Silicide bodies and related methods and articles

Abstract

Described are silicide bodies useful in an interior of a plasma reaction chamber; methods of preparing the silicide bodies; and methods of using the silicide bodies. Also described is a reaction chamber component adapted for use in a plasma reaction chamber, the component including an electrically conductive silicide body having at least 85percent by weight of a single silicide material comprising a metal, the silicide body including a density of at least 98 percent of theoretical density of the silicide, and containing less than 10 percent by weight silica

Description

[0001] H6003.144.111 / 2024P00095US

[0002] STLTCTDE BODIES AND RELATED METHODS AND ARTICLES

[0003] FIELD

[0004] [1] The description relates to silicide bodies useful in the interior of a plasma reaction chamber; methods of preparing the silicide bodies; and methods of using the silicide bodies.

[0005] BACKGROUND

[0006] [2] Reactive-ion etching (“RIE”) is an etching technology used in microfabrication. RIE uses chemically reactive plasma to remove material on a surface of a microelectronic substrate. The plasma is generated inside of a reaction chamber, under reduced pressure conditions, by an electromagnetic field. High-energy ions from the plasma react with materials at the substrate surface to cause anisotropic etching at the surface.

[0007] [3] The etching process is performed in a capacitively coupled plasma (“CCP”) reaction chamber that generates plasma between two electrodes while reactive gases are fed to the reaction chamber. The electrodes form parallel plates of a capacitor and hence the resulting plasma is called a capacitively coupled plasma. Radio frequency (RF) power is applied to one of the electrodes while the other electrode is grounded. Ions of the plasma are accelerated toward the powered electrode. The potential difference between the plasma and the powered electrode is the bias voltage. With the substrate placed on the powered electrode, the substrate experiences the bias voltage and the reactive ions as well as other reactive species from the plasma are impacted by the ions of the plasma, causing etching of the substrate.

[0008] [4] During these etching processes, the plasma generated within the reaction chamber will contact not just the surface of the substrate that is intended to be etched but will also contact other exposed surfaces that make up the interior of the reaction chamber, including functional components used during the etching process. Examples of different components found within an interior of a reaction chamber, which may be referred to herein as “reaction chamber components,” or “chamber components,” or merely “components,” include those structures sometimes referred to as: a focus ring (or “edge ring”), a gas distribution plate such as a “showerhead,” electrodes (e.g., a “top electrode”), among other functional internal components of a reaction chamber. H6003.144.111 / 2024P00095US

[0009] [5] During an etching process, the plasma will react with surfaces of these components that are exposed to the plasma in the reaction chamber interior and will cause etching or “erosion” at the component surfaces. The reaction between the reaction chamber component surface and the plasma will produce reaction products that are introduced into the reaction chamber. The types and amounts of reaction products can depend on the type of plasma and the material at the component surface. One general type of reaction product is a gaseous reaction product that is released from the component surface and becomes introduced into the reaction chamber as a gas, i.e., as gas molecules that become incorporated into the plasma. Other reaction products are non- gaseous chemical compounds, meaning solid reaction products that do not enter the plasma as a gas. These solid reaction products form at the surface of the reaction chamber component and are eventually released from the surface into the plasma and the reaction chamber interior as a particle contaminant. If the particle contaminant were to settle onto a surface of a substrate that is being etched inside of the reaction chamber, the particle could create a defect on the substrate.

[0010] [6] The etching effect of plasma on interior components of a reaction chamber cannot be completely prevented. But to the extent that such etching occurs, materials of reaction chamber components can be designed to undergo etching in a manner that will not negatively impact an intended etching process within the reaction chamber, or at least minimize negative impacts. Specifically, when a reaction chamber component experiences etching by exposure to plasma, reaction products of the etching process can preferably be gaseous and will preferably produce a low amount of particle-type contaminants that create defects in a substrate being etched.

[0011] SUMMARY

[0012] [7] Dielectric etch process tools used for etching semiconductor and microelectronic substrates include a reaction chamber. The reaction chamber includes a system of electrodes that are used to produce plasma, typically including an upper electrode and a lower electrode. The reaction chamber also includes a substrate support (or “chuck”) adapted to support a microelectronic or semiconductor substrate within the reaction chamber above the lower electrode. A focus ring, also known as an edge ring, surrounds the substrate held on the substrate support to improve etching uniformity at edges of the substrate. Other components at the reaction chamber are also necessary for performing a step of etching a substrate within the H6003.144.111 / 2024P00095US reaction chamber such as a flow device that is used to introduce gas into the reaction chamber interior.

[0013] [8] The etching process may use different types (chemistries) of plasma, such as those that contain fluorine, chlorine, or bromine. A gas or combination of gases used to produce a plasma may be any that is useful, with examples gases including CF4, SFe, Argon, among others, often or typically at a pressure of from 1 millitorr (mtorr) to 100 mtorr at the reaction chamber interior.

[0014] [9] During use within the reaction chamber, the interior reaction chamber components become exposed directly to the plasma. Accordingly, these components must be made from materials that will provide certain specific physical properties that are necessary to properly function within the reaction chamber and to do so without disrupting, interfering with, or detrimentally affecting an etching process, for example by not producing significant amounts of particle contaminants.

[0015]

[0010] Preferred reaction chamber components will tend not to produce particle contaminants when etched by plasma, and, when etched, may preferably experience relative uniform etching across a surface of the component. Such materials may be substantially homogeneous, i.e., made substantially or entirely from one single material. It can be expected that materials that are inhomogeneous, i.e., contain multiple different materials, will experience different etching rates of the different materials and will be etched and eroded in an un-even manner. Additionally, boundaries that are present at interfaces between different materials of a reaction chamber component are expected to be a source of particle contaminants; as one material erodes more rapidly, edge surfaces form at the remaining material, and those edge surfaces may tend to create particle contaminants. Therefore, it is expected that as opposed to inhomogeneous materials, when a more homogeneous material is etched by plasma, the material will tend to erode evenly without producing particle contaminants.

[0016]

[0011] Additionally, a silicide when reacted with fluorine plasma in a reaction chamber can preferably form a reaction product (a “fluorine reaction compound”) that is gaseous as opposed reaction product that is solid. A preferred silicide can form a fluorine reaction compound that has a relatively low boiling point at operating conditions within a reaction chamber, e.g., a boiling point that is below an operating temperature of a reaction chamber at the reaction chamber pressure, such as a boiling point that is less than 1000 degrees Celsius or less than 500 H6003.144.111 / 2024P00095US degrees Celsius, e.g., less than 100 degrees Celsius, which can be as measured either at atmospheric pressure (100 kPa) or at a pressure below 100 millitorr or below 10 millitorr. [121 In addition to erosion resistance, useful or preferred reaction chamber components as described may be electrically conductive. Electrical conductivity tends to improve the uniformity of plasma density within the reaction chamber, and also maintains a useful surface charge on the reaction chamber component.

[0017]

[0013] Furthermore, because it is expected that reaction chamber components will experience erosion, these components will need to be replaced after the components have experienced an amount of erosion that will affect performance. A significant amount of process uptime is lost each time a tool is removed from service to replace interior components that have experienced an amount of erosion to a point of affecting the performance of the tool. Accordingly, reaction chamber components are designed to have high resistance to erosion to allow the component to be used for a lengthy amount of time (or “useful lifetime”) before needing to be replaced.

[0018]

[0014] According to the following description, materials referred to as silicides have been identified as being useful materials for reaction chamber components. A silicide is a material that combines silicon and another element that is usually more electropositive than silicon, such as a metal. Silicides have been used in cladding of nuclear reactors, as interconnects in microelectronic devices, and as sputtering targets. The following description relates to reaction chamber components that contain a solid body that contains a silicide, more particularly to solid bodies that contain substantially a single silicide and low amounts of other materials different from the single silicide. These bodies, which contain a substantial amount of one silicide, such as at least 85 percent by weight of the silicide, more preferably at least 90%, are sometimes referred to herein as “single silicide bodies.”

[0019]

[0015] Moreover, according to the following description, materials referred to as carbides or borides also have been identified as being useful materials for reaction chamber components.

[0020]

[0016] Silicide, carbide or boride bodies as described can be electrically conductive, can have a high density, low porosity, a high hardness, and can be prepared to be highly resistant to the erosive effects of plasma.

[0021]

[0017] Silicides:

[0022]

[0018] A single-silicide body can be significantly homogeneous, meaning for example that a silicide body may be prepared to contain a single silicide material and not more than minor H6003.144.111 / 2024P00095US amounts of materials different from the single silicide materials as defined above. Example single silicide bodies may contain at least 85 percent by weight of a single silicide material and less or equal than 15 percent by weight of materials other than the single silicide material, more preferably at least 90%, with the balance impurities.

[0023]

[0019] Different silicide materials have different properties in terms of conductivity and etch resistance. In addition, silicide materials vary in cost, so that from a technical and commercial point of view, it may be advantageous to provide silicide bodies that contain different amounts of silicides within the scope of the above definition in order to adjust properties and costs thereof.

[0024]

[0020] In one aspect, the description relates to a reaction chamber component adapted for use in an interior of a plasma reaction chamber. The component includes an electrically conductive silicide body comprising at least 85 percent by weight of a silicide including a metal. Example silicide bodies may have a density of at least 95 percent of a theoretical density of the single silicide, a porosity of less than 5 percent, and may contain less than 10 percent by weight silica. In a further aspect, the silicide, when exposed to fluorine plasma, forms a fluorine reaction compound having a boiling temperature of less than 1000 degrees C, and more preferably less than 500 degrees C.

[0025]

[0021] In another aspect, the description relates to a reaction chamber component adapted for use in an interior of a capacitively coupled plasma reaction chamber. The component includes an electrically conductive silicide body that contains at least 85 percent by weight of a single silicide selected from one of a transition metal silicide and a rare earth metal silicide. Example silicide bodies may have a density of at least 95 percent of a theoretical density of the single silicide, a porosity of less than 5 percent, and may contain less than 10 percent by weight silica. In a further aspect, the silicide, when exposed to fluorine plasma, forms a fluorine reaction compound having a boiling temperature of less than 1000 degrees C, and more preferably less than 500 degrees C.

[0026]

[0022] In another aspect, the description relates to a reaction chamber component adapted for use in an interior of a capacitively coupled plasma reaction chamber. The component includes an electrically conductive silicide body that contains at least 85 percent by weight of a single silicide selected from one of a transition metal silicide and a rare earth metal silicide. Example silicide bodies may have a density of at least 98 percent of a theoretical density of the single silicide, a porosity of less than 5 percent, and may contain less than 10 percent by weight silica. H6003.144.111 / 2024P00095US

[0027] In a further aspect, the silicide, when exposed to fluorine plasma, forms a fluorine reaction compound having a boiling temperature of less than 1000 degrees C, and more preferably less than 500 degrees C.

[0028]

[0023] In another aspect, the description relates to a reaction chamber component adapted for use in an interior of a plasma reaction chamber. The component includes an electrically conductive silicide body that contains at least 5 percent by weight of a first silicide with higher etch resistance than a second silicide, and at least 85 percent by weight of a second silicide with lower etch resistance than a first silicide. The first silicide being selected from one of a rare earth metal silicide, and the second silicide being selected from one of a transition metal silicide.

[0029]

[0024] In another aspect, the description relates to a reaction chamber component adapted for use in an interior of a plasma reaction chamber, wherein a silicide is used, and the silicide body comprises at least 85% of the silicide and ZrC and / or ZrBn as additives.

[0030]

[0025] In another aspect, the description relates to a reaction chamber component adapted for use in an interior of a plasma reaction chamber, wherein a silicide is used, and the silicide body comprises at least 85% of the silicide and additives of carbon, boron or borides which form MoB, M02B, and M0C2 during sintering.

[0031]

[0026] In another aspect, the description relates to a reaction chamber component adapted for use in an interior of a plasma reaction chamber, wherein a silicide is used, and the silicide body comprises at least 85% of the silicide and additives of carbon, boron or borides which form MoB, Mo2B, and M0C2 during sintering, wherein the additives are selected from the group consisting of B (amorphous or crystalline), B2O3, B4C, B2H6, B5H9, B10H14, H3BO3, boron- containing silicate glasses, borate glasses, such as B2O3, BN, BF3, BC13, B4C14, B(C6Hs)3, B(C6HS)4, MgB2, M B4, CaBs, MgBe, CeBe, LaBs, BPO4 and C2B10H12.

[0032]

[0027] In another aspect, the description relates to a reaction chamber component adapted for use in an interior of a plasma reaction chamber, wherein MoSi2 as a silicide is used, and the silicide body comprises at least 85% of the silicide and ZrC and / or ZrBrc as additives.

[0033]

[0028] In another aspect, the description relates to a reaction chamber component adapted for use in an interior of a plasma reaction chamber, wherein MoSi2 as a silicide is used, and the silicide body comprises at least 85% of the silicide and additives of carbon, boron or borides which form MoB, M02B, and M0C2 during sintering. H6003.144.111 / 2024P00095US

[0034]

[0029] In another aspect, the description relates to a reaction chamber component adapted for use in an interior of a plasma reaction chamber, wherein MoSi? as a silicide is used, and the silicide body comprises at least 85% of the silicide and additives of carbon, boron or borides which form MoB, Mo2B, and M0C2 during sintering, wherein the additives are selected from the group consisting of B (amorphous or crystalline), B2O3, B4C, B2H6, B5H9, B10H14, H3BO3, boron- containing silicate glasses, borate glasses, such as B2O3, BN, BF3, BC13, B4C14, B(C6Hs)3, B(C6HS)4, MgB2, MgB4, CaBe, MgBr,, CeBe, LaBs, BPO4 and C2B10H12.

[0035]

[0030] In another aspect, the description relates to a reaction chamber component adapted for use in an interior of a plasma reaction chamber, wherein a silicide is used, and the silicide is provided in a Nowotny phase. The term Nowotny phase refers to a class of intermetallic compounds (also called Nowotny chimney ladder phases that are typically formed between transition metals (like Ti, V, Cr, Mn, Fe, Co, Ni) and a p-block element of Si. These phases have complex tetragonal or hexagonal structures derived from a combination of: a “chimney” of transition-metal atoms forming a helically arranged sublattice, an a “ladder” of the main-group atom Si forming a parallel helical structure within the metal framework.

[0036]

[0031] In another aspect, the description relates to a reaction chamber component adapted for use in an interior of a plasma reaction chamber, wherein a silicide MosSisC is present in the Nowotny phase.

[0037]

[0032] Carbides and borides:

[0038]

[0033] In yet another aspect, the description relates to a reaction chamber component adapted for use in an interior of a plasma reaction chamber. The component includes an electrically conductive body consisting of a carbide or boride. The body contains at least 90 percent by weight of a carbide or boride selected from one of a transition metal carbide or boride and a rare earth metal carbide or boride.

[0039]

[0034] In yet another aspect, the description relates to a reaction chamber component adapted for use in an interior of a plasma reaction chamber. The component includes an electrically conductive body consisting of a carbide or boride. The body contains at least 90 percent by weight of ZrC, ZrB or a combination thereof.

[0040]

[0035] In yet another aspect, the description relates to a reaction chamber component adapted for use in an interior of a plasma reaction chamber. The component includes an electrically H6003.144.111 / 2024P00095US conductive body consisting of a carbide or boride, wherein the carbide or boride body having a density of at least 95 percent of theoretical density of the carbide or boride.

[0041]

[0036] In yet another aspect, the description relates to a reaction chamber component adapted for use in an interior of a plasma reaction chamber. The component includes an electrically conductive body consisting of a carbide or boride, wherein the carbide or boride body having a density of at least 98 percent of theoretical density of the carbide or boride.

[0042]

[0037] In yet another aspect, the description relates to a reaction chamber component adapted for use in an interior of a plasma reaction chamber. The component includes an electrically conductive body consisting of a carbide or boride, wherein the carbide or boride body is present in the Nowotny phase. In yet another aspect, the description relates to a method of forming reaction chamber component adapted for use in an interior of a plasma reaction chamber. The component includes a sintered silicide body that includes at least 90 percent by weight of a silicide including a metal. The silicide body has a density of at least 95 percent of theoretical density of the silicide, in particular of at least 98 percent of theoretical density of the silicide, and contains less than 10 percent by weight silica. The method comprises: placing silicide powder in a chamber, the silicide powder comprising at least 99 weight percent of the silicide including a metal; and sintering the silicide powder in the chamber to cause the silicide powder to form the sintered silicide body.

[0043]

[0038] In still another aspect, the description relates to a method of forming reaction chamber component adapted for use in an interior of a plasma reaction chamber. The component includes a sintered silicide body that includes at least 90 percent by weight of a single silicide selected from one of a transition metal silicide and a rare earth metal silicide. The silicide body has a density of at least 95 percent of theoretical density of the silicide, in particular of at least of at least 98 percent of theoretical density of the single silicide, and contains less than 10 percent by weight silica. The method comprises: placing silicide powder in a chamber, the silicide powder comprising at least 99 weight percent of a single silicide selected from a transition metal silicide and a rare earth metal silicide; and sintering the silicide powder in the chamber to cause the silicide powder to form the sintered silicide body.

[0044]

[0039] In a further aspect, the sintering includes placing the silicide powder in a graphite die and placing the graphite die in a chamber, eliminating oxygen in the chamber, and applying pressure to the silicide powder in the die and passing electric current through the die to increase the H6003.144.111 / 2024P00095US temperature of the silicide powder to cause the silicide powder to sinter and form the sintered silicide body. In yet a further aspect, applying pressure is performed using a punch, the method further including disposing boron nitride between the punch and the silicide powder prior to applying pressure. In still yet a further aspect, the silicide powder forms a fluorine reaction compound when exposed to a fluorine plasma that has a boiling point of less than 1000 degrees C, more preferably less than 500 degrees C.

[0045]

[0040] In yet another aspect, the description relates to a method of forming a reaction chamber component adapted for use in an interior of a plasma reaction chamber. The component includes a sintered silicide body that contains at least 90 percent by weight of a silicide including a metal. The silicide body has a density of at least of at least 95 percent of theoretical density of the silicide, in particular of at least 98 percent of theoretical density of the silicide, and contains less than 10 percent by weight silica. The method includes placing a powder mixture in a chamber, the powder containing silicon powder containing least 99 percent of silicon, and a metal powder that contains at least 99 percent of the metal; and sintering the powder mixture in the chamber to cause the powder mixture to form a sintered silicide body.

[0046]

[0041] In still another aspect, the description relates to a method of forming a reaction chamber component adapted for use in an interior of a capacitively coupled plasma reaction chamber. The component includes a sintered silicide body that contains at least 90 percent by weight of a single silicide selected from one of a transition metal silicide and a rare earth metal silicide. The silicide body has a density of at least of at least 95 percent of theoretical density of the silicide, in particular of at least 98 percent of theoretical density of the single silicide, and contains less than 10 percent by weight silica. The method includes placing a powder mixture in a chamber, the powder containing silicon powder containing least 99 percent of silicon, and a metal powder that contains at least 99 percent of a metal selected from a transition metal and a rare earth metal; and sintering the powder mixture in the chamber to cause the powder mixture to form a sintered silicide body.

[0047]

[0042] According to still another aspect, the description relates to a plasma reaction chamber that includes a substrate holder disposed within the reaction chamber, a top electrode disposed in the reaction chamber, a bottom electrode disposed in the reaction chamber, a gas flow device, a radio frequency (RF) power source connected to the top electrode to generate a plasma in the etch chamber, and a focus ring disposed on the substrate holder and configured to surround a H6003.144.111 / 2024P00095US substrate placed on the substrate holder. One or more of the focus ring, top electrode, or gas flow device includes a silicide body that contains at least 90 percent by weight of a silicide including a metal. The silicide body has a density of at least of at least 95 percent of theoretical density of the silicide, in particular of at least 98 percent of theoretical density of the silicide and contains less than 10 percent by weight silica.

[0048]

[0043] According to yet another aspect, the description relates to a plasma reaction chamber that includes a substrate holder disposed within the reaction chamber, a top electrode disposed in the reaction chamber, a bottom electrode disposed in the reaction chamber, a gas flow device, a radio frequency (RF) power source connected to the top electrode to generate a plasma in the etch chamber, and a focus ring disposed on the substrate holder and configured to surround a substrate placed on the substrate holder. One or more of the focus ring, top electrode, or gas flow device includes a silicide body that contains at least 90 percent by weight of a single silicide selected from one of a transition metal silicide and a rare earth metal silicide. The silicide body has a density of at least of at least 95 percent of theoretical density of the silicide, in particular of at least 98 percent of a theoretical density of the single silicide and contains less than 10 percent by weight silica.

[0049] BRIEF DESCRIPTION OF THE FIGURES

[0050]

[0044] Figure 1 shows an example of a reaction chamber as described.

[0051]

[0045] Figures 2 through 8 show photomicrographs of example silicide bodies tested by an HF wet etch process.

[0052]

[0046] Figure 9 shows the erosion depth of examples of silicide bodies resulting from an ICP erosion test.

[0053]

[0047] Figure 10 illustrates the arithmetical mean height, Sa, resulting from the ICP erosion test.

[0054]

[0048] Figure 11 shows the developed interfacial area ratio, Sdr, for the ICP erosion test.

[0055]

[0049] Figure 12 shows the etch depth of different silicides and mixtures thereof after being subjected to ICP using SFe and SFe followed by O2.

[0056]

[0050] Figure 13 shows the etch depth of silicides, carbides and borides after being subjected to ICP using SFe and SFe followed by O2. H6003.144.111 / 2024P00095US

[0057] DETAILED DESCRTPTTON

[0058]

[0051] A capacitively coupled processing system 10 is shown in Figure 1. System 10 includes a reaction chamber (“plasma etch chamber”) 110 adapted to process (e.g., by etching) substrate 100. Substrate 100 can be an “in-process” semiconductor device that has undergone a number of conventional steps used to manufacture a microelectronic device, and will be further processed by system 10. Substrate 100 may contain multiple layers of materials that form microelectronic devices or that are useful in manufacturing microelectronic devices on a semiconductor substrate. Example substrates 100 may be in the form of a silicon wafer or a silicon-on-insulator (SOI) wafer. Substrate 100 may include a silicon germanium wafer, silicon carbide wafer, gallium arsenide wafer, gallium nitride wafer, or the like. Alternately, substrate 100 may include heterogeneous layers such as silicon germanium on silicon, gallium nitride on silicon, silicon carbon on silicon, as well layers of silicon on a silicon or SOI substrate. Alternately, substrate 100 can include patterned or embedded components of a semiconductor device.

[0059]

[0052] During use, a process gas or multiple process gases may be introduced into plasma etch chamber 110 by gas delivery system 116. Gas delivery system 116 may include one or more gas flow conduits to control the flow of gases into plasma etch chamber 110, including, for example, one or more gas distribution plates (sometimes referred to as “showerheads”) 118. Plasma etch chamber 110 may be equipped with one or more sensors such as pressure monitors, gas flow monitors, temperature sensors, or gas species density monitors. Plasma etch chamber 110 may be evacuated using one or more vacuum pumps 135, which may be a single stage pumping system or a multistage pumping system (e.g. a mechanical roughing pump combined with one or more turbomolecular pumps).

[0060]

[0053] Substrate holder 105 may be integrated with, or a part of, a chuck (e.g., a circular electrostatic chuck (ESC)) positioned near the bottom of plasma etch chamber 110 and connected to a bottom electrode 120. Substrate 100 may be maintained at a desired temperature using a temperature sensor and a heating element connected to temperature controller 140.

[0061]

[0054] Bottom electrode 120 may be connected to one or more RF power sources 130 to generate plasma 160 in plasma etch chamber 110. As illustrated, more than one RF power source may be used, for example, to provide a high frequency RF power (HF) and a low frequency RF power (LF) at the same time. The HF power may be used for plasma and radical generation, while the LF power may be used for ion acceleration in a sheath of the plasma 160 H6003.144.111 / 2024P00095US over substrate 100 that enables plasma etching on substrate 100. RF power sources 130 may be used to supply continuous wave (CW) or pulsed RF power to sustain the plasma 160. Plasma 160, shown between top electrode 150 and bottom electrode 120, exemplifies direct plasma generated close to substrate 100 in plasma etch chamber 110.

[0062]

[0055] Top electrode 150 may be an electrically-conductive circular plate inside plasma etch chamber 110 near the top of the chamber. Top electrode 150 may be connected to a direct current (DC) voltage source 165 of the system 10. Combined with the RF power from the RF power sources 130, the DC voltage is used to generate a DC superimposed RF plasma at the interior of plasma etch chamber 110. The DC voltage may be supplied to the top electrode 150. Alternately, the DC voltage may be supplied to the bottom electrode 120.

[0063]

[0056] Focus ring (or “edge ring”) 154 is positioned over bottom electrode 120 to surround substrate 100. Focus ring 154 may advantageously maintain and extend the uniformity of the plasma 160 to achieve process consistency at the edge of substrate 100. Focus ring 154 may have a width of a few centimeters and a diameter that is greater than the diameter of substrate 100, meaning a focus ring may have an inner diameter of greater than 200 centimeters, 300 centimeters, or 450 centimeters. A clearance gap may extend between the outer circumference of substrate 100 and the inner circumference of focus ring 154. Focus ring 154 may be connected to a RF power source 170, which is configured to apply a RF bias to focus ring 154. Applying a bias to focus ring 154 may advantageously improve the uniformity of the plasma 160 in plasma etch chamber 110. Temperature controller 140 may also be configured to control the temperature of focus ring 154.

[0064]

[0057] As described, one or more of the functional components at the interior of the plasma etch chamber 110 can include a silicide body that includes at least 90 percent by weight of a silicide including a metal. Preferably, the silicide body comprises a single silicide selected from one of a transition metal silicide and a rare earth metal silicide, i.e., a “single-silicide body.” Example single silicide bodies can include at least 95, 98, or 99 percent by weight of the single silicide. Examples of reaction chamber components that may include (comprise, consist of, or consist essentially of) a single-silicide body include an electrode (e.g., top electrode 150), a flow control device (e.g., plate 118), and focus ring 154.

[0065]

[0058] The silicide body can also have additional physical properties that allow the silicide body to perform as a reaction chamber component. These include a high electrical conductivity (low H6003.144.111 / 2024P00095US resistivity); relatively high purity, meaning a relatively low amount of materials other than the single silicide; a high density; a high hardness; low porosity; and resistance to etching or erosion in the presence of plasma.

[0066]

[0059] Single silicide bodies as described have been found to exhibit high electrical conductivity as is reflected by a low resistivity. Example single silicide bodies can have resistivity of less than 4 ohm-centimeter to less than 0.001 ohm-centimeter.

[0067]

[0060] A single-silicide body can also contain a relatively low amount of material that is different from the single silicide. Processes of making a silicide body can produce the desired silicide, but may also produce materials different from the desired silicide, such as silica (SiCh) or other silicide materials. Example single silicide bodies as described may contain less than 10 weight percent, e.g., less than 5 or 3 weight percent of silica or a different silicide.

[0068]

[0061] A single-silicide body can be prepared to have a high density relative to theoretical density of the single silicide. Example single silicide bodies can have a density that is at least 80, 90, 95, or 99 percent of the theoretical density of the single silicide.

[0069]

[0062] For erosion resistance in a plasma chamber, a reaction chamber component preferably has a low porosity. Pores within a reaction chamber component permit entrance of reactive gas or chemicals into the component, which increases the presence of surface that may be attacked by the plasma, and promotes undercutting of the component surface and particle generation. Preferred reaction chamber components can have a porosity that is less than 1 percent.

[0070]

[0063] Also desirably, a reaction chamber component can have a high hardness, e.g., as measured by a Vickers hardness test. Preferred reaction chamber components can have a hardness, as measured by a Vickers hardness test, that is at least 751 and up to 1495.

[0071]

[0064] Silicides that include properties as described, and that may be used to prepare a single- silicide body for use as a reaction chamber component include transition metal silicides and rare earth metal silicides. Specific examples include WSi2, WsSis, MoSi2, TaSi2, YSi2, and LaSi2. Particularly useful single silicide bodies can be made of a silicide that forms a gaseous reaction product when the silicide contacts plasma, such as MoSi2. These silicides may be used to prepare single silicide bodies that contain include at least 95, 98, or 99 percent by weight of the single silicide, less than 10 or 5 percent silica, and that exhibit a low porosity, electrically- conductivity, and hardness properties as described. H6003.144.111 / 2024P00095US

[0072]

[0065] In another aspect of the invention, a reaction chamber component can consist of at most 12 percent by weight of a first silicide with higher etch resistance than a second silicide and at least 88 percent by weight of a second silicide with lower etch resistance than a first silicide.

[0073]

[0066] In another aspect of the invention, a reaction chamber component can consist of at most 9 percent by weight of a first silicide with higher etch resistance than a second silicide and at least

[0074] 91 percent by weight of a second silicide with lower etch resistance than a first silicide.

[0075]

[0067] In another aspect of the invention, a reaction chamber component can consist of at most 8 percent by weight of a first silicide with higher etch resistance than a second silicide and at least

[0076] 92 percent by weight of a second silicide with lower etch resistance than a first silicide.

[0077]

[0068] In another aspect of the invention, a reaction chamber component can consist of at most 7 percent by weight of a first silicide with higher etch resistance than a second silicide and at least

[0078] 93 percent by weight of a second silicide with lower etch resistance than a first silicide.

[0079]

[0069] In another aspect of the invention, a reaction chamber component can consist of at most 6 percent by weight of a first silicide with higher etch resistance than a second silicide and at least

[0080] 94 percent by weight of a second silicide with lower etch resistance than a first silicide.

[0081]

[0070] In another aspect of the invention, a reaction chamber component can consist of at most 5 percent by weight of a first silicide with higher etch resistance than a second silicide and at least

[0082] 95 percent by weight of a second silicide with lower etch resistance than a first silicide.

[0083]

[0071] In another aspect of the invention, the first silicide with higher etch resistance than a second silicide is YSiz.

[0084]

[0072] In another aspect of the invention, the second silicide with lower etch resistance than the first silicide is M0S2.

[0085]

[0073] In another aspect of the invention, the silicide body comprises 90 percent by weight of M0S2 and 10 percent by weight of YS2.

[0086]

[0074] In another aspect of the invention, the silicide body comprises 91 percent by weight of M0S2 and 9 percent by weight of YS2.

[0087]

[0075] In another aspect of the invention, the silicide body comprises 92 percent by weight of M0S2 and 8 percent by weight of YS2.

[0088]

[0076] In another aspect of the invention, the silicide body comprises 93 percent by weight of M0S2 and 7 percent by weight of YS2. H6003.144.111 / 2024P00095US

[0089]

[0077] In another aspect of the invention, the silicide body comprises 94 percent by weight of M0S2 and 6 percent by weight of YS2.

[0090]

[0078] In another aspect of the invention, the silicide body comprises 95 percent by weight of M0S2 and 5 percent by weight of YS2.

[0091]

[0079] Figure 12 shows the etch testing of the conventionally used SiC and a single silicide body of MoSi2 in comparison to a single silicide body made of YSi2 and mixtures of MoSi2 and YSi2.

[0092]

[0080] While a single silicide body of MoSi2 already shows much lower etching in comparison to the conventionally used SiC, a single silicide body of YSi2 shows significantly lower etching than even MoSi2. However, the cost of YSi2is also significantly higher than the cost of MoSi2. Therefore, a material made of at most 11 percent by weight of YSi2 and at least 89 percent by weight of MoSi2 combines the higher etch resistance of YSi2 with the lower price of MoSi2, while keeping the conductivity properties of transition metal and rare earth metal silicides.

[0093]

[0081] As is shown in Figure 12, a combinations of 89 percent by weight of MoSi2 and 11 percent by weight of YSi2, 92 percent by weight of MoSi2 and 8 percent by weight of YSi2, and equal amounts of each show greater etch resistance than 100 percent by weight of MoSi2.

[0094]

[0082] In yet another aspect of the invention, a reaction chamber component can comprise a transition metal or rare earth metal carbides or borides.

[0095]

[0083] Figure 13 shows the results of etch testing of conventionally used SiC bodies and different single silicide bodies in comparison to MosSi2C, B4C, ZrC, TaC and ZrEh. Most of the carbides show etch resistances better than SiC and comparable to MoSi2. TaC has approximately the same etch rate as SiC. The smallest amount of etching was observed on ZrC and ZrEh. They showed etch results comparable to LaSi2 and YSi2 and therefore, much better than conventionally used SiC and even MoSi2.

[0096]

[0084] Therefore, another aspect of the present invention is a reaction chamber component which comprises ZrC and ZrEh.

[0097]

[0085] Another aspect of the present invention is a reaction chamber component which essentially consists of ZrC and ZrEh.

[0098]

[0086] The etch testing results of combinations of at least 5 percent by weight of YSi2 and at least 10 percent by weight of MoSi2, and ZrC or ZrE provide a solution for the problems of etching regarding the lifetime of a reaction chamber component and the particle contamination inside of the reaction chamber. H6003.144.111 / 2024P00095US

[0099]

[0087] A single-silicide body as described can be formed using a sintering method, many of which are known, including reactive sintering methods and non-reactive sintering methods. By a reactive sintering method, a powder mixture that contains a highly pre silicon powder and a highly pre transition metal powder or a highly pure rare earth metal powder are heated in a chamber (e g., a die or an oven) optionally with pressure being applied to the powder mixture, to cause the silicon and the metal to react to and to form a solid, dense, low porosity sintered silicide body. By a non-reactive sintering method, a silicide powder that contains (comprises, consists of, or consists essentially of) a high amount of a highly pure single silicide is heated in a chamber (e.g., a die or an oven), optionally with pressure being applied to the powder mixture, to cause particles of the silicide powder to become fused together, without melting, to form a solid, dense, low porosity sintered silicide body.

[0100]

[0088] According to examples of forming a single-silicide body from silicide, a silicide powder may be highly pure, containing at least 99 or 99.9 percent by weight of a single silicide selected from WSi2, W + WSi2 =WsSi3, MoSi2, TaSi2, YSi2, and LaSi2, and less than 5 percent impurity by weight silica and / or silicon as measured to the limit of x-ray diffraction (XRD) laboratory equipment. Sulfur content was less than 19 ppm by mass, and carbon content was less than 2614 ppm by mass.

[0101]

[0089] Desirably, the silicide powder can have particles that exhibit a mean particle size, a particle size distribution, and surface area, that facilitate the formation of a single-silicide body that has a high density and low porosity. Example silicide powders may have a surface area (measured by BET) of at least 0.2 square meters per gram, a mean particle size (D50) of no more than 20 microns, and a particle size distribution that includes a DIO of at least 0.13 microns and a D90 of below 67 microns.

[0102]

[0090] The silicide powder may be processed by sintering to form a single-silicide body as described. Examples of useful sintering methods include spark plasma sintering and hot press sintering, each of which applies a combination of heat and pressure to a silicide powder to form a single-silicide body. Other examples of sintering methods, referred to as pressure-less sintering, do not require pressure but cause sintering of a silicide powder by heat alone.

[0103]

[0091] As used herein the term “spark plasma sintering” (“SPS”) refers to a method of bonding together individual particles of a powder to form a dense (low porosity) sintered material (a.k.a. “sintered body”) by applying pressure to the particles while the particles are heated in a die by H6003.144.111 / 2024P00095US electric current passing through the die. The particles are heated to a temperature that is below the melting point of the particles but also sufficiently high to cause the individual particles to become bonded together by atomic diffusion at particle surfaces. A spark plasma sintering method uses contemporaneous application of uniaxial pressure and heat generated by electric current passing through the die to increase the temperature of the particles in the die. Spark plasma sintering differs from hot press sintering, which uses an external heat source such as a furnace or resistive heating element to heat a mold that contains powder for sintering. A hot- press may be used as an alternative to an SPS machine.

[0104]

[0092] According to example spark plasma sintering methods, a silicide powder can be placed within the interior of a graphite die in a controlled, oxygen-free atmosphere such as a vacuum or other atmosphere devoid of oxygen. The oxygen-free atmosphere is effective to prevent the graphite die from reacting or combusting. The pressure (“sintering pressure”), rate of temperature increase (temperature profile), maximum temperature or temperature range (“sintering temperature”), type of electric current passing through the die, and amount of time that the powder mixture is held at a sintering temperature (“sintering time”), are factors that can be controlled to produce a sintered silicide body.

[0105]

[0093] Examples of useful sintering pressures for forming a silicide body can be up to about 200 megapascals (MPa), e.g., up to 100 MPa, or up to 25 or 50 MPa, such as a pressure in a range from 10 to 50 MPa. Lower pressures in a range from 10 to 50 MPa are preferred to avoid damaging the die, and more preferably from 10 to 30 MPa.

[0106]

[0094] Examples of useful sintering temperatures may be up to 1700 degrees Celsius, e.g., from 1400 to 1700 such as from 1000 to 1650 degrees Celsius. A useful sintering time may be up to 180 or 120 minutes, e.g., up to 90 minutes or up to 60 minutes for dies of 100 mm to 150 mm diameter or less. Differently-sized dies may require different sintering times, with larger sized dies generally requiring longer sintering times.

[0107]

[0095] The present disclosure can be summarized as follows:

[0108] 1. A reaction chamber component adapted for use in an interior of a plasma reaction chamber, the component comprising an electrically conductive silicide body comprising at least 90 percent by weight of a silicide comprising a metal, the silicide body having a density of at least 98 percent of theoretical density of the silicide, and containing less than 10 percent by weight silica. H6003.144.111 / 2024P00095US

[0109] 2. The component of item 1 wherein the silicide body has a resistivity of less than 4 ohmcentimeter.

[0110] 3. The component of item 1, the silicide body comprising at least 99 percent of the silicide.

[0111] 4. The component of item 1, comprising at least 90 percent by weight WSi2, WsSis, MoSi2,

[0112] TaSi2, YSi2, or LaSi2, as the single silicide.

[0113] 5. The component of item 1, comprising at least 90 percent by weight MoSi2 as the silicide.

[0114] 6. The component of item 1, comprising at least 90 percent by weight WSi2 as the silicide and less than 1 percent by weight WsSis.

[0115] 7. The component of item 1, wherein said silicide is selected from the group consisting of ZrSi2, LaSi2, YSi2 and TaSi2.

[0116] 8. The component of item 1, having an annular shape with a thickness in a range from 1 to 10 millimeters and a diameter of at least 200 millimeters.

[0117] 9. The component of item 1, the silicide body having: a Vicker’s hardness of at least 751; a sulfur content of less than 19 ppm; a porosity below 1 percent; or a combination of these.

[0118] 10. The component of item 1, wherein said silicide forms a fluorine reaction compound having a boiling temperature of less than 1000 degrees C.

[0119] 11. The component of item 1 , wherein said silicide forms a fluorine reaction compound having a boiling temperature of less than 500 degrees C.

[0120] 12. A method of forming reaction chamber component adapted for use in an interior of a plasma reaction chamber, the component comprising a sintered silicide body comprising at least 90 percent by weight of a silicide comprising a metal, the silicide body having a density of at least 98 percent of theoretical density of the silicide, and containing less than 10 percent by weight silica, the method comprising: placing silicide powder in a chamber, the silicide powder comprising at least 99 weight percent of the silicide comprising a metal, sintering the silicide powder in the chamber to cause the silicide powder to form the sintered silicide body. H6003.144.111 / 2024P00095US

[0121] 13. The method of item 12, wherein the silicide powder has: a sulfur content of no more than 19 ppm; a BET of at least 0.02 square meters per gram, a mean particle size (D50) of no more than 20 microns and at least 0.4 microns; a particle size distribution of a DIO of at least 0.13 microns and a D90 of less than 67 microns.

[0122] 14. The method of item 12, comprising: placing the silicide powder in a graphite die and placing the graphite die in the chamber, eliminating oxygen in the chamber, and applying pressure to the silicide powder in the die and passing electric current through the die to increase the temperature of the silicide powder to cause the silicide powder to sinter and form the sintered silicide body.

[0123] 15. The method of item 14, said applying pressure is performed using a punch, the method further comprising disposing boron nitride between the punch and the silicide powder prior to applying pressure.

[0124] Examples

[0125]

[0096] Single silicide bodies having a thickness of approximately 2 millimeters and a diameter of approximately 40 millimeters were prepared by spark plasma sintering as follows. The samples were sintered from silicide powder in direct current sintering furnace, model DCS 50 available from Thermal Technology, LLC of Minden, Nevada. Each sample was prepared by placing the indicated amount of powder in Table 1 below into a graphite die of approximately 40 mm internal diameter between opposing graphite punches to form a die loaded with powder. Each loaded die was subsequently inserted into the direct current sintering furnace and the pressure reduced to near vacuum conditions, In the sintering furnace, uniaxial force was applied to the punches to compress the powder between the punches at the pressure indicated in Table 1 while the die was heated to the target temperature. Once the target temperature was achieved, the temperature was held for the indicated dwell time and thereafter the furnace allowed to cool back to ambient temperature. After cooling, the sintered material was removed from each die. The abbreviation “BN” in Table 1 indicates that a layer of boron nitride was disposed between the H6003.144.111 / 2024P00095US punch and the powder by spraying boron nitride on a surface of graphite foil facing the powder. The boron nitride acts as an electrical insulator so that more of the electrical current is directed through the die and not through the powder. The boron nitride may also act to reduce carbon contamination from the graphite foil in the resulting sintered silicide and in addition may prevent carbon in the graphite from reacting with the powder.

[0126] Table 1 Samples Sintered

[0127] Properties of the silicide bodies were measured as follows:

[0128]

[0097] Table 2 shows silicide bodies prepared as described herein that have densities that approach one-hundred percent of the theoretical density of the single silicide. Samples designated as “BN FOIL” were prepared using a boron nitride disposed on a surface of graphite placed between the silicide powder and the graphite die during spark plasma sintering, with the surface of the graphite foil having the boron nitride thereon facing the powder.

[0129] Table 2 Resistivity H6003.144.111 / 2024P00095US

[0130] Sample mm Raw Corrected

[0131] COMPOUND Resistivity’ Q-cm L W T Q Meter zero at 0.09 Q

[0132] ZrSi2 1.018E-03 19.93 10.04 2.02 0.1 0.01

[0133] ZrSi2_BN FOIL 1.008E-03 19.94 10 2.01 0.1 0.01

[0134] WSi2 1.012E-03 20.23 10.04 2.04 0.1 0.01

[0135] W5Si3 9.590E-04 20.02 10 1.92 0.1 0.01

[0136] MoSi2 9.989E-04 20.08 10.13 1.98 0.1 0.01

[0137] MoSi2_BN FOIL 1.018E-03 19.95 10.05 2.02 0.1 0.01

[0138] TaSi2 9.894E-04 20.35 10.22 1.97 0.1 0.01

[0139] TaSi2_BN FOIL 9.654E-04 20.2 10.21 1.91 0.1 0.01

[0140] YSi2_BN FOIL 2.100E-03 19.41 10.19 2 0.11 0.02

[0141] Prior Art CVD SiC 4.301E+00 13.27 9.45 1.73 35 34.91

[0142] Table 3 Vickers Hardness

[0143] COMPOUND Vickers HV (0.05)

[0144] ZrSi2 1121

[0145] ZrSi2_BN FOIL 1071

[0146] WSi2 1495

[0147] W5Si3 1188

[0148] MoSi2 1310

[0149] MoSi2_BN FOIL 1250

[0150] TaSi2 1049

[0151] TaSi2 BN FOIL 1043

[0152] YSi2 BN FOIL 751

[0153] YAG 1598

[0154] Table 4 Density

[0155] Density’ Archimedes

[0156] Compound g / cc theoretical % Theoretical

[0157] WSi2 9.58 9.3 103% **

[0158] MoSi2 6.02 6.26 96% *

[0159] YSi2 4.15 4.39 95% *

[0160] LaSi2 4.96 5.00 99% *

[0161] ZrSi2 4.11 4.88 84% * H6003.144.111 / 2024P00095US

[0162] TaSi2 8.75 9.14 96% *

[0163] W5Si3 14.13 14.64 97% *

[0164] Note: all materials had SiO2 amorphous 2nd phase which resulted in ~95% dense actual fully dense microstructure.

[0165] LaSi2 did not have 2nd phase and density measured 99%.

[0166] * Contain SiO2 liquid phase which lowers physical g / cc below theoretical. No visible porosity in microstructure

[0167] ** Likely residual metal W and observed liquid SiO2 lead to odd result

[0168] Table 4 Particle Size Distribution of Silicide Powders

[0169] DIO D50 D90

[0170] Compound microns microns microns

[0171] WSi2 3.6 7.0 11.5

[0172] MoSi2 1.1 2.3 4.2

[0173] YSi2 3.1 14.0 76.9

[0174] LaSi2 7.0 20.0 57.6

[0175] ZrSi2 0.1 0.4 1.5

[0176] TaSi2 1.5 8.0 47.8

[0177] Microstructure and Wet Etch Testing

[0178] [98J It was observed that ~1 pm nodules of SiCh were formed during sintering for all materials except for LaSi?. These may form from the surface oxide layer present on the starting powders of material and any small amount of oxygen left during the sintering process. The SiCh phase was liquid, likely amorphous, and was softer, causing recessed areas from polishing process.

[0179]

[0099] Figure 2 shows photomicrographs of a sample of a WSi2 silicide body prepared by spark plasma sintering WSi2 powder at 1625 degrees Celsius and 25 MPa. The left photo is prepared by back scattering detection (BSD) and the right photo is a topographical view of the surface (TOPO1). The upper photos show the sample after preparation and before an HF (hydrofluoric acid) wet etch test, and the lower photos show the sample following an HF wet etch test. The wet testing method for all samples involved applying a drop of 49 percent hydrofluoric acid onto a polished surface of a silicide body and allowing the acid to remain on the surface for approximately 10 minutes. The photos show that the silicide body contains a majority of WSi2 and minor amounts of SiO2 and W5Si3. The pre-and post-etch photos show that the WSi2 silicide body experienced relatively uniform etching across the surface upon wet etching by HF. It is estimated that the WSi2 body contained less than 10 percent SiO2. H6003.144.111 / 2024P00095US

[0180]

[0100] Figure 3 shows photomicrographs of a sample of a W5Si3 silicide body prepared by spark plasma sintering W + WSi2 which reacted to W5Si3 powder at 1700 degrees Celsius and 25 MPa. The left photo is prepared by back scattering detection (BSD) and the right photo is a topographical view of the surface (TOPO1). The upper photos show the sample after preparation and before an HF (hydrofluoric acid) wet etch test, and the lower photos show the sample following an HF wet etch test. The photos show that the silicide body contains a majority of W5Si3 and minor amounts of SiO2 and W or WSi2. The pre-and post-etch photos show that the W5Si3 silicide body experienced relatively uniform etching across the surface upon wet etching by HF. It is estimated that the W5Si3 body contained less than 10 percent SiO2.

[0181]

[0101] Figure 4 shows photomicrographs of a sample of a MoSi2 silicide body prepared by spark plasma sintering MoSi2 powder at 1625 degrees Celsius and 25 MPa. The left photo is prepared by back scattering detection (BSD) and the right photo is a topographical view of the surface (TOPO1). The upper photos show the sample after preparation and before an HF (hydrofluoric acid) wet etch test, and the lower photos show the sample following an HF wet etch test. The photos show that the silicide body contains a majority of MoSi2 and minor amounts of SiO2 and Mo5Si3. The pre-and post-etch photos show that the MoSi2 silicide body experienced relatively uniform etching across the surface upon wet etching by HF. It is estimated that the MoSi2 body contained less than 10 percent SiO2.

[0182]

[0102] Figure 5 shows photomicrographs of a sample of a TaSi2 silicide body prepared by spark plasma sintering TaSi2 powder at 1625 degrees Celsius and 25 MPa. The left photo is prepared by back scattering detection (BSD) and the right photo is a topographical view of the surface (TOPO1). The upper photo shows the sample after preparation and before an HF (hydrofluoric acid) wet etch test, and the lower photos show the sample following an HF wet etch test. The photos show that the silicide body contains a majority of TaSi2 and minor amounts of SiO2 and TaCx. The pre-and post-etch photos show that the TaSi2 silicide body experienced relatively uniform etching across the surface upon wet etching by HF. It is estimated that the TaSi2 body contained less than 10 percent SiO2.

[0183]

[0103] Figure 6 shows photomicrographs of a sample of a YSi2 silicide body prepared by spark plasma sintering TaSi2 powder at 1150 degrees Celsius and 25 MPa. The left photo is prepared by back scattering detection (BSD) and the right photo is a topographical view of the surface (TOPO1). The upper photos show the sample after preparation and before an HF (hydrofluoric H6003.144.111 / 2024P00095US acid) wet etch test, and the lower photos show the sample following an HF wet etch test. The photos show that the silicide body contains a majority of YSi2 and minor amounts of SiO2 and Si or SiC. The pre-and post-etch photos show that the YSi2 silicide body experienced relatively uniform etching across the surface upon wet etching by HF. It is estimated that the YSi2 body contained less than 10 percent SiO2.

[0184]

[0104] Figure 7 shows photomicrographs of a sample of a LaSi2 silicide body prepared by spark plasma sintering LaSi2 powder at 1200 degrees Celsius and 15 MPa. The left photo is prepared by back scattering detection (BSD) and the right photo is a topographical view of the surface (TOPO1). The upper photos show the sample after preparation and before an HF (hydrofluoric acid) wet etch test, and the lower photos show the sample following an HF wet etch test. The photos show that the silicide body contains homogeneous LaSi2. The post etch photos show a crack in the microstructure that was probably present prior to the HF acid test.

[0185]

[0105] Figure 8 shows photomicrographs of a sample of a ZrSi2 silicide body prepared by spark plasma sintering ZrSi2 powder at 1150 degrees Celsius and 25 MPa. The left photo is prepared by back scattering detection (BSD) and the right photo is a topographical view of the surface (TOPO1). The upper photos show the sample after preparation and before an HF (hydrofluoric acid) wet etch test, and the lower photo shows the sample following an HF wet etch test. The photos show that the silicide body contains a majority of ZrSi2 and minor amounts of SiO2. The post etch photos show the HF acid test caused severe etch damage. Due to the severe etch damage, ZrSi2 is not as preferred for a chamber component as one or more of the other silicide that did not show signs of severe etch damage in the post HF acid test photos.

[0186]

[0106] One of the most corrosive environments in a plasma reaction chamber results from using fluorine gas. Plasma produced from fluorine gas tends to cause the greatest erosion to chamber components by reacting with the materials comprising the component. CCP reaction chambers normally operate at a few hundreds of degrees Celsius, and the interior usually does not exceed 1000 deg. C, and typically does not rise above 500 deg. C. To avoid particle generation from erosion of a chamber component, such as a focus ring or electrode, it is desirable that the material comprising the component forms a reaction product (i.e., a “reaction compound”) with the plasma that is a vapor within the operating conditions (temperature, pressure) of the reaction chamber. If the reaction compound remains a vapor, solid particles are not generated that could settle on a wafer being processed and cause damage. Particle generation by a top electrode is H6003.144.111 / 2024P00095US particularly problematic because it is positioned over a wafer and particles fall downward due to gravity on to the wafer below. Table 5 below shows the reaction compound or compounds resulting from a fluorine plasma with the silicides disclosed herein along with the boiling point (at atmospheric pressure) for each reaction compound. For comparison, Table 5 also includes data for quartz glass (silica).

[0187] Table 5 Fluorine Plasma Reaction Compounds

[0188] Reaction

[0189] Compound Boiling from Fluorine Point

[0190] Material Plasma (degrees. C)

[0191] WSi2 WF4 17.1

[0192] W3Si3 WF4 17.1

[0193] MoSi2 MoF5 50.0

[0194] MoSi2 MoF6 34.0

[0195] YSi2 YF3 2230

[0196] LaSi2 LaF3 2327

[0197] ZrSi2 ZrF4 912

[0198] TaSi2 TaF3 229

[0199] TiS2 TiF3 1400

[0200] SiO2 (quartz) SiF4 -123

[0201]

[0107] Of the silicides in Table 5, WSi2 and W3Si3 each produce a reaction compound from fluorine plasma that has the lowest boing point, namely 17.1 deg. C. In the table, only the reaction compound from quartz glass (SiO2) has a lower boiling point. While a lower boiling point is desirable, quartz tends to erode rapidly, which necessitates frequent replacement of a quartz component, and idle time for the reaction chamber while replacement maintenance is performed. Therefore, the silicides WSi2 and W3Si3 have an advantage over quartz due to higher erosion resistance to HF acid and are a preferred material for a focus ring, electrode or other chamber component, compared to quartz.

[0202]

[0108] In Table 5, MoSi2 is listed twice because it produces two reaction compounds from a fluorine plasma, MoF5 and MoF6. The boiling point for MoF5 and MoF6 is respectively 50 deg. C and 34 deg. C. This is higher than the boing point for reaction compounds from WSi2 and W3Si3. In view of cost considerations however, MoSi2 is more preferable than WSi2 and W5Si3. Tungsten is expensive compared to molybdenum and therefore MoSi2 is more preferred than WSi2 and W5Si3 for a focus ring or electrode due to cost. While fluorine reaction products H6003.144.111 / 2024P00095US from MoSi2 may have higher boiling points than the fluorine reaction product from WSi2 and W5Si3, these boiling points are generally lower than the normal operating temperature of a CCP reaction chamber. Therefore, the higher boiling points for the fluorine reaction compounds MoF5 and M0F6 are acceptable and MoSi2 is preferred due to lower cost compared to WSi2 and W3Si3.

[0203]

[0109] The silicide TaSi2 produces a fluorine reaction product TaF3 having a boiling point of 229 deg. C. Due to its higher boiling point, it is not as preferred as MoSi2, WSi2 or W5Si3. Nonetheless, the boiling point of TaF3 at 229 deg. C is generally within the operating range of a plasma reaction chamber and thus it remains a preferred material for a focus ring or electrode. [HO] The remaining silicides in Table 5 each produce fluorine reaction products that have boiling points higher than the normal operating temperature for a CCP reaction chamber. Therefore, they are not as preferred as the silicides that produce fluorine reaction compounds having lower boiling temperatures. The silicide ZrSi2 is also not preferred as the other silicides because the HF wet etch test indicated severe etch damage to the sample as previously described in connection with Figure 8.

[0204] [Hl] The example silicide bodies were additionally tested for erosion resistance by exposing a sample coupon of each silicide / material to an inductively coupled plasma (ICP). The samples were exposed to sulfur hexafluoride (SFe) for 10 minutes and then to oxygen (O2) for 0.5 minutes as plasma gases in a cycle 18 times for a total of approximately three hours of exposure time. An Oxford Instruments 100 ICP was used to expose the samples to the plasma gases using 2000 watts forward power with 200 watts bias (an Oxford Instruments 100 ICP is available from Oxford Instruments America Inc. of Concord Massachusetts, USA). Before plasma exposure, half of each sample was masked with plasma-resistant Kapton tape, to induce a defined etch step at the transition from etched to protected surface. The height of this etch step was measured with laser scanning microscopy and the results are displayed in Fig. 9.

[0205]

[0112] As can be seen from Fig. 9, MoSi2 eroded less than prior art SiC and significantly better than WSi2 and W5Si3. Further, the erosion resistance of MoSi2 prepared with boron nitride disposed on graphite foil was even better, and equal to that of quartz. Fig. 10 illustrates the arithmetical mean height, Sa resulting from the ICP erosion test. It is preferable that Sa remain low to prevent particle generation and minimize attack surfaces. Based on Fig. 10, MoSi2 prepared with boron nitride disposed on graphite foil performed better than the MoSi2 without H6003.144.111 / 2024P00095US the boron nitride on the graphite foil. MoSi2 also performed better than both WSi2 and W5Si3. However, prior art SiC had a lower Sa than both MoSi2 samples.

[0206] [1131 Fig 11 shows the developed interfacial area ratio, Sdr, for the ICP erosion test. Sdr is a measure of the additional surface area contributed by texture in comparison to the planar definition area, and lower values of Sdr are preferable. Once again, MoSi2 prepared by boron nitride on graphite foil performed better than the other MoSi2 prepared without boron nitride disposed on graphite foil, in this case, much better. However, based on Sdr, WSi2 and W5Si3 each had lower Sdr values than the MoSi2 samples. Based on these etch results, MoSi2 is preferred as a silicide over WSi2 and W5Si3 for a focus ring, and MoSi2 prepared with boron nitride on graphite foil is more preferable. The amount of etching shown in Fig. 9 is thought to be the more important parameter. Table 6 below shows the data from which the charts in Figs. 9 through 11 where plotted.

[0207] Table 6 Results from ICP Erosion Test etch

[0208] Material (jam) Sa Sdr

[0209] SiO2 (Quartz) 8.9 0.304 0.894

[0210] Prior Art CVD SiC 15.2 0.098 0.1049

[0211] Si 47.8 0.636 0.0429

[0212] 315S24A MoSi2 11.9 0.55 13.92

[0213] 253S24A ZrSi2 3.1 0.329 0.819

[0214] 358S24A YSi2 0.37 0.265 0.571

[0215] 359S24A TaSi2_BN 22.9 2.127 5.75

[0216] 347S24A TaSi2 23.75 1.432 2.615

[0217] 455S24A LaSi2 0.69 0.157 0.047

[0218] 261S2A W5S13 37.8 2.65 2.27

[0219] 260S24A WSi2 38.4 1.552 2.619

[0220] 360S24A ZrSi2_BN 3.2 0.211 0.414

[0221] 361S24A MoSi2_BN 8.9 0.468 4.704

[0222]

[0114] Table 7 below shows samples of silicide bodies that were prepared from powder, and compares the carbon and sulfur present in ppm by weight in the powder and the resulting sintered silicide body. H6003.144.111 / 2024P00095US

[0223] Table 7 Carbon and Sulfur

[0224] Sintered Bodv Powder

[0225] Silicide C S C S

[0226] ZrSi2 863 27 1399 8

[0227] ZrSi2_BN FOIL 630 35 1399 8

[0228] WSi2 161 21 307 5

[0229] W5S13 368 22

[0230] MoSi2 498 24 253 10

[0231] MoSi2_BN FOIL 224 20 253 10

[0232] TaSi2 892 21 208 8

[0233] TaSi2_BN FOIL 1136 23 208 8

[0234] YSi2 BN FOIL 5133 67 2614 19

[0235]

[0115] Table 8 below shows the results of etch testing different materials. Coupons of material were subjected to inductively coupled plasma (ICP) using SFe or SFe followed by O2 and the resulting etch depth measured.

[0236] Table 8 Etch Test Results

[0237] Etch (pm)

[0238] Material SFe SFe / 02

[0239] Suprasil 7.5 7.5

[0240] Prior Art CVD SiC 16.4 17.15

[0241] SiC 4H wafer undoped 12.4 7

[0242] SiC 4H wafer dopes 12.3 7.7

[0243] Si B-Doped 104

[0244] Si P-Doped 100

[0245] MoSi2 Heeger 8.7 10.5

[0246] LaSi; 40 MPa 0.4 1.1

[0247] YSi240 MPa 0.1 0.1

[0248] NbSi29.2 13

[0249] MoYSi289-11 7.2 5.4

[0250] MoYSi292-8 5.3 5.9 H6003.144.111 / 2024P00095US

[0251] MOYSI250-50 0.7 1.2

[0252] Mo3Si2C-l 9 11.4

[0253] Mo3Si2C-2 8.9 10.8

[0254] B4C 10.6 10.7

[0255] ZrC 1.5 1.5

[0256] TaC 17.5 16.1

[0257] ZrB20.5 0.11

[0258] TiB217.6 14.2

[0259] Diamond CVD 3.2 3.7

[0260] Glassy Carbon MSE 11

[0261] ZrSi2Vac Sinter 6.7

[0262] MoSi2Vac Sinter 8.6

[0263]

[0116] The foregoing description has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limiting to the precise form or example disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from experimentation. Embodiments and examples were chosen and described in order to explain the principles and practical application in various embodiments and with various modifications as are suited to particular uses. It is intended that the scope of the invention be defined by the claims appended hereto, and their equivalents.

Claims

H6003.144.111 / 2024P00095USClaims:

1. A reaction chamber component adapted for use in an interior of a plasma reaction chamber, the component comprising an electrically conductive silicide body comprising at least 85 percent by weight of at least one silicide comprising a metal, the silicide body having a density of at least 95 percent of theoretical density of the silicide, and containing less than 10 percent by weight silica.

2. The reaction chamber component of claim 1, wherein the silicide body has a density of at least 98 percent of theoretical density of the silicide.

3. The component of claim 1, wherein the silicide body comprises at most 15 percent by weight of one first silicide comprising a metal and at least 85 percent by weight of one second silicide comprising a metal.

4. The component of claim 3, wherein said one first silicide comprising a metal is YSi2.

5. The component of claim 3 or 4, wherein said one second silicide comprising a metal is selected from WSi2, WsSis, MoSi2, TaSi2, or LaSi2.

6. The component of claim 3 or 4, wherein said one second silicide comprising a metal is MoSi2.

7. The component of claim 1, having an annular shape with a thickness in a range from 1 to 10 millimeters and a diameter of at least 200 millimeters.

8. The component of claim 1, the silicide body having: a Vicker’s hardness of at least 751; a sulfur content of less than 19 ppm; a porosity below 1 percent; or a combination of these.H6003.144.111 / 2024P00095US9. The component of claim 1, wherein the silicide body comprises at least 85% of the silicide and ZrC and / or ZrBn as additives.

10. The component of claim 9, wherein the silicide is MoSi .

11. The component of claim 1, wherein the silicide body comprises at least 85% of the silicide and additives of carbon, boron or borides to form MoB, Mo2B, and M0C2 during sintering.

12. The component of claim 1, wherein the silicide body comprises at least 85% of the silicide and additives of carbon, boron or borides to form MoB, Mo2B, and M0C2 during sintering, wherein the additives are selected from the group consisting of B (amorphous or crystalline), B2O3, B4C, B2H6, B5H9, B10H14, H3BO3, boron-containing silicate glasses, borate glasses, such as B2O3, BN, BF3, BC13, B4C14, B(C6H5)3, B(C6H5)4, MgB2, MgB4, CaB6, MgB6, CeBe, LaBe, BPO4 and C2B10H12.

13. The component of claim 1, wherein the silicide is in the form of the Nowotny phase.

14. The component of claim 1, wherein the silicide is MosSisC in the form of the Nowotny phase.

15. A reaction chamber component adapted for use in an interior of a plasma reaction chamber, the component comprising an electrically conductive body comprising at least 90 percent by weight of a carbide or boride comprising a metal.

16. The component of claim 15, wherein said electrically conductive body comprises at least 90 percent by weight of ZrC, ZrB2 or a combination thereof.

17. The component of claim 15, wherein said electrically conductive body comprises at least 90 percent by weight of ZrC or ZrB2.H6003.144.111 / 2024P00095US18. The component of claim 15, wherein the carbide or boride body having a density of at least 95 percent of theoretical density of the carbide or boride.

19. The component of claim 15, wherein the carbide or boride body having a density of at least 98 percent of theoretical density of the carbide or boride.

20. The component of claim 15, wherein the carbide or boride is present in the Nowotny phase.

21. A method of forming reaction chamber component adapted for use in an interior of a plasma reaction chamber, the component comprising an electrically conductive silicide body comprising at least 85 percent by weight of at least one silicide comprising a metal, the silicide body having a density of at least 95 percent of theoretical density of the silicide, and containing less than 10 percent by weight silica, the method comprising: placing at least one silicide powder in a chamber, the silicide powder comprising at least 99 weight percent of at least one silicide comprising a metal, sintering the silicide powder in the chamber to cause the silicide powder to form the sintered silicide body.

22. The method of claim 21, wherein the at least one silicide powder has: a sulfur content of no more than 19 ppm; a BET of at least 0.02 square meters per gram, a mean particle size (D50) of no more than 20 microns and at least 0.4 microns; a particle size distribution of a D10 of at least 0.13 microns and a D90 of less than 67 microns.

23. The method of claim 21 or 22, comprising: placing the at least one silicide powder in a graphite die and placing the graphite die in the chamber, eliminating oxygen in the chamber, andH6003.144.111 / 2024P00095US applying pressure to the silicide powder in the die and passing electric current through the die to increase the temperature of the silicide powder to cause the silicide powder to sinter and form the sintered silicide body.

24. The method of claim 21, said applying pressure is performed using a punch, the method further comprising disposing boron nitride between the punch and the silicide powder prior to applying pressure.

25. The method of claims 21, wherein the silicide body has a density of at least 98 percent of theoretical density of the silicide.

26. The method of claims 21, wherein the silicide body comprises at most 15 percent by weight of one first silicide comprising a metal and at least 85 percent by weight of one second silicide comprising a metal.

27. The method of claims 21, wherein said one first silicide comprising a metal is YSi2.

28. The method of claims 21, wherein said one second silicide comprising a metal is selected from WSi2, WsSis, MoSi2, TaSi2, or LaSi2.

29. The method of claims 21, wherein said one second silicide comprising a metal is MoSi2.

30. The method of claims 21, wherein the silicide body comprises at least 85% of the silicide and ZrC and / or ZrBn as additives.

31. The method of claims 30, wherein the silicide is MoSi2.

32. The method of claims 21, wherein the silicide body comprises at least 85% of the silicide and additives of carbon, boron or borides to form MoB, Mo2B, and M0C2 during sintering.H6003.144.111 / 2024P00095US33. The method of claims 21, wherein the silicide body comprises at least 85% of the silicide and additives of carbon, boron or borides to form MoB, Mo2B, and M0C2 during sintering, wherein the additives are selected from the group consisting of B (amorphous or crystalline), B2O3, B4C, B2H6, B5H9, B10H14, H3BO3, boron-containing silicate glasses, borate glasses, such as B2O3, BN, BF3, BCI3, B4CI4, B(C6H5)3, B(C6H5)4, MgB2, MgB4, CaB6, MgB6, CeB6, LaB6, BPO4and C2B10H12.

34. The method of claims 21, wherein the silicide is in the form of the Nowotny phase.

35. The method of claims 21, wherein the silicide is MosSisC in the form of the Nowotny phase.

36. A method of forming reaction chamber component adapted for use in an interior of a plasma reaction chamber, the component comprising an electrically conductive body comprising at least 90 percent by weight of a carbide or boride comprising a metal, the method comprising: placing at least one silicide powder in a chamber, the silicide powder comprising at least 99 weight percent of at least one silicide comprising a metal, sintering the silicide powder in the chamber to cause the silicide powder to form the sintered silicide body.

37. The method of claim 36, comprising: placing the at least one silicide powder in a graphite die and placing the graphite die in the chamber, eliminating oxygen in the chamber, and applying pressure to the silicide powder in the die and passing electric current through the die to increase the temperature of the silicide powder to cause the silicide powder to sinter and form the sintered silicide body.

38. The method of claim 36, wherein said applying pressure is performed using a punch, the method further comprising disposing boron nitride between the punch and the silicide powder prior to applying pressure.H6003.144.111 / 2024P00095US39. The method of claim 36, wherein said electrically conductive body comprises at least 90 percent by weight of ZrC, ZrE or a combination thereof.

40. The method of claim 36, wherein said electrically conductive body comprises at least 90 percent by weight of ZrC or ZrB2.

41. The method of claim 36, wherein the carbide or boride body having a density of at least 95 percent of theoretical density of the carbide or boride.

42. The method of claim 36, wherein the carbide or boride body having a density of at least 98 percent of theoretical density of the carbide or boride.

43. The method of claim 36, wherein the carbide or boride is present in the Nowotny phase.

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