Pyrochlore components for plasma processing chambers

Abstract

A component for use in a plasma processing chamber system is provided. The component body has a plasma-facing surface comprising a pyrochlore comprising at least one of zirconium and hafnium, and at least one of lanthanum (La), samarium (Sm), yttrium (Y), erbium (Er), cerium (Ce), gadolinium (Gd), ytterbium (Yb), and neodymium (Nd).

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to U.S. Application No. 63 / 408,571, filed September 21, 2022, which is incorporated herein by reference for all purposes.

[0002] The background discussion provided herein is intended to generally present the context for the present disclosure. The information described in this background section, as well as aspects of the description that may not otherwise be considered prior art at the time of filing, are not admitted expressly or impliedly as prior art to the present disclosure.

[0003] The present disclosure relates generally to semiconductor device manufacturing, and more particularly to plasma chamber components used in manufacturing semiconductor devices. [Background technology]

[0004] During semiconductor wafer processing, plasma processing chambers are used to process semiconductor devices. The plasma processing chambers are subjected to plasma, which can degrade components. Coatings can be placed on the plasma-facing surfaces of plasma processing chamber components to protect the surfaces.

[0005] Some of the coatings may be applied using plasma spraying. One type of coating that may be used is aluminum oxide or alumina (Al2O3). Alumina has been found to not provide sufficient etch resistance. Another type of coating that may be used is yttrium oxide or yttria (Y2O3). High purity yttria coatings have been found to be expensive to produce due to material and / or processing costs. Yttria is more sputter resistant than alumina, but yttria is more susceptible to spontaneous fluorination reactions or conversion processes than alumina. This fluorination reaction or conversion process can lead to undesirable and detrimental behavior. Summary of the Invention

[0006] To achieve the above, and in accordance with an object of the present disclosure, a component for use in a plasma processing chamber system is provided, comprising a component body having a plasma-facing surface comprising a pyrochlore comprising at least one of zirconium and hafnium, and at least one of lanthanum (La), samarium (Sm), yttrium (Y), erbium (Er), cerium (Ce), gadolinium (Gd), ytterbium (Yb), and neodymium (Nd).

[0007] In another embodiment, a method is provided for forming a component for use in a plasma processing chamber system. A component body is provided with a plasma-facing surface comprising a pyrochlore comprising at least one of zirconium (Zr) and hafnium (Hf), and at least one of lanthanum (La), samarium (Sm), yttrium (Y), erbium (Er), cerium (Ce), gadolinium (Gd), ytterbium (Yb), and neodymium (Nd).

[0008] These and other features of the present disclosure are described in more detail below in the detailed description and in connection with the following figures.

[0009] The present disclosure is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which like reference numerals refer to similar elements. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a high-level flowchart of an embodiment.

[0011] [Figure 2A] 1 is a schematic diagram of components processed according to an embodiment. [Figure 2B] 1 is a schematic diagram of components processed according to an embodiment.

[0012] [Figure 3] FIG. 1 is a schematic diagram of a plasma processing chamber that may be used in embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0013] In the drawings, like reference numerals may be used to designate like structural elements, and it should be appreciated that the depictions in the figures are schematic and not to scale.

[0014] The present disclosure will now be described in detail with reference to several preferred embodiments thereof, as illustrated in the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. However, it will be apparent to one skilled in the art that the present disclosure may be practiced without some or all of these specific details. In other instances, well-known process steps and / or structures have not been described in detail in order to avoid unnecessarily obscuring the present disclosure.

[0015] In the manufacture of semiconductor devices, plasma processing chambers may be used. Plasma processing chambers may have various components exposed to plasma during plasma processing. Such components may be aluminum to provide electrical and thermal characteristics useful in sustaining the plasma. Aluminum also allows for reduced weight and cost. Other components may have a dielectric. Such components may be made from alumina. Ceramic alumina may be used for components such as dielectric induction power windows or gas injectors.

[0016] Such components can be chemically etched by fluorine-, oxygen-, or chlorine-containing plasmas. In addition, the components can be chemically transformed or reacted, resulting in surface or bulk changes in the plasma-exposed areas of the component. Erosion by sputtering can change the shape of the component, disrupting the uniformity of the plasma process, or generate particles that become contaminants. Coatings can be placed on plasma-facing surfaces made of aluminum to provide protection from erosion.

[0017] Alumina is used as a protective coating. Alumina has some plasma etch resistance. Further etch-resistant coatings provide additional protection for such plasma chamber components. Coatings such as yttria and yttrium aluminum oxide are also used as coatings in some plasma processing chambers. Yttria is more resistant to sputtering than alumina. However, such yttria coatings do not meet the particle requirements of next-generation nodes. Instead, when exposed to a fluorine-containing plasma, fluorine is absorbed into the yttria coating, which fluorinates the yttria coating to form yttria (YO), yttrium fluoride (YF), or various forms of Y, which can be stable or metastable. x O y F zyttria coatings convert into fluorine-containing compounds. These compounds generate lattice and crystal defects with various intrinsic properties, resulting in particles that migrate from the yttria coating and become contaminants. The particles make it more difficult to meet contaminant reduction requirements. Additionally, due to the favorable fluorine conversion reaction of yttria, for example, some thermally sprayed yttria coatings can require undesirably long periods of time to reach chemical steady state when exposed to a fluorine-containing plasma environment.

[0018] Various embodiments provide a component with a plasma-facing surface comprising pyrochlore. Pyrochlore is a mineral with the general formula A2B2O7, where A and B are 3+ and 4+ metal cations, respectively. Pyrochlore materials are crystalline but are susceptible to considerable variation in their crystal structure and stoichiometry. In some embodiments, there can be up to 10% excess A or B site cations. In some embodiments, the pyrochlore comprises at least one of zirconium and hafnium and at least one of lanthanum (La), samarium (Sm), yttrium (Y), erbium (Er), cerium (Ce), gadolinium (Gd), ytterbium (Yb), and neodymium (Nd). In some embodiments, the pyrochlore comprises at least one of zirconium and hafnium and at least one of La, Ce, and Gd. In some embodiments, the pyrochlore consists essentially of zirconium and La. In some embodiments, the pyrochlore is formed from materials that do not form volatile halides and are resistant to surface damage from ion bombardment.

[0019] To facilitate understanding, Figure 1 is a high-level flowchart of a process used in an embodiment. A component body is provided (step 104). Figure 2A is a schematic cross-sectional view of a portion of a component body 204 of a component 200 used in an embodiment. In this example, the component 200 is a ceramic alumina dielectric induction power window. The component body 204 has a surface 208. In this embodiment, the surface 208 is a plasma-facing surface. The plasma-facing surface is the surface that faces the plasma when the component body 204 is used in a plasma processing chamber. In this embodiment, a layer 210 is formed on the plasma-facing surface. In some embodiments, one or more layers may be on the plasma-facing surface. In other embodiments, there is no layer on the plasma-facing surface.

[0020] Next, the surface 208 and layer 210 are coated with a pyrochlore coating 212. The pyrochlore coating 212 may be deposited on the surface by one or more of aerosol deposition (AD), atomic layer deposition (ALD), chemical vapor deposition (CVD), physical vapor deposition (PVD), and thermal spraying. In some embodiments, the thermal spraying may be at least one of suspension plasma spraying, vacuum plasma spraying, high velocity oxygen-fuel spraying, and atmospheric plasma spraying. In some embodiments, the spray powder may be provided by forming bulk pyrochlore and grinding the bulk pyrochlore into a powder. In some embodiments, the spray powder is formed by component powders of pyrochlore. For example, if the pyrochlore coating 212 is formed from lanthanum zirconium oxide (LZO), which may have a formula of LaZrO, the spray powder may comprise lanthanum oxide powder mixed with zirconium oxide powder, also known as zirconium dioxide. In some embodiments, pyrochlore coating 212 has a thickness in the range of 100 nm to 300 microns. The plasma-facing surface of pyrochlore coating 212 is the plasma-facing surface of component 200.

[0021] In some embodiments, component body 204 comprises one or more of a conductive metal or a ceramic. The conductive metal may comprise one or more of aluminum or a refractory metal. In some embodiments, the refractory metal may comprise one or more of stainless steel, titanium, or a nickel alloy. In some embodiments, the nickel alloy is at least 50% Ni by weight. In some embodiments, component body 204 is a refractory metal if the process of depositing the coating causes component body 204 to be heated to a temperature of at least 200° C. for at least 10 hours. In some embodiments, component body 204 comprises aluminum. An aluminum component body may be of an aluminum alloy, such as aluminum 6061. Such aluminum alloys are at least 95% pure aluminum by weight. In some embodiments, layer 210 may be one or more of an anodized layer or other layers. In other embodiments, there is no layer, and pyrochlore coating 212 is directly on surface 208. In some embodiments, component body 204 comprises a ceramic dielectric material, such as alumina. In some embodiments, coatings can be created using ceramic powders by various methods known in the art. These methods include thermal spraying (plasma, HYF, detonation gun, etc.), electron beam physical vapor deposition (EBPVD), laser cladding, and plasma transferred arc. When the coating technique used is electron beam physical vapor deposition (EB-CVD), the ceramic target used can be a pyrochlore, such as lanthanum oxide (powder or bulk).

[0022] In some embodiments, the pyrochlore coating is patterned. In some embodiments, the patterning is provided by masking the surface of the component body 204 before applying the coating.

[0023] In some embodiments, bulk component body 204 comprises pyrochlore. In such embodiments, layer 210 and pyrochlore coating 212 are not required because the plasma-facing surface is a pyrochlore plasma-facing surface. In some embodiments, bulk component body 204 is formed by sintering. In some embodiments, component body 204 is formed by spark plasma sintering. In some embodiments, ceramic powder can be provided by forming bulk pyrochlore and forming the bulk pyrochlore into a powder. In some embodiments, ceramic powder is formed by constituent powders of pyrochlore. For example, if the component body is formed from LZO, the ceramic powder can comprise lanthanum oxide powder mixed with zirconium oxide powder.

[0024] In some embodiments, the bulk component body 204 comprises multiple ceramic layers stacked together to form a ceramic stack, in which at least one surface of the bulk component body is pyrochlore. In some embodiments, the ceramic stack forming the bulk component body 204 can be formed by a sintering process, such as spark plasma sintering. In an example, a first ceramic powder can be placed in a mold. The first ceramic powder can fill more than 90% of the mold. A layer of a second ceramic powder is placed on top of the first ceramic powder in the mold. The second ceramic powder can fill less than 10% of the mold. The second ceramic powder is a pyrochlore-forming powder. In some embodiments, the second ceramic powder can be provided by forming bulk pyrochlore and forming the bulk pyrochlore into a powder. In some embodiments, the second ceramic powder is formed by pyrochlore component powders. For example, if the second ceramic powder is used to form LZO, the ceramic powder can comprise lanthanum oxide powder mixed with zirconium oxide powder. In some embodiments, the first ceramic powder does not form pyrochlore. For example, the first ceramic powder can be aluminum oxide to form an aluminum oxide ceramic part. In some embodiments, the resulting component comprises a ceramic component body comprised of the first ceramic powder and a protective pyrochlore layer on the surface of the ceramic component body. In some embodiments, a transition zone of the mixture of the first ceramic powder and the second ceramic powder is between the ceramic component body comprised of the first ceramic powder and the pyrochlore layer. In some embodiments, the ceramic component body can further comprise additional ceramic and transition layers when additional layers of different ceramic powders are provided.

[0025] The component body 204 is mounted in a plasma processing chamber (step 108). In this example, the component body 204 is mounted in the plasma processing chamber as a dielectrically inductive power window. The plasma processing chamber is used to process a substrate (step 112), where a plasma is generated in the chamber to process the substrate, such as etching the substrate, and the pyrochlore surface is exposed to the plasma. The pyrochlore provides increased etch resistance to protect the surface 208 of the component body 204.

[0026] FIG. 3 schematically illustrates an example plasma processing chamber system 300 that may be used in embodiments. The plasma processing chamber system 300 includes a plasma reactor 302 having a plasma processing confinement chamber 304 therein. A plasma power supply 306, tuned by a plasma matching network 308, powers a transformer-coupled plasma (TCP) coil 310 positioned near a dielectric-induced power window 312 to generate a plasma 314 in the plasma processing confinement chamber 304 by providing inductively coupled power. A pinnacle 372 (PINNACLE is a registered trademark) extends from a chamber wall 376 of the plasma processing confinement chamber 304 to the dielectric-induced power window 312, forming a pinnacle ring. The pinnacle 372 is angled with respect to the chamber wall 376 and the dielectric-induced power window 312 such that the interior angles between the pinnacle 372 and the chamber wall 376 and between the pinnacle 372 and the dielectric-induced power window 312 are greater than 90° and less than 180°, respectively. The pinnacle 372, as shown, provides an angled ring near the top of the plasma processing confinement chamber 304. The pinnacle 372 is more commonly referred to as a chamber liner. The TCP coil (upper power supply) 310 can be configured to create a uniform diffusion profile within the plasma processing confinement chamber 304. For example, the TCP coil 310 can be configured to generate a ring-shaped power distribution in the plasma 314. A dielectric-inductive power window 312 is provided to isolate the TCP coil 310 from the plasma processing confinement chamber 304 while allowing energy to transfer from the TCP coil 310 to the plasma processing confinement chamber 304. A wafer bias voltage power supply 316, regulated by a bias matching network 318, provides power to an electrode 320 to set a bias voltage on a substrate 366. The substrate 366 is supported by the electrode 320. A controller 324 controls the plasma power supply 306 and the wafer bias voltage power supply 316.

[0027] The plasma power supply 306 and the wafer bias voltage power supply 316 can be configured to operate at a specific radio frequency, such as, for example, 13.56 megahertz (MHz), 27 MHz, 2 MHz, 60 MHz, 400 kilohertz (kHz), 2.54 gigahertz (GHz), or a combination thereof. The plasma power supply 306 and the wafer bias voltage power supply 316 can be appropriately sized to provide a range of power to achieve desired process performance. For example, in one embodiment, the plasma power supply 306 can provide a power in the range of 50 to 5,000 watts, and the wafer bias voltage power supply 316 can provide a bias voltage in the range of 20 to 2,000 volts (V). In addition, the TCP coil 310 and / or the electrode 320 can be composed of two or more sub-coils or sub-electrodes. The sub-coils or sub-electrodes can be powered by a single power supply or by multiple power supplies.

[0028] As shown in FIG. 3 , the plasma processing chamber system 300 further includes a gas source / gas supply mechanism 330. The gas source 330 is fluidly connected to the plasma processing confinement chamber 304 through a gas inlet, such as a gas injector 340. The gas injector 340 may be positioned at any strategic location in the plasma processing confinement chamber 304 and may take any form for injecting gas. Preferably, however, the gas inlet is configured to create a “tunable” gas injection profile. The tunable gas injection profile allows for independent adjustment of the flow of gas to multiple zones in the plasma process confinement chamber 304. More preferably, the gas injector is mounted on the dielectric-induced power window 312. The gas injector may be mounted on, in, or form part of the power window. Process gases and by-products are removed from the plasma process confinement chamber 304 via a pressure control valve 342 and a pump 344. The pressure control valve 342 and the pump 344 also serve to maintain a specific pressure within the plasma processing confinement chamber 304. A pressure control valve 342 is capable of maintaining a pressure below 1 Torr during processing. An edge ring 360 is positioned around the substrate 366. The gas source / gas delivery mechanism 330 is controlled by a controller 324. A Kiyo manufactured by Lam Research, Fremont, California, can be used to practice embodiments.

[0029] In various embodiments, the component may be other parts of a plasma processing chamber, such as a confinement ring, an edge ring, an electrostatic chuck, a gas injector, a ground ring, a chamber liner such as pinnacle 372, a door liner, a dielectric window, a chamber wall, or other components. Other components of other types of plasma processing chambers may be used. For example, a plasma exclusion ring on a bevel etch chamber may be coated in embodiments. In another example, a showerhead of a dielectric processing chamber may be coated. In some embodiments, the chamber may have a dome shape, where the coating coats the dome. In some embodiments, one or more, but not all, surfaces of the component body 204 are coated.

[0030] In some embodiments, after a coating is deposited, it is machined, ground, and / or polished. In an example, a component may have a surface with a complex shape. Because the surface has a complex shape, the coating thickness may be non-uniform. Machining, grinding, and / or polishing can be used to provide a more uniform thickness. A uniform thickness can improve process uniformity, control coating stress to prevent mechanical coating failure, and ensure that parts can fit with adjacent components. In an embodiment, a coating with a thickness of approximately 1500 μm was deposited. Machining and grinding reduces the coating thickness to a uniform thickness of less than 1000 μm. Polishing using ultra-fine grit high-hardness abrasives embedded in either a polishing pad or a slurry can be used to reduce the roughness of the coating so that the plasma-facing surface of the chamber has a uniform roughness. In some embodiments, the roughness is less than 5 μm Ra. Such roughness can be achieved by spraying or with basic machining and / or grinding. In some embodiments, the roughness is less than 1.5 μm Ra. In some embodiments, the roughness is between 0.5 μm and 1.5 μm Ra. In some embodiments, the roughness is between 0.005 μm and 0.5 μm Ra.

[0031] While the present disclosure has been described with respect to several preferred embodiments, there are alterations, substitutions, modifications, and various substitute equivalents that fall within the scope of the present disclosure. It should also be noted that there are many alternative ways of implementing the method and apparatus of the present disclosure. Therefore, it is intended that the following appended claims be construed to include all alterations, substitutions, and various substitute equivalents that fall within the true spirit and scope of the present disclosure. As used herein, the phrase "A, B, or C" should be interpreted to mean a logic ("A OR B OR C") using a non-exclusive logical "OR," and not to mean "only one of A or B or C." Each step within a process may be optional and not required. Different embodiments may omit one or more steps or provide steps in a different order. In addition, various embodiments may provide different steps simultaneously instead of sequentially.

Claims

1. 1. A component for use in a plasma processing chamber system, comprising: a component body having a plasma-facing surface, the plasma-facing surface comprising: at least one of zirconium and hafnium; at least one of lanthanum (La), samarium (Sm), yttrium (Y), erbium (Er), cerium (Ce), gadolinium (Gd), ytterbium (Yb), and neodymium (Nd); A component comprising a pyrochlore comprising:

2. 10. The component of claim 1, wherein the pyrochlore comprises zirconium and La.

3. 10. The component of claim 1, wherein the component body comprises the pyrochlore forming a bulk component body.

4. The component of claim 1 , wherein the plasma-facing surface comprises a coating on a surface of the component body.

5. The component of claim 4 , wherein the component body comprises a conductive metal.

6. 6. The component of claim 5, wherein the conductive metal is a refractory metal.

7. The component of claim 4 , wherein the component body comprises a ceramic.

8. 5. The component of claim 4, wherein the coating has a thickness in the range of 100 nm to 300 microns.

9. 10. The component of claim 1, wherein the component forms at least one of a gas injector, a chamber liner, a chamber wall, and a dielectric window.

10. 10. The component of claim 1, wherein the component body comprises a ceramic laminate comprising a ceramic component body made of a first ceramic powder and a pyrochlore layer on a surface of the component body.

11. 11. The component of claim 10, wherein the ceramic component body comprised of the first ceramic powder is not a pyrochlore.

12. 1. A method for forming a component for use in a plasma processing chamber system, the method comprising: providing a component body having a plasma-facing surface, the plasma-facing surface comprising a pyrochlore comprising at least one of zirconium (Zr) and hafnium (Hf), and at least one of lanthanum (La), samarium (Sm), yttrium (Y), erbium (Er), cerium (Ce), gadolinium (Gd), ytterbium (Yb), and neodymium (Nd).

13. 13. The method of claim 12, wherein said forming said component body comprises spark plasma sintering a ceramic powder.

14. 13. The method of claim 12, wherein said forming said component body comprises: providing a bulk component body; forming a pyrochlore coating on a surface of the bulk component body; A method comprising:

15. 15. The method of claim 14, wherein said forming said pyrochlore coating is by at least one of atomic layer deposition, aerosol deposition, thermal spraying, PVD, and CVD.

16. 13. The method of claim 12, wherein the pyrochlore comprises zirconium and La.

17. 13. A product made by the method of claim 12.

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