component of claim 3, wherein the single phase comprises a stoichiometric phase of tungsten and oxygen and a non-stoichiometric phase out of the stoichiometric composition. 4. The component of claim 3, wherein the single phase or the composite phase comprises a solid solution added with impurities in the single phase or the composite phase. 2. The component of claim 1, wherein the part is selected from the group consisting of an edge ring, a focus ring, and a showerhead. The plasma processing apparatus according to claim 1, wherein the component is an edge ring for pressing the edge of the substrate placed in the susceptor, and the distribution of the plasma extends beyond an edge of the substrate. . 2. The component of claim 1, wherein the component has a critical thickness of 0.3 mm. The component of claim 1, wherein the component is a sintered bulk. The component of claim 1, wherein the component is a physical or chemical vapor deposited bulk.

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