Aluminum nitride assembly

Abstract

The present invention relates to an assembly of semiconductor processing equipment comprising a first aluminum nitride (AlN) component and a second aluminum nitride component, the first and second aluminum nitride components being connected by a joint, the joint comprising a composite glass-ceramic comprising Y2O3-Al2O3-SiO2 (YAS) glass and at least one of a crystalline aluminosilicate and aluminum nitride.

Description

[Technical Field]

[0001] The present invention relates generally to aluminum nitride assemblies including glass-ceramic joints for use in semiconductor processing equipment such as electrostatic chucks and heaters. In particular, the present invention relates to joining a pedestal to an electrostatic chuck or heater. [Background technology]

[0002] Semiconductor processing techniques such as etching, chemical vapor deposition, and ion implantation typically require exposure of processing equipment to corrosive gases, such as fluorine and chlorine, in a sealed chamber environment. In such processes, an electrostatic chuck can be used to hold and support a semiconductor wafer within the chamber. The chamber gases corrode the exposed metal leads that power the electrostatic chuck's embedded electrodes. A pedestal consisting of a cylindrical shaft joined to the electrostatic chuck / heater is utilized to safely remove and transport the electrostatic chuck and semiconductor wafer from the processing chamber, while also containing and protecting the metal leads from corrosion during processing.

[0003] Bonding such a pedestal to an electrostatic chuck / heater in a manner sufficient for use in a semiconductor processing chamber while preserving the properties and performance of the component subassemblies is a challenging feat. For example, US 2013 / 0319762 discloses the use of a slurry containing rare earth oxide transient liquid phase sintering additives applied to the joint interface to directly bond aluminum nitride ceramics via co-firing at high temperatures. While this technique produces hermetic joints similar to those of monolithic parts, maintaining geometric flatness when co-firing ceramics is difficult to achieve.

[0004] In another example, WO 2009 / 010427 discloses the use of a thin composite layer composed of AlN, Al2O3, and Y2O3, which is hot-pressed at high temperature and pressure to bond a pre-sintered ceramic. Re-firing a previously sintered ceramic to high temperature and pressure can damage its existing microstructure, dimensions, and properties, which is detrimental to precisely engineered devices such as electrostatic chucks.

[0005] Additionally, US6261708 discloses the preparation of a paste containing CaO-YO-AlO flux and AlN aggregates for joining AlN ceramics through a two-step, high-pressure, relatively low-temperature firing profile. While this approach utilizes slightly lower process temperatures than the previous example while maintaining good joint properties, the preparation of the joining paste and the subsequent use of extensive processing steps at long firing profiles and high pressures can incur significant additional costs to the overall manufacturing process and potentially hinder the properties and performance of the base materials. Furthermore, the use of dissimilar materials that may not match the thermal expansion coefficient of aluminum nitride or may wet the grain boundaries of the sintered aluminum nitride ceramic can result in poor bonding performance during use.

[0006] Therefore, there is a need for an aluminum nitride assembly that ameliorates at least some of the aforementioned limitations. Summary of the Invention

[0007] In a first aspect of the present disclosure, there is provided an assembly of or for semiconductor processing equipment comprising a first aluminum nitride (AlN) component and a second aluminum nitride component, the first and second aluminum nitride components being connected by a joint, the joint comprising: a) Y2O3-Al2O3-SiO2 (YAS) glass; b) an assembly is provided that includes a composite material that includes at least one or both of a crystalline aluminosilicate and aluminum nitride.

[0008] The sum of a)+b) is preferably at least 80% by weight, or at least 90% by weight, or at least 95% by weight, or at least 99% by weight of the total mass of the joint.

[0009] The joint material may contain at least three distinct phases: YAS glass, which allows flow across the joint and liquid phase diffusion bonding with the AlN ceramic body; an in situ crystalline aluminosilicate phase (e.g., mullite), which improves strength and fracture toughness; and AlN filler particles, which limit glass overflow and reduce the difference in thermal expansion coefficients across the joint, thereby enhancing the thermal shock resistance of the joint.

[0010] The composite glass-ceramic joining materials of the present invention have been found to form dense, strong, and hermetic joints between aluminum nitride ceramics. Furthermore, the joining methods used in the present invention should not significantly alter the properties of the aluminum nitride-based material due to the low temperature and pressure requirements of the joining method.

[0011] When present, the crystalline aluminosilicate and / or aluminum nitride is preferably incorporated within the YAS glass. The crystalline aluminosilicate and optional AlN particles may be dispersed within the YAS glass matrix.

[0012] The joint is 50 to 100 wt% Y2O3-Al2O3-SiO2 (YAS) glass, 0 or more than 0 to 30% by weight of crystalline aluminosilicate, and / or It may contain 0 or more than 0 to 50% by weight of aluminum nitride.

[0013] The sum of Y2O3 + Al2O3 + SiO2 in the YAS glass is preferably at least 95 wt%, at least 90 wt%, or at least 98 wt%, or at least 99 wt%, or at least 99.5 wt%. High purity reduces the likelihood of contaminating the semiconductor manufacturing environment in which it may be used.

[0014] The sum of YAS glass + crystalline aluminosilicate + AlN preferably represents at least 98 wt.%, or at least 99 wt.%, or at least 99.5 wt.% of the joint. Preferably, the joint contains less than 1.0 wt.%, or less than 0.5 wt.%, or less than 0.3 wt.%, or less than 0.2 wt.%, or less than 0.1 wt.% of unavoidable impurities. In some embodiments, the joint is substantially free (e.g., less than 0.10 wt.% or less than 0.05 wt.%) of volatile impurities (e.g., Cu and / or Na).

[0015] The density of the joint is preferably greater than 97%, more preferably greater than 98%, even more preferably greater than 99% of the theoretical maximum density of a ceramic material with 0% porosity. Alternatively, the void content of the first ceramic layer is preferably less than 3% v / v, more preferably less than 2% v / v, even more preferably less than 1% v / v. A high theoretical density and / or a low void content results in low gas leakage at the joint (good gas tightness).

[0016] YAS glass is 20-70 wt% Y2O3, 10 to 50 wt. % Al2O3, and It may contain 1 to 50% by weight of SiO2.

[0017] In a second aspect of the present invention, there is provided an assembly of semiconductor processing equipment comprising a first aluminum nitride (AlN) component and a second aluminum nitride component, the first and second aluminum nitride components being connected by a joint, the joint comprising: 20-70 wt% Y2O3, 10 to 50 wt. % Al2O3, and 1 to 50 wt. % SiO2, and a composite glass-ceramic containing a Y2O3-Al2O3-SiO2 (YAS) glass phase; An assembly is provided in which the sum of Y2O3 + Al2O3 + SiO2 is preferably at least 95% by weight.

[0018] In some embodiments, the YAS glass includes a peripheral region and a core region, the peripheral region being in interfacial contact with at least a portion of the first and / or second aluminum nitride components, and the core region being located in at least a central region of the joint. In some embodiments, the core region spans a portion of the first and second aluminum nitride components. The first and / or second aluminum nitride components may include a glass / amorphous phase derived from a sintering aid used in their formation. The glass / amorphous phase may be a YO-rich phase (i.e., YO is the major component or represents at least 30% by weight of the phase).

[0019] The peripheral region may include a YAS glass composition having a higher alumina content than the YAS glass of the core region. The peripheral region may include a YAS glass composition having a higher Y2O3 content than the YAS glass of the core region. The YAS glass composition of the peripheral region may include a lower Y2O3 content than the Y2O3-rich phase in the first and / or second AlN components. The gradually increasing Y2O3 content throughout the AlN components and the joint is believed to contribute to a more thermal shock resistant joint. The ratio of the peripheral region to the core region may be increased through extending the firing time and / or firing temperature. In some embodiments, the ratio of YAS glass from the peripheral region to the core region is a volume ratio of 1:20 to 1:1 or 1:10 to 1:2.

[0020] The presence of two glassy phases within the joint allows the coefficient of thermal expansion to increase gradually from the AlN component to the core of the joint, thereby enhancing thermal shock resistance.

[0021] In some embodiments, the YAS glass composition of the peripheral region is 45 to 70 wt % or 55 to 65 wt % Y2O3, 20 to 50 wt. % or 30 to 45 wt. % Al2O3, and It contains 1 to 20 wt %, or 2 to 10 wt %, or 3 to 7 wt % of SiO2.

[0022] In some embodiments, the YAS glass composition of the core region is 30-55 wt% Y2O3, 10 to 30 wt. % Al2O3, and Contains 15 to 50% by weight of SiO2.

[0023] The sum of Y2O3 + Al2O3 + SiO2 in the glass composition in the core and / or peripheral region may comprise at least 90 wt. % or 95 wt. % of the total weight of the glass.

[0024] In some embodiments, the joint comprises greater than 0 to 50 wt% AlN, or 2 to 30 wt% AlN, or 3 to 20 wt% AlN, or 4 to 10 wt% AlN. The AlN may be present as discrete particles. These particles may be encompassed by the YAS glass. The AlN particle size distribution may be less than 5 μm, or less than 3 μm, or less than 1 μm, and an arithmetic mean or D of at least 100 nm, or at least 200 nm, or at least 500 nm, or at least 800 nm. 50 (by weight).

[0025] In some embodiments, the joint comprises greater than 0 to 30 wt. % crystalline aluminosilicate, or 1 to 25 wt. %, or 2 to 24 wt. %, or 3 to 22 wt. %, or 5 to 20 wt. % crystalline aluminosilicate. In some embodiments, the crystalline aluminosilicate comprises or consists of mullite. The average crystalline aluminosilicate particle size can be less than 20 μm, or less than 15 μm, or less than 10 μm. The minimum size of the crystalline aluminosilicate particles can be at least 1 μm or at least 3 μm.

[0026] In some embodiments, the joint comprises 55-95% by weight YAS glass, or 60%-90% by weight YAS glass, or 65%-80% by weight YAS glass, or 70%-78% by weight YAS glass.

[0027] The joint thickness is typically no more than 150 μm, or no more than 100 μm, or no more than 50 μm. For a sufficiently robust joint, a thickness of at least 10 μm, or at least 20 μm, or at least 30 μm is preferred.

[0028] In some embodiments, 1×10 determined according to ASTM F19 -5 mbar-l / sec or less, or 1×10 -7 Assembly He leak rate of less than mbar-l / sec.

[0029] The assemblies of the present disclosure may be advantageously applied to a variety of semiconductor processing equipment. In some embodiments, the first AlN component is an electrostatic chuck and the second AlN component is a pedestal shaft.

[0030] In some embodiments, at least one AlN component includes a sintering aid such as Y2O3. The presence of Y2O3 in the AlN component (e.g., greater than 0 to 7 wt%, or greater than 0 to 5 wt%, or at least 1 wt% of at least 2 wt%, or at least 3 wt%, or at least 4 wt%) is believed to contribute to a strong joint by allowing the Y2O3 phase in the AlN component to extend from the AlN component and into the joint, as evidenced in a peripheral region of the YAS glass phase in the joint. It is believed that the Y2O3 in the joint material enhances wetting in the AlN component because it dissolves into the Y2O3-rich grain boundary phase in the AlN component, thereby forming a peripheral region of the YAS glass phase.

[0031] In a third aspect of the present disclosure, there is provided a process for forming an assembly of semiconductor processing equipment of the first aspect of the present disclosure, comprising: A. applying a paste comprising a solvent and a composite glass ceramic or precursor thereof to the surface of the first AlN and / or second AlN component; B. Bonding surfaces of the first and second AlN components together to form a green assembly; C. 1 × 10 determined according to ASTM F19 -5and firing the green assembly below the sintering temperature of the first and second AlN components for a time sufficient to form an assembly including a He leak rate of no more than mbar-l / sec.

[0032] Firing conditions can be adjusted to control the ratio of YAS glass peripheral region to YAS glass core region.

[0033] The green assembly may be fired at a temperature ranging from 1400 to 1600°C for at least 15 minutes. For clarity, a "green" assembly refers to an unsintered or unfired paste. The AlN component in the assembly is preferably a sintered AlN component. Indeed, the firing conditions, including time, pressure, and temperature, of the green assembly are preferably such that the functional properties or microstructure of the AlN component are not significantly affected. In some embodiments, the green assembly is fired at a temperature of 1550°C or less. In some embodiments, the green assembly is fired at a temperature of 1500°C or less. In some embodiments, the green assembly is fired under a non-oxidizing atmosphere (e.g., N2 or H2).

[0034] In some embodiments, the surface or the first and / or second AlN components have a roughness (R a ) value.

[0035] To ensure a mechanically robust joint, the green assembly is maintained under loads ranging from 100 Pa to 1000 Pa, or from 200 Pa to 800 Pa, or from 300 Pa to 600 Pa. Higher loads may cause the paste to squeeze out of the joint, resulting in too thin a joint. Lower loads may cause the paste to not form a continuous bond with the AlN component, resulting in insufficient hermeticity.

[0036] In a fourth aspect of the present disclosure, there is provided a process for manufacturing a semiconductor, comprising positioning an assembly defined in the first aspect of the present disclosure in a semiconductor processing chamber and exposing the assembly to an atmosphere containing a halogen gas, wherein the halogen gas may comprise or consist of chlorine or fluorine.

[0037] In a fifth aspect of the present disclosure, there is provided a paste for use in forming an assembly as defined in the first aspect of the present disclosure, comprising (on a solvent-free basis) 10 to 60 wt% Y2O3, 5-40 wt% Al2O3, 10 to 60 wt. % SiO2, and A paste is provided that includes a composite glass-ceramic having a composition including 0-30 wt % AlN or a precursor thereof.

[0038] In some embodiments, the sum of YO + AlO + SiO + AlN is at least 90 wt%, or at least 95 wt%, or at least 98 wt%, or at least 99 wt% of the total paste weight on a solvent-free basis. In some embodiments, the AlN content is less than 25 wt%, or less than 18 wt%, or less than 20 wt%, or less than 12 wt%. Excessive AlN particles in the paste will result in a paste that is too viscous at the application temperature, thereby compromising the paste's effectiveness in distributing evenly across the substrate interface and forming a hermetic bond.

[0039] In some embodiments, the paste comprises particles of AlN. In some embodiments, the paste comprises: 20-40 wt% Y2O3, 20-40 wt% Al2O3, 20-40 wt. % SiO2, and It contains 1 to 20 wt % AlN.

[0040] The paste, when applied under the process of the second aspect of the present disclosure, can produce an assembly under the first aspect of the present disclosure.

[0041] The paste offers the advantage of joining pre-sintered aluminum nitride bodies at relatively low temperatures and short cycle times to preserve the microstructure, properties, and geometry of the base aluminum nitride material. Additionally, the paste is designed to match the thermal expansion coefficient of aluminum nitride and possesses the desired etch and corrosion resistance properties that make it suitable for use in semiconductor processing applications.

[0042] The disclosed paste and method for joining pre-sintered aluminum nitride bodies utilizes a relatively simple and inexpensive process. The processing steps include dry-pressing or iso-pressing the aluminum nitride bodies to sinter them, grinding and polishing the joining surfaces, applying the paste to the joining surfaces in slurry form, mating the joining surfaces under load, and firing at a relatively low temperature and short cycle. The addition of AlN particles to the paste is believed to prevent the liquid component of the paste from relaxing from the joint during the mating process, promoting a stronger, more hermetic joint.

[0043] Unless otherwise stated, angular dark grains within the joint containing a large amount of aluminosilicate (e.g., greater than 70 wt. %, or 80 wt. %, or 90 wt. %) will be considered to be crystalline aluminosilicate phases. [Brief explanation of the drawings]

[0044] [Figure 1] FIG. 1 is a process flow diagram according to an exemplary embodiment of the present disclosure. [Figure 2] FIG. 1 is a cross-sectional view of an aluminum nitride substrate bonded to an aluminum nitride shaft using a composite glass-ceramic bonding material according to an exemplary embodiment of the present disclosure. [Figure 3] 1 is an SEM micrograph showing the microstructure of a composite glass-ceramic bonding material disposed between aluminum nitride substrates according to Example 1 of the present disclosure. [Figure 4]3 is a magnified SEM micrograph highlighting the analytical points displayed in Table 2. [Figure 5] 1 is an SEM micrograph showing the microstructure of a bonding material according to Example 2 disposed between aluminum nitride substrates. [Figure 6] FIG. 6 is an enlarged SEM micrograph of a section of FIG. 5 showing the joint microstructure in more detail. [Figure 7] 1 is an SEM micrograph showing the microstructure of an alternative bonding material according to Comparative Example #1 disposed between aluminum nitride substrates for comparison with the present disclosure. [Figure 8] 10 is an SEM micrograph showing the microstructure of another alternative bonding material according to Comparative Example #2 disposed between aluminum nitride substrates for comparison with the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0045] Representative applications of glass-ceramic joints and AlN assemblies containing them, as well as methods according to embodiments described herein, are provided in this section. These examples are provided solely to add context and aid in understanding the described embodiments. Thus, it will be apparent to one of ordinary skill in the art that the embodiments described herein can be practiced without some or all of these specific details. In other instances, well-known process steps have not been described in detail to avoid unnecessarily obscuring the embodiments described herein. As other applications are possible, the following examples should not be construed as limiting.

[0046] As illustrated in Figure 1, the process of joining AlN bodies together involves forming and sintering the AlN bodies, followed by surface preparation involving grinding and polishing to obtain smooth joining surfaces onto which a joining paste prepared as a viscous past of joining material is applied. The two AlN bodies are then mated under load and then fired to produce the final assembly.

[0047] Referring to Figure 2, shown is a cross-sectional view of the final assembled parts joined according to an exemplary embodiment of the present disclosure. The assembly consists of a sintered AlN substrate 1 and a sintered AlN pedestal shaft 2, which are joined using a composite glass-ceramic joining material 3 of the present disclosure disposed at the interface between 1 and 2. This assembly is preferably kept within good geometric constraints. Ideally, the process described in Figure 1 does not significantly alter the microstructure, function, or performance of the component pieces 1, 2.

[0048] In one embodiment, a green AlN body with at least 1 wt. % YO sintering aid is preferably formed into a desired shape through a dry press or isostatic press, such as the substrate and pedestal shaft of FIG. 2. The formed green AlN component is debonded using a slow and controlled heating rate of 2°C / min or less to 375°C, held for at least 1 hour, followed by a slow and controlled cool-to-room temperature hold at a rate of 4°C / min or less. The debonded AlN ceramic is then sintered using a heating rate of less than 15°C / min to 1850°C, held at 1850°C for at least 1 hour, and then cooled again to room temperature at a rate of 15°C / min or less. The sintered AlN component has a mass of at least 3.30 g / cm as measured via Archimedes' method. 3 It is preferable that the sintered AlN ceramic has a density of 0.01 mm or less and a uniform microstructure with an average grain size of 20 μm or less. The sintered AlN ceramic is then ground and polished on each joining surface to achieve a flat and smooth interface for joining. The surface roughness (R a ) is preferably 45 μm or less.

[0049] A paste containing the components of a composite glass-ceramic joining material is prepared for application to the joining interface. The raw powder materials for the joining material are preferably mixed in the following proportions: 50-100% Y2O3-Al2O3-SiO2 (YAS) glass-forming component and 0-50 wt% aluminum nitride raw powder. Here, the YAS glass-forming component contains 10-60 wt% Y2O3, 5-40 wt% Al2O3, and 10-60 wt% SiO2. A paste composition within this range has a relatively low melting point and can produce a crystalline aluminosilicate phase, such as mullite.

[0050] The raw powder materials used are preferably of high purity (e.g., greater than 98% by weight, or greater than 99% by weight, or greater than 99.5% by weight purity). The component powder joining materials are then mixed and milled with a binder and solvent to form a viscous paste. The joining material paste preferably exhibits a viscosity suitable for screen printing applications with a solids loading of at least 50% by weight, and the paste is fully homogenized through thorough mixing of the components. The prepared paste is then applied to the joining surfaces of each sintered AlN body in a thin, uniform layer. Preferably, the paste is applied using a screen printing method at a thickness of less than 0.005 inches (127 μm).

[0051] The sintered AlN bodies with the joining paste applied to their joining surfaces are then mated face-to-face and fired under a N2 atmosphere to form a solid-state joint. A load is preferably applied normal to the joining interface during the firing process to force contact between the joining surfaces and promote flow and uniform distribution of the glass phase along the joint. The assembly is preferably fired to a peak temperature of 1450°C to 1550°C with a dwell time of 5 minutes to 2 hours. More preferably, the heating and cooling rates during firing are 10 to 30°C / min.

[0052] As seen in Figure 3, an SEM micrograph of a cross-section of the bonded AlN ceramic joint region prepared according to this preferred embodiment, sintered AlN substrates 100, 105 are bonded between a composite glass-ceramic bonding material comprising AlN particles 130 and mullite particles 140 embedded within a YAS glass matrix 110, 120. The YAS glass matrix includes a lighter-colored peripheral region 110 and a darker-colored core region 120. The microstructure reveals a thin, uniform, and continuous bond layer free of voids and defects. Additionally, backscattered images allow for the identification of a continuous yttria-aluminosilicate glass phase with homogeneously distributed aluminosilicate (mullite) crystals and AlN filler particles. [Example]

[0053] Experiments were conducted to quantify the strength and hermeticity of AlN ceramics bonded using the disclosed glass-ceramic composite bonding material and other bonding materials that may be used in the semiconductor field as comparative examples using the ASTM F19 standardized procedure. AlN spray-dried powder containing 4 wt. % YO sintering aid was used as the base powder material. AlN isostatically pressed cylinders were formed, machined to ASTM F19 specimen specifications, and debonded at 375°C for 2 hours with heating and cooling rates of 1.5°C / min and 3°C / min, respectively. The debonded ceramics were then sintered to 1850°C for 3 hours with heating and cooling rates of 10°C / min to achieve a bond strength of at least 3.30 g / cm. 3 The surfaces to be joined were then ground flat and incrementally polished with an abrasive wheel and diamond slurry to a maximum roughness (Ra) of 9 μm.

[0054] Joining pastes of various compositions were prepared with about 65-70 wt. % solids, with the remainder being binder and solvent, to obtain a viscous, screen-printable paste. The composite glass-ceramic joining materials of the present disclosure are hereinafter referred to as: ● Referred to as "YAS+10%AlN" (Example 1), the solid content of the paste is composed of 30 wt% Y2O3, 30 wt% Al2O3, 30 wt% SiO2, and 10 wt% AlN; ● Referred to as YAS (1:1:1) (Example 2), the paste solid content is 30 parts by weight (pbw) of Y2O3, 30 pbw of Al2O3, and 30 pbw of SiO2; ● Designated YAS (9:2:9) (Example 3), the solid content of the paste was composed of 9 pbw Y2O3, 2 pbw Al2O3, and 9 pbw SiO2.

[0055] Example 2 differs from Example 1 in that the sample does not contain AlN (i.e., only YO, AlO, and SiO in a 1:1:1 weight ratio, which is effective to obtain a crystalline aluminosilicate phase upon joint formation. Example 3 differs from Example 2 in that the weight ratio of YO, AlO, and SiO was adjusted to 9:2:9, such that a crystalline aluminosilicate phase would not form.

[0056] An alternative bonding solution, hereafter referred to as "Comparative Example #1" (CE#1), had a paste solids content of 40 wt% AlN, 15 wt% Al2O3, 8 wt% Y2O3, and 37 wt% CaCO3. Another alternative bonding solution, hereafter referred to as "Comparative Example #2" (CE#2), had a paste solids content of 70 wt% AlN, 15 wt% Al2O3, and 15 wt% Y2O3.

[0057] Each joining paste was applied to the joining surfaces of each respective AlN ASTM F19 part in a thin layer approximately 0.003 inches (≈76 μm) thick. The parts were then mated under a load of approximately 5 g and fired under various profiles depending on their composition. Samples (1-3) were fired at 1500°C in a N2 atmosphere with a 10°C / min heating and cooling rate and a 30-minute dwell. For Comparative Example #1, the sample was fired at 10°C / min to 1400°C in a N2 atmosphere for 2 hours, followed by a second heating rate of 10°C / min up to 1600°C with an additional 2-hour dwell, and finally cooled to room temperature at 10°C / min. For Comparative Example #2, the sample was fired at 10°C / min to 1850°C in a N2 atmosphere with a 1-hour dwell, followed by a 10°C / min cooling rate to room temperature.

[0058] The bonded parts were then tested under ASTM F19 standard procedures for hermeticity using a He spectrometer and for tensile strength using an Instron. The ASTM F19 test results for each bonding material of the present disclosure are shown in Table 1.

[0059] As shown in Table 1, Example 1 had the highest average strength across the five samples at 23.6±4.6 MPa and a tensile strength of 1×10 -8 -1×10 -9 mbar-l / sec (1×10 -9 -1×10 -10 Example 2 achieved similar joint strength as Example 1, but with reduced hermetic performance. Example 3 achieved similar joint hermetic performance as Example 1, but with reduced hermetic strength. Comparative Example #1 (CE#1) achieved an average strength of only 10.8±3.9 MPa and a shear strength of approximately 1×10 across the five samples. -3 -1×10 -4 mbar-l / sec (1×10 -4 -1×10 -5 Finally, the poorest performing joint material was Comparative Example #2 (CE#2), which achieved a He leak rate in the range of only 6.3±1.9 MPa and a He leak rate of approximately 1×10 across the three samples. -1-1×10 -1 mbar-l / sec (1×10 -2 -1×10 -3 He leak rates in the range of 1000 kPa-l / sec were achieved. This data suggests that Example 1 (YAS+10%) AlN bonding solution of the present disclosure, followed by Examples 2 and 3, possess improved strength and hermeticity values ​​when compared to other potential bonding solutions of different compositions and bonding conditions.

[0060] [Table 1]

[0061] Joint microstructure To quantitatively analyze the microstructure of the composite glass-ceramic, dry-pressed AlN pellets were formed and then debonded, sintered, and ground / polished under the same conditions as the AlN ASTM F19 samples. The sintered pellets were then bonded using the same respective bonding pastes and bonding parameters as in the previous examples. The sintered pellets were then cross-sectioned and incrementally polished using a polishing wheel and diamond suspensions up to 1 μm in diameter. The polished samples were then analyzed for microstructure via SEM. The joint microstructure corresponding to the YAS + 10% AlN paste (Example 1) is presented in Figures 3 and 4 and shows a uniform and consistent bond layer formed at 1500 °C for 30 minutes, consisting of four distinct phases: yttria aluminosilicate glass (periphery region 110 and core region 120), aluminosilicate (mullite) crystals 140, and AlN filler particles 130.

[0062] Using semi-quantitative EDS analysis, the compositions of selected observed phases (FIG. 4) are provided in Table 2. A Y2O3-rich phase 210 (light phase) was also identified in the AlN component 100. The peripheral glassy phase 110 located at the interface of the AlN components may originate at least in part from the Y2O3 sintering additive in the AlN components 100, 105.

[0063] [Table 2]

[0064] The % surface areas of the YAS glass, mullite, and AlN phases were each approximately 2000 μm 2 The relative surface area of ​​the four joints was calculated by measuring the relative surface areas of the four joints, each having a surface area of ​​1000 μm. Buehler OmniMet™ software was used to measure image features identified as YAS glass, AlN particles, and mullite particles through XRD and EDS analysis. The area measurement tool in the software was used to measure the pixels of the AlN and mullite phases. The % surface area of ​​the AlN and mullite phases was determined by comparing the number of pixels to the total number of pixels within the joint area being measured. The weight % of YAS glass was determined by the difference (total - mullite - AlN). For purposes of this invention, the % surface area percentage of a phase is assumed to be equal to its weight % percentage (or its volume % percentage). For example, a 10% joint surface area of ​​YAS glass is considered equivalent to 10% by weight of YAS glass in the joint.

[0065] The ranges of relative portions of the phases are presented in Table 3 from four joints produced from the paste containing YAS+10 wt% AlN described above. For purposes of the present invention, the % surface area of ​​each of the phases can be considered as the weight % of each of the phases.

[0066] [Table 3]

[0067] Effect of AlN additional phase Generally, the YAS glass phase should flow, fill gaps, and create a dense, hermetic seal. However, in Example 2, the bond has a low hermetic value (Table 1). Visual analysis of the bond during its formation reveals some overflow of glass onto the side of the sample. The resulting bond shows a first AlN substrate 300 and a second AlN substrate 310 connected by a bond 320 containing numerous voids 330, as illustrated in FIG. 5.

[0068] Under increased magnification (FIG. 6), joint 320 includes a peripheral glass phase 340 and a core glass phase 350, although the ratio of peripheral to core glass phase is relatively low compared to Example 1. The angular, darker grains 360 correspond to a crystalline aluminosilicate phase. Peripheral glass phase 340 is located in a peripheral region that is in interfacial contact with at least a portion of first and / or second aluminum nitride substrates 300, 310. Core glass phase 350 is located in at least a central region of the joint. In one or more embodiments, core glass phase 350 extends from the first aluminum nitride substrate to the second aluminum nitride substrate 300, 310.

[0069] Without wishing to be bound by theory, it is believed that in Example 2, the glass was too fluid at the firing temperature, causing the amount of molten glass to be extruded from the joint substrate interface. This resulted in insufficient reaction between the joint material and the substrate at the substrate interface, and the migrated glass phase left voids at the joint interface. The lower ratio of peripheral glass phase to core glass phase may reflect this low level of reaction.

[0070] The addition of a small amount of AlN powder is believed to increase the glass viscosity at the application temperature, allowing the glass to be contained within the joint area, thereby preventing the YAS glass from migrating from the joint-substrate interface and ensuring a sufficiently dense and hermetic joint. The AlN particles also reduce the difference in thermal expansion coefficients across the joint. Without the AlN particles, the joint would also be more susceptible to thermal shock, which can result in microcracks, providing a gas path through the joint and thereby affecting hermeticity over time.

[0071] Effect of crystalline aluminosilicate The effect of crystalline aluminosilicate is illustrated in Comparative Example 3 (Table 1), where the absence of this component in the joint results in a reduction in joint strength of approximately 20%. The crystalline phase is believed to function as a crack inhibitor, thereby impeding crack propagation and improving joint strength and fracture toughness.

[0072] Comparative Example FIG. 7 shows the microstructure of Comparative Example #1 joining material 6 disposed between sintered AlN bodies 4 after firing at 1400°C and 1600°C for 2 hours, respectively. FIG. 7 shows evidence of less flow of the CaO-based glassy phase, leaving a uniform bond layer that is not fully homogenized. FIG. 8 shows the microstructure of Comparative Example #2 joining material 7 disposed between sintered AlN substrates 4 after firing at 1850°C for 1 hour. FIG. 8 presents a bond layer with a very non-uniform bond interface. Additionally, the high temperatures required for bonding may significantly affect the distribution of the liquid phase in the adjacent AlN substrates, which may potentially affect the properties and performance of the base AlN material. Overall, the results and microstructural analysis in Table 3 indicate that the bonds of Examples 1, 2, and 3 of the present disclosure exhibit improved hermeticity and strength (compared to CE#1 and CE#2). Additionally, the assemblies of the present invention possess good joint homogeneity, uniform distribution and controlled formation of distinct glassy and crystalline phases, if present.

[0073] Although the foregoing disclosure has been described in detail by way of illustration and example for purposes of clarity and understanding, it will be appreciated that the above disclosure can be embodied in many other specific variations and embodiments without departing from the spirit or essential characteristics of the disclosure. It will be understood that certain changes and modifications can be practiced and that the disclosure should not be limited by the foregoing details, but rather should be defined by the appended claims. [1] 1. An assembly of semiconductor processing equipment comprising a first aluminum nitride (AlN) component and a second aluminum nitride component, the first and second aluminum nitride components being connected by a joint, the joint comprising: (a)Y 2 O 3 -Al 2 O 3 -SiO 2 (YAS) Glass and (b) an assembly comprising a composite glass-ceramic comprising at least one of a crystalline aluminosilicate and aluminum nitride. [2] The Y 2 O 3 -Al 2 O 3 -SiO 2 The assembly according to [1], comprising (YAS) glass, the crystalline aluminosilicate, and the aluminum nitride. [3] 10. The assembly according to claim 1, wherein the at least one of the crystalline aluminosilicate and / or the aluminum nitride is encapsulated by the YAS glass. [4] The joint is 50-100% by weight of Y 2 O 3 -Al 2 O 3 -SiO 2 (YAS) glass, and The assembly according to [1], comprising more than 0 to 30% by weight of a crystalline aluminosilicate and / or more than 0 to 50% by weight of aluminum nitride. [5] The YAS glass is 20 to 70 wt% Y 2 O 3 、 10-50 wt% Al 2 O 3 , and 1 to 50 wt% SiO 2 Including, Y 2 O 3 +Al 2 O 3 +SiO 2 The assembly according to any one of [1] to [3], wherein the total of the above is at least 95% by weight. [6] The assembly described in any one of [1] to [5], wherein the YAS glass includes a peripheral region and a core region, the peripheral region being in interfacial contact with at least a portion of the first and / or second aluminum nitride components, and the core region being located in at least a central region of the joint. [7] 9. The assembly of claim 6, wherein the peripheral region comprises a YAS glass composition having a higher alumina content than the YAS glass of the core region. [8] The YAS glass composition of the peripheral region is 45-70 wt% Y 2 O 3 、 20-50 wt% Al 2 O 3 , and 1 to 20 wt% SiO 2 Including, The Y 2 O 3 +Al 2 O 3 +SiO 2 The assembly according to [6] or [7], wherein the total of [9] the YAS glass composition of the core region is 30-55 wt% Y 2 O 3 、 10-30 wt% Al 2 O 3 , and 15 to 50 wt% SiO 2 Including, The Y 2 O 3 +Al 2 O 3 +SiO 2 The assembly according to any one of [6] to [8], wherein the total of the above is at least 95% by weight.

[10] The assembly according to any one of [1] to [9], wherein the joint contains more than 0 to 50 wt % AlN.

[11] The assembly according to

[10] , wherein the joint contains 5 to 30 wt % AlN.

[12] The assembly according to

[10] or

[11] , wherein the joint contains 5 to 30% by weight of crystalline aluminosilicate.

[13] The first and / or second AlN components are Y 2 O 3 The assembly according to any one of [1] to

[12] , which includes a rich phase.

[14] The assembly according to any one of [1] to

[13] , wherein the crystalline aluminosilicate, when present, comprises or consists of mullite.

[15] The joint is made of Y in a weight ratio of 1:1:1. 2 O 3 +Al 2 O 3 +SiO 2 The assembly according to any one of [1] to

[14] , wherein the joining portion contains the crystalline aluminosilicate.

[16] The assembly according to any one of [1] to

[15] , wherein the thickness of the joint is 150 μm or less.

[17] 1 × 10 determined according to ASTM F19 -7 The assembly according to any one of [1] to

[16] , which includes a He leak rate of 0.05 mbar-l / sec or less.

[18] The assembly according to any one of [1] to

[17] , wherein the first AlN component is an electrostatic chuck and the second AlN component is a pedestal shaft.

[19] 1. An assembly of semiconductor processing equipment comprising a first aluminum nitride (AlN) component and a second aluminum nitride component, the first and second aluminum nitride components being connected by a joint, the joint comprising: 20 to 70 wt% Y 2 O 3 、 10-50 wt% Al 2 O 3 , and 1 to 50 wt% SiO 2 Contains Y 2 O 3 -Al 2 O 3 -SiO 2 (YAS) Composite glass-ceramic containing a glass phase, Y 2 O 3 +Al 2 O 3 +SiO 2 The sum of the above is at least 95% by weight.

[20] The first and / or second AlN component contains more than 0 to 7 wt. % Y. 2 O 3

[19] The assembly according to

[19] ,

[21] The first and / or second AlN components contain at least 1 wt. % Y 2 O 3

[19] The assembly according to

[19] ,

[22] An assembly according to any one of

[19] to

[21] , wherein the YAS glass comprises a peripheral region and a core region, the peripheral region being in interfacial contact with at least a portion of the first and / or second aluminum nitride components, and the core region being located in at least a central region of the joint.

[23] 22. The assembly of claim 21, wherein the peripheral region comprises a YAS glass composition having a higher alumina content than the YAS glass of the core region.

[24] The YAS glass composition of the peripheral region is 45-70 wt% Y 2 O 3 、 20-50 wt% Al 2 O 3 , and 1 to 20 wt% SiO 2 The assembly according to

[22] or

[23] , comprising:

[25] the YAS glass composition of the core region is 30-55 wt% Y 2 O 3 、 10-30 wt% Al 2 O 3 , and 15 to 50 wt% SiO 2 The assembly according to any one of

[22] to

[24] , comprising:

[26] A process for forming an assembly of semiconductor processing equipment according to any one of [1] to

[25] , (A) applying a paste comprising a solvent and the composite glass-ceramic or a precursor thereof to a surface of the first AlN and / or second AlN component; (B) bonding the surfaces of the first and second AlN components together to form a green assembly; (C) 1 × 10 determined according to ASTM F19 -5 firing the green assembly below the sintering temperature of the first and second AlN components for a time sufficient to form the assembly including a He leak rate of no more than mbar-l / sec.

[27]

[26] The process according to

[26] , wherein the green assembly is fired at a temperature in the range of 1400-1600°C for at least 15 minutes.

[28]

[26] The process according to

[26] , wherein the green assembly is fired at a temperature of 1500°C or less.

[29]

[26] -

[28] The process according to any one of

[26] to

[28] , wherein the green assembly is fired for a time sufficient to form a mullite phase within the joint.

[30] The process according to any one of

[26] to

[29] , wherein the green assembly is maintained under a load in the range of 100 Pa and 1000 Pa.

[31] The process according to any one of

[26] to

[30] , wherein the green assembly is fired in a non-oxidizing atmosphere.

[32] A process for manufacturing a semiconductor, comprising: positioning the assembly according to any one of [1] to

[25] in a semiconductor processing chamber; and exposing the assembly to an atmosphere containing a halogen gas.

[33] A paste for use in forming the assembly according to any one of [1] to

[25] , on a solvent-free basis, 10 to 60 wt% Y 2 O 3 、 5 to 40 wt% Al 2 O 3 、 10 to 60 wt% SiO 2 , and A composite glass-ceramic or a precursor thereof having a composition containing 0 to 30 wt. % AlN, The Y 2 O 3 +Al 2 O 3 +SiO 2 +AlN total at least 95 wt. %.

[34] 20-40 wt% Y 2 O 3 、 20-40 wt% Al 2 O 3 、 20-40 wt% SiO 2 , and The paste according to

[33] , containing 1 to 20 wt. % AlN.

[35] Y in a 1:1:1 weight ratio 2 O 3 +Al 2 O 3 +SiO 2 The paste according to

[33] , comprising:

Claims

1. 1. An assembly of semiconductor processing equipment comprising a first aluminum nitride (AlN) component and a second aluminum nitride component, the first and second aluminum nitride components being connected by a joint, the joint comprising: (a) Y 2 O 3 -Al 2 O 3 -SiO 2 (YAS) glass, (b) an assembly comprising a composite glass-ceramic comprising at least one of a crystalline aluminosilicate and aluminum nitride.

2. The Y 2 O 3 -Al 2 O 3 -SiO 2 The assembly of claim 1 comprising (YAS) glass, said crystalline aluminosilicate, and said aluminum nitride.

3. The assembly of claim 1 , wherein the at least one of the crystalline aluminosilicate and / or the aluminum nitride is encapsulated by the YAS glass.

4. The joint is 50 to 100% by weight of Y 2 O 3 -Al 2 O 3 -SiO 2 (YAS) glass, and 10. The assembly of claim 1, comprising 1 to 30% by weight of crystalline aluminosilicate and / or 2 to 50% by weight of aluminum nitride.

5. The YAS glass is 20 to 70% by weight of Y 2 O 3 , 10 to 50 wt. % Al 2 O 3 , and 1 to 50% by weight of SiO 2 Including, Y 2 O 3 +Al 2 O 3 +SiO 2 2. The assembly of claim 1, wherein the sum of is at least 95% by weight.

6. 2. The assembly of claim 1, wherein the YAS glass includes a peripheral region and a core region, the peripheral region being in interfacial contact with at least a portion of the first and / or second aluminum nitride components, and the core region being located in at least a central region of the joint.

7. The assembly of claim 6 , wherein the peripheral region comprises a YAS glass composition having a higher alumina content than the YAS glass of the core region.

8. the YAS glass composition of the peripheral region is 45 to 70% by weight of Y 2 O 3 , 20 to 50% by weight of Al 2 O 3 , and 1 to 20% by weight of SiO 2 Including, The Y 2 O 3 +Al 2 O 3 +SiO 2 7. The assembly of claim 6, wherein the sum of is at least 95% by weight.

9. the YAS glass composition of the core region is 30 to 55% by weight of Y 2 O 3 , 10 to 30% by weight of Al 2 O 3 , and 15 to 50% by weight of SiO 2 Including, The Y 2 O 3 +Al 2 O 3 +SiO 2 7. The assembly of claim 6, wherein the sum of is at least 95% by weight.

10. The assembly of claim 1 , wherein the joint comprises 5 to 50 weight percent AlN.

11. The assembly of claim 1 , wherein the joint comprises 5 to 30 weight percent crystalline aluminosilicate.

12. The assembly of claim 1 , wherein the first AlN component is an electrostatic chuck and the second AlN component is a pedestal shaft.

13. The first and / or second AlN components contain Y in the range of 1 to 7 wt. %. 2 O 3 The assembly of claim 1 , comprising:

14. 10. A paste for use in forming the assembly of claim 1, comprising, on a solvent-free basis: 10 to 60% by weight of Y 2 O 3 , 5 to 40% by weight of Al 2 O 3 , 10 to 60% by weight of SiO 2 , and a composite glass-ceramic having a composition comprising 0 to 30 wt. % AlN or a precursor thereof; The Y 2 O 3 +Al 2 O 3 +SiO 2 +AlN is at least 95% by weight.

15. A process for forming an assembly of semiconductor processing equipment according to any one of claims 1 to 13, comprising: (A) applying a paste comprising a solvent and the composite glass-ceramic or a precursor thereof to a surface of the first AlN and / or second AlN component; (B) bonding the surfaces of the first and second AlN components together to form a green assembly; (C) firing said green assembly below the sintering temperature of said first and second AlN components for a time sufficient to form said assembly containing a He leak rate of 1×10 −5 mbar-l / sec or less as determined in accordance with ASTM F19.

16. The process of claim 15, wherein the green assembly is fired at a temperature in the range of 1400 to 1600°C for at least 15 minutes.

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