Method for manufacturing vacuum containers

Abstract

To provide a technology that omits or reduces a polishing process after cutting work for restraining formation of a gas pocket by disclosing conditions for the cutting work.SOLUTION: A method of manufacturing a vacuum vessel by cutting work which cuts an aluminum inner peripheral wall while revolving along it is provided. A radius of curvature R of single crystal diamond serving as a tooth point in the cutting work is 0.5 mm-3 mm. An amount of cutting Z of the tooth point in the revolving direction is as shallow as equal to or less than 0.005 mm. A feed speed of the tooth point per revolution in the cutting work is as low as equal to or less than (the radius of curvature R×0.06) mm / rev. A revolving diameter of the tooth point is inclined within an inclination angle range of 0.2°- 5°toward a feed direction in the cutting work.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a vacuum vessel, and particularly to a method for manufacturing a vacuum vessel by cutting an inner peripheral wall made of aluminum.

Background Art

[0002] Conventionally, a processing technique for performing etching using low-frequency or high-frequency plasma inside a vacuum vessel has been known. For example, Patent Document 1 discloses a processing technique for performing uniform anisotropic etching on a large-area sample using low-frequency plasma generated inside a vacuum chamber (vacuum vessel).

[0003] Further, Patent Document 2 discloses, as a method for manufacturing this type of vacuum vessel, that "after performing a polishing treatment with abrasive grains on the inner peripheral wall of a stainless steel vacuum vessel, an electrolytic polishing treatment or a chemical polishing treatment is further repeated to polish the surface of the inner peripheral wall of the vacuum vessel."

[0004] Furthermore, for a vacuum vessel made of aluminum (such as pure aluminum or an aluminum alloy), a manufacturing method for processing the inner peripheral wall in the following procedure is known.

[0005] (1) First step: Cutting step (roughness of the inner peripheral wall after cutting: Ra 1.6 to 0.8 μm) (2) Second step: Buff polishing (roughness of the inner peripheral wall after polishing: Ra 1.0 to 0.2 μm) (3) Third step: Electrolytic polishing (roughness of the inner peripheral wall after polishing: Ra 0.4 to 0.025 μm)

[0006] FIG. 8 is a view showing a conventional aluminum vacuum vessel 800 manufactured by the above procedures (1) to (3). In FIG. 8, the inside of the conventional vacuum vessel 800 has a cylindrical inner peripheral wall 810 such as a cylinder or a polygonal cylinder, and the inner peripheral wall 810 is cut (first step) into a cylindrical surface shape perpendicular to the upper and lower surfaces, and then a polishing treatment (second step and third step) is performed.

Prior Art Documents

[0007] [Patent Document 1] Japanese Patent Application Publication No. 06-049666 [Patent Document 2] Japanese Patent Application Publication No. 03-180500 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] Generally, the inner circumferential wall of a vacuum vessel that has not undergone polishing retains irregularities such as fine grooves and depressions, which act as gas pockets. It is difficult to completely remove the gas adsorbed in these gas pockets. Therefore, when an unpolished vacuum vessel is subjected to vacuum, the more gas pockets there are, the longer it takes to reach the vacuum level required for plasma etching.

[0009] Furthermore, gas can be continuously or suddenly released from the gas pocket during the plasma etching process. This gas release can impair the vacuum environment, leading to problems such as reduced sample yield during plasma etching.

[0010] Furthermore, in plasma-based dry etching, the plasma is prone to colliding with irregularities in the gas pocket, easily causing etching damage and contamination to the inner wall of the vacuum vessel. As a result, maintenance such as cleaning and repolishing of the vacuum vessel becomes frequently necessary, which negatively impacts the workability of plasma etching.

[0011] On the other hand, in order to reduce such gas pockets, multiple polishing processes such as abrasive polishing, buffing, electrolytic polishing, and electrolytic composite polishing were essential for the inner circumferential wall of the vacuum vessel. As a result, the manufacturing of vacuum vessels had the problem of increasing the processing equipment, number of processes, and working time required for the polishing process, which increased the manufacturing cost of the vacuum vessels.

[0012] Furthermore, during the polishing process, hard abrasive material can become embedded (residue) in the soft inner walls, such as those made of aluminum. This left behind traces of the embedded material, which created new gas pockets—a problem that arose from the removal of these residues.

[0013] Therefore, the present invention aims to provide a technology that eliminates or reduces the polishing process after cutting by disclosing cutting conditions that suppress the formation of gas pockets, in order to solve at least one of the above-mentioned problems. [Means for solving the problem]

[0014] To solve the above problems, a typical manufacturing method of the present invention is a method for manufacturing a vacuum container by machining an aluminum inner circumferential wall, characterized by having the following machining steps. The radius of curvature R of the single-crystal diamond cutting edge used in the aforementioned machining process shall be 0.5 mm to 3 mm. The depth of cut Z in the circumferential direction of the cutting edge is made shallower, to 0.005 mm or less. The feed rate of the cutting edge per revolution during the aforementioned cutting process is slowed down to (the radius of curvature R × 0.06) mm / rev or less. The circumferential diameter of the cutting edge is inclined in the direction of the feed of the cutting process within a range of 0.2° to 5°. [Effects of the Invention]

[0015] The cutting conditions disclosed in this invention suppress the formation of gas pockets on the inner circumferential wall of the vacuum vessel. As a result, it becomes possible to omit or reduce the polishing process after cutting.

[0016] Further details regarding specific problems, configurations, and effects not mentioned above will be described in the embodiments of the invention described later. [Brief explanation of the drawing]

[0017] [Figure 1] Figure 1 is a cross-sectional view illustrating the shape of the vacuum vessel 100. [Figure 2] Figure 2[A] is a perspective view of the vacuum vessel 100. Figure 2[B] is an exploded perspective view of the vacuum vessel 100. [Figure 3] Figure 3 is an explanatory diagram for explaining the cutting of the inner peripheral wall 111 and the inner peripheral wall 121. [Figure 4] Figure 4 is a diagram showing the measurement results of the arithmetic mean roughness Ra after cutting in Example 1. [Figure 5] Figure 5 is a chart showing the measurement data (relationship between the depth of cut Z and the cutting roughness) of the first experiment in Example 2. [Figure 6] Figure 6 is a chart showing the measurement data (relationship between the feed rate and the cutting roughness) of the second experiment in Example 2. [Figure 7] Figure 7[A] is a perspective view of the vacuum vessel 500. Figure 7[B] is an exploded perspective view of the vacuum vessel 500. [Figure 8] Figure 8 is a diagram showing an aluminum vacuum vessel 800 manufactured by a conventional procedure.

MODE FOR CARRYING OUT THE INVENTION

[0018] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

EXAMPLE

[0019] 《Regarding the shape of the vacuum vessel 100》 First, the shape of the vacuum vessel 100 manufactured in Example 1 will be described. Figure 1 is a cross-sectional view for explaining the shape of the vacuum vessel 100. Figure 2[A] is a perspective view of the vacuum vessel 100. Figure 2[B] is an exploded perspective view of the vacuum vessel 100.

[0020] In these figures, the vacuum vessel 100 is formed by joining an aluminum upper reactor 110 that can cover the upper electrode 210 on the upper surface and an aluminum lower reactor 120 that can install the lower electrode 220 inside.

[0021] The upper reactor 110 is provided with an inner circumferential wall 111 that is partially chamfered into a conical shape that narrows upwards. The generatrix of this inner circumferential wall 111 has an inclination angle A in the range of 0.2° to 5° with respect to the vertical direction.

[0022] The lower reactor 120 is provided with an inner circumferential wall 121 that is partially chamfered into a conical shape that narrows downwards. The generatrix of this inner circumferential wall 121 has an inclination angle B in the range of 0.2° to 5° with respect to the vertical direction.

[0023] Regarding the machining of the inner circumferential walls 111 and 121: Figure 3 is an explanatory diagram illustrating the machining process of the inner circumferential walls 111 and 121. To avoid redundant explanations, the machining processes for the inner circumferential wall 111 and the inner circumferential wall 121 will be described together here. In the figure, the cutting edge 310 is made of single-crystal diamond. This cutting edge 310 is brazed onto the base tool tip 320.

[0024] With the cutting edge 310 of the tool tip 320 pressed against the inner circumferential walls 111 and 121, the reactors 110 and 120 are rotated by a numerically controlled lathe (NC lathe) or a machining center (MC), thereby cutting the inner circumferential walls 111 and 121 in the circumferential direction X.

[0025] Alternatively, the inner circumferential walls 111 and 121 may be cut in the circumferential direction X by rotating the cutting edge 310 of the tool tip 320 with a numerically controlled lathe (NC lathe) or machining center (MC) while the cutting edge 310 is pressed against the inner circumferential walls 111 and 121.

[0026] Furthermore, a spray nozzle 330 is positioned near the blade tip 310. This type of machining is carried out with the following steps:

[0027] Step S001: The radius of curvature R of the 310mm cutting edge of the single-crystal diamond should be 0.5mm to 3mm.

[0028] Step S002: The depth of cut Z in the circumferential direction X of the cutting edge 310 should be made shallower to 0.005 mm or less.

[0029] Step S003: The feed rate of the cutting edge 310 per revolution during machining shall be capped at (R × 0.06) mm / rev, depending on the radius of curvature R. For example, if the radius of curvature R = 0.5 mm, the feed rate shall be capped at 0.03 mm / rev. If the radius of curvature R = 1 mm, the feed rate shall be capped at 0.06 mm / rev. If the radius of curvature R = 2 mm, the feed rate shall be capped at 0.12 mm / rev.

[0030] Here, the larger the radius of curvature R, the larger the contact area (see Figure 3) of the cutting edge 310 as it cuts into the inner circumferential walls 111, 121. The larger this contact area and the slower the feed rate of the cutting edge 310, the stronger the surface leveling effect is, which smooths out the irregularities on the inner circumferential walls 111, 121 immediately after cutting. The condition of setting the upper limit of the feed rate to (R × 0.06) mm / rev as described above is the result of repeatedly prototyping the vacuum container 100 to confirm that mirror-like finish (the allowable elapsed roughness) is achieved through the surface leveling effect.

[0031] Step S004: When cutting the inner circumferential wall 111, the feed direction Y of the cutting edge 310 starts from the lower end of the inner circumferential wall 111 (height of the lower end opening of the upper reactor 110) and reaches the upper end of the inner circumferential wall 111 (height of the back side of the upper surface of the upper reactor 110). On the other hand, when cutting the inner circumferential wall 121, the feed direction Y of the cutting edge 310 starts from the upper end of the inner circumferential wall 121 (height of the upper end opening of the lower reactor 120) and reaches the lower end of the inner circumferential wall 121 (height of the inner bottom of the upper reactor 110).

[0032] Step S005: By narrowing the circumferential diameter of the cutting edge 310 at an angle of 0.2° to 5° in the feed direction Y of the cutting process, the inclination angles A and B of the inner circumferential walls 111 and 121 are set to 0.2° to 5°.

[0033] Step S006: During cutting, industrial IPA (isopropyl alcohol) is supplied from the spray nozzle 330 to the cutting area of ​​the cutting edge 310.

[0034] Step S007: The final depth of cut Z for surface finishing on the cutting surface shall be shallower than the previous depth of cut Z, and this shall be performed on at least two surfaces. The feed rate for the final finishing shall be limited to, for example, 0.08 to 0.03 mm / rev or less, and the feed phase of the contact area shall be shifted for each surface. For example, if the final finishing is performed on two surfaces, the feed phase of the contact area shall be shifted by 1 / 2 phase for each surface. Also, for example, if the final finishing is performed on N surfaces (N≧2), the feed phase of the contact area shall be shifted by 1 / N phase for each surface.

[0035] Here, by changing the depth of cut Z for the final finishing to a shallower depth, the cutting grooves that are created in the circumferential direction X of the inner circumferential walls 111 and 121 during the final finishing process become shallower. By shifting the feed phase in this state, the phases of the cutting grooves that ultimately remain in the circumferential direction X of the inner circumferential walls 111 and 121 are shifted and cancel each other out, thereby making the cutting grooves shallower. The conditions for step S007 described above are the result of repeatedly prototyping the vacuum vessel 100 to confirm that mirror-like finish (acceptable roughness) can be obtained by shifting the phase.

[0036] Effects of Example 1 The effects of the above-described Example 1 will be explained below.

[0037] (Effect 1) Figure 4 shows the measurement results of the arithmetic mean roughness Ra after the machining process described above. Here, the arithmetic mean roughness Ra was measured at three randomly sampled locations on the machined surface. The aluminum material used here is A7075 (generally a very hard aluminum material). According to these measurement results, after machining, the roughness of the inner circumferential walls 111 and 121 is approximately Ra 0.036 to 0.069 μm, achieving a mirror-like finish. The roughness of these inner circumferential walls 111,121 is comparable to the roughness after the final polishing treatment of the conventional vacuum vessel 800 (see Figure 8) described above (Ra 0.4~0.025 μm). Therefore, by machining alone as in this embodiment 1, it is possible to suppress the roughness (gas pockets) of the inner circumferential walls 111 and 121 to a level equivalent to that achieved by conventional polishing. As a result, it becomes possible to omit or reduce the polishing process after machining.

[0038] (Effect 2) The roughness (gas pockets) of the inner circumferential walls 111, 121 is reduced by the amount of the cutting conditions in this embodiment, which reduces the amount of gas adsorbed on the inner circumferential walls 111, 121. As a result, the vacuum vessel 100 manufactured by this embodiment is superior in that it can shorten the time required to reach the vacuum level necessary for plasma etching.

[0039] (Effect 3) The roughness (gas pockets) of the inner circumferential walls 111, 121 is reduced by the cutting conditions of this embodiment 1, which also reduces the amount of gas that may be continuously or suddenly released during the plasma etching process. As a result, the vacuum vessel 100 manufactured by this embodiment 1 is superior in that it can maintain a vacuum environment with high precision and improve the work yield of the plasma etching sample.

[0040] (Effect 4) The roughness (gas pockets) of the inner circumferential walls 111, 121 is reduced by the cutting conditions of this embodiment 1, thereby reducing etching damage and contamination caused by plasma collisions with gas pockets. As a result, the vacuum vessel 100 manufactured by this embodiment 1 is superior in that it reduces the number of maintenance procedures such as cleaning and polishing.

[0041] (Effect 5) Due to the reduction in the roughness (gas pockets) of the inner circumferential walls 111, 121 by the cutting conditions of this embodiment 1, the polishing process after cutting can be omitted or reduced. As a result, this embodiment 1 is superior in that it can reduce the processing equipment, number of processes, and working time required for the manufacture of the vacuum container 100. Consequently, the manufacturing cost of the vacuum container 100 is reduced.

[0042] (Effect 6) In this embodiment 1, by omitting or reducing the polishing process after cutting, it is possible to avoid or reduce the embedding of hard abrasive material remaining on the aluminum inner circumferential walls 111, 121 during the polishing process. As a result, this embodiment 1 is superior in that it can avoid or improve the problem of embedded residue forming new gas pockets.

[0043] (Effect 7) In this embodiment 1, industrial IPA (isopropyl alcohol) is supplied to the cutting area of ​​the blade tip 310 using a spray nozzle 330. Therefore, this embodiment 1 is superior in three respects: the effect of quickly removing chips (factors that roughen the inner circumferential walls 111, 121) from the cutting area using the spray nozzle 330, the effect of suppressing the temperature rise of the blade tip 310, and the effect of washing away residues that adhere to or are embedded in the inner circumferential walls 111, 121 to improve the cleanliness of the vacuum container 100.

[0044] (Effect 8) In this embodiment 1, the vacuum vessel 100 is narrowed vertically by inclining the inner circumferential wall 111 of the upper reactor 110 and the inner circumferential wall 121 of the lower reactor 120 in opposite directions. As a result, the internal volume of the vacuum vessel 100 can be reduced overall while maintaining a wide cross-sectional area near the center where the plasma etching sample (such as a semiconductor wafer) is placed. Therefore, the vacuum vessel 100 manufactured in this embodiment 1 is superior in that, by narrowing the internal volume vertically, it can secure a wide area near the center where the sample is placed, while reaching the desired vacuum level faster due to the overall reduction in internal volume.

[0045] (Effect 9) Based on the points described above, this embodiment 1 makes it possible to manufacture a vacuum vessel 100 that achieves both "high vacuum" and "high efficiency," which are required in plasma etching equipment, at a low cost. [Examples]

[0046] Next, we will describe Example 2. Unless otherwise specified, the same manufacturing method as in Example 1 will be used.

[0047] First, in Example 2, the specific requirements are defined as follows. Based on the allowable amount of gas pocket in the vacuum chamber 100 required during etching under vacuum (required specification), the upper limit of the allowable cutting roughness of the inner circumferential walls 111,121 (the surface roughness that can be considered mirror-finish) is set to, for example, 0.1 μm as the value of the arithmetic mean roughness Ra.

[0048] Based on this, the manufacturing conditions necessary to adequately and stably achieve the required machining roughness specifications will be determined from the following two experiments (Experiment 1 and Experiment 2).

[0049] Experiment 1 The first experiment will be conducted under the unified conditions of the following steps S101-S107.

[0050] Step S101: The radius of curvature R of the cutting edge 310 of the single-crystal diamond shall be 0.5 mm.

[0051] Step S102: The feed rate of the cutting edge 310 per revolution during machining shall be 0.03 mm / rev, which corresponds to (R × 0.06) mm / rev depending on the radius of curvature R.

[0052] Step S103: The rotational speed for the cutting process is set to 400 revolutions per minute. This rotational speed is set to a range that avoids or suppresses resonant vibrations during cutting, in accordance with the surrounding conditions such as the workpiece, the cutting edge 310, and the cutting device. This suppression of resonant vibrations ensures that the inner circumferential walls 111 and 121 are polished to a mirror finish.

[0053] Step S104: When cutting the inner circumferential wall 111, the feed direction Y of the cutting edge 310 starts from the lower end of the inner circumferential wall 111 (height of the lower end opening of the upper reactor 110) and reaches the upper end of the inner circumferential wall 111 (height of the back side of the upper surface of the upper reactor 110). On the other hand, when cutting the inner circumferential wall 121, the feed direction Y of the cutting edge 310 starts from the upper end of the inner circumferential wall 121 (height of the upper end opening of the lower reactor 120) and reaches the lower end of the inner circumferential wall 121 (height of the inner bottom of the upper reactor 110).

[0054] Step S105: By narrowing the circumferential diameter of the cutting edge 310 at an angle of 1.5° in the feed direction Y of the cutting process, the inclination angles A and B of the inner circumferential walls 111 and 121 are set to 1.5°.

[0055] Step S106: During cutting, industrial IPA (isopropyl alcohol) is supplied from the spray nozzle 330 to the cutting area of ​​the cutting edge 310.

[0056] Step S107: The final depth of cut Z for surface finishing on the cutting surface is shallower than the previous depth of cut Z, and this is performed on at least two surfaces, with the feed phase of the contact area shifted for each surface. For example, if the final finishing is done on two surfaces, the feed phase of the contact area is shifted by 1 / 2 phase for each surface. Also, for example, if the final finishing is done on N surfaces (N≧2), the feed phase of the contact area is shifted by 1 / N phase for each surface.

[0057] In the first experiment, under the unified conditions of steps S101 to S107 described above, the effect of increasing the depth of cut Z from 0.005 mm on the cutting roughness of the inner circumferential walls 111 and 121 after machining will be measured.

[0058] Figure 5 shows the measurement data obtained in this manner (relationship between depth of cut Z and cutting roughness). The aluminum material used here is A5052 (a standard softness aluminum material).

[0059] In the experimental results shown in Figure 5, the cutting roughness of the inner circumferential walls 111 and 121 did not fall below 0.138 μm, and the acceptable upper limit of cutting roughness, 0.1 μm, could not be sufficiently and stably achieved.

[0060] Furthermore, the experimental results shown in Figure 5 revealed that when the depth of cut Z exceeds 0.005 mm, the cutting roughness begins to deteriorate rapidly and fluctuates wildly, sometimes returning to a large value, and does not stabilize.

[0061] From these results, it was found that a shallow depth of cut Z of 0.005 mm or less is preferable in terms of stability (i.e., reproducibility).

[0062] Experiment 2 Based on the results of the first experiment described above, in the second experiment, the depth of cut Z was set to 0.005 mm in order to suppress variations in cutting roughness.

[0063] Furthermore, in the second experiment, under the unified conditions of steps S101, 103-107 described above, the feed rate was increased or decreased by approximately 0.03 mm / rev to measure its effect on the cutting roughness of the inner circumferential walls 111 and 121.

[0064] Figure 6 is a chart showing the measurement data obtained in this manner (relationship between feed rate and cutting roughness). The aluminum material used here is A5052 (a standard softness aluminum material). The experimental results shown in Figure 6 demonstrate a stable relationship (highly reproducible relationship) between feed rate and cutting roughness, which is roughly approximated by a quadratic curve. Furthermore, by reducing the feed rate to approximately 0.015 mm / rev, the cutting roughness of the inner circumferential walls 111 and 121 becomes 0.088 μm, achieving the acceptable upper limit of cutting roughness of 0.1 μm.

[0065] Summary of the experiment Based on the two experiments described above, the manufacturing conditions that can sufficiently and stably reproduce the acceptable upper limit of the cutting roughness of the inner circumferential walls 111 and 121 required during etching (arithmetic mean roughness Ra 0.1 μm) are as follows.

[0066] The radius of curvature R of the single-crystal diamond cutting edge (310) is assumed to be 0.5 mm. The depth of cut Z in the circumferential direction X of the cutting edge 310 is set to 0.005 mm. The feed rate of the cutting edge 310 per revolution during machining shall be 0.015 mm / rev. The upper inner circumferential wall 111 is formed by machining, creating an inclination angle A that narrows upward by 1.5°. The lower inner circumferential wall 121 is formed by machining, creating an inclination angle B that narrows downwards by 1.5°.

[0067] Effects of Example 2 This second embodiment achieves the same effects as the first embodiment described above. Furthermore, this second embodiment is superior in that it avoids the drawback of excessively long machining time because it does not make the depth of cut Z shallower than 0.005 mm and does not slow the feed rate down to less than 0.015 mm / rev. Furthermore, this embodiment 2 is superior in that it can achieve a difficult and highly advanced mirror finish, such as Ra 0.1 μm, which is set as the upper limit of the cutting roughness, with high reproducibility, even with a relatively soft aluminum material such as A5052.

[0068] 《Other supplementary information》 Furthermore, the upper surface portion inside the upper reactor 110 and the bottom portion inside the lower reactor 120 are not particularly limited, but they may be manufactured solely by cutting using a cutting edge 310 or the like, or they may be manufactured using a combination of cutting and polishing as in the conventional method.

[0069] Furthermore, in the above-described embodiment, the vacuum vessel 100 is manufactured by joining the upper reactor 110 and the lower reactor 120, which have been machined. However, the present invention is not limited thereto. The vacuum vessel 100 may also be manufactured by inserting a cutting edge 310 through an opening for covering the upper electrode 210 into the integrally formed vacuum vessel 100 and performing machining along the surface shape of the inner circumferential walls 111 and 121.

[0070] Furthermore, in the embodiments described above, the inner circumferential walls 111 and 121 are formed as part of the conical surface. However, the shape of the inner circumferential wall of the present invention is not limited to a part of the conical surface. For example, Figure 7 shows another example of the inner circumferential wall of the present invention. Figure 7[A] is a perspective view of the vacuum vessel 500. Figure 7[B] is an exploded perspective view of the vacuum vessel 500. In these figures, the vacuum vessel 500 is manufactured by joining a machined aluminum upper reactor 510 and a machined aluminum lower reactor 520. The upper reactor 510 has an inner circumferential wall 511 that is chamfered so as to narrow upward from the closed curve Qa. The generatrix of this inner circumferential wall 511 has an inclination angle A in the range of 0.2° to 5° with respect to the vertical. The lower reactor 520 has an inner circumferential wall 521 that is chamfered so as to narrow downward from the closed curve Qb. The generatrix of this inner circumferential wall 521 has an inclination angle B in the range of 0.2° to 5° with respect to the vertical. Furthermore, in terms of manufacturing methods, the same cutting conditions as described above can be applied, except that the cutting edge 310 of the tool tip 320 is cut along the circumferential trajectory of the inner circumferential walls 511 and 521 relative to the cutting method, using a numerically controlled lathe (NC lathe) or machining center (MC).

[0071] It should be noted that the present invention is not limited to the embodiments described above, and various further modifications are possible.

[0072] For example, the embodiments described above are explained in detail for the purpose of clearly illustrating the present invention, and the present invention is not necessarily limited to having all of the described configurations and processes.

[0073] For example, the numerical values ​​shown in this invention practically include engineering errors and tolerances, and therefore represent substantial values ​​within that range.

[0074] Furthermore, the conditions of Examples 1 and 2 and / or the supplementary information may be combined as appropriate. Also, it is possible to add, delete, or replace other configurations or processes in some of the embodiments. [Explanation of symbols]

[0075] 100...Vacuum vessel, 110...Upper reactor, 111...Inner wall, 120...Lower reactor, 121...Inner wall, 210...Upper electrode, 220...Lower electrode, 310...Cutting edge, 320...Tool tip, 330...Spray nozzle, 500...Vacuum vessel, 510...Upper reactor, 511...Inner wall, 520...Lower reactor, 521...Inner wall, 800...Vacuum vessel, 810...Inner wall, A...Inclination angle, B...Inclination angle, Qa...Closed curve, Qb...Closed curve, X...Circumference direction, Y...Feed direction, Z...Depth of cut

Claims

1. A method for manufacturing a vacuum container by machining the inner circumferential wall of an aluminum container, The radius of curvature R of the single-crystal diamond, which is the cutting edge of the aforementioned cutting process, is set to 0.5 mm to 3 mm. The depth of cut Z in the circumferential direction of the cutting edge is made shallower to 0.005 mm or less. The feed rate of the cutting edge per revolution of the aforementioned cutting process is slowed down to (the radius of curvature R × 0.06) mm / rev or less. The circumferential diameter of the cutting edge is inclined in the range of 0.2° to 5° in the feed direction of the cutting process. The upper side of the inner circumferential wall is formed by the cutting process to create an inclination angle that narrows upward in the range of 0.2° to 5°. The lower side of the inner circumferential wall forms the inclination angle that narrows downwards in the range of 0.2° to 5° by the cutting process. A method for manufacturing a vacuum container, characterized by the following:

2. A method for manufacturing a vacuum vessel according to claim 1, The cutting process is performed while supplying industrial IPA (isopropyl alcohol) to the cutting area of ​​the cutting edge of the single-crystal diamond. A method for manufacturing a vacuum container, characterized by the following:

3. A method for manufacturing a vacuum vessel according to any one of claims 1 to 2, The final surface finish of the aforementioned cutting process is performed in at least two cuts, and the feed phase of each cut in the final surface finish is shifted. A method for manufacturing a vacuum container, characterized by the following:

4. A method for manufacturing a vacuum vessel according to any one of claims 1 to 3, The radius of curvature R of the single-crystal diamond, which is the cutting edge of the aforementioned cutting process, is set to 0.5 mm. The depth of cut Z in the circumferential direction of the cutting edge is set to 0.005 mm. The feed rate of the cutting edge per revolution of the aforementioned cutting process shall be 0.015 mm / rev. The upper side of the inner circumferential wall is formed by the cutting process to create an inclination angle that narrows upward by 1.5°. The lower side of the inner circumferential wall forms an inclination angle that narrows downward by 1.5° as a result of the machining process. A method for manufacturing a vacuum container, characterized by the following:

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