Beryllium oxide base

Abstract

A substrate having a top and a bottom and comprising a beryllium oxide composition containing at least 95 wt% beryllium oxide and optionally fluorine / fluoride ions. The substrate exhibits a clamp pressure of at least 133 kPa at a temperature of at least 600 °C and a bulk resistivity of greater than 1 x 10 5 ohm-m at a temperature of 800 °C. A substrate having a top and a bottom and comprising a beryllium oxide composition containing at least 95 wt% beryllium oxide and optionally fluorine / fluoride ions. The substrate exhibits a clamp pressure of at least 133 kPa at a temperature of at least 600 °C and a bulk resistivity of greater than 1 x 10 5 ohm-m at a temperature of 800 °C. A substrate having a top and a bottom and comprising a beryll

Description

[0001] Divisional application statement

[0002] This application is a divisional application of Chinese invention patent application filed on August 13, 2020, with application number 2020800563537 and invention title "Beryllium Oxide Base".

[0003] Cross-reference to related applications

[0004] This application claims priority to U.S. Provisional Patent Application No. 62 / 887,282, filed August 15, 2019, the entire contents of which are incorporated herein by reference. Technical Field

[0005] This invention relates to ceramic substrates for high-temperature applications. In particular, this invention relates to beryllium oxide-containing substrates for semiconductor manufacturing processes. Background Technology

[0006] In many high-temperature substrate processing applications, substrates are processed in a high-temperature processing chamber for purposes such as etching, coating, cleaning, and / or activating their surface energy. To perform the processing, a processing gas is introduced into the processing chamber, which is then energized to achieve a plasma state. This energization can be accomplished by applying an RF voltage to an electrode (e.g., a cathode) and grounding the anode to create a capacitive field within the processing chamber. The substrate is then treated using the plasma generated within the processing chamber to etch or deposit material thereon.

[0007] In this process, the substrate must be supported (and held in place). In many cases, a ceramic base is used to achieve this. In some instances, an electrostatic chuck assembly (as part of the base) is used to hold the substrate in place. Other support mechanisms are also known, such as mechanical and vacuum. An electrostatic chuck typically comprises electrodes covered by a dielectric. When the electrodes are charged, a reverse electrostatic charge accumulates in the substrate, and the resulting electrostatic force holds the substrate on the electrostatic chuck. Once the substrate is securely held on the chuck, plasma processing continues.

[0008] Some known plasma processes are typically performed at slightly higher temperatures and in highly corrosive gases. For example, the etching of copper or platinum is carried out at temperatures between 250°C and 600°C, compared to 100°C to 200°C for aluminum etching. These temperatures and corrosive gases contribute to the thermal degradation of the materials used to manufacture the chuck. Conventional ceramic substrates employ various oxides, nitrides, and alloys, such as aluminum nitride, alumina, silicon dioxide, silicon carbide, silicon nitride, sapphire, zirconium oxide, or graphite or anodized metals, as the main components. In some cases, these requirements can be met using conventional ceramic materials such as alumina or aluminum nitride.

[0009] However, with technological advancements, higher substrate processing operating conditions (temperatures) are required, such as temperatures above 650°C, 750°C, or 800°C. Unfortunately, conventional ceramic substrate materials have been found to exhibit structural problems at these higher temperatures, such as decomposition, thermal and / or mechanical degradation, pulverization, and delamination.

[0010] Furthermore, it has been found that conventional ceramic substrates exhibit inconsistent temperature uniformity across the substrate surface during operation, possibly due to the inherent properties of aluminum nitride, silicon dioxide, or graphite. This, in turn, leads to inconsistencies that cause problems in the processing of semiconductor wafers. Attempts have been made to improve the temperature uniformity of conventional substrates. However, these attempts involve much more complex heating configurations and control mechanisms, such as increasing the number of heating zones and thermocouples, which increases the cost and uncertainty of the forming process.

[0011] Furthermore, conventional non-beryllium substrates struggle to provide sufficient clamping force (holding pressure) to hold the wafer in place, especially at higher temperatures. Conventional substrates also encounter problems at high temperatures related to microcracks, surface pulverization, (thermal) decomposition, and reduced effusivity. Even at moderate temperatures, conventional substrates exhibit release time (YRGLYGOMRK XMQ I) issues, potentially due to high capacitance.

[0012] Furthermore, many conventional substrates employ layered structures that rely on adhesive bonding, such as the use of brazing materials, or lamination via diffusion bonding to anchor the metal conductor within multiple (ceramic) layers. However, such laminated structures repeatedly suffer from structural problems and delamination, often due to stress from high-temperature operation.

[0013] Additionally, rapid cooling of the substrate may be ideal to maintain the substrate or cleaning pedestal, substrate, or chamber within a narrow temperature range. However, temperature fluctuations occur in high-power plasmas due to the coupling variations in RF energy and plasma ion density across the substrate. These temperature fluctuations can cause rapid increases or decreases in substrate temperature, requiring stabilization. Therefore, it is ideal to have a pedestal that requires little or no cooling during the cleaning process, e.g., a pedestal that can be cleaned at operating temperatures and / or requires little or no cleaning cycle time, which advantageously improves process efficiency (by reducing / eliminating downtime).

[0014] Even considering conventional base technologies, there is still a need for improved base components with enhanced performance, such as reduced decomposition, thermal reduction, reduced microcracks and / or mechanical degradation, improved temperature uniformity and / or better clamping pressure, especially at higher temperatures, such as above 650°C, without exhibiting interlayer delamination. Attached Figure Description

[0015] Figure 1 The graphs show the thermal diffusivity of the embodiments and comparative examples plotted in the temperature range of 0°C to 900°C.

[0016] Figure 2 The graphs show the specific heat of the examples and comparative examples plotted in the temperature range of 0°C to 900°C.

[0017] Figure 3 The graphs show the thermal conductivity of the embodiments and comparative examples plotted in the temperature range of 0°C to 900°C.

[0018] Figure 4 This is a graph showing the heat absorption coefficients of the embodiments and comparative examples plotted in the temperature range of 0°C to 850°C.

[0019] Figure 5 The graphs show the bulk resistivity of the examples and comparative examples plotted in the temperature range of 0°C to 850°C.

[0020] Figure 6 The graphs show the volume resistivity of the embodiments and comparative examples plotted in the temperature range of 0°C to 850°C. Summary of the Invention

[0021] In some embodiments, the present invention relates to a base assembly comprising a shaft and a substrate, the shaft comprising a first beryllium oxide composition containing beryllium oxide and fluorine / fluoride ions (1 ppb to 1000 ppm or 10 ppb to 800 ppm), and the substrate comprising a second beryllium oxide composition containing at least 95 wt% beryllium oxide and optionally fluorine / fluoride ions. The substrate exhibits a clamping pressure of at least 133 kPa and / or greater than 1 x 10⁻⁶ kPa at 800 °C. 5The volume resistivity is measured in ohm-m. The first beryllium oxide composition may contain more fluorine / fluoride ions than the second beryllium oxide composition and may be processed to achieve the required fluorine / fluoride ion concentration. The first beryllium oxide composition may also include: less than 50 wt% magnesium oxide and less than 50 wt% ppm silicon dioxide and / or 1 ppb to 50 wt% aluminum oxide; 1 ppb to 10,000 ppm sulfite; and / or 1 ppb to 1 wt% ppm boron, barium, sulfur, or lithium, or combinations thereof, including oxides, alloys, composites, or allotropes, or combinations thereof. The first beryllium oxide composition may have an average grain boundary size greater than 0.1 micrometers and / or an average grain size less than 100 micrometers. The second beryllium oxide composition may also include 1 ppb to 10 wt% magnesium oxide and 1 ppb to 10 wt% silicon dioxide and / or 1 ppb to 10 wt% ppm magnesium trisilicate and / or 1 ppb to 1 wt% lithium oxide. The first beryllium oxide composition may contain more magnesium oxide and / or magnesium trisilicate than the second beryllium oxide composition. The first beryllium oxide composition may contain less than 75 wt% aluminum nitride and / or the second beryllium oxide composition may contain less than 5 wt% aluminum nitride. The first beryllium oxide composition may have a conductivity of less than 300 W / mK at room temperature and / or may have a theoretical density in the range of 90% to 100%, while the second beryllium oxide composition may have a conductivity of less than 400 W / mK at room temperature. When heated to temperatures above 700°C, the substrate may exhibit a temperature variance of less than ±3°C, and / or a bulk resistivity greater than 1 × 10⁻⁶ at 800°C. 4 The substrate has the following properties: ohm-m, and / or corrosion loss less than 0.016 wt%, and / or dielectric constant less than 20, and / or surface hardness of 45 N or at least 50 Rockwell hardness, and / or coefficient of thermal expansion of the entire substrate of 5 to 15, and / or minimum lateral dimension of at least 100 mm, and / or flatness of less than 50 micrometers camber over a distance of 300 mm. The substrate may also include heating elements encapsulated in the substrate and / or mesa, optionally having a height greater than 1 micrometer. The substrate may contain fewer than two layers of stack and / or no separating layers. The shaft may include a stub portion having a similar coefficient of thermal expansion.

[0022] The present invention also relates to a substrate having a top and a bottom and comprising a beryllium oxide composition containing at least 95 wt% beryllium oxide and optionally fluorine / fluoride ions. The substrate may exhibit a clamping pressure of at least 133 kPa at a temperature of at least 600°C, and / or exhibit a decomposition change of less than 1 wt% at a temperature greater than 1600°C, and / or exhibit a temperature variance of less than ±3% when heated to a temperature above 700°C; and / or greater than 1 x 10⁻⁶ kPa. 8The volume resistivity; and / or corrosion loss less than 0.016 wt%; and / or dielectric constant less than 20; and / or surface hardness of at least 50 Rockwell hardness at a grade of 45 N; and / or volume resistivity greater than 1 x 10⁻⁶ at 800 °C. 5 The substrate may have an ohm-m coefficient of thermal expansion of 5 to 15 over the entire substrate (the coefficient of thermal expansion may vary by less than 25% from top to bottom), and / or a cleaning cycle time of less than 2 hours, and / or a temperature variance of less than ±3%. The substrate may include a beryllium oxide composition comprising 1 ppb to 10 wt% ppm (e.g., 1 ppm to 5 wt%) of magnesium oxide, 1 ppb to 10 wt% ppm (e.g., 1 ppm to 5 wt%) of silicon dioxide, and / or 1 ppb to 10 wt% ppm (e.g., 1 ppm to 5 wt%) of magnesium trisilicate. The substrate may not contain a separation layer and may have a decreasing thermal conductivity gradient from top to bottom; and / or a decreasing resistivity gradient from top to bottom; and / or a decreasing purity gradient from top to bottom; and / or a decreasing theoretical density gradient from top to bottom; and / or an increasing dielectric constant gradient from top to bottom. The substrate may also include heating elements, optionally comprising niobium and / or platinum, and optionally include wound and / or coiled heating elements and / or antennas. The highest purity may be at least 0.4% higher than the lowest purity.

[0023] The present invention also relates to a substrate having a top and a bottom and comprising a beryllium oxide composition, wherein the substrate has: a decreasing thermal conductivity gradient from top to bottom; and / or a decreasing resistivity gradient from top to bottom; and / or a decreasing purity gradient from top to bottom; and / or a decreasing theoretical density gradient from top to bottom; and / or an increasing dielectric constant gradient from top to bottom. When measured at room temperature, the top thermal conductivity of the substrate may be in the range of 125 to 400 W / mK, and the bottom thermal conductivity may be in the range of 146 to 218 W / mK; and / or when measured at 800°C, the top thermal conductivity may be in the range of 25 W / mK to 105 W / mK, and the bottom thermal conductivity may be in the range of 1 W / mK to 21 W / mK, wherein when measured at room temperature, the top thermal conductivity is optionally at least 6% greater than the bottom thermal conductivity; and / or when measured at 800°C, the top thermal conductivity is optionally at least 6% greater than the bottom thermal conductivity. The top purity is in the range of 99.0 to 99.9%, and the bottom purity is in the range of 95.0 to 99.5%. The top purity may be at least 0.4% higher than the bottom purity. The top theoretical density is in the range of 93% to 100%, and the bottom theoretical density is in the range of 93% to 100%. The top theoretical density may be at least 0.5% higher than the bottom theoretical density. The top dielectric constant is in the range of 1 to 20, and the bottom dielectric constant is in the range of 1 to 20. The substrate may not contain a release layer. The substrate may exhibit the above-mentioned clamping pressure, temperature variance, and corrosion loss.

[0024] The present invention also relates to a shaft for a base assembly, the shaft comprising a beryllium oxide composition containing beryllium oxide and (10 ppb to 800 ppm) fluorine / fluoride ions. The beryllium oxide composition has an average grain boundary greater than 0.1 micrometers, and / or an amorphous grain structure, and / or an average grain size less than 100 micrometers, and / or exhibits a thermal conductivity of less than 300 W / mK at room temperature, and / or a theoretical density in the range of 90 to 100. When measured at room temperature, the shaft exhibits a top thermal conductivity in the range of 146 W / mK to 218 W / mK and a bottom thermal conductivity in the range of 1 W / mK to 218 W / mK; and / or when measured at 800°C, a top thermal conductivity between 1 W / mK and 21 W / mK and a bottom thermal conductivity between 1 W / mK and 21 W / mK, with a top theoretical density at least 0.5% greater than the bottom theoretical density. The beryllium oxide composition may include less than 75 wt% aluminum nitride. The first beryllium oxide composition may include: 1 ppb to 1000 ppm fluorine / fluoride ions, and / or less than 50 wt% magnesium oxide, and / or less than 50 wt% ppm silicon dioxide, and / or 1 ppb to 50 wt% ppm aluminum oxide, and / or 1 ppb to 10000 ppm sulfite, and / or 1 ppb to 1 wt% ppm boron, barium, sulfur or lithium, or combinations thereof, including oxides, alloys, composites or allotropes, or combinations thereof.

[0025] The present invention also relates to a base assembly comprising: a shaft of any of the foregoing embodiments, a substrate containing a plurality of layers optionally bonded to each other by brazing material, and an optional printed heating element.

[0026] The present invention also relates to a substrate having a top and a bottom and comprising a ceramic composition, wherein the substrate exhibits: a clamping pressure of at least 133 kPa; a temperature variance of less than ±3% when heated to above 700°C; and / or a bulk resistivity greater than 1 x 10⁻⁶ at 800°C. 8 ; and / or corrosion loss less than 0.016 wt%; and / or dielectric constant less than 20; and / or surface hardness of 45 N grade with a minimum Rockwell hardness of 50; and / or coefficient of thermal expansion of the entire substrate in the range of 5 to 15.

[0027] The present invention also relates to a method of manufacturing a substrate, the method comprising the steps of: providing a first BeO powder and a third BeO powder; forming a second powder from the first powder and the third powder; and forming a first (bottom) region from the first powder;

[0028] A second (middle) region is formed from the second powder; a third (top) region is formed from the third powder to form a substrate precursor, wherein the second region is disposed between the first region and the third region; optionally, the substrate precursor is co-mingled to combine the powders; optionally, a heating element is placed in the crimp of one of these regions and / or a terminal; optionally, the substrate precursor is cold-formed and fired to form a substrate. The first and third (and second) powders may contain different grades of virgin BeO.

[0029] The present invention also relates to a method of manufacturing a base shaft, comprising treating a beryllium oxide composition to achieve a fluorine / fluorine ion concentration in the range of 1 ppb to 1000 ppm fluorine / fluorine ion concentration.

[0030] The present invention also relates to a method for cleaning a contaminated substrate assembly, comprising: providing a substrate assembly and a wafer, the wafer being disposed on the substrate assembly; heating the wafer to a temperature above 600°C; cooling the wafer to a cooling temperature (or without cooling) by less than 100°C; cleaning the assembly at the cooling temperature; optionally reheating the wafer to 600°C; wherein the cleaning cycle time from the cooling step to the reheating step is less than 2 hours. The cleaning cycle time can be between 0 and 10 minutes. Detailed Implementation

[0031] As mentioned above, in processing procedures such as chemical vapor deposition and etching, conventional pedestal assemblies are typically used to support and hold semiconductor substrates in place. Typical ceramic pedestals employ various oxides, nitrides, and alloys, such as aluminum nitride, alumina, silicon dioxide, or graphite, as the main components. These ceramic materials meet the requirements of processing methods at medium to high temperatures (e.g., below 650°C or below 600°C). However, with technological advancements, higher substrate processing operating temperatures are required, such as above 650°C or even above 800°C. Unfortunately, conventional ceramic pedestal materials have been found to exhibit structural problems at these higher temperatures, such as decomposition, thermal degradation and / or mechanical degradation, and delamination. Furthermore, conventional pedestal materials are known to have insufficient bulk resistivity. In some cases, poor resistivity can lead to insufficient clamping / holding forces required to hold the wafer in place, especially at higher temperatures.

[0032] Furthermore, it has been found that conventional ceramic substrates exhibit inconsistent temperature uniformity on the substrate surface, leading to inconsistencies in the processing of semiconductor wafers. Additionally, many conventional layered substrate configurations have been found to be prone to structural problems and delamination, typically caused by stresses from high-temperature operation.

[0033] The inventors have now discovered that using the disclosed beryllium oxide (BeO) compositions (with high purity levels and phase composition contents) yields base assemblies (or base substrates and shaft components) exhibiting a synergistic combination of high-temperature performance and high clamping force (“clamping pressure”), which may be related to resistivity. Without being bound by theory, it is assumed that selectively combining certain specific components of the BeO composition (in some cases, at the disclosed component concentrations) with specific processing parameters results in favorable microstructures in the BeO, such as grain boundaries and grain size, thereby providing a combination of high-temperature performance and high clamping pressure. Furthermore, without being bound by theory, the disclosed BeO compositions yield base substrates with optimal (smaller) amounts of magnesium oxide, silicon dioxide, and / or magnesium trisilicate, which contributes to high bulk resistivity.

[0034] Furthermore, the inventors have discovered that, in some cases, certain combinations of the disclosed beryllium oxide (BeO) compositions with specific processing parameters unexpectedly yielded favorable microstructures (discussed in more detail herein).

[0035] Furthermore, it was found that the components in the BeO composition provide a low dielectric constant, which results in low capacitance and consequently improves the release time delay. The disclosed BeO composition was also found to exhibit improved corrosion resistance, improved thermal endothermic coefficient, improved thermal diffusivity, improved thermal conductivity, improved specific heat, and lower thermal hysteresis, all of which contribute to the synergistic performance disclosed herein.

[0036] Conventional ceramic substrates, such as those made primarily of aluminum nitride, alumina, silicon dioxide, silicon carbide, silicon nitride, sapphire, zirconium oxide, anodized metals, or graphite, can no longer achieve high-temperature performance. They also cannot achieve acceptable clamping pressure at these temperatures—clamping pressure has been found to be depleted / reduced, especially at high temperatures.

[0037] Base assembly

[0038] This document discloses a base assembly. The base assembly includes a substrate disposed on or above a shaft. The shaft contains (and is formed therefrom) a first BeO composition containing BeO and fluoride ions and / or fluorine. The substrate contains (and is formed therefrom) a second BeO composition containing (at a high purity level, e.g., at least 95.0 wt%) BeO and optionally fluoride ions and / or fluorine. In some embodiments, the BeO in the disclosed compositions is synthetic BeO, for example, BeO made from raw materials (powder), which, in contrast to natural BeO, is a solid found in nature. The inventors have found that the use of beryllium oxide as a major component in the compositions (and optionally other components discussed herein) provides or contributes to the performance characteristics discussed herein, such as high-temperature performance and / or excellent clamping pressure.

[0039] In some embodiments, the disclosed base assembly (or its substrate) exhibits a wide range of clamping pressure performance. In some cases, the disclosed base assembly is a Johnsen-Rahbek base. For example, the disclosed base assembly may exhibit clamping pressures greater than 133 kPa, such as greater than 135 kPa, greater than 140 kPa, greater than 145 kPa, or greater than 150 kPa. Up to the upper limit, the base assembly may exhibit clamping pressures less than 160 kPa, such as less than 155 kPa, less than 150 kPa, less than 145 kPa, less than 140 kPa, or less than 135 kPa. In terms of range, the base assembly may exhibit clamping pressures in the range of 133 kPa to 160 kPa, such as 133 kPa to 155 kPa, 133 kPa to 150 kPa, 135 kPa to 150 kPa, 135 kPa to 145 kPa, or 138 kPa to 143 kPa.

[0040] As used herein, the terms “greater than,” “less than,” etc., are considered to include actual numerical limits; for example, they should be understood as “greater than or equal to.” These ranges are considered to include endpoint values.

[0041] In other cases, the disclosed base assembly is a coulombic pedestal. For example, the disclosed base assembly may exhibit a clamping pressure greater than 0.1 kPa, such as greater than 0.5 kPa, greater than 1 kPa, greater than 1.3 kPa, greater than 2 kPa, or greater than 4 kPa. In terms of upper limits, the base assembly may exhibit a clamping pressure less than 15 kPa, such as less than 14 kPa, less than 13 kPa, less than 12 kPa, or less than 10 kPa. In terms of range, the base assembly may exhibit a clamping pressure in the range of 0.1 kPa to 15 kPa, such as 0.5 kPa to 14 kPa, 1 kPa to 14 kPa, 1.3 kPa to 13 kPa, 2 kPa to 12 kPa, or 4 kPa to 10 kPa.

[0042] In other cases, the disclosed base assembly is a partially Johnsen-Rahbek / partial Coulomb base. For example, the disclosed base assembly can exhibit clamping pressures greater than 0.1 kPa, such as greater than 1 kPa, greater than 10 kPa, greater than 13 kPa, greater than 20 kPa, greater than 40 kPa, or greater than 60 kPa. At the upper limit, the base assembly can exhibit clamping pressures less than 160 kPa, such as less than 155 kPa, less than 135 kPa, less than 133 kPa, less than 130 kPa, less than 120 kPa, less than 100 kPa, or less than 80 kPa. In terms of range, the base assembly can exhibit clamping pressures in the range of 0.1 kPa to 160 kPa, for example, 1 kPa to 155 kPa, 1 kPa to 135 kPa, 1 kPa to 133 kPa, 10 kPa to 130 kPa, 13 kPa to 133 kPa, 20 kPa to 120 kPa, 40 kPa to 100 kPa, or 60 kPa to 80 kPa.

[0043] In some embodiments, the disclosed base assembly may exhibit a clamping pressure greater than 0.1 kPa, for example, greater than 1 kPa, greater than 1.3 kPa, greater than 3 kPa, greater than 5 kPa, greater than 10 kPa, or greater than 20 kPa. In terms of upper limits, the base assembly may exhibit a clamping pressure less than 70 kPa, for example, less than 60 kPa, less than 55 kPa, less than 50 kPa, or less than 45 kPa. In terms of range, the base assembly may exhibit a clamping pressure in the range of 0.1 kPa to 70 kPa, for example, 1 kPa to 60 kPa, 1.3 kPa to 55 kPa, 5 kPa to 50 kPa, or 10 kPa to 45 kPa.

[0044] In some embodiments, the disclosed base assembly may exhibit a clamping pressure greater than 70 kPa, for example, greater than 100 kPa, greater than 135 kPa, greater than 150 kPa, greater than 200 kPa, or greater than 250 kPa. In terms of upper limits, the base assembly may exhibit a clamping pressure less than 550 kPa, for example, less than 500 kPa, less than 450 kPa, less than 400 kPa, or less than 350 kPa. In terms of range, the base assembly may exhibit a clamping pressure in the range of 70 to 550 kPa, for example, 100 kPa to 500 kPa, 135 kPa to 450 kPa, 150 kPa to 400 kPa, 200 kPa to 400 kPa, or 250 kPa to 350 kPa.

[0045] Furthermore, specific compositional and processing parameters have been found to cause characteristic gradients in the thickness of the substrate and / or along the length of the substrate axis. Advantageously, these gradients have been found to better distribute the thermal and mechanical stresses present during high-temperature deposition operations (which can eliminate stress risers). Importantly, these gradients are achieved without the need for a separation layer.

[0046] Under more demanding operating conditions, such as temperature, pressure, and / or voltage (compared to conventional base assemblies), the disclosed base assembly unexpectedly achieves the aforementioned clamping pressure. In some embodiments, the base is capable of achieving the aforementioned clamping pressure at temperatures greater than 400°C, for example, greater than 500°C, greater than 600°C, greater than 700°C, or greater than 800°C, and / or at voltages greater than 300V, for example, greater than 400V, greater than 450V, greater than 500V, greater than 550V, greater than 600V, or greater than 650V. In contrast, conventional aluminum nitrate bases have been found to be very ineffective at clamping under harsh operating conditions—in most cases, conventional aluminum nitrate decomposes under these conditions and cannot provide limited (if any) clamping capability.

[0047] axis

[0048] The present invention also relates to shafts. The shafts comprise BeO compositions, such as the first BeO composition described above. Due to their composition and optional processing, the shafts exhibit the excellent performance characteristics and microstructure disclosed herein. In particular, the shafts have an average grain boundary or amorphous grain structure greater than 0.1 micrometers, as discussed herein. In some cases, the shafts have a favorable property gradient along their length (see discussion below).

[0049] The first BeO composition comprises BeO as a major component. The amount of BeO present can be from 50 wt% to 99.9 wt%, for example, 75 wt% to 99.9 wt%, 85 wt% to 99.7 wt%, 90 wt% to 99.7 wt%, or 92 wt% to 99.5 wt%. At the lower limit, the first BeO composition may contain more than 50 wt% BeO, for example, more than 75 wt%, more than 85 wt%, more than 90 wt%, more than 92 wt%, more than 95 wt%, more than 98 wt%, or more than 99 wt%. At the upper limit, the first BeO composition may contain less than 99.9 wt% BeO, for example, less than 99.8 wt%, less than 99.7 wt%, less than 99.6 wt%, less than 99.5 wt%, or less than 99.0 wt%.

[0050] In some embodiments, the first BeO composition, such as the BeO composition of a shaft, comprises fluoride ions and / or fluorine from 1 ppb to 1000 ppm, for example, 10 ppb to 800 ppm, 100 ppb to 500 ppm, 500 ppb to 500 ppm, 1 ppb to 300 ppm, 25 ppm to 250 ppm, 25 ppm to 200 ppm, 50 ppm to 150 ppm, or 75 ppm to 125 ppm. At the lower limit, the first BeO composition may comprise fluoride ions and / or fluorine greater than 1 ppb, for example, greater than 10 ppb, greater than 100 ppb, greater than 500 ppb, greater than 1 ppm, greater than 2 ppm, greater than 50 ppm, or greater than 75 ppm. At the upper limit, the first BeO composition may comprise fluoride ions and / or fluorine less than 1000 ppm, for example, less than 800 ppm, less than 500 ppm, less than 300 ppm, less than 250 ppm, less than 200 ppm, less than 150 ppm, or less than 125 ppm. In some embodiments, the first BeO composition is processed to achieve a fluorine / fluoride ion concentration, for example, by performing a separation operation to achieve the desired fluorine / fluoride ion concentration. In some cases, the desired fluorine / fluoride ion concentration does not occur naturally, requiring such a separation operation. Furthermore, it has been surprisingly found that the disclosed amounts of fluorine / fluoride ions in the BeO composition provide unexpected benefits. It is believed that fluorine / fluoride ions (optionally in the disclosed amounts) contribute to / obtain a microstructure that is surprisingly effective in disrupting phonon wave functions, phonon transport, and / or transport (by scattering).

[0051] In some embodiments, the first BeO composition contains more fluoride ions and / or fluorine than the second BeO composition. The inventors have surprisingly discovered that the difference in fluoride ion and / or fluorine content between the substrate and the shaft is significant, at least due to the aforementioned phonon interruption characteristics. In some embodiments, the first BeO composition contains at least 10% more fluoride ions and / or fluorine than the second BeO composition, for example, at least 20%, at least 30%, at least 50%, at least 75%, or at least 100%.

[0052] In some cases, the first BeO composition further includes magnesium oxide. For example, the first BeO composition may include 1 ppb to 50 wt% ppm of magnesium oxide, such as 100 ppm to 25 wt%, 500 ppm to 10 wt%, 0.1 wt% to 10 wt%, 0.5 wt% to 8 wt%, 0.5 wt% to 5 wt%, 0.7 wt% to 4 wt%, or 0.5 wt% to 3.5 wt%. At the lower limit, the first BeO composition may contain more than 1 ppb of magnesium oxide, such as more than 10 ppb, more than 100 ppm, more than 500 ppm, more than 0.1 wt%, more than 0.5 wt%, more than 0.7 wt%, or more than 1 wt%. At the upper limit, the first BeO composition may include less than 50 wt% of magnesium oxide, such as less than 25 wt%, less than 10 wt%, less than 8 wt%, less than 5 wt%, less than 4 wt%, or less than 3.5 wt%.

[0053] In some specific embodiments, the first BeO composition comprises silica. For example, the first BeO composition may comprise 1 ppb to 50 wt% ppm of silica, such as 100 ppm to 25 wt%, 500 ppm to 10 wt%, 0.1 wt% to 10 wt%, 0.5 wt% to 8 wt%, 0.5 wt% to 5 wt%, 0.7 wt% to 4 wt%, or 0.5 wt% to 3.5 wt%. At the lower limit, the first BeO composition may comprise more than 1 ppb of silica, such as more than 10 ppb, more than 100 ppm, more than 500 ppm, more than 0.1 wt%, more than 0.5 wt%, more than 0.7 wt%, or more than 1 wt%. At the upper limit, the first BeO composition may comprise less than 50 wt% of silica, such as less than 25 wt%, less than 10 wt%, less than 8 wt%, less than 5 wt%, less than 4 wt%, or less than 3.5 wt%.

[0054] The first BeO composition may include magnesium trisilicate. For example, the first BeO composition may include 1 ppb to 5 wt% magnesium trisilicate, such as 1 ppb to 2 wt%, 100 ppm to 2 wt%, 500 ppm to 1.5 wt%, 1000 ppm to 1 wt%, 2000 ppm to 8000 ppm, 3000 ppm to 7000 ppm, or 4000 ppm to 6000 ppm. At the lower limit, the first BeO composition may include more than 1 ppb of magnesium trisilicate, such as more than 1 ppm, more than 100 ppm, more than 500 ppm, more than 1000 ppm, more than 2000 ppm, more than 3000 ppm, or more than 4000 ppm. At the upper limit, the first BeO composition may contain less than 5 wt% magnesium trisilicate, such as less than 2 wt%, less than 1.5 wt%, less than 1 wt%, less than 8000 ppm, less than 7000 ppm, or less than 6000 ppm.

[0055] In some cases, the first BeO composition further includes alumina. For example, the first BeO composition may include 1 ppb to 50 wt% ppm of alumina, such as 100 ppm to 25 wt%, 500 ppm to 10 wt%, 0.1 wt% to 10 wt%, 0.5 wt% to 8 wt%, 0.5 wt% to 5 wt%, 0.7 wt% to 4 wt%, or 0.5 wt% to 3.5 wt%. At the lower limit, the first BeO composition may include more than 1 ppb of alumina, such as more than 10 ppb, more than 100 ppm, more than 500 ppm, more than 0.1 wt%, more than 0.5 wt%, more than 0.7 wt%, or more than 1 wt%. At the upper limit, the first BeO composition may contain less than 50 wt% of alumina, such as less than 25 wt%, less than 10 wt%, less than 8 wt%, less than 5 wt%, less than 4 wt%, or less than 3.5 wt%.

[0056] In some cases, the first BeO composition further includes sulfites. For example, the first BeO composition may include sulfites in the range of 1 ppb to 10,000 ppm, such as 1 ppb to 5,000 ppm, 1 ppm to 2,000 ppm, 10 ppm to 1,500 ppm, 10 ppm to 1,000 ppm, 10 ppm to 500 ppm, 25 ppm to 200 ppm, or 50 ppm to 150 ppm. At the lower limit, the first BeO composition may include sulfites in the range of greater than 1 ppb, such as greater than 1 ppm, greater than 10 ppm, greater than 25 ppm, or greater than 50 ppm. At the upper limit, the first BeO composition may include sulfites in the range of less than 10,000 ppm, such as less than 5,000 ppm, less than 2,000 ppm, less than 1,500 ppm, less than 1,000 ppm, less than 500 ppm, less than 300 ppm, less than 200 ppm, or less than 150 ppm.

[0057] In some cases, the first BeO composition comprises a small amount of non-BeO ceramic, such as oxide ceramic. For example, the first beryllium oxide composition may contain less than 75 wt% of non-BeO ceramic, such as less than 50 wt%, less than 25 wt%, less than 10 wt%, less than 5 wt%, or less than 1 wt%. In terms of range, the first BeO composition may comprise from 1 wt% to 75 wt% of non-BeO ceramic, such as 5 wt% to 50 wt%, 5 wt% to 25 wt%, or 1 to 10 wt%.

[0058] The first BeO composition may also include other components, such as boron, barium, sulfur, or lithium, or combinations thereof, including oxides, alloys, composites, or allotropes, or combinations thereof. The first BeO composition may include these components in amounts ranging from 1 ppb to 1 wt% ppm, for example, 10 ppb to 0.5 wt%, 10 ppb to 1000 ppm, 10 ppb to 900 ppm, 50 ppb to 800 ppm, 500 ppb to 000 ppm, 1 ppm to 600 ppm, 50 ppm to 500 ppm, 50 ppm to 250 ppm, or 50 ppm to 150 ppm. At the lower limit, the first BeO composition may include these components in amounts greater than 1 ppb, for example, greater than 10 ppm, greater than 50 ppb, greater than 100 ppb, greater than 500 ppb, greater than 1 ppm, greater than 50 ppm, greater than 100 ppm, or greater than 200 ppm. In terms of upper limits, the first BeO composition may include less than 1 wt% of these components, for example, less than 0.5 wt%, less than 1000 ppm, for example, less than 900 ppm, less than 800 ppm, less than 700 ppm, less than 600 ppm, less than 500 ppm, less than 250 ppm or less than 150 ppm.

[0059] In some embodiments, the first BeO composition comprises less than 75 wt% of non-BeO ceramics, such as aluminum nitride, for example, less than 50 wt%, less than 25 wt%, less than 10 wt%, less than 5 wt%, less than 3 wt%, or less than 1 wt%. In terms of range, the first BeO composition may comprise 0.01 wt% to 75 wt% of non-BeO ceramics, for example, 0.05 wt% to 50 wt%, 0.05 wt% to 25 wt%, or 0.1 wt% to 10 wt%.

[0060] Other components may also be present, such as aluminum (different from alumina described above), lanthanum, magnesium (other than magnesium oxide or magnesium trisilicate described above), silicon (other than silicon dioxide and magnesium trisilicate described above), or yttrium oxide, or combinations thereof, including oxides, alloys, composites, or allotropes, or combinations thereof. The foregoing scope and limits apply to these additional components.

[0061] Second phase

[0062] In some cases, the shaft and / or substrate comprises a primary phase (first phase) and a secondary phase (second phase). The primary phase comprises the grains of the material, while the secondary phase comprises the material that forms grain boundaries, such as the material between grains. The compositions of the primary and secondary phases can differ from each other. The respective compositions of the secondary phases in the shaft and substrate can affect their performance characteristics, such as thermal conductivity, (theoretical) density, and ability to scatter phonons. Typically, the secondary phase will be a relatively small part of the overall composition of the shaft and / or substrate. In some cases, the shaft will contain more secondary phase than the substrate, for example, at least 5%, at least 10%, at least 25%, or at least 50% more, which contributes to improved component performance.

[0063] In some embodiments, the shaft comprises 0.001 wt% to 50 wt% of a second phase, for example, 0.01 wt% to 25 wt%, 0.01 wt% to 10 wt%, 0.05 wt% to 10 wt%, 0.1 wt% to 10 wt%, 0.1 wt% to 5 wt%, 0.5 wt% to 5 wt%, or 0.5 wt% to 3 wt%. At the upper limit, the shaft may comprise less than 50 wt% of a second phase, for example, less than 25 wt%, less than 10 wt%, less than 5 wt%, less than 3 wt%, or less than 2 wt%. At the lower limit, the shaft may comprise more than 0.001 wt% of a second phase, for example, more than 0.01 wt%, more than 0.05 wt%, more than 0.1 wt%, more than 0.5 wt%, or more than 1 wt%. These weight percentages are calculated based on the total weight of the shaft.

[0064] In some embodiments, the substrate comprises 0.05 wt% to 10 wt% of a second phase, for example, 0.05 wt% to 5 wt%, 0.1 wt% to 5 wt%, 0.1 wt% to 3 wt%, or 0.1 wt% to 1 wt%. At the upper limit, the substrate may comprise less than 10 wt% of a second phase, for example, less than 5 wt%, less than 3 wt%, less than 2 wt%, or less than 1 wt%. At the lower limit, the substrate may comprise more than 0.05 wt% of a second phase, for example, more than 0.1 wt%, more than 0.2 wt%, more than 0.5 wt%, more than 0.7 wt%, or more than 1 wt%. These weight percentages are calculated based on the total weight of the substrate.

[0065] In some cases, the second phase may include non-BeO components. For example, the second phase constituting the first BeO composition of the shaft may include magnesium oxide (MgO), silicon dioxide (SiO2), aluminum oxide, yttrium oxide, titanium dioxide, lithium oxide, lanthanum oxide, or magnesium trisilicate, or mixtures thereof. The first BeO composition (and the shaft made therefrom) includes non-BeO components, each present in an amount ranging from 1 ppb to 500 ppm, for example, 500 ppb to 500 ppm, 1 ppb to 300 ppm, 1 ppm to 200 ppm, 10 ppm to 200 ppm, 50 ppm to 150 ppm, or 75 ppm to 125 ppm. At the upper limit, the first BeO composition may include non-BeO components, each present in an amount less than 500 ppm.

[0066] For example, less than 300 ppm, less than 200 ppm, less than 150 ppm, or less than 125 ppm. With regard to the lower limit, the first BeO composition may include non-BeO components, each present in an amount greater than 1 ppb, for example, greater than 500 ppb, greater than 1 ppm, greater than 10 ppm, greater than 25 ppm, greater than 50 ppm, greater than 75 ppm, or greater than 100 ppm. These weight percentages are calculated based on the total weight of the first BeO composition (e.g., the total weight of the shaft).

[0067] In some specific embodiments, the first BeO composition comprises 1 ppb to 10,000 ppm of second-phase magnesium oxide, for example, 100 ppb to 9,000 ppm, 2,000 ppm to 10,000 ppm, 5,000 ppm to 10,000 ppm, 5,000 ppm to 9,000 ppm, 6,000 ppm to 9,000 ppm, or 7,000 ppm to 8,000 ppm. As a lower limit, the first BeO composition may comprise more than 1 ppb of second-phase magnesium oxide, for example, more than 10 ppb, more than 100 ppb, more than 1 ppm, more than 50 ppm, more than 100 ppm, more than 200 ppm, more than 1,000 ppm, more than 2,000 ppm, more than 3,000 ppm, more than 4,000 ppm, more than 5,000 ppm, more than 6,000 ppm, or more than 7,000 ppm. In terms of upper limits, the first BeO composition may include less than 10,000 ppm of second-phase magnesium oxide, for example, less than 9,000 ppm, less than 8,000 ppm, less than 7,000 ppm, less than 6,000 ppm, less than 5,000 ppm, or less than 4,000 ppm.

[0068] In some specific embodiments, the first BeO composition comprises 1 ppb to 5000 ppm of second-phase silica, for example, 100 ppb to 1000 ppm, 100 ppb to 500 ppm, 1 ppb to 500 ppm, 1 ppm to 100 ppm, 5 ppm to 50 ppm, 1 ppm to 20 ppm, or 2 ppm to 10 ppm. At the lower limit, the first BeO composition comprises more than 1 ppb of second-phase silica, for example, more than 10 ppb, more than 100 ppb, more than 200 ppb, more than 500 ppb, more than 1 ppm, more than 2 ppm, more than 5 ppm, or more than 7 ppm. At the upper limit, the first BeO composition comprises less than 5000 ppm of second-phase silica, for example, less than 1000 ppm, less than 500 ppm, less than 100 ppm, less than 50 ppm, less than 20 ppm, or less than 10 ppm.

[0069] In some specific embodiments, the first BeO composition comprises 1 ppb to 5000 ppm of second-phase alumina, for example, 100 ppb to 1000 ppm, 100 ppb to 500 ppm, 1 ppb to 500 ppm, 1 ppm to 100 ppm, 5 ppm to 50 ppm, 1 ppm to 20 ppm, or 2 ppm to 10 ppm. At the lower limit, the first BeO composition comprises more than 1 ppb of second-phase alumina, for example, more than 10 ppb, more than 100 ppb, more than 200 ppb, more than 500 ppb, more than 1 ppm, more than 2 ppm, more than 5 ppm, or more than 7 ppm. At the upper limit, the first BeO composition comprises less than 5000 ppm of second-phase alumina, for example, less than 1000 ppm, less than 500 ppm, less than 100 ppm, less than 50 ppm, less than 20 ppm, or less than 10 ppm.

[0070] The second phase of the first BeO composition may also include other components such as carbon, calcium, cerium, iron, hafnium, molybdenum, selenium, titanium, yttrium, or zirconium, or combinations thereof, including oxides, alloys, composites, or allotropes, or combinations thereof. These components may also be present in the first phase (and axial phase) of the first BeO composition. For example, the first BeO composition may include these components in amounts ranging from 1 ppb to 5 wt%, such as 10 ppb to 3 wt%, 100 ppb to 1 wt%, 1 ppm to 1 wt%, 1 ppm to 5000 ppm, 10 ppm to 1000 ppm, 50 ppm to 500 ppm, or 50 ppm to 300 ppm. At the upper limit, the presence of these components may be less than 5 wt%, such as less than 3 wt%, less than 1 wt%, less than 5000 ppm, less than 1000 ppm, less than 500 ppm, or less than 300 ppm. As for the lower limit, the presence of these components can be greater than 1 ppb, for example, greater than 10 ppb, greater than 100 ppb, greater than 1 ppm, greater than 10 ppm, or greater than 50 ppm.

[0071] It has been found that a specific composition of the first BeO composition, optionally combined with its processing technology, provides a specific microstructure that is particularly advantageous for high-temperature performance. Without being bound by theory, it is assumed that magnesium oxide, silicon dioxide, and / or magnesium trisilicate inadvertently increase grain boundaries and / or reduce grain size, thereby forming a more thermally limited barrier between grains, such as establishing a barrier choke between grains. This improved microstructure is thought to contribute to improved high-temperature performance. In some embodiments, the average grain boundaries of the first BeO composition are greater than 0.05 micrometers, for example, greater than 0.07 micrometers, greater than 0.09 micrometers, greater than 0.1 micrometers, greater than 0.3 micrometers, greater than 0.5 micrometers, greater than 0.7 micrometers, greater than 1.0 micrometers, greater than 2 micrometers, greater than 4 micrometers, greater than 5 micrometers, greater than 7 micrometers, or greater than 10 micrometers. In terms of range, the average grain boundaries of the first BeO composition are in the range of 0.05 micrometers to 25 micrometers, for example, 0.05 micrometers to 15 micrometers, 0.07 micrometers to 12 micrometers, 0.1 micrometers to 10 micrometers, 0.5 micrometers to 10 micrometers, or 1 micrometer to 7 micrometers. In addition to magnesium oxide, silicon dioxide, and / or magnesium trisilicate, it is assumed that other trace components disclosed herein may further advantageously promote improvement, although perhaps not to the same extent.

[0072] In some embodiments, the average grain size of the BeO composition is less than 100 micrometers, for example, less than 90 micrometers, less than 75 micrometers, less than 60 micrometers, less than 50 micrometers, less than 40 micrometers, less than 35 micrometers, less than 25 micrometers, less than 15 micrometers, less than 10 micrometers, or less than 5 micrometers. In a range, the average grain size of the BeO composition can be in the range of 0.1 micrometers to 100 micrometers, for example, 1 micrometer to 75 micrometers, 1 micrometer to 35 micrometers, 3 micrometers to 25 micrometers, or 5 micrometers to 15 micrometers. This smaller grain size has been found to be beneficial in preventing heat transfer, thereby contributing to or improving high-temperature performance—heat transfer from the plate to the opposite ends of the shaft is limited, which keeps adjacent ends of the substrate and shaft hot, while the opposite ends of the shaft (away from the substrate) remain cold. It is assumed that a specific grain size also has a favorable effect on phonon scattering.

[0073] In some cases, the shaft includes a "short section" (thermal choke section). In some cases, the short section can be a ring or a washer. The short section can be used for the central shaft temperature. The coefficient of thermal expansion is similar to that of the rest of the shaft, for example, within 25%, 20%, 15%, 10%, 5%, 3%, or 1%.

[0074] substrate

[0075] The present invention also relates to a substrate. The substrate has a top and a bottom and comprises a BeO composition, such as the aforementioned second BeO composition. Due to its composition and optional processing methods, the substrate exhibits the excellent performance characteristics disclosed herein. In particular, the substrate exhibits the clamping pressure described herein.

[0076] In some embodiments, the second BeO composition, such as the BeO composition of the substrate, contains a high level of BeO purity. It has been found that the purity level of the beryllium oxide composition used for the substrate (optionally in conjunction with the substrate forming process) advantageously contributes to high-temperature performance. The BeO used for the second BeO composition (or the first BeO composition used for the substance) can be treated to achieve a specific purity level. Furthermore, the substrate has very few separation (lamination) layers, for example, less than 3, less than 2. In some cases, the substrate has no separation layers, which helps to eliminate conventional delamination and degradation problems.

[0077] The amount of BeO present can range from 50 wt% to 99.99 wt%, for example, 75 wt% to 99.95 wt%, 75 wt% to 99.9 wt%, 85 wt% to 99.7 wt%, 90 wt% to 99.7 wt%, or 92 wt% to 99.5 wt%. At the lower limit, the first BeO composition may comprise more than 50 wt% of BeO, for example, more than 75 wt%, more than 85 wt%, more than 90 wt%, more than 92 wt%, more than 95 wt%, more than 98 wt%, or more than 99 wt%. At the upper limit, the first BeO composition may comprise less than 99.99 wt% of BeO, for example, less than 99.95 wt%, less than 99.90 wt%, less than 99.70 wt%, less than 99.50 wt%, or less than 99.0 wt%. In some embodiments, the BeO concentration of the second BeO composition is greater than that of the first BeO composition, for example, by at least 1%, at least 2%, at least 3%, at least 5%, at least 7%, or at least 10%. Alternatively, the substrate BeO composition can be purer than the shaft BeO composition, which is advantageous because it has been found that inherent properties, dielectric properties, and thermal properties are more important on the top of the board than in the shaft.

[0078] Without being bound by theory, it is considered that the synergistic properties of the substrate (or shaft), such as improved high-temperature performance and excellent clamping pressure, are at least partially attributable to the BeO concentration. Conventional substrates (or shafts), such as those comprising non-BeO ceramics (e.g., aluminum nitride, alumina, silica, or graphite) as a major component, have been found not to achieve these properties. In some embodiments, the second BeO composition contains less than 5 wt% of these non-BeO ceramics, for example, less than 3 wt%, less than 1 wt%, less than 0.5 wt%, or less than 0.1 wt%. In terms of range, the second BeO composition may include 0.01 wt% to 5 wt% of non-BeO ceramics, for example, 0.05 wt% to 3 wt%, 0.05 wt% to 1 wt%, or 0.1 wt%.

[0079] The second BeO composition may also include fluoride / fluoride ions. The fluoride / fluoride ions may be present in the amounts described above with respect to the first BeO composition. However, as mentioned above, in some cases, the second BeO composition contains more fluoride ions and / or fluorine than the first BeO composition.

[0080] In some cases, the second BeO composition may also include magnesium oxide, silicon dioxide, and / or magnesium trisilicate. It has been found that the concentrations of these components and their effects on the microstructure (see discussion above) unexpectedly provide substrates exhibiting lower corrosion losses and higher bulk resistivity. The low resistivity (optionally combined with other features) provides improved clamping performance (combined with improved high-temperature performance).

[0081] In some cases, the second BeO composition further includes magnesium oxide. For example, the second BeO composition may include 1 ppb to 10 wt% ppm of magnesium oxide, such as 1 ppb to 5 wt%, 10 ppm to 1 wt%, 100 ppm to 1 wt%, 500 ppm to 8000 ppm, 1000 ppm to 8000 ppm, 3000 ppm to 7000 ppm, or 4000 ppm to 6000 ppm. At the lower limit, the second BeO composition may include more than 1 ppb of magnesium oxide, such as more than 10 ppb, more than 1 ppm, more than 10 ppm, more than 100 ppm, more than 500 ppm, more than 1000 ppm, more than 2000 ppm, more than 3000 ppm, or more than 4000 ppm. At the upper limit, the first BeO composition may include less than 10 wt% of magnesium oxide, such as less than 5 wt%, less than 1 wt%, less than 8000 ppm, less than 7000 ppm, or less than 6000 ppm.

[0082] In some cases, the second BeO composition further includes silicon dioxide, aluminum oxide, yttrium oxide, titanium dioxide, lithium oxide, lanthanum oxide, or magnesium trisilicate, or mixtures thereof. These components may be present in the amounts specified for magnesium oxide in the second BeO composition.

[0083] In some cases, the second BeO composition also contains a small concentration of lithium oxide, for example, 1 ppb to 1 wt%, for example, 100 ppb to 0.5 wt%, 1 ppm to 0.1 wt%, 100 ppm to 900 ppm, 200 ppm to 800 ppm, 300 ppm to 700 ppm, or 400 ppm to 600 ppm. At the lower limit, the second BeO composition may contain more than 1 ppb of lithium oxide, for example, more than 100 ppb, more than 1 ppm, more than 100 ppm, more than 200 ppm, more than 200 ppm, more than 300 ppm, or more than 400 ppm. At the upper limit, the first BeO composition may contain less than 10 wt% of lithium oxide, for example, less than 1 wt%, less than 0.5 wt%, less than 0.1 wt%, less than 900 ppm, less than 800 ppm, less than 700 ppm, or less than 600 ppm.

[0084] The second BeO composition may also include other components such as carbon, calcium, cerium, iron, hafnium, molybdenum, selenium, titanium, yttrium, or zirconium, or combinations thereof, including oxides, alloys, composites, or allotropes, or combinations thereof. These components may also be present in the second phase (and substrate) of the second BeO composition. For example, the second BeO composition may include amounts of these components ranging from 1 ppb to 5 wt%, such as 10 ppb to 3 wt%, 100 ppb to 1 wt%, 1 ppm to 1 wt%, 1 ppm to 5000 ppm, 10 ppm to 1000 ppm, 50 ppm to 500 ppm, or 50 ppm to 300 ppm. At the upper limit, the presence of these components may be less than 5 wt%, such as less than 3 wt%, less than 1 wt%, less than 5000 ppm, less than 1000 ppm, less than 500 ppm, or less than 300 ppm. As for the lower limit, the presence of these components can be greater than 1 ppb, for example, greater than 10 ppb, greater than 100 ppb, greater than 1 ppm, greater than 10 ppm, or greater than 50 ppm.

[0085] In some embodiments, the second BeO composition may further include other components described with respect to the first BeO composition. These compositional ranges and limitations also apply to the second BeO composition.

[0086] In some embodiments, the first beryllium oxide composition contains more magnesium oxide and / or magnesium trisilicate and / or other components than the second beryllium composition. The benefits of these components in terms of microstructure have been discussed above.

[0087] Second phase

[0088] In some cases, the second phase of the second BeO composition may contain non-BeO components. For example, the second phase of the second BeO composition constituting the substrate may include magnesium oxide, silicon dioxide, aluminum oxide, yttrium oxide, titanium dioxide, lithium oxide, lanthanum oxide, or magnesium trisilicate, or mixtures thereof. The second BeO composition (and the substrate made therefrom) includes non-BeO second phase components, each present in an amount ranging from 1 ppb to 500 ppm, for example, 500 ppb to 500 ppm, 1 ppb to 300 ppm, 1 ppm to 200 ppm, 10 ppm to 200 ppm, 50 ppm to 150 ppm, or 75 ppm to 125 ppm. At the upper limit, the first BeO composition may include non-BeO second phase components, each present in an amount less than 500 ppm, for example, less than 300 ppm, less than 200 ppm, less than 150 ppm, or less than 125 ppm. With regard to the lower limit, the second BeO composition may include non-BeO components, each present in an amount greater than 1 ppb, for example, greater than 500 ppb, greater than 1 ppm, greater than 10 ppm, greater than 25 ppm, greater than 50 ppm, greater than 75 ppm, or greater than 100 ppm. These weight percentages are calculated based on the total weight of the first BeO composition (e.g., the total weight of the shaft).

[0089] performance

[0090] In addition to clamping pressure, substrates have been found to exhibit synergistic performance characteristics. For example, substrates can exhibit superior performance in one or more of the following aspects:

[0091] Temperature uniformity

[0092] Volume resistivity

[0093] Corrosion loss

[0094] • Dielectric constant.

[0095] The numerical ranges and limits of these performance characteristics will be described in detail below.

[0096] In some embodiments, the substrate has a uniform coefficient of thermal expansion (CTE) from top to bottom; for example, the CTE does not change from top to bottom. For instance, the change in CTE from top to bottom may be less than 25%, such as less than 20%, less than 15%, less than 10%, less than 7%, less than 5%, less than 3%, or less than 1%.

[0097] In one embodiment, the substrate, such as the pedestal, exhibits a low (if any) cycle cleaning time. During operation, cleaning of the substrate, wafer substrate, and / or chamber may be necessary to remove accumulated overspray. Conventionally, the substrate assembly requires a cooling step, e.g., at least one hour to reach 300°C to achieve a suitable cleaning temperature, followed by an additional heating step, e.g., at least another hour to return to temperature. The wafer must stabilize with temperature changes. Due to the disclosed substrate / substrate composition, cooling (or subsequent reheating) is not required—cleaning can be performed at the operating temperature, cycle cleaning time is minimized (if not eliminated), and the wafer does not need to be (too) stable. In some embodiments, the cycle cleaning time of the substrate / substrate is less than 2 hours, e.g., less than 1.5 hours, less than 1 hour, less than 45 minutes, less than 30 minutes, less than 20 minutes, less than 10 minutes, or less than 5 minutes.

[0098] In some embodiments, the present invention also relates to a method for cleaning a contaminated substrate assembly / wafer / chamber. The method includes the steps of: providing a substrate assembly and a wafer to a chamber, wherein the wafer is disposed on top of the substrate assembly, and heating the wafer to an operating temperature of at least 400°C, at least 450°C, at least 500°C, at least 550°C, at least 600°C, at least 650°C, or at least 700°C. Once at production temperature (if contaminated), the method includes the steps of: cooling the wafer to less than 150°C, for example, less than 100°C, less than 50°C, less than 25°C, or less than 10°C (or no cooling at all for BeO) to a cooling temperature, and cleaning the board at the cooling temperature. In some embodiments, the method further includes the step of reheating the wafer to an operating temperature of at least 400°C, at least 450°C, at least 500°C, at least 550°C, at least 600°C, at least 650°C, or at least 700°C. Importantly, the cleaning cycle time from the cooling step to the reheating step is shorter than that of conventional methods, for example, less than 2 hours, such as less than 1.5 hours, less than 1 hour, less than 45 minutes, less than 30 minutes, less than 20 minutes, less than 10 minutes, or less than 5 minutes. Advantageously, due to the disclosed substrate / base composition, cooling (or subsequent reheating) is not required or is minimized—cleaning can be performed at the operating temperature (or only slightly below the operating temperature), the cycle cleaning time is minimized (if not eliminated), and the wafer does not need to be (too) stable.

[0099] The disclosed substrates may be larger than some conventional substrates, yet still exhibit the excellent performance characteristics described herein. Conventionally, manufacturers strive to produce larger substrates that exhibit suitable characteristics. As is known in the art, maintaining performance and manufacturing substrates become increasingly difficult as substrate size increases. Some reasons include the high CTE values ​​of conventional substrate materials, which detrimentally lead to cracking problems, and size limitations of conventional commercial machinery. In some embodiments, the minimum lateral dimension on the substrate is at least 100 mm, for example, at least 125 mm, at least 150 mm, at least 175 mm, at least 200 mm, at least 225 mm, at least 250 mm, at least 300 mm, at least 400 mm, at least 500 mm, at least 750 mm, or at least 1000 mm.

[0100] In some embodiments, the substrate has a flatness with a curvature of less than 50 micrometers over a distance of 300 mm, for example, less than 40 micrometers, less than 30 micrometers, less than 25 micrometers, less than 15 micrometers, less than 10 micrometers, or less than 5 micrometers.

[0101] In some cases, the substrate also includes mesa (feet). The mesa is used to lift the wafer. In some embodiments, the mesa projects upwards from the top surface of the substrate. The average height of the mesa can range from 1 micrometer to 50 micrometers, for example, 1.5 micrometers to 40 micrometers, 2 micrometers to 30 micrometers, 2 micrometers to 20 micrometers, 2.5 micrometers to 18 micrometers, or 5 micrometers to 15 micrometers. At the lower limit, the average height of the mesa can be greater than 1 micrometer, for example, greater than 1.5 micrometers, greater than 2 micrometers, greater than 2.5 micrometers, greater than 3 micrometers, or greater than 5 micrometers. At the upper limit, the average height of the mesa can be less than 50 micrometers, for example, less than 40 micrometers, less than 30 micrometers, less than 20 micrometers, less than 18 micrometers, or greater than 15 micrometers.

[0102] In some cases, the substrate also includes a heating element encapsulated therein. In some cases, the heating element is a wound or coiled heating element. Compared to conventional substrates employing non-BeO ceramics and / or other types of heating elements, the combination of BeO composition and / or wound or coiled heating elements unexpectedly provides improved temperature uniformity (see discussion below).

[0103] The substrate may also include other hardware, such as antennas. These features will be discussed in more detail below. In some cases, the antenna and / or heating element comprises niobium and / or platinum and / or titanium. The inventors have found that niobium and / or platinum and / or titanium, when used with BeO compositions, provide unexpected performance in terms of synergistic effects on coefficients of thermal expansion, corrosion resistance, and electrical resistance. In some cases, when these metals are used as hardware, they possess thermal compatibility factors that work well with BeO materials. These thermal compatibility factors have been found to prevent stress-induced failure, for example, due to temperature cycling.

[0104] Substrate gradient concept / performance

[0105] The present invention also relates to substrates designed to have various property gradients from top to bottom. These substrates can be manufactured by the following steps: forming precursors using multiple powders, each with different properties, and then heating the precursors to form a substrate with property gradients. Importantly, the resulting substrates have no delamination layers, which provides advantages over layered substrate assemblies.

[0106] In some embodiments, the substrate is made of two or more grades of virgin BeO powder. In one embodiment, the top surface includes a first grade, the bottom includes a second grade, and the central region includes a mixture of the first and second grades. For example, the first grade may be a material with higher purity / higher thermal conductivity / higher (theoretical) density / lower porosity, and the second grade may be a material with lower purity / lower thermal conductivity / lower (theoretical) density / higher porosity. Of course, various other amounts and combinations of virgin BeO powder are also considered.

[0107] The substrate may exhibit one or more of the following desired performance gradients.

[0108] • Decreasing thermal conductivity gradient from top to bottom

[0109] • Resistivity gradient decreasing from top to bottom

[0110] • Purity gradient decreasing from top to bottom

[0111] Theoretical density gradient decreasing from top to bottom

[0112] • A dielectric constant gradient that increases from top to bottom.

[0113] Each of these performance gradients has a “top value” measured at the top of the plate and a “bottom value” measured at the bottom of the plate. The endpoints of the ranges in this paper can be used as upper and lower limits. For example, the 231 to 350 W / mK range can be given an upper limit of less than 350 W / mK and a lower limit of 231 W / mK.

[0114] Thermal conductivity: In some embodiments, when measured at room temperature, the substrate has a top thermal conductivity in the range of 125 to 400 W / mK, for example, 231 to 350 W / mK, 250 to 350 W / mK, 265 to 335 W / mK, or 275 to 325 W / mK. When measured at room temperature, the substrate has a bottom thermal conductivity in the range of 146 to 218 W / mK, for example, 150 to 215 W / mK, 160 to 205 W / mK, 165 to 200 W / mK, or 170 to 190 W / mK. At the upper limit, the substrate may have a thermal conductivity of less than 400 W / mK at room temperature, for example, less than 375 W / mK, less than 350 W / mK, less than 300 W / mK, less than 275 W / mK, less than 255 W / mK, or less than 250 W / mK.

[0115] When measured at 800°C, the substrate may have a top thermal conductivity in the range of 25 to 105 W / mK, such as 35 to 95 W / mK, 45 to 85 W / mK, or 55 to 75 W / mK. When measured at 800°C, the substrate may have a bottom thermal conductivity in the range of 1 to 21 W / mK, such as 3 to 20 W / mK, 5 to 15 W / mK, 7 to 13 W / mK, or 9 to 11 W / mK.

[0116] Generally, the thermal conductivity at the bottom will be lower than that at the top. When measured at room temperature or 800°C, or regardless of the measurement temperature, the thermal conductivity at the top may be at least 6% greater than that at the bottom, for example, at least 10%, at least 20%, at least 35%, at least 50%, at least 100%, or at least 200%.

[0117] Resistivity: In some cases, the top resistivity at room temperature is 1 x 10⁻⁶. 5 Up to 1x 10 16 Within the ohm-m range, for example, 1 x 10 6 Up to 1x 10 16 1x10 7 Up to 5x 10 15 1x10 8 Up to 1x 10 15 , or 1x 10 9 Up to 1x 10 15 The bottom resistivity can be less than the top resistivity. The bottom resistivity can be 1 x 10⁻⁶. 5 Up to 1x 10 16 Within the ohm-m range, for example, 1x10 5 Up to 1x 10 15 1x10 5 Up to 5x 10 14 1x10 6 Up to 1x 10 13, or 1x 10 7 Up to 5x 10 12 .

[0118] In these cases, the top resistivity is greater than the bottom resistivity. Typically, the bottom resistivity will be less than the top resistivity, by at least 150%, at least 200%, at least 250%, at least 300%, at least 500%, or at least 1000%.

[0119] Purity: In some embodiments, the top purity is in the range of 99.0% to 99.9%, for example, 99.1% to 99.9%, 99.4% to 99.8%. The bottom purity may be in the range of 95.0% to 99.5%, for example, 95.5% to 99.5%, 96% to 99.5%, or 96.5% to 98.5%. Generally, the bottom purity will be lower than the top purity by at least 0.2%, at least 0.4%, at least 0.5%, or at least 1.0%.

[0120] Theoretical density: In some cases, the top theoretical density may be in the range of 93 to 200, such as 94 to 100, 95 to 100, 96 to 99.5, or 97 to 99. The bottom theoretical density may be in the range of 93 to 100, such as 94 to 99.5, 95 to 99, or 96 to 98. Generally, the bottom theoretical density will be less than the top theoretical density. The top theoretical density may be at least 0.1% greater than the bottom theoretical density, such as at least 0.2%, at least 0.4%, at least 0.5%, or at least 1.0%.

[0121] The theoretical density of the substrate can be similar to that of the shaft. In some cases, the theoretical density of the shaft is less than that of the substrate, and / or the porosity of the shaft is greater than that of the substrate.

[0122] Grain size: In some cases, the top (maximum) grain size can range from 5 to 60 micrometers, for example, 10 to 50 micrometers, 15 to 45 micrometers, or 20 to 40 micrometers. The bottom (maximum) grain size can range from 10 to 100 micrometers, for example, 20 to 90 micrometers, 25 to 85 micrometers, or 30 to 80 micrometers. Generally, the bottom (maximum) grain size will be larger than the top grain size. The top grain size can be at least 0.1% smaller than the bottom grain size, for example, at least 0.2%, at least 0.4%, at least 0.5%, or at least 1.0%.

[0123] Grain boundaries: In some cases, grain boundaries are typically in the range of amorphous to 10 micrometers, for example, 1 to 9 micrometers, 2 to 8 micrometers, or 3 to 7 micrometers. In some cases, the bottom grain boundary will be smaller than the top grain boundary. In other embodiments, the top grain boundary will be smaller than the bottom grain boundary.

[0124] Specific heat: In some embodiments, when measured at room temperature, the substrate has a top specific heat in the range of 0.9 to 1.19 J / gK, for example, 0.95 to 1.15 J / gK, or 1.0 to 1.1 J / gK. When measured at room temperature, the substrate may have a bottom specific heat in the range of 0.9 to 1.19 J / gK, for example, 0.95 to 1.15 J / gK, or 1.0 to 1.1 J / gK.

[0125] When measured at 800°C, the substrate may have a top specific heat in the range of 1.8 to 2.06 J / gK, for example, 1.85 to 2.03 J / gK, or 1.87 to 1.97 J / gK. When measured at 800°C, the substrate may have a bottom specific heat in the range of 1.8 to 2.03 J / gK, for example, 1.85 to 2.03 J / gK, or 1.87 to 1.97 J / gK.

[0126] Generally, the specific heat at the bottom will be less than that at the top. When measured at room temperature or 800°C, or regardless of the measurement temperature, the specific heat at the top may be at least 0.5% greater than that at the bottom, for example, at least 1%, at least 2%, at least 5%, at least 5%, at least 10%, or at least 20%.

[0127] Thermal diffusivity: In some embodiments, when measured at room temperature, the substrate has a thermal diffusivity of 90 to 115 mm. 2 Top thermal diffusivity in the range of / second, for example, 95 to 110 mm 2 / second or 97 to 108 mm 2 / second. When measured at room temperature, the substrate can have a thickness of 58 to 115 mm. 2 Bottom thermal diffusivity in the range of / second, for example, 65 to 105 mm 2 / second, or 75 to 95 mm 2 / Second.

[0128] When measured at 800°C, the substrate can have a thickness of 5 to 21 mm. 2 Top thermal diffusivity in the range of / second, for example, 7 to 19 mm 2 / second, 9 to 17mm 2 / second or 10 to 15mm 2 / second. When measured at 800°C, the substrate can have a thickness of 3 to 7.7 mm. 2 Bottom thermal diffusivity in the range of / second, for example, 3.5 to 7 mm. 2 / second, or 4 to 6 mm 2 / Second.

[0129] Generally, the thermal diffusivity at the bottom will be less than the specific heat at the top. When measured at room temperature or 800°C, or regardless of the measurement temperature, the thermal diffusivity at the top may be at least 0.5% greater than the thermal diffusivity at the bottom, for example, at least 1%, at least 2%, at least 5%, at least 5%, at least 10%, or at least 20%.

[0130] Heat absorption coefficient: In some embodiments, when measured at room temperature, the substrate may have a heat absorption coefficient between 22.0 and 30.02S. 0.5 W / K / km 2 The top endothermic coefficient is within the range, for example, 24.0 to 30.02S. 0.5 W / K / km 2 25.0 to 29.0

[0131] S 0.5 W / K / km 2 or 26.0 to 28.0 seconds. 0.5 W / K / km 2 When measured at room temperature, the substrate can have a temperature range of 1.0 to 25.0 s. 0.5 W / K / km 2 The bottom heat absorption coefficient is within the range, for example, 3.0 to 24.0 S. 0.5 W / K / km 2 Or 5.0 to 23.0 seconds 0.5 W / K / km 2 In some embodiments, the substrate has a strength greater than 22.0S. 0.5 W / K / km 2 The (top) heat absorption coefficient, for example, is greater than 23.0S. 0.5 W / K / km 2 greater than 24.0s 0.5 W / K / km 2 Greater than 25.0 seconds 0.5 W / K / km 2 Greater than 27.0 seconds 0.5 W / K / km 2 Greater than 28.0 seconds 0.5 W / K / km 2 or greater than 30.0 seconds 0.5 W / K / km 2 .

[0132] When measured at 800°C, the substrate can exhibit a strength ranging from 11.0 to 16.4 s. 0.5 W / K / km 2 The top endothermic coefficient is within the range, for example, 12.0 to 15.0S. 0.5 W / K / km 2 12.5 to 14.5 seconds 0.5 W / K / km2 Or 13.0 to 14.0 seconds 0.5 W / K / km 2 When measured at 800°C, the substrate can exhibit a temperature range of 0.1 to 12.0 s. 0.5 W / K / km 2 The bottom heat absorption coefficient is within the range, for example, 0.5 to 11.0 S. 0.5 W / K / km 2 , or 1.0 to 10.0S 0.5 W / K / km 2 In some embodiments, the substrate has a density greater than 14.0S. 0.5 W / K / km 2 The (top) heat absorption coefficient, for example, is greater than 15.0S. 0.5 W / K / km 2 Greater than 16.0s 0.5 W / K / km 2 Greater than 17.0s 0.5 W / K / km 2 Greater than 18.0 seconds 0.5 W / K / km 2 Greater than 19.0s 0.5 W / K / km 2 or greater than 20.0s 0.5 W / K / km 2 Improvements in the endothermic coefficient can also be observed at other temperatures, for example, as shown in the examples.

[0133] Generally, the heat absorption coefficient at the bottom will be less than that at the top. When measured at room temperature or 800°C, or regardless of the measurement temperature, the heat absorption coefficient at the top can be at least 0.5% greater than that at the bottom, for example, at least 1%, at least 2%, at least 5%, at least 5%, at least 10%, or at least 20%.

[0134] Average CTE: In some embodiments, the substrate has a top average CTE in the range of 7.0 to 9.5, for example, 7.2 to 9.3, 7.5 to 9.0, or 7.7 to 8.8. The substrate may have a bottom average CTE in the range of 7.0 to 9.5, for example, 7.2 to 9.3, 7.5 to 9.0, or 7.7 to 8.8. In some cases, the bottom average CTE will be less than the top average CTE. In other cases, the bottom average CTE will be greater than the top average CTE. When measured at room temperature or 800°C, or regardless of the measurement temperature, this difference may be at least 0.5%, for example, at least 1%, at least 2%, at least 5%, at least 10%, or at least 20%.

[0135] In some implementations, the top dielectric constant is in the range of 1 to 20, for example, to 15, 3 to 12, or 5 to 9. The bottom dielectric constant may be similar to the top dielectric constant. In some cases, the bottom dielectric constant may be greater than the top dielectric constant. In other cases, the top dielectric constant may be greater than the bottom dielectric constant.

[0136] The BeO compositions described herein can be used to form substrates with desired performance gradients, which in some cases can be achieved by modifying the compositional parameters of these BeO compositions. Furthermore, the substrates can also exhibit other performance characteristics, such as clamping pressure, corrosion loss, temperature uniformity, etc., as disclosed herein.

[0137] Axial gradient concept / performance

[0138] In some embodiments, when measured at room temperature, the shaft has a top thermal conductivity in the range of 146 W / mK to 218 W / mK, for example, 150 W / mK to 215 W / mK, 160 W / mK to 205 W / mK, 165 W / mK to 200 W / mK, or 170 W / mK to 190 W / mK. When measured at room temperature, the shaft has a bottom thermal conductivity in the range of 1 W / mK to 218 W / mK, for example, 50 W / mK to 218 W / mK, 100 W / mK to 218 W / mK, 146 W / mK to 218 W / mK, 150 W / mK to 215 W / mK, 160 W / mK to 205 W / mK, 165 W / mK to 200 W / mK, or 170 W / mK to 190 W / mK.

[0139] When measured at 800°C, the shaft may have a top thermal conductivity in the range of 1 to 21, for example, 3 to 20, 5 to 15, 7 to 13, or 9 to 11. When measured at 800°C, the shaft may have a bottom thermal conductivity in the range of 1 to 21, for example, 3 to 20, 5 to 15, 7 to 13, or 9 to 11.

[0140] Generally, the bottom thermal conductivity will be less than the top thermal conductivity. When measured at room temperature or 800°C, or regardless of the measurement temperature, the top thermal conductivity may be at least 6% greater than the bottom thermal conductivity, for example, at least 10%, at least 20%, at least 35%, at least 50%, at least 100%, or at least 200%. In some cases, the gradient may be non-linear, such as a step function or a maximum integer function. In other cases, the gradient may be linear.

[0141] General performance

[0142] The substrate and shaft also exhibit excellent performance figures, generally without considering gradients. In some cases, generally or overall, the performance range and limits of the substrate may be similar to the “top values” and / or “bottom values” discussed above. These will not be repeated for the sake of brevity. Additional performance ranges and limits are also provided.

[0143] Thermal diffusivity: In some embodiments, when measured at room temperature, the substrate has a thermal diffusivity of 75 to 115 mm. 2 (Top) thermal diffusivity in the range of / second, for example, 90 to 115 mm 2 / second, 95 to 110 mm 2 / second or 97 to 108 mm 2 / second. When measured at room temperature, the substrate can have a thickness of 58 to 115 mm. 2 Bottom thermal diffusivity in the range of / second, for example, 65 to 105 mm. 2 / second, or 75 to 95 mm 2 / second. In some embodiments, the substrate has a diameter greater than 75mm. 2 (Top) thermal diffusivity per second, for example, greater than 80 mm. 2 / second, greater than 85mm 2 / second, greater than 90mm 2 / second, greater than 95mm 2 / second, greater than 100mm 2 / second or greater than 110mm 2 / Second.

[0144] When measured at 800°C, the substrate can have a thickness of 5 to 21 mm. 2 Top thermal diffusivity in the range of / second, for example, 7 to 19 mm 2 / second, 9 to 17mm 2 / second or 10 to 15mm 2 / second. When measured at 800°C, the substrate can have a thickness of 3 to 7.7 mm. 2 Bottom thermal diffusivity in the range of / second, for example, 3.5 to 7 mm. 2 / second, or 4 to 6 mm 2 / second. In some embodiments, the substrate has a diameter greater than 5mm. 2 (Top) thermal diffusivity per second, for example, greater than 10 mm. 2 / second, greater than 12mm 2 / second, greater than 14mm 2 / second, greater than 15mm 2 / second or greater than 20mm 2 / second. Improved thermal diffusivity can also be observed at other temperatures, for example, as shown in the examples.

[0145] Specific heat: In some embodiments, when measured at room temperature, the substrate has a top specific heat in the range of 0.7 to 1.19 J / gK, for example, 0.9 to 1.19 J / gK, 0.95 to 1.15 J / gK, or 1.0 to 1.1 J / gK. When measured at room temperature, the substrate may have a bottom specific heat in the range of 0.9 to 1.19 J / gK, for example, 0.95 to 1.15 J / gK, or 1.0 to 1.1 J / gK. In some embodiments, the substrate has a (top) specific heat greater than 0.7 J / gK, for example, greater than 0.8 J / gK, greater than 0.9 J / gK, greater than 0.95 J / gK, or greater than 1.0 J / gK.

[0146] When measured at 800°C, the substrate may have a top specific heat in the range of 1.0 to 2.06 J / gK, for example, 1.8 to 2.06 J / gK, 1.85 to 2.03 J / gK, or 1.87 to 1.97 J / gK. When measured at 800°C, the substrate may have a bottom specific heat in the range of 1.8 to 2.03 J / gK, for example, 1.85 to 2.03 J / gK, or 1.87 to 1.97 J / gK. In some embodiments, the substrate has a (top) specific heat greater than 1.0 J / gK, for example, greater than 1.5 J / gK, greater than 1.7 J / gK, greater than 1.8 J / gK, or greater than 1.85 J / gK. Improvements in specific heat may also be observed at other temperatures, for example, as shown in the examples.

[0147] Thermal conductivity: In one embodiment, the second beryllium oxide composition (and the substrate) generally has a thermal conductivity of less than 400 W / mK at room temperature, for example, less than 375 W / mK, less than 350 W / mK, less than 300 W / mK, less than 275 W / mK, less than 255 W / mK, or less than 250 W / mK. In terms of range, the second beryllium oxide composition has a thermal conductivity in the range of 125 W / mK to 400 W / mK, for example, 145 W / mK to 350 W / mK, 175 W / mK to 325 W / mK, or 200 W / mK to 300 W / mK. In some embodiments, the substrate has a (top) thermal conductivity greater than 125 W / mK, for example, greater than 150 W / mK, greater than 175 W / mK, greater than 200 W / mK, greater than 250 W / mK, or greater than 255 W / mK. Thermal conductivity can be measured at the top of the substrate.

[0148] In one embodiment, the second beryllium oxide composition (and the substrate) generally has a thermal conductivity of less than 150 W / mK at 800°C, for example, less than 105 W / mK, less than 95 W / mK, less than 85 W / mK, or less than 75 W / mK. In terms of range, when measured at 800°C, the second beryllium oxide composition has a thermal conductivity in the range of 25 to 105 W / mK, for example, 35 to 95 W / mK, 45 to 85 W / mK, or 55 to 75 W / mK. The thermal conductivity can be measured at the top of the substrate. In some embodiments, the substrate has a (top) thermal conductivity greater than 25 W / mK, for example, greater than 30 W / mK, greater than 35 W / mK, greater than 40 W / mK, greater than 42 W / mK, or greater than 45 W / mK. Improvements in thermal conductivity can also be observed at other temperatures, for example, as shown in the examples. The thermal conductivity can be measured at the top of the substrate.

[0149] Thermal conductivity of the shaft: In some embodiments, the first beryllium oxide composition (and the shaft) generally has a thermal conductivity of less than 300 W / mK at room temperature, for example, less than 275 W / mK, less than 250 W / mK, less than 225 W / mK, less than 220 W / mK, less than 218 W / mK, or less than 210 W / mK. In terms of range, the first beryllium oxide composition has a thermal conductivity in the range of 100 W / mK to 300 W / mK, for example, 125 W / mK to 275 W / mK, 125 W / mK to 250 W / mK, or 140 W / mK to 220 W / mK. In some embodiments, the shaft has a (top) thermal conductivity greater than 125 W / mK, for example, greater than 150 W / mK, greater than 175 W / mK, greater than 200 W / mK, greater than 250 W / mK, or greater than 255 W / mK. Thermal conductivity can be measured at the top of the substrate. Thermal conductivity can be measured at the top of the shaft.

[0150] In some cases, the first beryllium oxide composition (and substrate) generally has a thermal conductivity of less than 25 W / mK at 800°C, for example, less than 23 W / mK, less than 21 W / mK, less than 20 W / mK, less than 15 W / mK, less than 10 W / mK, or less than 5 W / mK. In terms of range, when measured at 800°C, the second beryllium oxide composition has a thermal conductivity in the range of 1 to 5 W / mK, for example, 2 to 23 W / mK, 4 to 21 W / mK, or 5 to 20 W / mK. In some embodiments, the shaft has a (top) thermal conductivity greater than 25 W / mK, for example, greater than 30 W / mK, greater than 35 W / mK, greater than 40 W / mK, greater than 42 W / mK, or greater than 45 W / mK. Improvements in thermal conductivity may also be observed at other temperatures, for example, as shown in the examples. The thermal conductivity can be measured at the top of the substrate.

[0151] Theoretical density of the shaft: In some embodiments, the first BeO composition (and the shaft) generally has a theoretical density in the range of 90 to 100, for example, 92 to 100, 93 to 99, 95 to 99, or 97 to 99. At the lower limit, the shaft has a theoretical density greater than 90, for example, greater than 92, greater than 93, greater than 95, or greater than 97. At the upper limit, the shaft has a theoretical density less than 100, for example, less than 99.5, less than 99, less than 98.7, or less than 98. It is assumed that the desired theoretical density and porosity can be derived from the microstructural characteristics provided by the first BeO composition, such as grain boundaries and grain size.

[0152] In some embodiments, the substrate exhibits a strength greater than 1 x 10⁻⁶ at 800°C. 4 The volume resistivity of ohm-m, for example, greater than 5 x 10⁻⁶. 4 Greater than 1 x 10 5 Greater than 5 x 10 5 Greater than 1 x 10 6 Greater than 5 x 10 6 Greater than 1 x 10 7 Greater than 5 x 10 7 Greater than 1 x 10 8 Greater than 5 x 10 8 Greater than 1 x 10 9 or greater than 1 x 10 10 This resistivity at least partially provides improved clamping performance.

[0153] The inventors have discovered that a lower axial density / more pores in the substrate may be advantageous. The microstructure of each BeO composition has been adjusted accordingly, as disclosed herein. This configuration is considered to surprisingly avoid heat sink effects (causing cold spots) and / or

[0154] Or it avoids deformation (melting) of the original plate / shaft seal.

[0155] The theoretical density of the base component is an important characteristic. In some cases, theoretical density (and / or porosity) affects or contributes to thermal conductivity.

[0156] Porosity has been found to advantageously delay the propagation of microcracks. In some embodiments, the substrate and / or shaft has a porosity ranging from 0.1% to 10%, for example, 0.5% to 8%, 1% to 7%, 1% to 5%, or 2% to 4%. At the upper limit, the substrate and / or shaft may have a porosity of less than 10%, for example, less than 9%, less than 8%, less than 7%, less than 6%, less than 5%, less than 4%, less than 3%, less than 2%, or less than 1%. At the lower limit, the substrate and / or shaft may have a porosity greater than 1%, for example, greater than 2%, greater than 3%, greater than 4%, greater than 5%, greater than 6%, greater than 7%, greater than 8%, or greater than 9%.

[0157] The second BeO composition advantageously contributes to uniform temperature performance on the substrate, especially at higher temperatures. This temperature uniformity is not achieved using conventional non-BeO ceramics. In some embodiments, when heated to temperatures above 700°C (e.g., above 750°C, above 800°C, or 850°C), the substrate exhibits a temperature variance of less than ±3%, for example, less than ±2.5%, less than ±2%, less than ±1%, or less than ±0.5%. The temperature can be measured on the top surface of the plate, as is known in the art, for example by thermocouples, IR, or TCR devices.

[0158] In some cases, the substrate may exhibit corrosion loss of less than 0.016 wt%, for example, less than 0.015 wt%, less than 0.013 wt%, less than 0.012 wt%, less than 0.010 wt%, less than 0.008 wt%, or less than 0.005 wt% after 200 cycles. Corrosion loss can be measured by measuring the weight of the sample before and after cycling according to a test protocol, for example, 200 cycles (5.5 hours) in NF3 at 400 °C and 4 cycles (12 hours) in ClF at 300 °C.

[0159] In some cases, the substrate may exhibit a decomposition change of less than 1 wt% at temperatures greater than 1600°C, for example, less than 0.1 wt% or less than 0.005 wt%. Decomposition can be defined as the breakdown of its precursor components (in some cases, separation), such as a chemical change. It has been found that the disclosed substrate advantageously has improved softening and decomposition points. In some embodiments, the substrate has a softening point greater than 1600°C, for example, greater than 1700°C, greater than 1750°C, greater than 1800°C, greater than 1850°C, greater than 1900°C, or greater than 2000°C. In some embodiments, the substrate (in nitrogen) has a melting point greater than 2200°C, for example, greater than 2325°C, greater than 2350°C, greater than 2400°C, or greater than 2450°C. Unlike conventional substrates, the disclosed substrate is capable of providing the aforementioned clamping pressures at these temperatures. Conventional substrates, such as aluminum nitride substrates, decompose at temperatures below 1600°C and melt at temperatures below 2200°C.

[0160] In some embodiments, the substrate has a dielectric constant of less than 20, for example, less than 17, less than 15, less than 12, less than 10, less than 8, or less than 7.

[0161] In some cases, the surface hardness of the substrate, measured on a 45N scale, is at least 50 Rockwell hardness, for example, at least 50 Rockwell hardness, at least 52 Rockwell hardness, at least 55 Rockwell hardness, at least 57 Rockwell hardness, at least 60 Rockwell hardness, at least 65 Rockwell hardness, or at least 70 Rockwell hardness.

[0162] In some embodiments, the substrate has a coefficient of thermal expansion in the range of 5 to 15 throughout the substrate, for example, 6 to 13, 6.5 to 12, 7 to 9.5, 7.5 to 9, or 7 to 9. At the upper limit, the substrate may have a coefficient of thermal expansion greater than 5, for example, greater than 6, greater than 6.5, greater than 7, or greater than 7.5. At the upper limit, the substrate may have a coefficient of thermal expansion less than 15, for example, less than 13, less than 12, less than 9.5, or less than 9. The variation in coefficient of thermal expansion from top to bottom is less than 25%, for example, less than 10%, less than 5%, less than 3%, or less than 1%.

[0163] Base component assembly

[0164] The disclosed substrate and shaft can be used in combination with each other. Alternatively, these components can be used in combination with other components known in the art. For example, the disclosed substrate can be used with a conventional shaft, or the disclosed shaft can be used with a conventional substrate.

[0165] In some embodiments, the base assembly includes the disclosed shaft and a substrate comprising two or more (laminated) layers and / or co-fired ceramic material. These layers may be bonded together with a brazing material. Examples of such substrates are those disclosed in U.S. Patent Nos. 7,667,944 and 5,737,178, which are incorporated herein by reference. In addition to the shaft and substrate, these assemblies may include additional hardware such as heating elements, antennas, etc.

[0166] The present invention also relates to a method of manufacturing a substrate. The substrate may be made from two or more grades of virgin BeO powder. The BeO powder may be used to form a precursor plate, which is then sintered into the substrate. In one embodiment, the top surface comprises a first grade, the bottom comprises a second grade, and the central region comprises a mixture of the first and second grades. Of course, various other amounts and combinations of virgin BeO powder are also contemplated.

[0167] In one embodiment, the method includes the steps of: providing a first BeO powder and a third BeO powder, and forming a second powder from the first powder and the third powder. The first powder and the second powder may include different grades of raw BeO. The method may also include forming a first (bottom) region from the first powder, a second (middle) region from the second powder, and a third (top) region from the third powder to form a substrate precursor. This molding can be achieved by dispensing the corresponding powders into a mold in a predetermined order. The second region may be disposed between the first region and the third region. Additional regions formed from additional powder may also be formed in different configurations. The method may also include the step of firing the substrate precursor to form a substrate.

[0168] Importantly, in some cases, once the precursor is formed, it can be blended, for example by vibration (optionally under controlled conditions), to allow the powder to be partially blended or bonded, which can provide a compositional gradient after firing. Partial blending is important for maintaining the compositional gradient. In some cases, insufficient blending or no blending at all can result in a truly delamination of the substrate, which may not achieve all the benefits described herein. Over-blending can result in a homogeneous mixture of BeO powder without any desired compositional gradient.

[0169] The method may further include placing a heating element in the crimp of at least one and / or terminal in these regions. The method also includes a cold forming step followed by firing (sintering) the substrate precursor to form the substrate.

[0170] A similar method can be used to manufacture shafts.

[0171] Some embodiments relate to methods of manufacturing a base assembly. The method includes providing a disclosed substrate and a disclosed shaft, and attaching the shaft to the substrate.

[0172] Example

[0173] Examples 1-4 and Comparative Example AC

[0174] Examples 1-4 used samples (coupons) prepared from various BeO grades, while Comparative Example AC used samples prepared from various AlN grades, as shown in Table 1. Samples were machined from large ceramic blocks using standard abrasive diamond grinding and cleaning methods.

[0175]

[0176] *Other components may exist in trace amounts.

[0177] The dimensions of the specimens conform to various ASTM standards, as shown in Table 2.

[0178]

[0179] Thermal diffusivity was tested for Examples 1-4 and Comparative Example AC. Thermal diffusivity was measured using a NETZSCH LFA 467HT Hyperflash according to ASTM E 1461-13 (2013). Half-rise time was greater than 10 ms. Samples were sputter-coated with 0.2 μm gold and spray-coated with 5 μm graphite. Specific heat was measured using a Netzsch DSC 404F1Pegasus differential scanning calorimeter according to ASTM E 1269 (2013). Values ​​were extrapolated at 25 °C.

[0180] Thermal diffusivity results are as follows Figure 1 As shown. Figure 1 As shown, at temperatures up to 500°C, BeO Examples 1-4 advantageously exhibited significantly higher thermal diffusivity than the AlN comparative example AC. Examples 1-4 also showed higher thermal diffusivity at temperatures above 500°C. The differences were not large, but still significant—even small differences contribute to substantial performance improvements.

[0181] The specific heat of Examples 1-4 and Comparative Example AC was tested. Specific heat is the energy required to change the bulk temperature. The specific heat results are as follows: Figure 2 As shown. Figure 2 As shown, BeO Examples 1-4 advantageously exhibit higher specific heat values ​​than the AlN comparative example AC. In fact, across the temperature range, all Examples 1-4 show results superior to all comparative examples AC. Advantageously, Examples 1-4 respond more slowly to power changes (lower hysteresis), especially once the operating temperature is reached.

[0182] The thermal conductivity of Examples 1-4 and Comparative Example AC was tested, and the results are as follows: Figure 3 As shown. Thermal conductivity was calculated from specific heat, thermal diffusivity, and density using the Fourier thermodynamic equation. Thermal conductivity modulates the steady-state thermal changes of the bulk. As shown, at temperatures up to 500°C, BeO Examples 1-4 advantageously reached the steady-state temperature faster than the AlN comparative example AC. Above 500°C, Examples 1-4 also exhibited higher thermal conductivity. The differences were small, but still significant. Similar to the case with thermal diffusivity, even small differences contribute to significant performance improvements.

[0183] The endothermic coefficients of Examples 1-4 and Comparative Example AC were measured, and the results are as follows: Figure 4 As shown. The endothermic coefficient was calculated from other calorific values. The endothermic coefficient controls the temperature at the contact point and at the moment of contact between the two components, for example, between the heating element and BeO, and between BeO and the back He gas and Si wafer. As shown, BeO Examples 1-4 advantageously exhibit higher endothermic coefficient values ​​than AlN Comparative Example AC across the entire temperature range. All Examples 1-4 exhibit higher endothermic coefficient values ​​than all Comparative Example AC across the temperature range. Compared to Comparative Example AC, Examples 1-4 maintain a more stable temperature, experience less temperature drop upon contact with the back gas and wafer, and have a shorter thermal stress history.

[0184] The volume resistivity of Examples 1-4 and Comparative Example AC was measured, and the results are as follows: Figure 5 As shown. Volume resistivity was measured using a Keithley 237 HV source according to ASTM D 257 / ASTM D 1829 Procedure A. Volume resistivity is related to clamping (at higher temperatures). Higher volume resistivity is beneficial at higher temperatures. JR clamping is typically at 1x10⁻⁶. 7 Up to 1x10 9 It is electrostatically activated in the range of Ω-m (4 at 400V to 600V). Figure 5 The resistivity slopes of the highest values ​​in Examples 1-4 and the highest value in Comparative Example AC are shown. The slope of the curve is related to 1x10. 7 Up to 1x10 9 The time is related to the "clamping / holding zone" of Ω-m. For example... Figure 5 As shown, Examples 1-4 surprisingly exhibit much flatter curves and spend more time in the clamping / holding zone. This demonstrates improved clamping performance and provides the superior clamping pressure performance disclosed herein, for example, a clamping pressure of at least 133 kPa.

[0185] Examples 5 and 6

[0186] The volume resistivity of additional samples of BeO material was tested in a similar manner. The composition of the BeO material is shown in Table 3. Examples 5 and 6 were prepared from mixtures of substantially similar ceramic powders. Examples 5 and 6 were measured at different times using different equipment. Figure 6 As shown, the curves of Examples 1, 5 and 6 are very similar and fall within the expected typical batch-to-batch variation, especially within the clamping / holding range.

[0187]

[0188] *Other components may exist in trace amounts.

[0189] The results are as follows Figure 6 As shown in the figure, Examples 1, 5, and 6 performed particularly well, especially at higher temperatures.

[0190] Example 7 and Comparative Example D

[0191] Example 7 used a sample containing a BeO composition (>99.5% purity). Comparative Example D used a sample containing an AlN composition. The corrosion resistance of Examples 7 and Comparative Example D was tested by measuring the initial weight, treatment, and then the final weight. Treatment was performed in NF3 at 400°C for 200 cycles (5.5 hours) and in ClF at 300°C for 4 cycles (12 hours). Example 7 surprisingly showed an average percentage loss of only 0.007 wt%, while Comparative Example D showed an average percentage loss of 0.016 wt%—more than twice that of Example 7 (the weight loss of Example 7 was 56% less than that of Comparative Example D).

[0192] Example 8

[0193] The substrate of Example 8 was prepared as follows. A pre-pressed (RTP) powder (high TC powder) containing high thermal conductivity grade BeO and optional binders, lubricants, and sintering aids was prepared. A similar powder was prepared using low thermal conductivity grade BeO (low TC powder). A certain amount of high TC powder and low TC powder were mixed to prepare a medium TC powder.

[0194] The bottom third volume is filled with a plate-shaped elastomer / graphite cavity mold using high-TC powder. A niobium metal heating element in the form of foil, deposit, film, or wire is placed in the powder bed. Medium-TC powder is then added to the middle third volume. A metal ground plane, RF antenna, or niobium electrode is placed in the powder bed. The top third volume is then filled with low-TC powder.

[0195] Electrical connection posts and terminals are inserted into each powder layer and connected to the embedded metal element. The mold is sealed and pressurized at room temperature to compact / densify the powder. The compacted powder shape is held together with a temporary organic or inorganic binder, and the green body is machined into an object close to the final shape. The object is then sintered in a furnace to induce densification. The object is machined to meet finished dimensional requirements, resulting in a final substrate with the various property gradients disclosed herein. Electrical and other connections are applied to the electrical connection posts to operate devices for heating and electrostatic clamping.

[0196] The substrate was heated in a testing chamber, raising the surface of the silicon wafer resting on it to 800°C (preferably the operating temperature of a semiconductor manufacturing chamber). Surprisingly, the substrate performed well at the high temperature. For example, the substrate did not crack and exhibited the values ​​discussed above. Figure 5 This exhibits volume resistivity properties similar to those of resistivity (e.g., resistivity). These unexpected resistivity values ​​are associated with excellent clamping properties at high temperatures, such as maintaining electrostatic clamping / holding (at high temperatures). Conventional substrate materials (such as AlN) fail to achieve this performance.

[0197] Example

[0198] Among other things, the following implementation methods are disclosed.

[0199] Embodiment 1: A base assembly comprising: a shaft containing a first beryllium oxide composition comprising beryllium oxide and fluorine / fluoride ions; and a substrate containing a second beryllium oxide composition comprising at least 95 wt% beryllium oxide and optionally fluorine / fluoride ions; wherein the substrate exhibits a clamping pressure of at least 133 kPa.

[0200] Embodiment 2: According to the embodiment described in Embodiment 1, wherein the first beryllium oxide composition contains 1 ppb to 1000 ppm of fluorine / fluoride ions.

[0201] Embodiment 3: According to Embodiment 1 or 2, wherein the first beryllium oxide composition contains more fluorine / fluoride ions than the second beryllium oxide composition.

[0202] Embodiment 4: According to any one of Embodiments 1-3, the first beryllium oxide composition is treated to achieve a fluorine / fluoride ion concentration.

[0203] Embodiment 5: According to any one of Embodiments 1-4, wherein the first beryllium oxide composition further comprises less than 50 wt% magnesium oxide and less than 50 wt% ppm silicon dioxide.

[0204] Embodiment 6: According to any one of Embodiments 1-5, wherein the first beryllium oxide composition further comprises: 1 ppb to 50 wt% ppm of alumina; 1 ppb to 10,000 ppm of sulfite; and / or 1 ppb to 1 wt% ppm of boron, barium, sulfur, or lithium, or combinations thereof, including oxides, alloys, composites, or allotropes, or combinations thereof.

[0205] Embodiment 7: According to any one of Embodiments 1-6, wherein the average grain boundary of the first beryllium oxide composition is greater than 0.1 micrometers.

[0206] Embodiment 8: According to any one of Embodiments 1-7, wherein the average grain size of the first beryllium oxide composition is less than 100 micrometers.

[0207] Embodiment 9: According to any one of Embodiments 1-8, wherein the second beryllium oxide composition comprises 1 ppb to 10 wt% ppm of magnesium oxide and 1 ppb to 10 wt% ppm of silicon dioxide.

[0208] Embodiment 10: An embodiment according to any one of Embodiments 1-9, wherein the second beryllium oxide composition comprises 1 ppb to 10 wt% ppm magnesium trisilicate.

[0209] Embodiment 11: According to any one of Embodiments 1-10, wherein the first beryllium oxide composition contains more magnesium oxide and / or magnesium trisilicate than the second beryllium composition.

[0210] Embodiment 12: According to any one of Embodiments 1-11, wherein the second beryllium oxide composition contains 1 ppb to 1 wt% lithium oxide.

[0211] Embodiment 13: According to any one of Embodiments 1-12, wherein the first beryllium oxide composition contains less than 75 wt% aluminum nitride and / or the second beryllium oxide composition contains less than 5 wt% aluminum nitride.

[0212] Embodiment 14: According to any one of Embodiments 1-13, wherein the electrical conductivity of the first beryllium oxide composition at room temperature is less than 300 W / mK.

[0213] Embodiment 15: According to any one of Embodiments 1-14, wherein the electrical conductivity of the second beryllium oxide composition at room temperature is less than 400 W / mK.

[0214] Embodiment 16: According to any one of Embodiments 1-15, wherein the theoretical density of the first beryllium oxide composition is in the range of 90% to 100%.

[0215] Embodiment 17: According to any one of Embodiments 1-16, wherein when heated to a temperature above 700°C, the substrate exhibits a temperature variance of less than ±3%.

[0216] Embodiment 18: According to any one of Embodiments 1-17, wherein the substrate exhibits a strength greater than 1 x 10 at 800°C. 4 The volume resistivity of ohm-m.

[0217] Embodiment 19: According to any one of Embodiments 1-18, wherein the substrate exhibits a corrosion loss of less than 0.016 wt%.

[0218] Embodiment 20: According to any one of Embodiments 1-19, wherein the substrate has a dielectric constant of less than 20.

[0219] Embodiment 21: According to any one of Embodiments 1-20, wherein the surface hardness of the substrate on a 45N scale is at least 50 Rockwell hardness.

[0220] Embodiment 22: According to any one of Embodiments 1-21, wherein the coefficient of thermal expansion of the substrate over the entire substrate is in the range of 5-15.

[0221] Embodiment 23: According to any one of Embodiments 1-22, the embodiment further includes a heating element encapsulated in the substrate.

[0222] Embodiment 24: According to any one of Embodiments 1-23, the minimum lateral dimension across the substrate is at least 100 mm.

[0223] Embodiment 25: According to any one of Embodiments 1-24, the flatness of the substrate is such that the curvature is less than 50 micrometers over a distance of 300 mm.

[0224] Embodiment 26: According to any one of Embodiments 1-25, the substrate further includes a mesa having a height greater than 1 micrometer.

[0225] Embodiment 27: According to any one of Embodiments 1-26, the shaft includes a short section having a similar coefficient of thermal expansion.

[0226] Embodiment 28: According to any one of Embodiments 1-27, wherein the substrate contains fewer than two layers of laminate.

[0227] Embodiment 29: According to any one of Embodiments 1-28, wherein the substrate does not contain a separation layer.

[0228] Embodiment 30: A substrate having a top and a bottom and comprising a beryllium oxide composition containing at least 95 wt% beryllium oxide and optionally fluorine / fluoride ions; wherein the substrate exhibits a clamping pressure of at least 133 kPa at a temperature of at least 600°C, and wherein the substrate exhibits a decomposition change of less than 1 wt% at a temperature greater than 1600°C.

[0229] Embodiment 31: According to the embodiment described in Embodiment 30, when heated to a temperature above 700°C, the substrate exhibits a temperature variance of less than ±3%; and / or greater than 1 x 10⁻⁶. 8 The volume resistivity; and / or corrosion loss less than 0.016 wt%; and / or dielectric constant less than 20; and / or surface hardness of at least 50 Rockwell hardness at grade 45 N; and / or coefficient of thermal expansion of 5 to 15 over the entire substrate.

[0230] Implementation method 32: According to the implementation method 30 or 31, the coefficient of thermal expansion changes by less than 25% from top to bottom.

[0231] Embodiment 33: An embodiment according to any one of Embodiments 30-32, wherein the substrate exhibits a cleaning cycle time of less than 2 hours and a temperature variance of less than ±3%.

[0232] Embodiment 34: An embodiment according to any one of Embodiments 30-33, wherein the beryllium oxide composition comprises 1 ppb to 10 wt% ppm of magnesium oxide and 1 ppb to 10 wt% ppm of silicon dioxide.

[0233] Embodiment 35: An embodiment according to any one of Embodiments 30-34, wherein the beryllium oxide composition comprises 1 ppb to 10 wt% ppm magnesium trisilicate.

[0234] Embodiment 36: According to any one of Embodiments 30-35, wherein the substrate does not include a separation layer.

[0235] Embodiment 37: According to any one of Embodiments 30-36, wherein the substrate has: a decreasing thermal conductivity gradient from top to bottom; and / or a decreasing resistivity gradient from top to bottom; and / or a decreasing purity gradient from top to bottom; and / or a decreasing theoretical density gradient from top to bottom; and / or an increasing dielectric constant gradient from top to bottom.

[0236] Embodiment 38: According to any one of Embodiments 30-37, the embodiment further includes a heating element, which may optionally be a wound and / or coiled heating element.

[0237] Embodiment 39: According to any one of Embodiments 30-38, the embodiment further includes an antenna.

[0238] Embodiment 40: An embodiment according to any one of Embodiments 30-39, wherein the heating element and / or the antenna comprises niobium and / or platinum.

[0239] Example 41: A substrate having a top and a bottom and comprising a beryllium oxide composition, wherein the substrate has: a decreasing thermal conductivity gradient from top to bottom; and / or a decreasing resistivity gradient from top to bottom; and / or a decreasing purity gradient from top to bottom; and / or a decreasing theoretical density gradient from top to bottom; and / or an increasing dielectric constant gradient from top to bottom.

[0240] Implementation 42: According to the implementation of Implementation 41, wherein when measured at room temperature, the top thermal conductivity ranges from 125 to 400 W / mK and the bottom thermal conductivity ranges from 146 to 218 W / mK; and / or when measured at 800°C, the top thermal conductivity ranges from 25 W / mK to 105 W / mK and the bottom thermal conductivity ranges from 1 W / mK to 21 W / mK.

[0241] Implementation 43: According to the implementation of Implementation 41 or 42, when measured at room temperature, the top thermal conductivity is at least 6% greater than the bottom thermal conductivity; and / or when measured at 800°C, the top thermal conductivity is at least 6% greater than the bottom thermal conductivity.

[0242] Implementation method 44: According to any one of implementation methods 41-43, the top purity ranges from 99.0 to 99.9, and the bottom purity ranges from 95.0 to 99.5.

[0243] Implementation 45: According to any one of Implementations 41-44, wherein the purity of the top is at least 0.4% greater than the purity of the bottom.

[0244] Embodiment 46: An embodiment according to any one of Embodiments 41-45, wherein the theoretical density at the top ranges from 93% to 100%, and the theoretical density at the bottom ranges from 93% to 100%.

[0245] Implementation method 47: According to any one of implementation methods 41-46, the top theoretical density is at least 0.5% greater than the bottom theoretical density.

[0246] Embodiment 48: According to any one of Embodiments 41-47, the top dielectric constant ranges from 1 to 20, and the bottom dielectric constant ranges from 1 to 20.

[0247] Embodiment 49: According to any one of Embodiments 41-48, wherein the substrate does not include a separation layer.

[0248] Embodiment 50: An embodiment according to any one of Embodiments 41-49, wherein the substrate exhibits a clamping pressure of at least 133 kPa.

[0249] Embodiment 51: According to any one of Embodiments 41-50, wherein when heated to a temperature above 700°C, the substrate exhibits a temperature variance of less than ±3%.

[0250] Embodiment 52: An embodiment according to any one of Embodiments 41-51, wherein the substrate exhibits a corrosion loss of less than 0.016 wt%.

[0251] Embodiment 53: A shaft for a base assembly comprising a beryllium oxide composition containing beryllium oxide and fluorine / fluoride ions; wherein the beryllium oxide composition has an average grain boundary or amorphous grain structure greater than 0.1 micrometers.

[0252] Embodiment 54: According to the embodiment described in Embodiment 53, the average grain size of the beryllium oxide composition is less than 100 micrometers.

[0253] Embodiment 55: An embodiment according to Embodiment 53 or 54, wherein the beryllium oxide composition contains less than 75 wt% aluminum nitride.

[0254] Embodiment 56: An embodiment according to any one of Embodiments 53-55, wherein the thermal conductivity of the first beryllium oxide composition at room temperature is less than 300 W / mK.

[0255] Embodiment 57: An embodiment according to any one of Embodiments 53-56, wherein the theoretical density of the beryllium oxide composition is in the range of 90 to 100.

[0256] Embodiment 58: An embodiment according to any one of Embodiments 53-57, wherein: when measured at room temperature, the top thermal conductivity ranges from 146 W / mK to 218 W / mK, and the bottom thermal conductivity ranges from 1 W / mK to 218 W / mK; and / or when measured at 800°C, the top thermal conductivity ranges from 1 W / mK to 21 W / mK, and the bottom thermal conductivity ranges from 1 W / mK to 21 W / mK.

[0257] Implementation 59: According to any one of Implementations 53-58, wherein the top theoretical density is at least 0.5% greater than the bottom theoretical density.

[0258] Embodiment 60: An embodiment according to any one of Embodiments 53-59, wherein the first beryllium oxide composition contains 1 ppb to 1000 ppm of fluorine / fluoride ions.

[0259] Embodiment 61: According to any one of Embodiments 53-60, wherein the first beryllium oxide composition further comprises less than 50 wt% magnesium oxide and less than 50 wt% ppm silicon dioxide.

[0260] Embodiment 62: According to any one of Embodiments 53-61, wherein the first beryllium oxide composition further comprises: 1 ppb to 50 wt% ppm of alumina; 1 ppb to 10000 ppm of sulfite; and / or 1 ppb to 1 wt% ppm of boron, barium, sulfur or lithium, or combinations thereof, including oxides, alloys, composites or allotropes, or combinations thereof.

[0261] Example 63: A base assembly comprising: a shaft as described in any one of embodiments 53-62; a substrate comprising a plurality of layers optionally bonded to each other by a soldering material; and an optional printed heating element.

[0262] Example 64: A substrate having a top and a bottom and comprising a ceramic composition, wherein the substrate exhibits: a clamping pressure of at least 133 kPa; a temperature variance of less than ±3% when heated to above 700°C; and / or a bulk resistivity greater than 1 x 10⁻⁶ at 800°C. 8 ; and / or corrosion loss less than 0.016 wt%; and / or dielectric constant less than 20; and / or surface hardness of 45 N grade with a minimum Rockwell hardness of 50; and / or coefficient of thermal expansion of the entire substrate in the range of 5 to 15.

[0263] Embodiment 65: A method for manufacturing a substrate, the method comprising the steps of: providing a first BeO powder and a third BeO powder; forming a second powder from the first powder and the third powder; forming a first (bottom) region from the first powder; forming a second (middle) region from the second powder; forming a third (top) region from the third powder to form a substrate precursor, wherein the second region is disposed between the first region and the third region; and firing the substrate precursor to form the substrate.

[0264] Implementation 66: According to the implementation of implementation 65, wherein the first and third (and second) powders contain different grades of raw BeO.

[0265] Embodiment 67: According to the embodiment described in Embodiment 65 or 66, the heating element is further placed in the rolled edge of one and / or terminal in the region.

[0266] Embodiment 68: According to any one of Embodiments 65-67, the embodiment further includes blending the substrate precursor to bind the powder.

[0267] Embodiment 69: According to any one of Embodiments 65-68, the embodiment further includes a step of cold forming the substrate precursor.

[0268] Implementation 70: A method of manufacturing a base shaft, comprising treating a beryllium oxide composition to achieve a fluorine / fluorine ion concentration in the range of 1 ppb to 1000 ppm fluorine / fluorine ion concentration.

[0269] Implementation 71: A method for cleaning a contaminated base assembly, comprising: providing the base assembly and a wafer, wherein the wafer is disposed on top of the base assembly; heating the wafer to a temperature above 600°C; cooling the wafer to a cooling temperature (or not cooling at all) by less than 100°C; cleaning the plate at the cooling temperature; optionally reheating the wafer to 600°C; wherein the cleaning cycle time from the cooling step to the reheating step is less than 2 hours.

[0270] Implementation 72: According to the implementation of implementation 71, the cleaning cycle time is 0 to 10 minutes.

[0271] Embodiment 73: A substrate having a top and a bottom and comprising a beryllium oxide composition containing at least 95 wt% beryllium oxide and optionally fluorine / fluoride ions; wherein the substrate exhibits a clamping pressure of at least 133 kPa at a temperature of at least 600°C and a clamping pressure greater than 1 x 10⁻⁶ kPa at a temperature of 800°C. 5 The volume resistivity of ohm-m.

[0272] Embodiment 74: According to the embodiment described in Embodiment 73, the substrate exhibits: a temperature variance of less than ±3% when heated to a temperature above 700°C; and / or a decomposition change of less than 1% wt% at a temperature above 1600°C; and / or a dielectric constant of less than 20; and / or a surface hardness of at least 50 Rockwell hardness at a surface hardness of 45N; and / or a coefficient of thermal expansion of 5 to 15 over the entire substrate.

[0273] Embodiment 75: According to the embodiment of Embodiment 73 or 74, the substrate comprises a beryllium oxide composition comprising 1 ppm to 5 wt% ppm of magnesium oxide and 1 ppm to 5 wt% of silicon dioxide and 1 ppm to less than 5 wt% ppm of magnesium trisilicate.

[0274] Embodiment 76: An embodiment according to any one of Embodiments 73-75, wherein the coefficient of thermal expansion varies by less than 25% from top to bottom.

[0275] Embodiment 77: An embodiment according to any one of Embodiments 73-76, wherein the substrate exhibits a corrosion loss of less than 0.016 wt%.

[0276] Embodiment 78: An embodiment according to any one of Embodiments 73-77, wherein the substrate exhibits a cleaning cycle time of less than 2 hours and a temperature variance of less than ±3%.

[0277] Embodiment 79: According to any one of Embodiments 73-78, wherein the substrate does not include a separation layer.

[0278] Embodiment 80: According to any one of Embodiments 73-79, wherein when heated to a temperature above 700°C, the substrate exhibits a temperature variance of less than ±3%.

[0279] Embodiment 81: According to any one of Embodiments 73-80, the substrate has: a thermal conductivity gradient decreasing from top to bottom; a resistivity gradient decreasing from top to bottom; and a purity gradient decreasing from top to bottom.

[0280] Embodiment 82: An embodiment according to any one of Embodiments 73-81, wherein the purity of the top is at least 0.4% greater than the purity of the bottom.

[0281] Embodiment 83: A base assembly comprising: a shaft containing a first beryllium oxide composition comprising beryllium oxide and fluorine / fluoride ions; and a substrate containing a second beryllium oxide composition comprising at least 95 wt% beryllium oxide; wherein the substrate exhibits a clamping pressure of at least 133 kPa at a temperature of at least 600°C and a clamping pressure greater than 1 x 10⁻⁶ kPa at a temperature of 800°C. 5 The volume resistivity of ohm-m.

[0282] Embodiment 84: According to the embodiment described in Embodiment 83, the average grain boundary of the first beryllium oxide composition is greater than 0.1 micrometers.

[0283] Embodiment 85: According to the embodiment described in Embodiment 83 or 84, wherein the average grain size of the first beryllium oxide composition is less than 100 micrometers.

[0284] Embodiment 86: An embodiment according to any one of Embodiments 83-85, wherein the first beryllium oxide composition contains 10 ppb to 800 ppm of fluorine / fluoride ions.

[0285] Embodiment 87: An embodiment according to any one of Embodiments 83-86, wherein the first beryllium oxide composition contains more fluorine / fluoride ions than the second beryllium oxide composition.

[0286] Embodiment 88: According to any one of Embodiments 83-87, the first beryllium oxide composition further comprises: 1 ppb to 50 wt% ppm of alumina; 1 ppb to 10,000 ppm of sulfite; and / or 1 ppb to 1 wt% ppm of boron, barium, sulfur, or lithium, or combinations thereof, including oxides, alloys, composites, or allotropes, or combinations thereof.

[0287] Embodiment 89: An embodiment according to any one of Embodiments 83-88, wherein the first beryllium oxide composition contains less than 75 wt% aluminum nitride, and the second beryllium oxide composition contains less than 5 wt% aluminum nitride.

[0288] Embodiment 90: A shaft for a base assembly comprising a beryllium oxide composition containing beryllium oxide and fluorine / fluoride ions from 10 ppb to 800 ppm; wherein the beryllium oxide composition has an average grain boundary or amorphous grain structure greater than 0.1 micrometers and an average grain size less than 100 micrometers.

[0289] Embodiment 91: A method for manufacturing a substrate, the method comprising the steps of: providing a first BeO powder and a third BeO powder; forming a second powder from the first and third powders; forming a first (bottom) region from the first powder; forming a second (middle) region from the second powder; forming a third (top) region from the third powder to form a substrate precursor, wherein the second region is disposed between the first region and the third region; and firing the substrate precursor to form the substrate.

[0290] Implementation 92: According to the implementation of implementation 91, wherein the first and third and optional second powders contain different grades of raw BeO.

[0291] While the invention has been described in detail, modifications within the spirit and scope of the invention will be apparent to those skilled in the art. In view of the foregoing discussion, relevant knowledge in the art, and the references to the foregoing discussion, as well as the background and specific embodiments, the entire disclosure thereof is incorporated herein by reference. Furthermore, it should be understood that various aspects of the invention, as well as portions of various embodiments and features, as set forth in the following and / or appended claims, can be combined or interchanged in whole or in part. As will be understood by those skilled in the art, in the foregoing description of various embodiments, embodiments referring to another embodiment may be suitably combined with other embodiments. Moreover, it will be understood by those skilled in the art that the foregoing description is by way of example only and is not intended to be limiting.

Claims

1. A substrate having a top and a bottom and comprising a beryllium oxide composition containing at least 95 wt% beryllium oxide and fluorine and / or fluoride ions; The substrate exhibits a clamping force of at least 133 kPa at a temperature of at least 600°C, and greater than 1 x 10⁻⁶ kPa at a temperature of 800°C. 5 The volume resistivity of ohm-m; The substrate has a resistivity gradient that decreases from top to bottom.

2. The substrate according to claim 1, wherein, The substrate comprises a beryllium oxide composition comprising 1 ppm to 5 wt% magnesium oxide, 1 ppm to 5 wt% silicon dioxide, and 1 ppm to less than 5 wt% magnesium trisilicate.

3. The substrate according to claim 1, wherein, The substrate exhibits the following characteristics: When heated to temperatures above 700 °C, the temperature variance is less than ±3%; and / or At temperatures above 1600℃, the decomposition change is less than 1 wt%; and / or Dielectric constant less than 20; and / or The surface hardness is at least 50 Rockwell hardness at a grade of 45 N.

4. The substrate according to claim 1, wherein, The coefficient of thermal expansion changes by less than 25° from top to bottom.

5. The substrate according to claim 1, wherein, The substrate does not contain a release layer.

6. The substrate according to claim 1, wherein, The substrate has a decreasing thermal conductivity gradient from top to bottom.

7. The substrate according to claim 1, wherein, The substrate has a purity gradient that decreases from top to bottom.

8. A substrate having a top and a bottom and comprising a beryllium oxide composition containing at least 95 wt% beryllium oxide and fluorine and / or fluoride ions; The substrate exhibits a clamping force of at least 133 kPa at a temperature of at least 600°C, and greater than 1 x 10⁻⁶ kPa at a temperature of 800°C. 5 The volume resistivity of ohm-m; The substrate has a purity gradient that decreases from top to bottom.

9. The substrate according to claim 8, wherein, The purity at the top is at least 0.4% higher than that at the bottom.

10. The substrate according to claim 8, wherein, The substrate has a resistivity gradient that decreases from top to bottom.

11. The substrate according to claim 8, wherein, The substrate has a decreasing thermal conductivity gradient from top to bottom.

12. A base assembly, comprising: A shaft containing a first beryllium oxide composition, wherein the first beryllium oxide composition contains beryllium oxide and fluorine and / or fluoride ions; and The substrate according to claim 1 or 8 contains a second beryllium oxide composition, wherein the second beryllium oxide composition contains at least 95 wt% beryllium oxide; The substrate exhibits a clamping pressure of at least 133 kPa at a temperature of at least 600ºC, and a clamping pressure greater than 1 x 10⁻⁶ kPa at a temperature of 800ºC. 5 The volume resistivity of ohm-m; The substrate has a resistivity gradient that decreases from top to bottom.

13. The component of claim 12, wherein, The first beryllium oxide composition has an average grain boundary greater than 0.1 micrometers and an average grain size less than 100 micrometers.

14. The component of claim 12, wherein, The first beryllium oxide composition comprises 10 ppb to 800 ppm of fluorine and / or fluoride ions, wherein the first beryllium oxide composition contains more fluorine and / or fluoride ions than the second beryllium oxide composition.

15. The component of claim 12, wherein, The first beryllium oxide composition further includes: Alumina from 1 ppb to 50 wt%; Sulfites ranging from 1 ppb to 10,000 ppm; and / or From 1 ppb to 1 wt% boron, barium, sulfur or lithium, or combinations thereof, including oxides, alloys, composites or allotropes, or combinations thereof.

16. A base assembly, comprising: A shaft containing a first beryllium oxide composition, wherein the first beryllium oxide composition contains beryllium oxide and fluorine and / or fluoride ions; and A substrate comprising a second beryllium oxide composition, wherein the second beryllium oxide composition contains at least 95 wt% beryllium oxide; The substrate exhibits a clamping pressure of at least 133 kPa at a temperature of at least 600ºC, and a clamping pressure greater than 1 x 10⁻⁶ kPa at a temperature of 800ºC. 5 The volume resistivity of ohm-m; The substrate has a purity gradient that decreases from top to bottom.

17. The component of claim 16, wherein, The first beryllium oxide composition has an average grain boundary greater than 0.1 micrometers and an average grain size less than 100 micrometers.

18. The component of claim 16, wherein, The first beryllium oxide composition comprises 10 ppb to 800 ppm of fluorine and / or fluoride ions, wherein the first beryllium oxide composition contains more fluorine and / or fluoride ions than the second beryllium oxide composition.

19. The component of claim 16, wherein, The first beryllium oxide composition further includes: Alumina from 1 ppb to 50 wt%; Sulfites ranging from 1 ppb to 10,000 ppm; and / or From 1 ppb to 1 wt% boron, barium, sulfur or lithium, or combinations thereof, including oxides, alloys, composites or allotropes, or combinations thereof.

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