Stage

Abstract

This stage includes: a base material including a first surface and a second surface opposite the first surface; and an insulating film which is provided on the first surface including pores defined by a scale parameter α (the numerical value α is greater than 0) of 0-2.5 and by a pore diameter λ of 5-8. The scale parameter α and the pore diameter λ are coefficients defining mathematical expression (1) calculated provided that y is a double logarithm of cumulative probability F(x) calculated for a plurality of the pore diameters included in the insulating film, and x is the pore diameter of the pores.

Description

stage

[0001] One embodiment of the present invention relates to a stage for placing a substrate.

[0002] Semiconductor devices are devices that utilize the semiconducting properties of silicon and other materials. In recent years, semiconductor devices have been installed in almost all electronic devices, enabling control according to the functions of each electronic device. Semiconductor devices are constructed by stacking insulating and conductive films on a substrate such as a silicon wafer (Si-wafer), and then patterning these films or the substrate. For example, these films are stacked on the substrate using semiconductor manufacturing equipment that enables evaporation, sputtering, chemical vapor deposition (CVD), or chemical reactions on the substrate, and these films or the substrate are patterned using semiconductor manufacturing equipment that enables photolithography processes.

[0003] A semiconductor manufacturing apparatus includes a mounting table (hereinafter referred to as a stage) on which a substrate is placed. For example, components included in the stage include a base material, an insulating film formed on the base material, a cooling plate, an electrostatic chuck, and the like. Also, methods for forming an insulating film on the surface of the base material included in the stage, such as thermal spraying and anodic oxidation, are known. Patent Documents 1 and 2 describe stages including a base material on whose surface an insulating film is formed by ceramic thermal spraying, with the aim of preventing deterioration of the stage's insulating properties.

[0004] JP 2014-013874 A Registered Utility Model No. 2600558 A

[0005] The properties of the insulating and conductive films used in semiconductor devices are greatly influenced by the conditions under which these films are formed and etched. For example, these conditions include the gas (reactive gas) supplied to the semiconductor manufacturing equipment and the voltage applied to the stage. Therefore, for example, the insulating film formed on the surface of the stage substrate is required to be resistant to degradation due to the applied voltage, i.e., to have a high withstand voltage (high insulating properties).

[0006] One of the objects of the embodiments of the present invention is to provide a stage having an insulating film with good withstand voltage (insulating characteristics).

[0007] A stage for placing a substrate according to one embodiment of the present invention includes a base material including a first surface and a second surface opposite to the first surface, and an insulating film provided on the first surface and including pores having a scale parameter α (the numerical value α is greater than 0) greater than 0 and not greater than 2.5, and a pore diameter λ (the numerical value λ is greater than 0) defined as 5 or greater and 8 or less.

[0008] According to one embodiment of the present invention, a stage is provided that has an insulating film with good withstand voltage (insulating characteristics).

[0009] FIG. 1 is a perspective view showing the configuration of a stage according to a first embodiment of the present invention. FIG. 2 is a plan view showing the configuration of a stage according to a first embodiment of the present invention. FIG. 3 is a schematic diagram showing, as an example, a cross section of the stage taken along line A1-A2 of the stage shown in FIG. 2, illustrating a method for manufacturing a stage according to a first embodiment of the present invention. FIG. 4 is a flowchart showing a method for evaluating an insulating film according to a first embodiment of the present invention. FIG. 5 is a schematic diagram showing the relationship between pore diameter, the double logarithm of the cumulative probability of an insulating film, and a thermally sprayed volume film according to a first embodiment of the present invention. FIG. 6 is a plot diagram showing the relationship between a scale parameter α and a withstand voltage according to a first embodiment of the present invention. FIG. 7 is a plot diagram showing the relationship between a predicted maximum pore diameter and a withstand voltage according to a first embodiment of the present invention. FIG. 8 is a schematic diagram showing a cross section of a semiconductor manufacturing apparatus including a stage according to a second embodiment of the present invention.

[0010] A stage including an insulating film according to one embodiment of the present invention will be described below with reference to the drawings. However, the present invention can be embodied in various forms without departing from the spirit and scope of the present invention, and should not be construed as being limited to the description of the embodiment exemplified below.

[0011] In order to clarify the description, the drawings may show the width, thickness, shape, etc. of each part schematically compared to the actual embodiment, but these are merely examples and do not limit the interpretation of the present invention. Furthermore, in this specification and each drawing, elements having the same functions as those explained with reference to the previous drawings may be assigned the same reference numerals, and duplicate explanations may be omitted.

[0012] In this specification and drawings, the same reference numerals are used to collectively refer to the same or similar components, and a hyphen and a number are added after the reference numerals to refer to them individually.

[0013] In this specification, the letters "first," "second," or "third" attached to each component are convenient labels used to distinguish each component, and have no other meaning unless otherwise specified.

[0014] In the following description, for convenience of explanation, terms indicating directions such as "up" and "down" may be used. The direction in which gravity acts on the stage is "down" and the opposite direction is "up."

[0015] 1. Background of the Invention Research is being conducted, for example, to improve the withstand voltage (insulating performance) of an insulating film included in a stage on which a semiconductor device is placed.

[0016] Generally, insulating films with high breakdown voltages have low porosity. As described in the "Problem to be Solved by the Invention" section, in order to identify insulating films with high breakdown voltages, the porosity is used to evaluate the breakdown voltage (insulating properties) of insulating films. However, when evaluating insulating films based on porosity, low porosity may result in low breakdown voltages, and high porosity may result in high breakdown voltages. In other words, when evaluating insulating films, low porosity does not guarantee high breakdown voltages (good insulating performance). Therefore, it is important to find new methods for evaluating insulating films in order to improve their breakdown voltages (insulating performance).

[0017] In one embodiment of the present invention, an attempt is made to use extreme value statistics in an evaluation method for insulating films, with the aim of improving the withstand voltage (insulating performance). As a result, it has been found that by using extreme value statistics in an evaluation method for insulating films, the withstand voltage (insulating performance) of an insulating film can be expressed by the maximum pore diameter predicted by extreme value statistics. Note that the method using extreme value statistics is a commonly known method, and a detailed description thereof will be omitted here. For example, an estimation method using extreme value statistics is disclosed in "Method for Estimating Maximum Localized Corrosion Depth Using Extreme Value Statistics Method" (Boshoku Gijutsu 37, 768-773 (1988)), published by the Corrosion and Protection Society of Japan, Subcommittee 60-1.

[0018] 1 to 8 , one embodiment of the present invention is a stage or semiconductor manufacturing apparatus including an insulating film based on a mathematical formula evaluated using an insulating film evaluation method. For example, a stage 100 according to one embodiment of the present invention includes a substrate 110 including a first surface 112 and a second surface 114 opposite to the first surface 112, and an insulating film 120 provided on the first surface 112, the insulating film 120 including a plurality of pores 126, 127 having a scale parameter α greater than 0 and not greater than 2.5 and a pore diameter λ of 5 or greater and not greater than 8.

[0019] Furthermore, the scale parameter α (numerical value α is greater than 0) and the pore diameter λ (numerical value λ is greater than 0) are parameters calculated by a method for evaluating the insulating film 120. For example, the evaluation method for the insulating film 120 includes acquiring m (numerical value m is a positive integer) SEM images for n (numerical value n is a positive integer) SEM samples acquired using the insulating film 120 including a plurality of pores 126, 127, binarizing the m SEM images to generate m binary images, using the m binary images to extract a maximum pore 127 from the plurality of pores 126, 127 for each of the m binary images and acquiring the m largest pores 127, calculating a pore diameter for each of the n largest pores 127 and acquiring the m pore diameters, calculating the double logarithm of the cumulative probability F(x) for the m pore diameters, and The method includes plotting the double logarithm of the cumulative probability F(x), defining the double logarithm of the cumulative probability F(x) as y, and defining a pore diameter as x, where α is the scale parameter as described above, and λ is the pore diameter when the double logarithm of the cumulative probability F(x) is 0, calculating a volume Vs, which is the product of the sum of the areas of the m SEM images and the average of the largest pore diameters extracted from each SEM image, and a volume Va of the insulating film, and calculating a volume ratio T between the volume Vs and the volume Va, and calculating a predicted value of the largest pore diameter (predicted largest pore diameter), which is the largest value among the pore diameters of the plurality of pores 126, 127 contained in the insulating film 120, based on the relationship between the volume ratio T and y, as shown in the method (5) described below.

[0020] As a result, the stage 100 according to an embodiment of the present invention is defined by Equation (1), which is calculated using the evaluation method for the insulating film 120, and has good withstand voltage and insulating characteristics for supporting a substrate. Therefore, the stage according to an embodiment of the present invention can suppress a decrease in long-term reliability.

[0021] In the following embodiments, a stage and a semiconductor manufacturing apparatus that are one embodiment of the present invention will be described in detail.

[0022] 2. First Embodiment A stage 100 according to a first embodiment of the present invention will be described with reference to FIGS.

[0023] 2-1. Overview of Stage 100 An overview of the stage 100 will be described with reference to Figures 1 to 3. Figure 1 is a perspective view showing the configuration of the stage 100. Figure 2 is a plan view showing the configuration of the stage 100. Figure 3 is a cross-sectional view showing a cross section of the stage 100 taken along the line A1-A2.

[0024] The stage 100 has a disk-like shape. For example, the stage 100 has a diameter large enough to support a 12-inch silicon wafer. The stage 100 also includes a base material 110, an insulating film 120, a top surface (first surface 122) on which a substrate (e.g., a silicon wafer) can be placed, a bottom surface (second surface 114), holes 102, and grooves 104. The arrangement, number, and shape of the holes 102 and grooves 104 may be changed as appropriate depending on the specifications and applications of the semiconductor manufacturing equipment. The stage 100 may also include a cooling plate, an electrostatic chuck, etc.

[0025] The substrate 110 includes a first surface 112 and a second surface 114 opposite to the first surface 112. Note that the substrate 110 may be formed by bonding a plurality of substrates together.

[0026] The insulating film 120 includes a first surface 122 and a second surface 124 opposite to the first surface 122. The insulating film 120 covers the substrate 110 and is provided so as to be in contact with the substrate 110. The second surface 124 of the insulating film 120 is in contact with the first surface 112 of the substrate 110. The insulating film 120 is also provided so as to cover the inner walls of the holes 102 and the grooves 104 and to be in contact with the inner walls of the holes 102 and the grooves 104. Although not shown, the insulating film 120 is also provided so as to cover the side surfaces of the substrate 110 and to be in contact with the side surfaces of the substrate 110. As an example, the insulating film 120 in the stage 100 shown in FIG. 2 is provided on the first surface 112 of the substrate 110, but the insulating film 120 may be provided so as to cover the second surface 114 and be in contact with the second surface 114.

[0027] The groove portion 104 may be a flow path for circulating a medium, or may be a groove in which a heat source is disposed. For example, the medium and heat source are used to control the temperature of a substrate placed on the stage 100. For example, the medium is a liquid such as water, alcohol such as isopropanol or ethylene glycol, or silicone oil. The medium may be used to cool the stage 100, or may be used to heat the stage 100. For example, the heat source is a sheathed heater. A sheathed heater has the function of generating heat when electricity is passed through it.

[0028] For example, the holes 102 are holes for lift pins that lift up the substrate placed on the stage 100 .

[0029] For example, the grooves 104 and the holes 102 may be included within a bonded substrate formed by bonding multiple substrates, or may be a space (not shown) included within a bonded substrate formed by bonding multiple substrates. The grooves 104 and the holes 102 may also be formed of a porous body. For example, by configuring the grooves 104 and the holes 102 to include a porous body, a medium such as gas can be caused to flow (circulate) from one side of the grooves 104 and the holes 102 to the other side. More specifically, the porous body has multiple through-holes formed therein, allowing a medium to pass through the grooves 104 and the holes 102 and flow (circulate) therethrough. For example, the porous body is porous ceramics.

[0030] The material used for the substrate 110 is metal, ceramic, or the like. The material used for the substrate 110 may also be glass. For example, the metal is an alloy such as aluminum (Al), titanium (Ti), or stainless steel. One example of the material used for the substrate 110 is aluminum.

[0031] The material used for the insulating film 120 may be a material capable of satisfying the desired insulating properties and may be a material capable of satisfying the desired withstand voltage characteristics. For example, the material used for the insulating film 120 is an inorganic insulating material. For example, the inorganic insulating material is a metal oxide, specifically an oxide containing at least one element selected from alkaline earth metals, rare earth metals, aluminum, tantalum (Ta), titanium, chromium (Cr), zirconium (Zr), yttrium (Y), and silicon (Si), or a composite oxide thereof. For example, the material used for the insulating film 120 is aluminum oxide (Al ２ O ３ )

[0032] [2-2. Example of a Cross Section of the Stage 100] The cross-sectional configuration of the stage 100 will be described with reference to Fig. 3. Fig. 4 is a schematic diagram showing the cross section of a conventional stage. Configurations that are the same as or similar to those in Figs. 1 and 2 will be described as necessary.

[0033] As described in “2-1”, the insulating film 120 contains aluminum oxide and is provided to cover the base material 110 and to be in contact with the base material 110 .

[0034] Furthermore, as shown in the enlarged view of region 125 at the top of FIG. 3 , insulating film 120 includes a plurality of pores 126. The pore diameter of pore 126 is pore diameter X. For example, the pore diameter of the largest pore 127 among the plurality of pores 126 is maximum pore diameter X m. Note that although the pores shown in FIG. 3 are circular, actual pore shapes vary. For example, pore 126 may be a minute cavity contained in insulating film 120, a bubble, a void, an open pore connected to the outside air, or a closed pore inside insulating film 120. Pore 126 may also be called a pore, void, or the like.

[0035] For example, the thickness H1 of the insulating film 120 is not less than 150 μm and not more than 600 μm.

[0036] 2-3. Fabrication of the Stage 100 A method for fabricating the stage 100 will be described with reference to Fig. 3. Configurations that are the same as or similar to those in Figs. 1 and 2 will be described as necessary.

[0037] When the production of stage 100 begins, insulating film 120 is formed on prepared substrate 110 using thermal sprayer 180. At this time, the angle between first surface 112 and thermal sprayer 180 is set to a thermal spraying angle θ, and the speed (e.g., particle velocity) at which thermal spray material 182 is sprayed from thermal sprayer 180 is set to a particle velocity Vx. Furthermore, the distance between sprayer 181 and first surface 112 is set to distance D, and spraying angle θ is adjustable by moving nozzle 181 of thermal sprayer 180 on a semicircle or circle with a radius equal to distance D.

[0038] Various thermal spraying methods can be used as the thermal spraying method used in the method for manufacturing the stage 100. For example, atmospheric (pressure) plasma spraying is used as the thermal spraying method used in the method for manufacturing the stage 100. By using atmospheric pressure plasma spraying as the method for manufacturing the stage 100, the adhesion between the insulating film 120 and the substrate 110 is improved.

[0039] For example, the thermal sprayer 180 may move in a first direction D11 from one end of the substrate 110 along the first surface 112 to the other end, while spraying the particulate thermal spray material 182 onto the first surface 112 (first thermal spraying). Alternatively, the thermal sprayer 180 may move in a first direction D12 from the other end of the substrate 110 along the first surface 112 to one end, while spraying the particulate thermal spray material 182 onto the first surface 112 (second thermal spraying), and the thermal sprayer 180 may repeat the first thermal spraying and the second thermal spraying. Furthermore, the thermal sprayer 180 may move in the first direction D11 along the first surface 112 from the other end to one end of the substrate 110, while spraying the particulate thermal spray material 182 onto the first surface 112, and then the thermal sprayer 180 may move a predetermined distance along the first surface 112 in a direction intersecting the first direction D11, and move in the first direction D12 from the other end to one end of the substrate 110, while spraying the particulate thermal spray material 182 onto the first surface 112. The thermal sprayer 180 may also spray the particulate thermal spray material 182 onto the first surface 112 of the rotating substrate 110.

[0040] Although not shown, the sprayed material 182 formed on the substrate 110 is flat, and the insulating film 120 includes a plurality of flat sprayed materials 182. The sprayed material 182 also includes aluminum oxide, and the insulating film 120 also includes aluminum oxide. For example, the insulating film 120 including the flat sprayed materials 182 is formed so as to overlap the substrate 110. As a result, the insulating film 120 becomes dense.

[0041] At this time, the spraying angle θ is 45 degrees or more and 90 degrees or less, and the speed Vx is 250 m / sec or more and 600 m / sec or less.

[0042] For example, if the thermal sprayer 180 forms the insulating film 120 on the substrate 110 at a spraying angle θ of less than 45 degrees, the sprayed material 182 on the substrate 110 will be distorted, resulting in the resulting insulating film 120 containing many defects such as cracks. Furthermore, if the thermal sprayer 180 forms the insulating film 120 on the substrate 110 at a particle velocity Vx of less than 250 m / sec, the sprayed material 182 on the substrate 110 will not be formed sufficiently flat, resulting in the resulting insulating film 120 containing many defects such as cracks. Furthermore, if the thermal sprayer 180 forms the insulating film 120 on the substrate 110 at a particle velocity Vx of more than 600 m / sec, the sprayed material 182 will scatter on the substrate 110, resulting in the resulting insulating film 120 containing many defects such as cracks.

[0043] On the other hand, by using the method for fabricating the stage 100, it is possible to form an insulating film 120 having a maximum pore diameter Xm of 40 μm or less (see FIG. 7 ) on the substrate 110. Also, by using the method for fabricating the stage 100, it is possible to form an insulating film 120 on the substrate 110 that includes pores 126 having a scale parameter α of 2.5 or less.

[0044] As will be described in detail later, the insulating film 120 including the pores 126 with a scale parameter α of 2.5 or less has a high withstand voltage (see FIG. 6 ) and good insulating properties. As a result, the stage 100 including the insulating film 120 has a high withstand voltage and good insulating properties. Therefore, the stage 100 can be prevented from decreasing in long-term reliability.

[0045] [2-4. Evaluation Method of Insulating Film 120] A method of evaluating the insulating film 120 will be described with reference to Figs. 4 to 6. Fig. 4 is a flowchart showing the evaluation method of the insulating film 120. Fig. 5 is a schematic diagram showing the relationship between the pore diameter X, the double logarithm of the cumulative probability of the insulating film 120, and the sprayed film volume T. Fig. 6 is a plot diagram showing the relationship between the scale parameter α and the withstand voltage. Fig. 7 is a plot diagram showing the relationship between the predicted maximum pore diameter and the withstand voltage. Configurations that are the same as or similar to those in Figs. 1 to 3 will be explained as necessary.

[0046] For example, the method for evaluating the insulating film 120 includes steps 110 (S110) to 180 (S180).

[0047] When evaluation of the insulating film 120 begins, an SEM image of a cross section of the insulating film 120 containing a plurality of pores is acquired using an imaging device (not shown) such as a digital camera (S110). For example, using the insulating film 120 containing a plurality of pores, n (where n is a positive integer) SEM samples containing the cross section of the insulating film 120 for use in SEM observation are created, and images are taken of the n SEM samples, resulting in m (where m is a positive integer) SEM images. For example, when the value n is plural, images may be taken of each of the n SEM samples, resulting in m SEM images. Alternatively, SEM images may be taken and acquired for the n SEM samples so that the total number of SEM images is m. When the value n is 1, images are taken of one SEM sample, resulting in m SEM images. For example, the magnification of the microscope used to observe the cross section (SEM sample) of the insulating film 120 is 500x to 700x. For example, the SEM samples are samples of different cross sections of the entire same insulating film 120. Alternatively, the multiple SEM samples may be SEM samples obtained from the cross sections of each of multiple different insulating films 120, such as insulating film 120-1, insulating film 120-2, and so on, so that there are a total of n SEM samples.

[0048] Next, the SEM image acquired in S110 is binarized (step 120 (S120)). For example, the acquired SEM image is converted into an image (binarized image) containing only two colors, black and white, based on a set predetermined threshold. That is, a binarized image is generated using the acquired SEM image. For example, binarizing the acquired SEM image includes converting SEM image data of the acquired SEM image into binarized binary image data using an image processing device including an arithmetic processing circuit such as a CPU. For example, in S120, images are captured using multiple SEM samples (where n is 2 or more) so that a total of 60 images (m = 60) are captured, and 60 binarized images are acquired based on the 60 SEM images.

[0049] Next, the binarized image converted in S120 is used to extract the largest pores (maximum pores) from the multiple pores in the binarized image (step 130 (S130)). For example, extracting the maximum pores includes using an image processing device to detect the boundaries (boundaries) between black and white in the image data of the binarized image and extracting the largest pores from the multiple pores. S130 is performed for each of the acquired binarized images. For example, if 60 binarized images are acquired in S120, S130 is performed for each of the 60 binarized images. As a result, the 60 largest pores are extracted.

[0050] Next, the pore diameter of the largest pore extracted in S130 is calculated (step 140 (S140)). For example, calculating the pore diameter of the largest pore involves using an image processing device to calculate the diameter (pore diameter) of a circle with the boundary line detected in S130 as its circumference. As described with reference to FIG. 3, the pores in the mechanism shown in FIG. 3 are circular, but actual pore shapes vary. Therefore, the pore diameter of the largest pore is calculated by the process in S140. For example, if 60 largest pores are extracted in S130, the pore diameters of each of the 60 largest pores are calculated.

[0051] Next, the double logarithm of the cumulative probability F(x) of the pore diameter of the largest pore is plotted against the pore diameter of the largest pore extracted in S140 (step 150 (S150)). For example, the double logarithm of the cumulative probability F(x) of the pore diameter of each largest pore is calculated using an arithmetic processing circuit in the image processing device, or an arithmetic processing circuit including a CPU included in a control circuit for controlling the image processing device and the imaging device, and a plot (e.g., FIG. 5) is created with the pore diameter (μm) of the largest pore on the x-axis and the double logarithm of the cumulative probability F(x) on the y1-axis.

[0052] Next, using the plot created in S150, the slope of graph 152 and the pore diameter of the largest pore when the double logarithm of the cumulative probability F(x) is 0 are calculated (step 160 (S160)). The graph obtained by extrapolating graph 152 is graph 154. For example, using an arithmetic processing circuit in an image processing device, or an arithmetic processing circuit including a CPU included in a control circuit for controlling the image processing device and the imaging device, Equation (1) is defined by the least squares method. Here, F(x) is called the cumulative probability (-), x is called the pore diameter (μm) of the largest pore, the number α is called the scale parameter, and the number λ is called the position parameter (pore diameter of the largest pore) (μm). The slope of the graph is 1 / α, and the number λ is the pore diameter λ of the largest pore when the double logarithm of the cumulative probability F(x) is 0. The numbers α and λ are greater than 0. When the number of acquired images is small, the scale parameter α and the position parameter λ may be calculated using the minimum variance linear unbiased estimator method (MVLUE method).

[0053]

[0054] ​Next, the volume ratio between the volume of the insulating film 120 and the volume of the target insulating film 120 (target insulating film) is calculated (step 170 (S170)). For example, the volume ratio is calculated using an arithmetic processing circuit in the image processing device, or an arithmetic processing circuit including a CPU included in a control circuit for controlling the image processing device and the imaging device. For example, the plot created in S150 is a plot of the pore diameters of the 60 largest pores. Here, the average value of the thicknesses (μm) of the 60 SEM samples used in the SEM observation to obtain the original 60 SEM images from which the pore diameters of the 60 largest pores were extracted is defined as the average thickness h, and the area (μm) of the 60 SEM images is defined as the area (μm) of the 60 SEM images. ２ ) is defined as the total area s of the SEM image, and the volume (μm ３ ) (volume Vs), that is, the total volume Vs of the 60 SEM samples is expressed by the following formula (2). ２ ) is the area Sa, and the volume (μm ３ ) (volume Va) is expressed by equation (3). As a result, the volume ratio T is expressed by equation (4). For example, the area of ​​the SEM image may be the surface area of ​​the captured insulating film 120, the average thickness h may be the average pore diameter of the largest pores, and the area Sa required for the stage 100 to withstand voltage (insulation performance) may be the area of ​​the first surface 122 of the insulating film 120 or the surface area of ​​the substrate placed on the stage 100. Note that the surface area of ​​the substrate placed on the stage 100 is, for example, 12 inches (approximately 300 mm).

[0055]

[0056]

[0057]

[0058] Next, the predicted maximum pore diameter is calculated (S180). The natural logarithm of the volume ratio T is proportional to the double logarithm of the cumulative probability F(x), and is therefore expressed by Equation (5). That is, the natural logarithm of the volume ratio T is equivalent to Equation (1). For example, the predicted maximum pore diameter corresponding to the volume ratio T is calculated using an arithmetic processing circuit in the image processing device, or an arithmetic processing circuit including a CPU included in a control circuit for controlling the image processing device and the imaging device. At this time, the calculated predicted maximum pore diameter is a predicted value of the maximum pore diameter, which is the largest value among the pore diameters of all the pores contained in the insulating film 120.

[0059]

[0060] For example, as shown in Fig. 5, the predicted maximum pore diameter X1 at a volume ratio T1 can be calculated by setting the first axis (y1 axis) to the double logarithm of the cumulative probability F(x) and the second axis (y2) to the natural logarithm (lnT) of the volume ratio T. Note that the pore diameter on the x-axis shown in Fig. 5 is the pore diameter of the largest pore on the y1 axis, and the predicted maximum pore diameter on the y2 axis.

[0061] For example, as the scale parameter α increases, the slope of the graph decreases, and therefore the graph is plotted in region 170 shown in FIG. 5. At this time, the predicted maximum pore diameter calculated using the volume ratio T becomes larger than the pore diameter of the largest pore or the predicted maximum pore diameter shown in Equation (1) and Equation (5). Also, as the scale parameter α decreases, the slope of the graph increases, and therefore the graph is plotted in region 160 shown in FIG. 5. At this time, the predicted maximum pore diameter calculated using the volume ratio T becomes smaller than the pore diameter of the largest pore or the predicted maximum pore diameter shown in Equation (1) and Equation (5).

[0062] Once the predicted maximum pore diameter X1 is calculated, the evaluation of the insulating film 120 is completed. For example, if the predicted maximum pore diameter X1 is equal to or smaller than the maximum pore diameter set to satisfy a predetermined withstand voltage of the insulating film 120, the evaluated characteristics of the insulating film 120 are determined to be good. On the other hand, if the predicted maximum pore diameter X1 is larger than the maximum pore diameter set to satisfy a predetermined withstand voltage of the insulating film 120, the evaluated characteristics of the insulating film 120 are determined to be poor.

[0063] For example, a plot of the relationship between the scale parameter α of an insulating film 120 evaluated using an insulating film evaluation method according to one embodiment of the present invention and the measurement results of the withstand voltage (kV / mm) of the insulating film 120 is shown in the plot diagram of FIG. 6 . Furthermore, a plot of the predicted maximum pore diameter of an insulating film 120 evaluated using an insulating film evaluation method according to one embodiment of the present invention and the measurement results of the withstand voltage (kV / mm) of the insulating film 120 is shown in the plot diagram of FIG. 7 . In FIG. 7 , a linear approximation based on multiple plots and an extrapolation of the linear approximation are shown by dashed lines 156. Note that, as an example, the thickness H1 of the insulating film 120 in the plot diagrams shown in FIGS. 6 and 7 is 200 μm or more and 250 μm or less.

[0064] 6 , there is a good negative correlation between the withstand voltage of the insulating film 120 and the scale parameter α. That is, it can be understood that as the scale parameter α decreases (the slope 1 / α of Equation (1) increases), the withstand voltage increases. Therefore, by using the evaluation method for the insulating film 120, it is possible to calculate the scale parameter α for the required withstand voltage, and it is also possible to calculate the required withstand voltage corresponding to the scale parameter α of the pores 126, 127 in the insulating film 120.

[0065] 7 , there is a good negative correlation between the withstand voltage of the insulating film 120 and the predicted maximum pore diameter of the insulating film 120. That is, it can be understood that the smaller the predicted maximum pore diameter, the higher the withstand voltage. Therefore, by using the evaluation method for the insulating film 120, it is possible to calculate the predicted maximum pore diameter of the insulating film 120 for the required withstand voltage, and it is also possible to calculate the required withstand voltage corresponding to the predicted maximum pore diameter of the insulating film 120.

[0066] For example, the withstand voltage of a stage including a cooling plate of a semiconductor device is generally set to 10 kV / mm or more. For example, the condition for the insulating film 120 to satisfy the withstand voltage of 10 kV / mm or more may be that the scale parameter α is greater than 0 and less than 2.5, greater than 0 and less than 1.5, or greater than 0 and less than 1.0. Furthermore, the condition for the insulating film 120 to satisfy the withstand voltage of 10 kV / mm or more may be that the position parameter (pore diameter) λ is greater than 5 and less than 8. That is, when the scale parameter α is greater than 0 and less than 2.5 and the position parameter λ is greater than 5 and less than 8, the withstand voltage of the insulating film 120 is 10 kV / mm or more, and the insulating characteristics of the insulating film 120 are excellent.

[0067] In general, it is believed that the thickness of an insulating film varies depending on the product, and that the pore diameter increases as the thickness of the insulating film 120 increases. However, the formulas (1) to (5) calculated using the insulating film evaluation method according to the embodiment of the present invention make it possible to calculate the predicted maximum pore diameter regardless of the thickness of the insulating film 120, and to define an insulating film with a predetermined withstand voltage.

[0068] 3. Second Embodiment The configuration of a semiconductor manufacturing apparatus according to a second embodiment of the present invention will be described with reference to FIG. 8. The semiconductor manufacturing apparatus includes a stage 100. For example, the semiconductor manufacturing apparatus is a film processing apparatus 200. The film processing apparatus 200 is a so-called CVD apparatus. Note that the configuration of the film processing apparatus 200 described with reference to FIG. 8 is one example, and the configuration of the film processing apparatus 200 is not limited to the configuration shown in FIG. 8. Furthermore, the film processing apparatus 200 is not limited to a CVD apparatus. In the description of the film processing apparatus 200, configurations that are the same as or similar to the configurations described with reference to FIGS. 1 to 7 will be described as necessary.

[0069] 8 is a schematic cross-sectional view of a film processing apparatus 200. The film processing apparatus 200 chemically reacts a reactive gas and can chemically form various films on a substrate. The film processing apparatus 200 includes a chamber 202. The chamber 202 provides a space in which the reactive gas is chemically reacted and various films are chemically formed on a substrate.

[0070] An exhaust device 204 is connected to the chamber 202. For example, the exhaust device 204 can reduce the pressure inside the chamber 202. An inlet pipe 206 is provided in the chamber 202. The inlet pipe 206 can introduce a reactive gas into the chamber 202 via a valve 208. Various gases can be used as the reactive gas depending on the film to be formed. The reactive gas may also be a liquid at room temperature. For example, the reactive gas may be silane, dichlorosilane, tetraethoxysilane, tungsten fluoride, trimethylaluminum, or the like. By using silane, dichlorosilane, tetraethoxysilane, or the like, a thin film of silicon, silicon oxide, silicon nitride, or the like is formed on a substrate. By using tungsten fluoride, trimethylaluminum, aluminum oxide, or the like, a thin film of a metal such as tungsten or aluminum, or a thin film of a metal oxide, is formed on a substrate.

[0071] A microwave source 212 is provided above the chamber 202 via a waveguide 210. The microwave source 212 includes an antenna for supplying microwaves. The microwaves generated by the microwave source 212 are introduced into the chamber 202 via the waveguide 210. The reactive gas is converted into plasma by the microwaves, a chemical reaction of the gas is promoted by various active species contained in the plasma, and a product obtained by the chemical reaction is deposited on a substrate, forming a thin film on the substrate.

[0072] As an optional configuration, a magnet 244 may be provided inside the chamber 202. The magnet 244 can increase the density of the plasma. Magnets 216 and 218 may also be provided on the side of the chamber 202. The magnets 216 and 218 may be permanent magnets or electromagnets having electromagnetic coils.

[0073] A stage 100 for placing a substrate thereon is provided at the bottom of the chamber 202, and a thin film can be formed on the substrate with the substrate placed on the stage 100. As an optional configuration, a power supply 224 may be connected to the stage 100. The power supply 224 can apply a voltage equivalent to high-frequency power to the stage 100.

[0074] For example, if the stage 100 is equipped with a sheathed heater (not shown), a heater power supply 230 that controls the sheathed heater is connected to the stage 100. As an optional configuration, a power supply 226 for an electrostatic chuck that secures the substrate to the stage 100, a temperature controller 228 that controls the temperature of a medium circulated inside the stage 100 (groove 104), and a rotation control device (not shown) that rotates the stage 100 about the rotation axis 106 may be connected to the stage 100. For example, by using the sheathed heater, the heater power supply 230, and the temperature controller 228, it is possible to control the temperature of the stage 100 and the temperature of a substrate placed on the stage 100.

[0075] The film processing apparatus 200 according to the second embodiment includes a stage 100. As a result, the cleaning apparatus 200 can uniformly heat the substrate and precisely control the heating temperature. The stage 100 has excellent insulating properties, which improves the withstand voltage of the film processing apparatus 200 against the voltage applied to the substrate. Furthermore, the film processing apparatus 200 with improved withstand voltage has excellent long-term reliability, allowing the user to reduce the frequency of maintenance of the film processing apparatus 200.

[0076] Although an example in which the insulating film 120 is provided on the substrate 110 included in the stage 100 of a semiconductor manufacturing apparatus has been described as an embodiment of the present invention, the embodiment of the present invention is not limited to semiconductor manufacturing apparatuses. For example, the substrate 110 provided with the insulating film 120 may be a member used in the aerospace field, or a member used in the automotive field, and the insulating film 120 may be applied to applications including a member provided on the substrate 110 containing aluminum.

[0077] The respective components of the insulating film, stage, stage fabrication method, insulating film evaluation method, and semiconductor manufacturing apparatus described above as embodiments of the present invention can be combined as appropriate to the extent that they are not mutually inconsistent. Furthermore, the respective components of the insulating film, stage, stage fabrication method, insulating film evaluation method, and semiconductor manufacturing apparatus described above as embodiments of the present invention can be interchanged as appropriate to the extent that they are not mutually inconsistent. Furthermore, even if a person skilled in the art appropriately adds, deletes, or modifies components based on each embodiment, such addition, deletion, or design change is made, the scope of the present invention is included as long as the gist of the present invention is maintained.

[0078] Furthermore, even if there are other effects and advantages different from those brought about by the above-mentioned embodiments, those that are clear from the description in this specification or that can be easily predicted by a person skilled in the art are naturally understood to be brought about by the present invention.

[0079] 100: stage, 102: hole, 104: groove, 106: rotation axis, 110: substrate, 112: first surface, 114: second surface, 120: insulating film, 120-1: insulating film, 120-2: insulating film, 122: first surface, 124: second surface, 125: region, 126: pore, 127: pore, 152: graph, 154: graph, 156: dashed line, 160: region, 170: Area, 180: Thermal spraying machine, 181: Spray nozzle, 182: Thermal spray material, 200: Film processing device, 202: Chamber, 204: Exhaust device, 206: Inlet pipe, 208: Valve, 210: Waveguide, 212: Microwave source, 216: Magnet, 218: Magnet, 224: Power supply, 226: Power supply, 228: Temperature controller, 230: Heater power supply, 244: Magnet

Claims

1. A stage for placing a substrate, comprising: a base material including a first surface and a second surface opposite to the first surface; and an insulating film provided on the first surface, the insulating film including pores having a scale parameter α (the numerical value α is greater than 0) of 0 or more and 2.5 or less, and a pore diameter λ defined as 5 or more and 8 or less.

2. The scale parameter α and the pore diameter λ are coefficients that define the mathematical formula (1) calculated by setting the double logarithm of the cumulative probability F(x) calculated for the plurality of pore diameters contained in the insulating film as y and the pore diameter of the pore as x, The stage according to claim 1 , wherein the pore diameter λ is the pore diameter when the double logarithm of the cumulative probability F(x) is 0.

3. The stage of claim 1, wherein the substrate comprises aluminum.

4. The stage of claim 1, wherein the insulating film comprises aluminum.

5. The stage of claim 1, further comprising a groove through which the medium can circulate.

6. The stage of claim 1, further comprising a groove in which a heat source can be placed.

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