Ceramic heater for semiconductor manufacturing equipment

Abstract

A ceramic heater for semiconductor manufacturing equipment is disclosed, which has excellent volume resistance at high temperatures and thermal conductivity at room temperature, especially, compared to ordinary ceramic heaters for semiconductor manufacturing equipment. The ceramic heater for semiconductor manufacturing equipment is made of a) aluminum nitride (AlN), b) magnesium oxide (MgO), alumina (Al 2 O 3 ) and spinel (MgAl 2 O 4 ), c) calcium oxide (CaO) and d) titanium dioxide (TiO 2 ) a ceramic substrate comprising a heat generating element; and a resistive heating element.

Description

[Technical field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0160465 filed on November 19, 2021 and Korean Patent Application No. 10-2022-0126575 filed on October 4, 2022, and incorporates all contents disclosed in the documents of said Korean patent applications as part of this specification.

[0002] The present invention relates to a ceramic heater for use in semiconductor manufacturing equipment, and more specifically to a ceramic heater for semiconductor manufacturing equipment which is superior in volume resistance at high temperatures and thermal conductivity at room temperature compared to ordinary ceramic heaters for semiconductor manufacturing equipment. [Background technology]

[0003] Heaters for PECVD or CVD processes used in semiconductor manufacturing equipment include a ceramic substrate and a resistance heating element. Of these, the ceramic substrate must have plasma resistance and high volume resistance at low and high temperatures to improve productivity in the wafer deposition process. For this reason, aluminum nitride (AlN) has been proposed as the main component of the ceramic substrate. This aluminum nitride is stable at high temperatures and has excellent physical properties such as electrical insulation and thermal conductivity. In addition, since it has a thermal expansion coefficient similar to that of silicon, it is mainly used in semiconductor manufacturing equipment that requires high electrical resistance at high temperatures.

[0004] Meanwhile, in recent semiconductor manufacturing processes, the miniaturization of processes and the enlargement of equipment diameters are progressing in order to improve yields, but such miniaturization of processes and the enlargement of equipment diameters cause various problems in the semiconductor manufacturing process. Therefore, next-generation semiconductor processing technology that can overcome these problems is required. In response to this, the process is carried out at a harsher environment of 600°C to 700°C, and ceramic characteristics are required that have a volume resistivity of at least 5.0E+9Ω.cm to 1.0E+10Ω.cm at 500°C and a volume resistivity of at least 1.0E+8Ω.cm to 1.0E+9Ω.cm at 600°C to 700°C. In addition, general aluminum nitride ceramic heaters tend to have a rapid decrease in volume resistivity from 500°C onwards, causing leakage current.

[0005] In this regard, Korean Patent Publication No. 10-2006-0111279 (hereinafter referred to as Patent Document 1), Korean Patent Publication No. 10-2006-0103146 ​​(hereinafter referred to as Patent Document 2), and Korean Patent Publication No. 10-2018-0126142 (hereinafter referred to as Patent Document 3) are all related to aluminum nitride heaters, and all of them sinter rare earth oxides (yttrium oxide, etc.) in addition to aluminum nitride and magnesium oxide, and disclose that Patent Document 1 has a volume resistivity of 1.0E+15 Ω.cm or more at room temperature, Patent Document 2 has a volume resistivity of 1.0E+15 Ω.cm or more at 200°C, and Patent Document 3 has a volume resistivity of more than 1.0E+8 Ω.cm at 400°C.

[0006] However, none of these patent documents provide a volume resistivity in the range of 1.0E+8Ω.cm to 1.0E+9Ω.cm at 600°C to 700°C, which is the temperature condition of recent semiconductor processes, and a volume resistivity in the range of 5.0E+9Ω.cm to 1.0E+10Ω.cm at 500°C. This is due to the material characteristics of aluminum nitride, which only decreases in volume resistivity above 500°C, as stated in many papers and patent documents, and at this time, a problem of a sudden increase in leakage current occurs. To improve this, manufacturers of semiconductor device heaters have been continuously researching ways to improve volume resistivity above 500°C (especially 600°C to 700°C), but no satisfactory solution has yet been found.

[0007] In addition, conventional aluminum nitride ceramic heaters containing magnesium oxide and rare earth oxides have a thermal conductivity of only about 40W / mk to 50W / mk at room temperature, which causes problems such as a large deviation in temperature uniformity and a decrease in yield. Generally, when a deposition process is performed at high temperatures, the temperature is lowered to an appropriate temperature (about 200°C to 300°C) for chamber cleaning after the process and the process is performed in a dry or wet manner. At this time, if the thermal conductivity is low, it takes a cooling time to lower the cleaning temperature and a heat up time to raise the temperature to the required temperature again after cleaning. In addition, if the thermal conductivity is low, more unnecessary time is required than in other cases, which inevitably leads to a decrease in yield. In particular, since quality and yield are priorities in semiconductors, it is necessary to increase the thermal conductivity of conventional ceramic heaters to improve yield. In addition, if there is a large deviation in temperature uniformity of thermal conductivity, it can result in a shortened product life due to thermal stress and thermal shock. Therefore, in order to be compatible with next-generation semiconductor processes, there is a demand for ceramic heaters that simultaneously have a thermal conductivity of 60 W / mk or more, and preferably 80 W / mk or more. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Korean Patent Publication No. 10-2006-0111279 [Patent Document 2] Korean Patent Publication No. 10-2006-0103146 [Patent Document 3] Korean Patent Publication No. 10-2018-0126142 Summary of the Invention [Problem to be solved by the invention]

[0009] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a ceramic heater for semiconductor manufacturing equipment which is superior in volume resistivity at high temperatures and thermal conductivity at room temperature compared to conventional ceramic heaters for semiconductor manufacturing equipment. [Means for solving the problem]

[0010] In order to achieve the above object, the present invention provides a ceramic ceramic material comprising a) aluminum nitride (AlN), b) magnesium oxide (MgO), alumina (Al 2 O 3 ) and spinel (MgAl 2 O 4 ), c) calcium oxide (CaO) and d) titanium dioxide (TiO 2 and a ceramic heater for semiconductor manufacturing equipment, the ceramic heater comprising: a ceramic substrate comprising: Effect of the Invention

[0011] The ceramic heater for semiconductor manufacturing equipment according to the present invention has the advantage that it is superior in volume resistance at high temperatures and thermal conductivity at room temperature, as compared with ordinary ceramic heaters for semiconductor manufacturing equipment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The present invention will be described in detail below.

[0013] The ceramic heater for semiconductor manufacturing equipment according to the present invention is made of a) aluminum nitride (AlN), b) magnesium oxide (MgO), and c) alumina (Al 2 O 3 ) and spinel (MgAl 2 O 4 ), c) calcium oxide (CaO) and d) titanium dioxide (TiO 2 ) and a resistive heating element.

[0014] Ceramic heaters used in semiconductor manufacturing equipment are composed of a ceramic substrate and a resistance heating element, and the ceramic substrate must have plasma resistance and high volume resistance at high temperatures in order to improve the productivity of semiconductor manufacturing equipment that includes the ceramic heater. For this reason, aluminum nitride (AlN), which is stable at high temperatures, has excellent physical properties such as electrical insulation and thermal conductivity, and has a thermal expansion coefficient similar to that of silicon, is used as the main component of the substrate for ceramic heaters for semiconductor manufacturing equipment (other components include additives such as magnesium oxide and rare earth metal oxides).

[0015] However, in recent semiconductor processes, the miniaturization of processes and the enlargement of equipment diameters for improved yields have led to a demand for next-generation semiconductor process technology. In particular, since semiconductor manufacturing processes are carried out at 600°C to 700°C, excellent ceramic properties are required, such as a volume resistivity at 500°C ranging from at least 5.0E+9Ω.cm to 1.0E+10Ω.cm and a volume resistivity at 600°C to 700°C ranging from at least 1.0E+8Ω.cm to 1.0E+9Ω.cm. However, conventional ceramic heaters containing aluminum nitride as the main component of the ceramic substrate have a problem that the volume resistivity drops sharply from 500°C and leakage current occurs. In addition, conventional aluminum nitride ceramic heaters containing rare earth oxides have a thermal conductivity of only about 40W / mk to 50W / mk at room temperature, so they are also required to have a thermal conductivity of 60W / mk or more, preferably 80W / mk or more, to be suitable for next-generation semiconductor processes.

[0016] Therefore, the applicant has conducted extensive research and has found that, in addition to aluminum nitride (AlN), magnesium oxide (MgO), alumina (Al 2 O 3 ) and Spinel (MgAl 2 O 4 ) and calcium oxide (CaO) and titanium dioxide (TiO 2 ), it has been confirmed that the volume resistivity is excellent even at temperatures of 500°C or higher, preferably 600°C to 700°C, and more preferably about 650°C, and that the thermal conductivity at room temperature is also excellent, at 80 W / mK or higher.

[0017] More specifically, the aluminum nitride contained in the ceramic substrate of the ceramic heater for semiconductor manufacturing equipment according to the present invention is a material that does not contain other components, namely, magnesium oxide (MgO), alumina (Al 2 O 3 ) and Spinel (MgAl 2 O 4 ), calcium oxide (CaO); and titanium dioxide (TiO 2 Specifically, the aluminum nitride may be included in an amount of 75% by weight to 98% by weight. The magnesium oxide may be included to improve the thermal conductivity and volume resistivity of the ceramic heater. The magnesium oxide is organically combined with the aluminum nitride and alumina described below (sintering, particularly sintering with alumina) to form MgAl 2 O 4It is used to form a spinel ceramic phase. The content of the magnesium oxide may be 0.1 to 10% by weight, preferably 0.1 to 5% by weight, more preferably 1 to 4% by weight. If the content of the magnesium oxide is less than 0.1% by weight, MgAl formed by sintering aluminum nitride and magnesium oxide and sintering alumina and magnesium oxide may be used. 2 O 4 The spinel phase is hardly formed, and the effect may be slight or nonexistent. If the content of magnesium oxide exceeds 10% by weight, the density after sintering may be low and the thermal conductivity may decrease.

[0018] Meanwhile, the aluminum nitride is preferably made of only micrometer-sized particles. The magnesium oxide may be made of only particles having an average size of nanometer-sized (tens to hundreds of nanometers), or may be made of only particles having an average size of micrometer-sized (several micrometers), or may be a mixture of nanometer-sized and micrometer-sized particles. However, the magnesium oxide is preferably made of only nanometer-sized particles or only micrometer-sized particles rather than a mixture of nanometer-sized and micrometer-sized particles, and more preferably made of only nanometer-sized particles to have better sinterability, volume resistance and thermal conductivity.

[0019] That is, the aluminum nitride constituting the ceramic heater of the present invention, more precisely the ceramic substrate, may be contained as micro-sized particles, and the magnesium oxide may be contained as nano-sized particles, micro-sized particles, or nano / micro-sized particles. In this case, the magnesium oxide is preferably contained as nano-sized particles or micro-sized particles, and more preferably as nano-sized particles. If the aluminum nitride and magnesium oxide powder particles do not have micro-nano, micro-micro, or micro-nano / micro sizes, the physical properties such as volume resistance and thermal conductivity of the ceramic heater required in the next generation semiconductor process cannot be satisfied. The average particle size of the aluminum nitride particles is preferably 0.9 μm to 1.4 μm. In addition, when the magnesium oxide particles are nanometer-level, the average particle size is preferably 50 nm to 100 nm, and when the magnesium oxide particles are micrometer-level, the average particle size is preferably 3 μm to 5 μm.

[0020] Next, the alumina contained in the ceramic substrate of the present invention is sintered with the magnesium oxide to form MgAl 2 O 4 The alumina content may be 0.05% to 5% by weight, preferably 0.05% to 3.5% by weight, more preferably 0.5% to 2% by weight. If the alumina content is less than 0.05% by weight, the MgAl formed by sintering with the magnesium oxide may be used to form a spinel phase. 2 O 4 The spinel phase may be barely formed and may have little or no effect, and if the alumina content exceeds 5 wt. %, the problem of a large decrease in thermal conductivity may occur.

[0021] On the other hand, the present invention uses magnesium oxide (MgO) and alumina (Al) on the ceramic substrate of the ceramic heater for semiconductor manufacturing equipment. 2 O 3 ), instead of including spinel (MgAl 2 O4 ) may be included alone. That is, the main purpose of using magnesium oxide and alumina in the present invention is to 2 O 4 The formation of the spinel phase is the cause of the spinel (MgAl 2 O 4 ) can also be included as a raw material. In addition, spinel (MgAl 2 O 4 ) may be basically contained, and one or more of magnesium oxide and alumina may be contained together.

[0022] And, excluding the magnesium oxide and alumina, spinel (MgAl 2 O 4 ) alone, spinel (MgAl 2 O 4 The content of the spinel (MgAl 2 O 4 If the content of ) is less than 1 wt %, a sufficient spinel phase will not be present, and the desired volume resistivity will not be obtained. If it exceeds 12 wt %, the amount of spinel phase, which has a relatively low thermal conductivity, will increase, and there is a risk of a decrease in the overall thermal conductivity.

[0023] In addition, the spinel (MgAl 2 O 4 ) is also included together with any one or more of magnesium oxide and alumina. 2 O 4 ) may be contained in the same amount as above. However, MgAl may also be contained by sintering between aluminum nitride and magnesium oxide, and between alumina and magnesium oxide. 2 O 4 The formation of the spinel phase reduces the spinel (MgAl 2 O 4It is preferable that the content of the spinel (MgAl) does not exceed 12% by weight. 2 O 4 ) is included together with any one or more of the magnesium oxide and alumina, MgAl produced by sintering between the aluminum nitride and magnesium oxide and between the alumina and magnesium oxide 2 O 4 The spinel phase and the single spinel (MgAl 2 O 4 ) should not exceed 12% by weight in total.

[0024] Furthermore, from the first production, spinel (MgAl 2 O 4 Even when magnesium oxide and alumina are included without the spinel (MgAl 2 O 4 The content of MgAl is preferably 1 to 12% by weight, as described above. In this case, if the content of magnesium oxide relative to the alumina is excessively contained so as to exceed the stoichiometric ratio, the magnesium oxide that remains without reacting with the alumina is further converted to MgAl through reaction with alumina that is generated when a part of aluminum nitride reacts with oxygen during high-temperature sintering. 2 O 4 In some cases, a spinel phase may be formed. In such cases, the spinel (MgAl 2 O 4 ) is preferably the same as above.

[0025] Next, calcium oxide contained in the ceramic substrate of the present invention is used to maximize the volume resistivity and thermal conductivity of the ceramic heater. The content of calcium oxide may be 0.01 to 4% by weight, preferably 0.1 to 3% by weight. If the content of calcium oxide is less than 0.01% by weight, it is difficult to maximize the volume resistivity and thermal conductivity of the ceramic heater of the present invention, and if the content of calcium oxide is more than 4% by weight, there may be no further advantage in maximizing the volume resistivity and thermal conductivity of the ceramic heater of the present invention.

[0026] Titanium dioxide contained in the ceramic substrate of the present invention is also used to maximize the volume resistivity and thermal conductivity of the ceramic heater of the present invention. The content of the titanium dioxide may be 0.01 to 7% by weight, preferably 0.1 to 5% by weight. If the content of the titanium dioxide is less than 0.01% by weight, it may be difficult to maximize the volume resistivity and thermal conductivity of the ceramic heater of the present invention, and if the content of the titanium dioxide is more than 7% by weight, there may be no further advantage in maximizing the volume resistivity and thermal conductivity of the ceramic heater of the present invention.

[0027] The above-mentioned aluminum nitride (AlN), magnesium oxide (MgO), and alumina (Al 2 O 3 ) and Spinel (MgAl 2 O 4 ), calcium oxide (CaO); and titanium dioxide (TiO 2 ) is preferably included in the ceramic substrate in a sintered form. In this case, the ceramic substrate is preferably made of MgAl 2 O 4 Spinel phase (formed by sintering between aluminum nitride and magnesium oxide or between alumina and magnesium oxide) or by adding spinel (MgAl 2 O 4) formed by the proprietary process) and, when alumina is used, the AlON phase formed by sintering between aluminum nitride and alumina.

[0028] Therefore, the ceramic substrate is MgAl 2 O 4 The MgAl phase may include an AlON phase while basically including a spinel phase. 2 O 4 When the spinel phase and the AlON phase are contained together, the MgAl 2 O 4 The spinel phase and the AlON phase are preferably contained in the ceramic substrate in a weight ratio of 7 to 10:1 (at this time, the AlON phase may be contained in an amount of 0.1 to 2% by weight). If MgAl 2 O 4 If the weight ratio of the spinel phase to the AlON phase exceeds the above range, the volume resistivity at high temperatures may decrease, or the thermal conductivity at high temperatures may decrease. 2 O 4 In addition to the spinel phase and the AlON phase, raw materials such as aluminum nitride may be included together.

[0029] The ceramic heater for semiconductor manufacturing equipment according to the present invention (more precisely, the ceramic substrate or ceramic sintered body) as described above is characterized in that the volume resistivity at 500°C is 1.0E+10 Ω.cm to 9.0E+10 Ω.cm, the volume resistivity at 650°C is 1.0E+9 Ω.cm to 8.0E+9 Ω.cm, and the thermal conductivity at room temperature is 80 W / mk or more, preferably 80 W / mk to 90 W / mk. In other words, the purpose of the present invention cannot be achieved unless the ceramic heater simultaneously satisfies all of the volume resistivity at 500°C, the volume resistivity at 650°C, and the thermal conductivity at room temperature. Another characteristic of the ceramic heater of the present invention is that the leakage current is less than 0.05 μA, preferably 0.01 μA to 0.035 μA.

[0030] If the volume resistivity is not satisfied, it is difficult to apply the ceramic heater to the next-generation semiconductor manufacturing process, and even if it is applied, the leakage current increases rapidly, which may cause problems such as cracking of the wafer. Also, if the thermal conductivity is not satisfied, the deviation of temperature uniformity becomes large, which may cause problems such as a decrease in yield. In general, when a deposition process is performed at high temperature, the temperature is lowered to an appropriate temperature (about 200°C to 300°C) for chamber cleaning after the process, and the process is performed in a dry or wet manner. In this case, if the thermal conductivity is low, unnecessary time is required, such as a cooling time to lower the cleaning temperature and a heat up time to raise the temperature to the required temperature after cleaning, which inevitably leads to a decrease in yield. Also, if the deviation of temperature uniformity of thermal conductivity is large, the product life may be shortened due to thermal stress and thermal shock.

[0031] On the other hand, the ceramic substrate of the present invention is made of the above-mentioned aluminum nitride (AlN), magnesium oxide (MgO), alumina (Al 2 O 3 ) and Spinel (MgAl 2 O 4 ), calcium oxide (CaO); and titanium dioxide (TiO 2 ), as well as titanium nitride (TiN); tungsten carbide (WC); carbon nanotubes (CNT); boron nitride (BN); silicon dioxide (SiO 2); graphene; and one or more rare-earth metal oxides selected from the group consisting of scandium (Sc), yttrium (Y), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (YB), and lutetium (Lu). The ceramic substrate of the present invention does not contain manganese oxide such as MnO. If manganese oxide is included in the ceramic substrate, problems such as a sudden drop in volume resistivity will occur.

[0032] The rare earth metal oxide may contain one rare earth metal, or may contain two to five different rare earth metals, which can be advantageous in improving the thermal conductivity of the ceramic heater. Examples of rare earth metal oxides containing two to five different rare earth metals include europium-gadolinium composite oxide (EuGdO X ), samarium-gadolinium oxide (SmGdO X ), cerium-europium oxide (CeEuO X ), samarium-cerium oxide (SmCeO X ), gadolinium-samarium oxide (GdSmO X ) and lanthanum-cerium composite oxide (LaCeO X ) and other composite oxides containing two different rare earth metals; samarium-cerium-europium composite oxide (SmCeEuO X ), gadolinium-cerium-lanthanum composite oxide (GdCeLaO X ) and europium-gadolinium-samarium oxide (EuGdSmO X ) and other composite oxides containing three different rare earth metals; samarium-cerium-gadolinium-europium composite oxide (SmCeGdEuO X) and gadolinium-samarium-europium-lanthanum composite oxide (GdSmEuLaO X ), and samarium-cerium-europium-gadolinium-lanthanum composite oxide (SmCeEuGdLaO X ) and other composite oxides containing two to five different rare earth metals (oxides) can be used without any particular restrictions.

[0033] The rare earth metal oxide containing two to five different rare earth metals can contain a variety of rare earth metals in various mixing ratios. For example, the rare earth metal oxide containing two to five different rare earth metals can contain two rare earth metals (oxides) in a weight ratio of 2.5 to 3.5:1, three rare earth metals (oxides) in a weight ratio of 1 to 3.5:0.5 to 2.5:1, four rare earth metals (oxides) in a weight ratio of 1.5 to 3.5:0.5 to 2.5:1 to 2.5:1, or five rare earth metals (oxides) in a weight ratio of 1 to 3:0.5 to 1.5:0.5 to 1.5:1 to 2:1, etc., so that the desired effect of the rare earth metal oxide can be maximized. More specifically, SmCeEuO X The ratio of rare earth metals (oxides) is 2:1:1, GdCeLaO X 3:2:1, EuGdSmO X is 1.5:1.5:1, SmCeGdEuO X is 2:1:1.5:1, GdSmEuLaO X is 3:2:2:1, SmCeEuGdLaO X can be in a weight ratio of 2:1:1:1.5:1.

[0034] When the rare earth metal oxide contains two or more different rare earth metals (oxides), one of the rare earth metals may be dissolved in the remaining one (or any one) rare earth metal oxide. This changes the crystal of the rare earth metal oxide, and therefore the rare earth composite oxide may have more oxygen lattice defects than a single rare earth metal oxide. In this way, the rare earth composite oxide with increased oxygen lattice defects has improved interface reactivity, and can effectively react with raw material components contained in the ceramic substrate and interface or lattice oxygen of the sintered body.

[0035] Further, a method for manufacturing a ceramic heater for semiconductor manufacturing equipment according to the present invention will be described. The method for manufacturing a ceramic heater for semiconductor manufacturing equipment includes the steps of: a) mixing aluminum nitride, "one or more of magnesium oxide, alumina, and spinel," calcium oxide, titanium dioxide, an alcohol compound, and a binder, b) drying the mixture to produce a powder from which the alcohol compound component has been removed, c) compressing and molding the dried powder (first molding) to produce a preform processed into a certain shape, d) degreasing the preform to remove the binder component, and e) sintering (second molding) and polishing the degreased preform to produce a ceramic substrate.

[0036] The spinel in step a) can be prepared by mixing magnesium oxide and alumina in a ball mill and heat-treating them. The spinel can be used alone without magnesium oxide and alumina, or can be used together with a small amount of magnesium oxide and / or alumina. Step a) is a step of mixing components constituting the ceramic substrate, and can be mixed with an alcohol compound (e.g., an alcohol compound having 1 to 5 carbon atoms) and a binder. In this case, the purity of each of the components constituting the ceramic substrate (especially aluminum nitride, magnesium oxide, and alumina) is preferably 99% or more. The alcohol compound used in step a) is used to properly mix the components constituting the ceramic substrate, and examples of the alcohol compound include ethanol, methanol, and isopropyl alcohol. Similarly, examples of the binder used in step a) are polyvinyl alcohol (PVA), polyvinyl butyral (PVB), and the like, for improving the binding strength of the components constituting the ceramic substrate and preparing a molded body.

[0037] Step b) is a step of drying the powder mixture mixed in step a) to remove the alcohol component. The drying may be performed by a method known in the art such as spray drying or vacuum drying, and the drying time may vary depending on the properties of the intended ceramic heater.

[0038] The step c) is a step of compressing and molding the dried powder to produce a preform processed into a certain shape. The compression molding is the first molding (i.e., first molding) process for controlling the powder dried in the step b) into a desired size and shape, and may be press molding. In this case, in order to produce a product with a denser specification, cold isostatic pressing (CIP) may be additionally performed as necessary. The press molding is preferably performed at room temperature and under normal air, but is not limited thereto, and the atmosphere during molding may be such that it does not affect the molding of the mixture. In addition, after the molding process in the step c), a preform may be produced by processing using a green processing method (also called raw processing as it is performed before sintering) or the like.

[0039] Step d) is a step of degreasing the preform to remove binder components. The degreasing is a process for removing binders and oily contaminants, and can be performed at a temperature of 350° C. to 600° C. for 60 hours or less.

[0040] Step e) is a step of sintering (second molding) and polishing the degreased preform to manufacture a ceramic substrate. The sintering is a second molding (i.e., second molding) process to further improve the volume resistivity, etc. of the ceramic heater, and can be carried out in a high-temperature pressure sintering furnace at a pressure of 300 bar or less and a temperature of 1,300°C to 1,900°C (hot press). At this time, MgAl 2 O 4 Spinel and AlON phases may form, and thus MgAlO phases may form in the sintered ceramic substrate. 2 O 4 , AlON and residual aluminum nitride, etc. may be present.

[0041] Meanwhile, during the step c), a resistive heating element may be provided in at least one of the inside and the surface of the preform, or a resistive heating element may be provided on the surface of the ceramic substrate manufactured in the step e), and the resistive heating element may be provided in accordance with techniques known in the art.

[0042] [Mode for carrying out the invention] The present invention will be described in more detail with reference to the following specific examples. The following examples are provided to illustrate the present invention, and are not intended to limit the present invention.

[0043] [Examples 1 to 6, Comparative Examples 1 to 10] Ceramic heater manufacturing Raw materials such as aluminum nitride were mixed according to the composition in Table 1 below, and small amounts of ethanol and polyvinyl butyral (binder) were further mixed and then dried. The dried mixture was then press-molded and processed to produce a preform, which was then degreased at a temperature of 500°C for 30 hours, and the degreased preform was sintered in a high-temperature pressure sintering furnace (pressure of 250 bar, temperature of 1,700°C) and polished to produce a ceramic substrate. Finally, a resistance heating element was provided on the surface of the produced ceramic substrate to produce an aluminum nitride ceramic heater. Meanwhile, the spinel (MgAl 2 O 4 ) was prepared by mixing magnesium oxide and alumina in a ball mill and heat treating it.

[0044] [Table 1]

[0045] [Experimental Example 1] Evaluation of volume resistance and thermal conductivity of ceramic heaters A voltage of 500 V / mm was applied to each of the ceramic heaters manufactured in Examples 1 to 6 and Comparative Examples 1 to 10, and the current was measured after 1 minute (measured in a vacuum atmosphere and at room temperature) to calculate the volume resistivity. The results are shown in Table 2 below.

[0046] In addition, test pieces were prepared for each of the ceramic heaters manufactured in Examples 1 to 6 and Comparative Examples 1 to 10 according to the standard ASTM C0408-88R11 using a NETZSCH LFA 467 device, and the thermal conductivity was measured at room temperature to calculate the thermal conductivity. The results are also shown in Table 2 below.

[0047] Furthermore, the density of each of the ceramic heaters manufactured in Examples 1 to 6 and Comparative Examples 1 to 10 was calculated using Archimedes' method, and the results are also shown in Table 2 below.

[0048] [Table 2]

[0049] The volume resistivity, thermal conductivity and density of each of the ceramic heaters manufactured in Examples 1 to 6 and Comparative Examples 1 to 10 were measured. As a result, as shown in Table 2, the ceramic heaters of Examples 1 to 6 all exceeded the minimum volume resistivity at 500°C (5.0E+9Ω.cm to 1.0E+10Ω.cm) and the minimum volume resistivity at 600°C to 700°C (1.0E+8Ω.cm to 1.0E+9Ω.cm), as well as the thermal conductivity at room temperature (60 W / mk or more, preferably 80 W / mk or more), required in the next-generation semiconductor manufacturing process.

[0050] In the case of Comparative Examples 1 and 2, not only were calcium oxide and titanium dioxide not used, but the contents of the components (AlN, MgO) used also exceeded the scope of the present invention, resulting in low volume resistivity or even inability to measure it.

[0051] In the case of Comparative Examples 3 to 5, although all of the components constituting the ceramic substrate of the present invention were contained, the content of any one or more of magnesium oxide, alumina, and aluminum nitride exceeded the range of the present invention, and thus the samples exhibited low volume resistivity or low thermal conductivity.

[0052] In the cases of Comparative Examples 6 to 10, all of the components constituting the ceramic substrate of the present invention were contained, and the contents of these components were also within the scope of the present invention. However, since they contained manganese oxide, they exhibited low volume resistivity or low thermal conductivity.

[0053] Therefore, the ceramic substrate is made of aluminum nitride (AlN); magnesium oxide (MgO); alumina (Al 2 O 3 ) and Spinel (MgAl 2 O 4 ), calcium oxide (CaO); and titanium dioxide (TiO 2 It can be seen that by including all of the above-mentioned elements in appropriate amounts while not including manganese oxide, the volume resistivity and thermal conductivity targeted by the present invention can be simultaneously achieved.

Claims

1. a) Aluminum nitride (AlN), b) Magnesium oxide (MgO), alumina (Al 2 O 3 ) and spinel (MgAl 2 O 4 ) one or more of the following: c) Calcium oxide (CaO) and d) Titanium dioxide (TiO 2 A ceramic heater for semiconductor manufacturing equipment comprising: a ceramic substrate comprising: a ceramic material; and a resistance heating element.

2. 2. The ceramic heater for semiconductor manufacturing equipment according to claim 1, wherein the ceramic substrate contains aluminum nitride, magnesium oxide, alumina, calcium oxide and titanium dioxide.

3. 2. The ceramic heater for semiconductor manufacturing equipment according to claim 1, wherein the ceramic substrate contains aluminum nitride, spinel, calcium oxide and titanium dioxide.

4. 2. The ceramic heater for semiconductor manufacturing equipment according to claim 1, wherein the ceramic substrate contains aluminum nitride, magnesium oxide, alumina, spinel, calcium oxide, and titanium dioxide.

5. 2. The ceramic heater for semiconductor manufacturing equipment according to claim 1, wherein the ceramic heater has a volume resistivity of 1.0E+10 Ω.cm to 9.0E+10 Ω.cm at 500°C.

6. 2. The ceramic heater for semiconductor manufacturing equipment according to claim 1, wherein the ceramic heater has a volume resistivity of 1.0E+9 Ω.cm to 8.0E+9 Ω.cm at 650°C.

7. 3. The ceramic heater for semiconductor manufacturing equipment according to claim 2, wherein the ceramic substrate contains 0.1% to 10% by weight of magnesium oxide, 0.05% to 5% by weight of alumina, 0.01% to 4% by weight of calcium oxide, 0.01% to 7% by weight of titanium dioxide, and the remaining aluminum nitride.

8. 4. The ceramic heater for semiconductor manufacturing equipment according to claim 3, wherein the ceramic substrate contains 1% by weight to 12% by weight of spinel, 0.01% by weight to 4% by weight of calcium oxide, 0.01% by weight to 7% by weight of titanium dioxide, and the remainder being aluminum nitride.

9. 5. The ceramic heater for semiconductor manufacturing equipment according to claim 4, wherein the ceramic substrate contains 0.1% to 10% by weight of magnesium oxide, 0.05% to 5% by weight of alumina, 1% to 12% by weight of spinel, 0.01% to 4% by weight of calcium oxide, 0.01% to 7% by weight of titanium dioxide, and the remaining aluminum nitride.

10. The components a) to d) are included in a ceramic substrate in a sintered form, and the ceramic substrate is made of MgAl 2 O 4 2. The ceramic heater for semiconductor manufacturing equipment according to claim 1, comprising a spinel phase and an AlON phase.

11. The MgAl 2 O 4 11. The ceramic heater for semiconductor manufacturing equipment according to claim 10, wherein the spinel phase and the AlON phase are contained in the ceramic substrate in a weight ratio of 7 to 10:

1.

12. 2. The ceramic heater for semiconductor manufacturing equipment according to claim 1, wherein the ceramic heater has a thermal conductivity of 80 W / mk or more at room temperature.

13. 2. The ceramic heater for semiconductor manufacturing equipment according to claim 1, wherein the ceramic substrate does not contain manganese oxide.

14. The ceramic substrate is made of titanium nitride (TiN); tungsten carbide (WC); carbon nanotubes (CNT), boron nitride (BN), silicon dioxide (SiO 2 ); graphene; and one or more rare earth metal oxides selected from the group consisting of scandium (Sc), yttrium (Y), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (YB), and lutetium (Lu). The ceramic heater for semiconductor manufacturing equipment according to claim 1, further comprising one or more additives selected from the group consisting of: oxides of rare earth metals selected from the group consisting of scandium (Sc), yttrium (Y), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (YB), and lutetium (Lu).

Images