Aln ceramic material for semiconductor heater parts and manufacturing method thereof

Abstract

This invention relates to an AlN ceramic material for semiconductor heater components and a method for manufacturing the same. The AlN ceramic material for semiconductor heater components of this invention includes titanium nitride (TiN), magnesium aluminate (MgAl2O4), and aluminum nitride (AlN).

Description

[Technical Field]

[0001] This invention relates to an AlN ceramic material for semiconductor heater components and a method for manufacturing the same. [Previous Technology]

[0002] With the advancement of semiconductor components and semiconductor manufacturing technology, the process temperature is constantly increasing, and the chemical substances used are becoming more and more diverse, which makes the process conditions more stringent. In semiconductor manufacturing, aluminum nitride (AlN) ceramic materials are often used as heater components due to their thermal expansion coefficient being similar to that of Si wafers, excellent thermal conductivity, insulation, plasma resistance, and high volume resistivity.

[0003] Although AlN ceramic materials possess excellent properties, they are difficult to sinter as a single raw material due to their inherent resistance to sintering. Additives must be added to improve sintering density and thermal conductivity. Existing companies producing AlN ceramic heaters use various additives to increase density, reduce porosity, improve thermal conductivity, and enhance bonding properties, thereby producing materials with excellent sintering density / thermal conductivity. The most representative additive is yttrium oxide, with different manufacturers using varying amounts. Without yttrium oxide, it is difficult to achieve densification, reduce porosity, improve thermal conductivity, and enhance bonding properties. However, while adding this element can increase the volume resistivity of the gas within a certain range, it also forms oxygen vacancies and yttrium oxide binary oxides such as YAG and YAM in the gas, thereby reducing the volume resistivity at high temperatures and increasing leakage current.

[0004] Leakage current in semiconductor manufacturing processes caused by the decrease in volume resistivity at high temperatures can affect semiconductor wafers and reduce yield. This phenomenon is a common characteristic of ceramic materials where volume resistivity decreases with increasing temperature. As AlN materials experience a decrease in volume resistivity and an increase in leakage current at high temperatures, the wafer chucking force weakens, ultimately leading to defects such as wafer detachment.

[0005] As the temperature of semiconductor manufacturing processes rises to over 500°C, the number of high-temperature processes requiring ceramic heaters is increasing. There is a need to develop ceramic heaters with high resistance characteristics in order to minimize leakage current at high temperatures.

[0006] The background technology described herein is something that the inventor has mastered or learned in the process of developing this invention, and should not be construed as necessarily being a generally known technology disclosed before the application for this invention. [Summary of the Invention]

[0007] In order to solve the above problems, the present invention aims to provide an AlN ceramic material for semiconductor heater components with excellent volume resistivity even at high temperatures and a method for manufacturing the same.

[0008] However, the technical problem to be solved by the present invention is not limited to the issues mentioned above, and other issues not mentioned will be clearly understood by those skilled in the art through the following description.

[0009] The AlN ceramic material for semiconductor heater components according to the present invention comprises titanium nitride (TiN), magnesium aluminate (MgAl2O4), and aluminum nitride (AlN).

[0010] According to one embodiment, the AlN ceramic material used for the semiconductor heater component is free of yttrium oxide.

[0011] According to one embodiment, the semiconductor heater component is a semiconductor heater plate, a semiconductor heater shaft, or both.

[0012] According to one embodiment, the magnesium aluminate (MgAl2O4) exists as the second phase of the Mg-Al-O system.

[0013] According to one embodiment, the X-ray diffraction (XRD) peaks of the second phase of the Mg-Al-O system are included, wherein the 2θ value of the XRD diffraction peaks is 44° to 46°.

[0014] According to one embodiment, the XRD diffraction peak does not have a 2θ value of 28° to 30° or 33° to 35° for yttrium oxide XRD diffraction peaks.

[0015] According to one embodiment, the grain size is 1.5 μm to 2.5 μm.

[0016] According to one embodiment, the high-temperature resistance value above 500°C is 1.0E+8Ω·cm to 1.0E+10Ω·cm.

[0017] According to one embodiment, the resistance value at room temperature is 1.0E+10Ω·cm to 1.0E+12Ω·cm.

[0018] According to one embodiment, the relative density is 99.5% to 100.5%.

[0019] According to one embodiment, the porosity is 0.02% to 0.2%.

[0020] According to one embodiment, the thermal conductivity is 80 W / mK to 95 W / mK at room temperature and 40 W / mK to 50 W / mK at high temperatures above 500°C.

[0021] A method for manufacturing an AlN ceramic material for a semiconductor heater component according to an embodiment includes the following steps: mixing titanium dioxide (TiO2), magnesium oxide (MgO), and aluminum nitride (AlN) to form a composite powder; and sintering the composite powder.

[0022] According to one embodiment, based on 100 parts by weight of the composite powder, the content of titanium dioxide (TiO2) is 0.2 parts by weight to 0.5 parts by weight, and based on 100 parts by weight of the composite powder, the content of magnesium oxide (MgO) is 0.2 parts by weight to 1.5 parts by weight.

[0023] According to one embodiment, the sintering step is performed at a temperature of 1500°C to 2000°C.

[0024] According to one embodiment, the sintering step is pressure sintering at a unit area pressure of 5 MPa to 25 MPa.

[0025] The invention can provide an AlN ceramic material for semiconductor heater components that has excellent volume resistivity even at high temperatures, and a method for manufacturing the same.

[0026] Specifically, the AlN ceramic material of the present invention exhibits excellent volume resistivity at high temperatures above 500°C, and can also solve the problem of performance and yield reduction caused by leakage current. Furthermore, it exhibits excellent bonding and thermal conductivity even without the addition of substances such as yttrium oxide.

Implementation Method

[0032] The embodiments will now be described in detail with reference to the accompanying drawings. It should be understood that various modifications can be made to the embodiments, and the scope of this application is not limited to the embodiments described below. All modifications to the embodiments, their equivalents, and even their substitutes are within the scope of this invention.

[0033] The terminology used in this invention is for illustrative purposes only and is not intended to limit the scope. Unless otherwise specified in the content, singular expressions include plural meanings. In this specification, terms such as "comprising" or "having" are used to express the presence of the features, numbers, steps, operations, constituent elements, accessories, or combinations thereof described in the specification, and do not exclude the possibility of the presence or additional addition of one or more other features, numbers, steps, operations, constituent elements, accessories, or combinations thereof.

[0034] Unless otherwise defined, all terms used herein, including technical or scientific terms, shall have their ordinary meaning as understood by one of ordinary skill in the art. Terms commonly used, such as those defined in dictionaries, shall be understood as having the meaning in the relevant technical content, and shall not be interpreted as having an idealized or overly formal meaning unless explicitly defined in this specification.

[0035] Furthermore, in the description with reference to the accompanying drawings, the same reference numerals are used for the same constituent elements regardless of the drawing numbers, and repeated descriptions are omitted. In the description of embodiments, detailed descriptions of relevant well-known technologies are omitted when it is determined that such detailed descriptions would unnecessarily obscure the embodiments. Furthermore, when describing the constituent elements of an embodiment, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish one constituent element from other constituent elements and are not used to limit the nature or order of the corresponding constituent elements. When it is stated that a component is "connected," "linked," or "attached" to another component, it should be understood that a component can be directly connected or attached to another component, and intermediate components can also be "connected," "linked," or "attached" to that component.

[0036] When a constituent element has a common function with a constituent element of a certain embodiment, the same name is used in other embodiments for description. Unless otherwise stated, the description of one embodiment can be applied to other embodiments, and detailed descriptions of repeated content may be omitted.

[0037] The AlN ceramic material for semiconductor heater components of the present invention includes titanium nitride (TiN), magnesium aluminate (MgAl2O4), and aluminum nitride (AlN).

[0038] In components of semiconductor manufacturing equipment, a semiconductor heater is used for heating while fixing the wafer during the semiconductor manufacturing process, which may adopt a ceramic material, and, the structure may include a ceramic substrate and a heat-generating heater. Ceramic substrates must have plasma resistance properties and higher volume resistivity at low and high temperatures to maintain stable production during wafer deposition, which requires them to have excellent electrical insulation and thermal conductivity. Because aluminum nitride (AlN) is stable at high temperatures and has excellent physical properties such as electrical insulation and thermal conductivity, ceramic materials containing aluminum nitride (AlN) can be used as the main composition of ceramic substrates. However, the volume resistivity of aluminum nitride decreases with increasing temperature. Therefore, for ceramic heaters employing aluminum nitride, the volume resistivity of the ceramic body decreases as the temperature increases, which may cause leakage current. Meanwhile, in the recent semiconductor process, the volume resistivity of the aluminum nitride ceramic heater is rapidly reduced due to the constant increase in the process temperature, resulting in a leakage current situation. Therefore, it is necessary to find overcoming methods to maintain the volume resistivity of said ceramic material at high temperatures.

[0039] The AlN ceramic material used in semiconductor heater components of the present invention contains titanium nitride and magnesium aluminate, which exhibits excellent volume resistivity at high temperature and has high resistance characteristics at high temperature, which can solve the problem of performance and yield caused by leakage current.

[0040] The titanium nitride may be a second phase formed from titanium dioxide (TiO2) and the magnesium aluminate may be a second phase formed from magnesium oxide (MgO).

[0041] According to an embodiment, the AlN ceramic material for use in a semiconductor heater component may be Yttria-free.

[0042] Existing AlN ceramic materials for semiconductor heater components are made by adding titanium oxide, thereby improving density, reducing pores, improving thermal conductivity and improving bonding characteristics. However, the addition of titanium oxide produces oxygen vacancies, YAG, YAM, etc. second phase of titanium oxide, which increases the problem of leakage current at high temperatures. The present invention provides an AlN ceramic material that, as a titanium oxide-free ceramic material, can exhibit excellent volume resistivity at high temperatures while not having problems in terms of bonding properties.

[0043] According to one embodiment, the semiconductor heater component may be a plate of the semiconductor heater, a shaft of the semiconductor heater, or including both of them.

[0044] The AlN material of the present invention can be applied only to the plate, only to the shaft, or simultaneously to both the plate and the shaft in a semiconductor heater consisting of a plate and a shaft.

[0045] According to one embodiment, the magnesium aluminate (MgAl2O4) can exist as a second phase of the Mg-Al-O system.

[0046] The second phase can be confirmed by the diffraction peak in the XRD pattern measured using CuK α rays at 40 kV / 40 mA.

[0047] According to one embodiment, the present invention may include two or more XRD diffraction peaks of the second phase of the Mg-Al-O system, wherein the 2θ value of the XRD diffraction peak may be 44° to 46°.

[0048] The XRD diffraction peaks representing the second phase of the Mg-Al-O system can be two or more. This is because MgO is uniformly distributed and reacts within the material, forming a certain amount or more of the Mg-Al-O phase. Preferably, two XRD diffraction peaks can be identified, and the 2θ value of at least one of the XRD diffraction peaks can be between 44° and 46°.

[0049] Figure 1 shows the XRD analysis results according to an embodiment of the present invention. Referring to Figure 1, the diffraction peaks of the two Mg-O-Al second phases and the TiN second phase can be confirmed.

[0050] According to one embodiment, the 2θ value of the XRD diffraction peak of the TiN second phase can be 42° to 44°.

[0051] The ratio of the diffraction peak intensity of titanium nitride to that of aluminum nitride (TiN / AlN) can be 0.05% to 1%, and the ratio of the diffraction peak intensity of the second phase of the Mg-Al-O system to that of aluminum nitride (MgAl2O4 / AlN) can be 0.05% to 6%.

[0052] Compared with the main peak of aluminum nitride, when the second phase of titanium nitride and Mg-Al-O system exhibits the diffraction peak intensity within the range described, it can exhibit an increase in intensity caused by TiN and an increase in resistance caused by Mg-Al-O, while preventing a decrease in volume resistivity caused by TiN and a decrease in thermal conductivity caused by Mg-Al-O.

[0053] According to one embodiment, the XRD diffraction peak may not have XRD diffraction peaks of the yttrium oxide system with 2θ values ​​of 28° to 30° or 33° to 35°.

[0054] The AlN ceramic material of the present invention does not exhibit XRD diffraction peaks of the yttrium oxide system in its XRD pattern, i.e., no diffraction peaks of the yttrium oxide second phase appear. In other words, since no yttrium oxide additive is added during the manufacture of the AlN ceramic material, no yttrium oxide second phase is formed, thus exhibiting the absence of yttrium oxide XRD diffraction peaks. Since no XRD diffraction peaks are detected within the range of 2θ values ​​of 28° to 30° or 33° to 35°, it can be confirmed that it does not contain yttrium oxide and that it does not contain a γ-Al-O second phase.

[0055] The preferred XRD measurement conditions are an accelerating voltage / current of 40kV / 40mA, CuK α rays (wavelength 1.54060), a scanning speed of 1° / minute, and a 2θ range of 10° to 80°.

[0056] According to one embodiment, the grain size can be from 1.5 μm to 2.5 μm.

[0057] The grain size is measured using EBSD and may be related to the density of grain boundaries (the boundaries between grains). As the grain size decreases, the number of grain boundaries increases, and the potential boundary increases, which can hinder charge movement. In addition, the grain size is related to thermal conductivity, and a certain level of thermal conductivity may be required to reduce the temperature distribution deviation of the heater.

[0058] The grain size is preferably 1.5 μm to 2.0 μm, or 2.0 μm to 2.5 μm. If the grain size exceeds the range, there may be a problem of reduced high-temperature volume resistivity.

[0059] The preferred measurement conditions for the grains are as follows: after the sample roughness is reduced to Ra 0.09 to 0.03 through mirror polishing, the mapped image is captured at 2000x magnification and 20kV accelerating voltage. The final grain size is the median obtained based on the grain boundary of the captured image.

[0060] According to one embodiment, the high-temperature resistance value above 500°C can be from 1.0E+8Ω·cm to 1.0E+10Ω·cm.

[0061] Preferably, the resistance value can be measured using an AC resistor at a high temperature of 500°C to 650°C. Specifically, the analytical sample used for resistance measurement can be made into a disk shape, with platinum (Pt) coated electrodes formed at its top and bottom ends, thereby performing the measurement. The measurement range is 10 kHz to 10 mHz, and the E range is -10 V to 10 V, increasing from room temperature to 500°C in units of 100°C. The temperature is measured after reaching and maintaining the measurement temperature for 5 minutes to minimize resistance characteristic errors caused by temperature changes.

[0062] If the high-temperature resistance value is below the specified range, leakage current between the mesh and the molybdenum (Mo) heating wire cannot be blocked, causing the heater to malfunction and affecting the stable production of the CVD process. Specifically, the resistance value of traditional AlN ceramic materials decreases at high temperatures, leading to leakage current between the electrostatically charged mesh and the Mo heating wire. If the leakage current moves along the radio frequency (RF) mesh direction, the RF mesh cannot perform its functions such as wafer chucking and grounding in plasma processes. Compared with traditional AlN materials, the AlN ceramic material of this invention exhibits a higher high-temperature resistance value within the specified range, thereby blocking the leakage current between the mesh and the Mo heating wire, enabling the heater to operate stably, and thus achieving stable production of the CVD process. This solves the problem of performance and yield degradation caused by leakage current.

[0063] According to one embodiment, the room temperature resistance value can be from 1.0E+10Ω·cm to 1.0E+12Ω·cm.

[0064] The room temperature may be between 15°C and 25°C.

[0065] The heater can be operated when the room temperature resistance value is within the stated range. If it is below the stated range, the heater may be unusable due to excessive impurities.

[0066] According to one embodiment, the relative density can be between 99.5% and 100.5%.

[0067] The relative density is the density of the AlN ceramic material of the present invention, measured using the Archimedes method, compared with the theoretical density of AlN 100% (3.26 g / cm3). If the relative density is lower than the specified range, problems such as decreased mechanical properties and thermal conductivity may occur due to reduced sinterability. When the relative density is within the specified range, there will be no heater operation problems when using the product.

[0068] According to one embodiment, the porosity can be from 0.02% to 0.2%.

[0069] Porosity is formed during the sintering process by the filling of voids through the movement and diffusion of powder particles within the sintering temperature range. A porosity close to 0 indicates a single-crystal state. The preferred porosity is 0.02% to 0.15%; 0.02% to 0.1%; 0.02% to 0.05%; 0.05% to 0.2%; 0.05% to 0.15%; 0.05% to 0.1%; 0.1% to 0.2%; 0.1% to 0.15%; or 0.15% to 0.2%.

[0070] If the porosity is below the stated range, there will be no potential energy wells due to the absence of grain boundaries, which may lead to a decrease in volume resistivity; while if it exceeds the stated range, the porosity will increase significantly, potentially reducing the performance of the structural ceramics. When the porosity is within the stated range, there will be no heater operation problems when using the product.

[0071] According to one embodiment, the thermal conductivity at room temperature can be from 80 W / mK to 95 W / mK, while the thermal conductivity at high temperatures above 500°C can be from 40 W / mK to 50 W / mK.

[0072] If the thermal conductivity is below the stated range, the relative density will decrease, porosity will increase, and mechanical properties will decrease due to poor sinterability; if it exceeds the stated range, the grain size may increase, the grain boundary density may decrease, and the volume resistivity may decrease. In particular, in order to minimize the temperature distribution deviation of the heater (below 10°C at 500°C), a certain level of thermal conductivity is required even at high temperatures, so a thermal conductivity within the stated range is preferred.

[0073] The present invention provides a method for manufacturing AlN ceramic material for semiconductor heater components, comprising the following steps: mixing titanium dioxide (TiO2), magnesium oxide (MgO), and aluminum nitride (AlN) to form a composite powder; and sintering the composite powder.

[0074] The step of forming the composite powder may be to add titanium dioxide powder and magnesium oxide powder to aluminum nitride powder and mix them by dry or wet method.

[0075] To maintain the volume resistivity of ceramic materials at high temperatures, metallic additives can be added to aluminum nitride. However, these metallic additives may reduce the thermal conductivity of the ceramic heater, leading to poor temperature uniformity. The AlN ceramic material manufacturing method of the present invention solves this problem by forming a composite powder or particles containing appropriate amounts of titanium dioxide and magnesium oxide. Adding a small amount of titanium dioxide increases the resistance, while magnesium oxide increases the volume resistivity by forming a composite material. Furthermore, by not adding yttrium oxide, the potential thermal conductivity variation factors that may occur when forming second phases such as YAG and YAM to generate resistance and thermal conductivity are eliminated, thus ensuring stable material manufacturing.

[0076] According to one embodiment, based on 100 parts by weight of the composite powder, the content of titanium dioxide (TiO2) can be from 0.2 parts by weight to 0.5 parts by weight, and based on 100 parts by weight of the composite powder, the content of magnesium oxide (MgO) can be from 0.2 parts by weight to 1.5 parts by weight.

[0077] As the titanium dioxide content increases, the high-temperature electrical resistance of AlN ceramic materials decreases; while as the magnesium oxide content increases, the grain size decreases, the high-temperature electrical resistance increases, or the porosity increases. Therefore, it is necessary to form a suitable composite powder to react with AlN within an appropriate content range.

[0078] If the titanium dioxide content is below the range, it exists in the material as Ti, existing only in a state that does not affect the material itself, and therefore its phase may not be identifiable; if it exceeds the range, due to the low resistance characteristics of TiN, the overall resistance of the material will be reduced, leading to a problem of reduced volume resistivity at high temperatures.

[0079] If the magnesium oxide content exceeds the aforementioned range, it may volatilize during sintering, forming numerous small pores, thereby causing problems with material properties such as decreased density, increased porosity, and decreased structural characteristics and thermal conductivity. The magnesium oxide content is preferably 0.2 parts by weight to 1.0 parts by weight; 0.2 parts by weight to 0.5 parts by weight; 0.5 parts by weight to 1.5 parts by weight; 0.5 parts by weight to 1.0 parts by weight; or 1.0 parts by weight to 1.5 parts by weight.

[0080] According to one embodiment, the sintering step can be carried out at a temperature of 1500°C to 2000°C.

[0081] Through the sintering process, an AlN ceramic material for semiconductor heater components containing a second phase of TiN and Mg-Al-O system can be manufactured.

[0082] Preferably, the operation can be carried out at a temperature of 1600°C to 2000°C, or 1600°C to 1900°C, or 1700°C to 1900°C.

[0083] If the sintering temperature is below the range, densification cannot be achieved during sintering, and problems such as reduced density, increased porosity, decreased structural physical properties, and reduced thermal conductivity may occur; if the temperature exceeds the range, problems such as increased grain size, reduced grain boundaries, and decreased volume resistivity may occur.

[0084] According to one embodiment, the sintering step may be performed under pressure sintering at a unit area pressure of 5 MPa to 25 MPa.

[0085] The pressure sintering is a sintering process condition used to achieve densification under yttrium oxide-free conditions.

[0086] Preferably, pressure sintering can be performed at pressures of 5 MPa to 20 MPa; 5 MPa to 15 MPa; 5 MPa to 10 MPa; 10 MPa to 25 MPa; 10 MPa to 20 MPa; 10 MPa to 15 MPa; 15 MPa to 25 MPa; 15 MPa to 20 MPa; or 20 MPa to 25 MPa.

[0087] If the pressure is below the range, problems such as reduced density, increased porosity, and reduced thermal conductivity may occur; if it exceeds the range, heater performance problems such as deformation (closer proximity) of the distance between the heater and the grid, increased leakage current, and deformation of heat distribution may occur.

[0088] The present invention will now be described in more detail through examples and comparative examples.

[0089] However, these embodiments are only used to illustrate the invention in more detail, and the scope of the invention is not limited thereto.

[0090] Example

[0091] An AlN ceramic material for semiconductor heater components was manufactured by sintering a composite powder of mixed titanium dioxide (TiO2), magnesium oxide (MgO), and aluminum nitride (AlN). The compositions of the examples and comparative examples are shown in Table 1 below. Table 2 below shows the analysis results of the second phases of the examples and comparative examples where the second phases of TiN and Mg-Al-O were confirmed.

[0092] [Table 1] First component (AlN, mass%) Second component (TiO2, mass%) Third component (MgO, mass%) Fourth component (Y2O3, mass%) Crystalline phase Main phase Second phase Example 1 99.25 0.25 0.5 0 AlN TiN, Mg-Al-O Example 2 98.75 0.25 1 0 AlN TiN, Mg-Al-O Example 3 98.25 0.25 1.5 0 AlN TiN,Mg-Al-O Comparative Example 1 98.75 0.75 0.5 0 AlN TiN, Mg-Al-O Comparative Example 2 98.25 0.75 1 0 AlN TiN, Mg-Al-O Comparative Example 3 100 0 0 0 AlN - Comparative Example 4 95 0 0 5 AlN Y-Al-O Comparative Example 5 99.6 0.1 0 0.3 AlN Al-O

[0093] [Table 2] project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 XRD second phase (Phase separation rate) TiN O (0.10) O (0.11) O (0.09) O (0.8) O (0.77) spinel (MgAl2O) O (2.0) O (2.3) O (5.7) O (2.6) O (5.0) Diffraction peak intensity ratio (%) MgAl2O4 / AlN 1.55 1.78 5.99 2.80 3.15 Diffraction peak intensity ratio (%) TiN / AlN 0.08 0.36 0.26 1.54 1.32

[0094] As shown in Table 1 above, the second phase of the examples and comparative examples was confirmed. In the comparative example with added yttrium oxide, Y-Al-O was confirmed as the second phase.

[0095] Figures 2a and 2b show the XRD analysis results of the embodiments and comparative examples of the present invention. By measuring the XRD diffraction peaks, the crystal properties of the AlN ceramic material were confirmed, and it was confirmed that a second phase of TiN and Mg-Al-O system was formed.

[0096] Referring to Figures 2a and 2b and Table 2, XRD diffraction peaks of Mg-Al-O were confirmed in the composite powder phase within the range of 0.5 / 1 / 1.5 wt% MgO content, and these peaks occurred between 36° and 38° and 44° and 46° with 2-theta (2θ). In particular, the second diffraction peak (2nd Peak) of Mg-Al-O occurring between 44° and 46° in the XRD can be considered a characteristic of the high-temperature composition of the AlN ceramic material of this invention. That is, the presence of only one main peak indicates formation only at the seed level, while the presence of multiple diffraction peaks of the Mg-Al-O phase indicates the formation of a phase with a certain or greater distribution. In summary, the presence of multiple diffraction peaks of the Mg-Al-O phase indicates the formation of a greater Mg-Al-O phase, which may be influenced by process conditions such as the amount and dispersibility of MgO. Furthermore, it can be confirmed that with the increase of MgO content, the intensity of the diffraction peak increases (the intensity ratio compared with the AlN main peak), and shows a preferred range of less than 6% compared with the AlN main peak.

[0097] XRD diffraction peaks of TiN were confirmed in the composite powder phase with TiO2 content in the range of 0.25 / 0.75 wt%, and were generated between 42° and 44° with 2-theta (2θ). In addition, it was confirmed that the intensity of the diffraction peak increased with increasing TiO2 content (intensity ratio compared with the AlN main peak), and showed a preferred range of less than 1% compared with the AlN main peak.

[0098] The relative density, porosity, grain size, volume resistivity and other characteristics of the embodiments and comparative examples described herein are analyzed and shown in Table 3, Figure 3, Figure 4, Figure 5a and Figure 5b below.

[0099] [Table 3] Relative density (%) Porosity (%) Crystallization (μm) Volume resistivity (Ω·cm) 25℃ 500℃ Example 1 99.866 0.03 2.28 1.5E+11 4.8E+8 Example 2 100.198 0.04 1.83 1.5E+11 1.1E+9 Example 3 100.45 0.18 1.89 4.0E+10 8.4E+8 Comparative Example 1 100.416 0.06 2.24 6.1E+10 9.4E+7 Comparative Example 2 100.519 0.10 1.74 5.5E+10 9.0E+7 Comparative Example 3 99.981 0.09 4.96 2.1E+10 1.2E+6 Comparative Example 4 101.533 0.38 5.63 8.1E+10 1.4E+7 Comparative Example 5 99.079 0.3 7.37 4.8E+11 2.4E+7

[0100] The relative density and porosity of the sintering gas must meet the requirements of a relative density of ≥99% and a porosity of ≤0.2% to produce structural ceramics. Referring to Table 3 and Figure 3 above, it can be confirmed that the compositions of Examples 1 to 3 meet the target relative density and porosity. In particular, it can be confirmed that the grain growth control effect based on the Mg increment is effective, and a significant crystal growth control effect is confirmed in the range of 0.5 to 1 wt%, but the grain size is similar when reaching the limit of 1 wt% and 1.5 wt%. Porosity tends to increase with increasing Mg content, and it increases significantly when the Mg content is 1.5 wt%. It can be expected that when the Mg content is above this level, the performance of the structural ceramics will decrease due to porosity. Therefore, it can be confirmed that the appropriate limit range of Mg content is ≤1.5 wt%.

[0101] To measure volume resistivity, a sample with a thickness of 2 mm and a diameter of 12 mm was prepared. Electrodes made of platinum were formed on the top and bottom of the sample with a diameter of 12 mm, thus forming a sample. Bio-Logig HTF-1100 and SP-300 instruments were used, with a measurement voltage of 2.5 V and a measurement frequency of 10 mHz to 10 kHz, and an AC resistor was used for measurement.

[0102] Referring to Table 3 and Figure 4 above, for TiN, when a high-temperature volume resistivity of 1.0E+8 Ω·cm or higher is required, an addition of 0.25 wt% TiO2 in the composite powder is sufficient. Furthermore, the volume resistivity decreases with increasing TiN yield. The composite powder exhibits high-temperature, high-resistivity characteristics within the range of 0.2 to 0.5 wt% TiO2 and 0.2 to 1.5 wt% MgO, satisfying the high-temperature volume resistivity requirement of 1.0E+8 Ω·cm. That is, in the composite powder formation step, for materials sintered with added TiO2 and MgO, the range where the volume resistivity measured at 500°C satisfies 1.0E+8 Ω·cm or higher is the range where 0.25% TiO2 is added. It can be expected that the volume resistivity will meet 1.0E+8 Ω·cm within the range of 0.2 to 0.5 wt%. Furthermore, for AlN ceramic materials sintered with added Ti and Mg oxides, the range in which the volume resistivity measured within the 500℃ range meets or exceeds 1.0E+8 Ω·cm is the range with the addition of 0.25 wt% TiO2 and 0.5 / 1 / 1.5 wt% MgO. It can be expected that the volume resistivity of MgO in the range of 0.2 to 1.5 wt% will meet or exceed 1.0E+8 Ω·cm.

[0103] When the MgO content is 1 wt%, it exhibits the highest high-temperature volume resistivity characteristics at 500°C, and the high-temperature volume resistivity decreases from 1.5 wt%. It can be expected that the high-temperature resistivity will decrease as the MgO content is further increased. In addition, since the composition of Example 3 shows a trend of increased porosity, it can be determined that it is difficult to obtain the desired effect by increasing the content when the MgO content is above 1.5 wt%.

[0104] Referring to Figures 5a and 5b, the high-temperature volume resistivity based on grain size exhibits the characteristic that the high-temperature volume resistivity increases as the grain size decreases. In particular, when MgO is 1 wt%, the grain size is the smallest and the high-temperature volume resistivity is the highest. With the increase of TiO2 content, the grain size shows a decreasing trend, but the high-temperature volume resistivity also decreases, indicating that TiO2 has a greater impact on increasing TiN yield than on reducing grain size.

[0105] In summary, embodiments have been described with reference to the limited accompanying drawings. Those skilled in the art can make various modifications and variations based on the description. For example, appropriate results can be obtained by performing the described techniques in a different order than the described methods, and / or by combining or integrating the described constituent elements in a different manner than the described methods, or by replacing or substituting them with other constituent elements or equivalents.

[0106] Therefore, other embodiments, other implementations and equivalents of the claims are all within the scope of the appended patent applications. [Simplified Explanation of the Diagram]

[0027] Figure 1 is the XRD analysis result according to an embodiment of the present invention.

[0028] Figures 2a and 2b are the XRD analysis results of the embodiments and comparative examples of the present invention.

[0029] Figure 3 is a graph showing the relative density, porosity, and grain size of the embodiments and comparative examples of the present invention.

[0030] Figure 4 is a graph of the volume resistivity of the embodiments and comparative examples of the present invention.

[0031] Figures 5a and 5b are comparison diagrams of grain size and volume resistivity in embodiments and proportions of the present invention.

Claims

1. An AlN ceramic material for use in semiconductor heater components, characterized in that it comprises titanium nitride (TiN), magnesium aluminate (MgAl2O4), and aluminum nitride (AlN), and does not contain yttrium oxide.

2. The AlN ceramic material for a semiconductor heater component as claimed in claim 1, characterized in that the semiconductor heater component is a plate of a semiconductor heater, or a shaft of a semiconductor heater, or includes both.

3. The AlN ceramic material for semiconductor heater components as claimed in claim 1, characterized in that the magnesium aluminate (MgAl2O4) exists as a second phase of the Mg-Al-O system.

4. The AlN ceramic material for semiconductor heater components as claimed in claim 1, characterized in that it comprises two or more Mg-Al-O second phases with X-ray diffraction (XRD) peaks, the 2θ value of said XRD diffraction peaks being 44° to 46°.

5. The AlN ceramic material for semiconductor heater components as claimed in claim 4, characterized in that the XRD diffraction peaks do not have yttrium oxide XRD diffraction peaks with 2θ values ​​of 28° to 30° or 33° to 35°.

6. The AlN ceramic material for semiconductor heater components as claimed in claim 1, characterized in that the grain size is 1.5 μm to 2.5 μm.

7. The AlN ceramic material for semiconductor heater components as claimed in claim 1, characterized in that its high-temperature resistance value at temperatures above 500°C is 1.0E+8Ω·cm to 1.0E+10Ω·cm.

8. The AlN ceramic material for a semiconductor heater component as claimed in claim 1, characterized in that its resistivity at room temperature is from 1.0E+10Ω·cm to 1.0E+12Ω·cm.

9. The AlN ceramic material for semiconductor heater components as claimed in claim 1, characterized in that its relative density is 99.5% to 100.5%.

10. The AlN ceramic material for a semiconductor heater component as claimed in claim 1, characterized in that the porosity is 0.02% to 0.2%.

11. The AlN ceramic material for semiconductor heater components as claimed in claim 1, characterized in that it has a thermal conductivity of 80 W / mK to 95 W / mK at room temperature and a thermal conductivity of 40 W / mK to 50 W / mK at high temperatures above 500°C.

12. A method for manufacturing an AlN ceramic material for a semiconductor heater component as claimed in claim 1, characterized in that it comprises the following steps: mixing titanium dioxide (TiO2), magnesium oxide (MgO), and aluminum nitride (AlN) to form a composite powder; and sintering the composite powder.

13. The method for manufacturing AlN ceramic material for semiconductor heater components as claimed in claim 12, characterized in that, based on 100 parts by weight of the composite powder, the content of titanium dioxide (TiO2) is 0.2 parts by weight to 0.5 parts by weight, and based on 100 parts by weight of the composite powder, the content of magnesium oxide (MgO) is 0.2 parts by weight to 1.5 parts by weight.

14. The method for manufacturing AlN ceramic material for semiconductor heater components as claimed in claim 12, characterized in that the sintering step is performed at a temperature of 1500°C to 2000°C.

15. The method for manufacturing AlN ceramic material for semiconductor heater components as claimed in claim 12, characterized in that the sintering step is pressure sintering at a unit area pressure of 5 MPa to 25 MPa.

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