Film formation method

Abstract

To provide a film formation method that can stably form a yttrium oxide film having conductivity to a substrate with an arc ion plating PVD method.SOLUTION: This film formation method comprises: disposing, in a chamber, a target comprising yttrium and a substrate that is an object on which a film is to be formed; introducing at least oxygen into the chamber; applying a prescribed bias voltage to the substrate; evaporating the surface of the target in oxygen to form a yttrium oxide film on the substrate; and setting the oxygen partial pressure in the chamber during the evaporation so as to be a pressure of less than 0.4 Pa, and setting an O / Y ratio, which is the ratio of oxygen to yttrium in the yttrium oxide film on the substrate, so as to be 1.5 or less.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a film-forming method for forming a film excellent in plasma resistance on the surface of a substrate.

Background Art

[0002] Conventionally, for members used in an environment exposed to plasma, such as semiconductor manufacturing equipment, materials excellent in plasma resistance have been demanded. Patent Document 1 discloses a technique for forming a yttrium oxide (Y2O3) film on the surface of a substrate by a thermal spraying method in order to obtain such a material. In this technique, yttrium oxide is formed in a film shape on the surface of a member where damage by plasma becomes a problem by thermal spraying using Y2O3 powder as a raw material.

[0003] On the other hand, in recent years, formation of a yttrium oxide film on a substrate by a vacuum film-forming method (PVD method: Physical Vapor Deposition) has been studied. In such a PVD method, since a film is formed on a substrate using an ionized material, it is possible to form a dense film as compared with a thermal spraying method that may have defects in the film. Generally, in the PVD method, it is known that a certain ratio of evaporated atoms is ionized to become ions. Therefore, by applying a voltage (bias) to the substrate to be film-formed and changing the incident ion energy, the denseness of the film and film characteristics (crystal structure and mechanical properties) can be controlled.

[0004] Among PVD methods, AIP (Arc Ion Plating) is a film deposition method that relies on the evaporation and ionization of cathode material by vacuum arc discharge under conditions of high current (tens to hundreds of amperes) and low voltage. In this case, when depositing insulating materials such as oxides, it is necessary to perform reactive deposition in an oxygen-containing atmosphere using a metal target. At this time, since the discharge surface of the cathode is oxidized, if there is an area on the cathode surface where arc discharge does not occur, oxide will accumulate in that area, and as that area expands, it becomes difficult to sustain the discharge. To solve this problem, Patent Document 2 discloses that stable discharge can be achieved by using an evaporation source with a weak magnetic field of 3 to 50 gauss. Patent Document 3 discloses that oxides are formed under conditions of pure oxygen by applying bipolar pulses using this method. Furthermore, the same document discloses that oxides containing Zr, Cr, Mo, and Al, Si, Fe, Co, Ni, and Y are deposited by superimposing a high-current pulsed arc on a DC current. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2001-164354 [Patent Document 2] Patent No. 5306198 [Patent Document 3] Patent No. 5877147 [Overview of the project] [Problems that the invention aims to solve]

[0006] The inventors of the present invention diligently attempted to form a Y2O3 film in an oxygen atmosphere using the method disclosed in Patent Document 2, but found that during prolonged discharge, oxides formed on the target surface, eventually making discharge impossible. Furthermore, high-current pulsed arcs, as described in Patent Document 3, have the problem of being difficult to apply industrially because the power supply system is more complex and expensive than that of a normal DC power supply.

[0007] The object of the present invention is to provide a film deposition method that enables stable maintenance of discharge during film deposition when stably forming a conductive yttrium oxide film on a substrate using the arc ion plating method. [Means for solving the problem]

[0008] To achieve the above objective, the inventors of this application diligently conducted repeated experiments to form a conductive yttrium oxide film, and as a result, discovered a new film formation method.

[0009] The present invention relates to a film deposition method for depositing a yttrium oxide film on a substrate to be deposited on by an arc ion plating method, comprising: arranging a target made of yttrium and the substrate in a chamber; introducing at least oxygen into the chamber; applying a predetermined bias voltage to the substrate; evaporating the surface of the target in oxygen to deposit a yttrium oxide film on the substrate; and setting the partial pressure of oxygen in the chamber during evaporation to a pressure of less than 0.4 Pa such that the O / Y ratio, which is the ratio of oxygen to yttrium in the yttrium oxide film on the substrate, is 1.5 or less.

[0010] This method allows for the reduction of the electrical resistance of a yttrium oxide film and the acquisition of a conductive yttrium oxide film by controlling the oxygen partial pressure in the chamber during film formation and thereby changing the amount of oxygen in the yttrium oxide film. In particular, since the oxygen partial pressure is set to less than 0.4 Pa, oxide formation is less likely to occur on the target surface, and the increase in discharge voltage that would make it difficult to sustain the discharge can be suppressed.

[0011] The above method may further include setting the oxygen partial pressure in the chamber during evaporation so that the O / Y ratio is less than 1.4.

[0012] This method further reduces the electrical resistance of the film, making it possible to stably obtain a conductive yttrium oxide film.

[0013] The above method may further include setting the oxygen partial pressure in the chamber such that the electrical resistance of the yttrium oxide film is 10,000 Ω or less.

[0014] According to this method, by controlling the partial pressure of oxygen during film formation and thereby changing the amount of oxygen in the film, a conductive yttrium oxide film with an electrical resistance of 10,000 Ω or less can be stably obtained.

[0015] The above method may further include setting the oxygen partial pressure such that the discharge voltage during film formation is 20V or less.

[0016] According to this method, the rate of increase in discharge voltage caused by a high discharge voltage is suppressed by the partial pressure of oxygen, thereby stably maintaining the discharge during film formation.

[0017] The above method may further be provided with the condition that the partial pressure of oxygen is 0.17 Pa or higher.

[0018] This method makes it possible to suppress the increase in film roughness as the oxygen partial pressure decreases.

[0019] The above method may further include introducing argon in addition to oxygen into the chamber.

[0020] This method makes it possible to lower the discharge voltage during film formation and stabilize the discharge during film formation.

[0021] The above method may further include applying a pulse voltage as the bias voltage to the substrate.

[0022] According to this method, even when the resistance of the film formed on the substrate is relatively high, it is possible to suppress charge-up in which charges accumulate due to incident ions.

Advantages of the Invention

[0023] According to the present invention, it is possible to provide a film-forming method capable of stably maintaining discharge during film formation when stably forming an yttrium oxide film having conductivity on a substrate using an arc ion plating method.

Brief Description of the Drawings

[0024] [Figure 1] It is a schematic diagram showing a schematic configuration of a film-forming apparatus for performing the film-forming method according to an embodiment of the present invention. [Figure 2] In an example of the present invention, it is a graph showing the relationship between the O / Y ratio, which is the ratio of oxygen to yttrium in the yttrium oxide film on the substrate, and the electrical resistance of the yttrium oxide film. [Figure 3] In an example of the present invention, it is a graph showing the relationship between the oxygen flow rate and the oxygen partial pressure. [Figure 4] In an example of the present invention, it is a graph showing the relationship between the oxygen partial pressure and the discharge voltage. [Figure 5] In an example of the present invention, it is a graph showing the relationship between the oxygen partial pressure and the discharge voltage. [Figure 6] In an example of the present invention, it is a graph showing the surface roughness of the yttrium oxide film formed by changing the oxygen partial pressure. [Figure 7] In an example of the present invention, it is a graph showing the change in the oxygen partial pressure during long-time discharge. [Figure 8] In an example of the present invention, it is a graph showing the change in the discharge voltage during long-time discharge. [Figure 9] In an example of the present invention, it is a graph showing the O / Y ratio of the yttrium oxide film formed by changing the oxygen partial pressure.

Embodiments for Carrying Out the Invention

[0025] The embodiments of the present invention will be described in detail below with reference to the attached drawings. Figure 1 is a schematic diagram showing the general configuration of a film deposition apparatus 10 for performing a film deposition method according to one embodiment of the present invention. The film deposition method according to the embodiment of the present invention is a method for forming a film with excellent plasma resistance on the surface of a substrate.

[0026] Note that the film deposition apparatus 10 shown in Figure 1 is an example of a film deposition apparatus for carrying out the film deposition method according to an embodiment of the present invention, and the film deposition apparatus for carrying out the film deposition method is not limited to the one shown in Figure 1. 0 This utilizes the physical vapor deposition (PVD) method, in a vacuum chamber. 1 This is a device for forming a film on the surface of a workpiece W (substrate) placed inside 2. 0 These include AIP (Automated Ion Plating) systems that perform film deposition using the arc ion plating method, and sputtering systems that perform film deposition using the sputtering method.

[0027] The film deposition apparatus 10 is an arc ion plating apparatus. The film deposition apparatus 10 comprises a vacuum chamber 12, a rotary table 14, a plurality of substrate holders 16, a bias power supply 18, a target 20 as an evaporation source, an arc power supply 22, a heater 24, an argon tank 30, an oxygen tank 32, a vacuum pump P, and a controller 50.

[0028] The vacuum chamber 12 houses a rotary table 14 and a plurality of substrate holders 16 arranged on the rotary table 14. The inside of the vacuum chamber 12 (i.e., the space housing the rotary table 14 and the plurality of substrate holders 16) is maintained in a vacuum or near-vacuum state by a vacuum pump P during various processes, including the film deposition process. The vacuum chamber 12 is provided with a gas inlet 12A and an exhaust port 12B.

[0029] The rotary table 14 has a disc shape including a center line extending in the vertical direction in Figure 1. The rotary table 14 is located inside the vacuum chamber 12. During the film deposition process, the rotary table 14 rotates around its center line while supporting a plurality of substrate holders 16. The rotary table 14 may further include a rotating base on which each of the plurality of substrate holders 16 is individually positioned so that each of the plurality of substrate holders 16 can rotate on its own axis. The number of substrate holders 16 is not limited to the two shown in Figure 1.

[0030] Multiple substrate holders 16 each support a workpiece W on which a film is to be formed. In this embodiment, the workpiece W is arranged on the outer circumferential surface of the substrate holder 16. Note that only some of the workpiece W are shown in Figure 1.

[0031] In this embodiment, the workpiece W is made of A6061 alloy (Al alloy) and is a square plate measuring 20 mm x 20 mm. However, the material and shape of the workpiece W are not limited to this.

[0032] Each of the multiple base material holders 16 is formed of a conductive material. The conductive material is, for example, stainless steel.

[0033] Multiple substrate holders 16 are arranged at equal intervals in the circumferential direction of the rotary table 14. In this state, the center line of each of the multiple substrate holders 16 is parallel to the center line of the rotary table 14.

[0034] The bias power supply 18 applies a negative bias voltage to each of the multiple substrate holders 16 via the rotary table 14. In this embodiment, the bias power supply 18 intermittently applies a negative bias voltage to each of the multiple substrate holders 16. In other words, the bias power supply 18 is a pulse power supply. When the resistance of the film formed on the workpiece W is relatively high, applying a DC bias as the bias voltage can cause a problem of charge accumulation (charge up) due to incident ions. On the other hand, as in this embodiment, by applying a pulse voltage as the bias voltage, the above problem can be suppressed even when the resistance of the film formed on the workpiece W is relatively high. More specifically, by switching the bias between the negative side and 0V or the positive side as a pulse voltage on the order of μS or mS, the charge up problem can be suppressed.

[0035] Furthermore, when a negative bias voltage is not applied to the bias power supply 18 during the film deposition process, no bias is applied. Alternatively, the bias power supply 18 can alternately apply a negative bias voltage and a positive bias voltage to each of the multiple substrate holders 16. The absolute value of the negative bias voltage is greater than the absolute value of the positive bias voltage.

[0036] Furthermore, if negative and positive bias voltages are applied alternately, the bias power supply 18 may be, for example, an AC power supply or an RF power supply.

[0037] Target 20 is a disc-shaped component made of yttrium. For example, Target 20 is a disc with a diameter of 100 mm.

[0038] Arc power supply 22 is for the vacuum chamber 1This is a DC power supply that functions as a discharge power source to generate a vacuum arc discharge on target 20 located at 2. In this case, target 20 functions as the cathode in the discharge. On the other hand, as shown in Figure 1, the vacuum chamber 12 functions as the anode in the discharge. Target 20 receives the discharge generated by the arc power supply 22 and releases yttrium ions evaporated from its surface. The arc power supply 22, together with target 20, constitutes an arc evaporation source.

[0039] The heater 24 is located inside the vacuum chamber 12 and generates heat by receiving current from a heater power supply (not shown). As a result, the environment inside the vacuum chamber 12 and the workpiece W are heated.

[0040] The argon tank 30 contains argon and supplies argon gas to the vacuum chamber 12. Similarly, the oxygen tank 32 contains oxygen and supplies oxygen to the vacuum chamber 12. The amount of gas supplied from these tanks is controlled by adjusting the opening of a regulator (not shown) in response to a command from the controller 50. In other embodiments, the amount of gas supplied may be adjusted manually by an operator.

[0041] The vacuum pump P creates a vacuum in the internal space of the vacuum chamber 12 through the exhaust port 12B (vacuuming).

[0042] In addition to the regulators mentioned above, the controller 50 controls the vacuum pump P, the bias power supply 18 and arc power supply 22, the various voltages and current values ​​of the heater 24, and the rotation of the rotary table 14. [Examples]

[0043] Next, an example of the film formation method according to this embodiment will be described. In the following description, oxygen may be denoted as O and yttrium as Y. Furthermore, the present invention is not limited to the scope of the following examples.

[0044] <Example 1> The following describes Example 1. In carrying out this film deposition method, as shown in Figure 1, the target 20 and workpiece W are installed in the film deposition apparatus 10, and the vacuum chamber 12 is evacuated to a vacuum state using a vacuum pump P.

[0045] Next, after preheating the vacuum chamber 12 with the heater 24, argon gas is introduced from the argon tank 30 into the vacuum chamber 12 through the gas inlet 12A, and as a pretreatment, bombardment is performed on the surface of the workpiece W with argon gas ions. Here, bombardment means generating heavy inert gas ions such as argon ions by plasma discharge, and heating the surface of the workpiece W by irradiating it with these ions, thereby cleaning the surface.

[0046] After the bombardment described above, pure oxygen gas is introduced at a flow rate of approximately 240 sccm so that the pressure inside the chamber is around 1 Pa. In other embodiments, instead of pure oxygen gas, an Ar-O2 mixed gas (e.g., 450 sccm of Ar and 50-75 sccm of oxygen) may be introduced so that the pressure inside the chamber is around 2 Pa. To maintain a stable discharge, it is desirable to set the total pressure inside the chamber in the range of 0.6 Pa to 4 Pa.

[0047] Next, a discharge is performed in the vacuum chamber 12 while the target 20 functions as a cathode to deposit a yttrium oxide film on the workpiece W. During this process, the temperature of the workpiece W is around 300°C (200°C to 400°C), the arc current is in the range of 100A to 150A, and the voltage applied to the workpiece W is a unipolar pulse with a frequency of 200kHz, duty cycle of 56% or 300kHz, duty cycle of 60%, with the average voltage varying between 10 and 50V. The thickness of the yttrium oxide film formed on the workpiece W is approximately 5 to 100 μm. As mentioned above, as an example, A6061Al (20 mm x 20 mm rectangular piece shape) is used as the workpiece W. The amount of oxygen in the formed yttrium oxide film is controlled by changing the pressure of the oxygen flowing into the chamber, i.e., the partial pressure of oxygen (oxygen flow rate).

[0048] Next, we will explain the evaluation method for the yttrium oxide film formed on the workpiece W, along with the indicators used.

[0049] (1) O / Y ratio (ratio of oxygen to yttrium in the yttrium oxide film on workpiece W) The formed test specimen (workpiece W) was cut along the film thickness direction, embedded in the evaluation resin, and after polishing the cross-section, O and Y were measured at 10 points in the film using EDX (Energy Dispersive X-ray Spectroscopy) from the cross-sectional direction. The O / Y ratio was calculated from the average value.

[0050] (2) Electrical resistance of yttrium oxide film Electrodes were brought into contact with the back and front surfaces of the workpiece W (substrate), and a voltage (3.5 to 350 mV, varying depending on the resistance) was applied between the two electrodes. The electrical resistance of the film was calculated from the current that flowed at that time. A milliohm high-tester (HIOKI3540) was used for the measurement.

[0051] Figure 2 shows the electrical resistance of yttrium oxide films with different O / Y ratios. As mentioned above, the O / Y ratio is controlled by changing the partial pressure of oxygen (oxygen flow rate) in the chamber. As shown in Figure 2, when the O / Y ratio of the yttrium oxide film falls below 1.4, the electrical resistance of the film drops sharply, confirming that it is conductive. It is more desirable to set the O / Y ratio to 1.35 or less. In this case, the electrical resistance of the yttrium oxide film can be stably maintained at 10,000 Ω or less. In this measurement, since the upper limit of the resistance value measurement of the measuring instrument is 30,000 Ω, all measurement points of 30,000 Ω in Figure 2 indicate an electrical resistance of that value or higher.

[0052] Furthermore, when a film is deposited using oxygen alone and the oxygen flow rate is low, the pressure inside the chamber decreases, the discharge voltage increases, and the discharge tends to become unstable. Therefore, it is more desirable to introduce Ar gas into the chamber and deposit the film under an Ar-O2 atmosphere. As an example, when only 50 sccm of oxygen is introduced into the chamber and a discharge is performed, the pressure inside the chamber is 1 × 10⁻⁶. -2 While the discharge voltage was high at 25V at approximately Pa, when 450 sccm of Ar gas and 50 sccm of oxygen gas were introduced, and the chamber pressure was set to 2.5 Pa, the discharge voltage was low at around 17V, and stable discharge could be maintained. It is even more preferable to introduce Ar so that the chamber pressure during discharge is 1 Pa or higher.

[0053] In this invention, the yttrium oxide film is a state in which Y2O3 and Y are mixed within the film, and as a result of a change in the ratio of Y2O3 to Y, the ratio of Y to O within the film changes. In this invention, films in such a mixed state of Y2O3 and Y are collectively referred to as "yttrium oxide films." In this case, the ratio of Y to O is an atomic ratio. As an example, the film thickness of the yttrium oxide film on workpiece W is 50 μm or more.

[0054] <Example 2> Next, Example 2 will be described. In Example 2 as well, an arc ion plating apparatus (Figure 1) connected to an arc power supply 22 consisting of a DC power supply is used, and a target 20 (diameter 100 mm) made of metal Y is attached to the arc evaporation source, and after vacuum evacuation and preheating, the vacuum chamber 1 Argon gas at a rate of 150 sccm or 450 sccm was introduced into the vacuum chamber. 1 The pressure (total pressure) inside chamber 2 was introduced to approximately 1-2 Pa. Then, a constant amount of pure oxygen gas (e.g., 45 sccm) was introduced, and the arc evaporation source was discharged with a current of 100A to 150A for 5 minutes. The change in discharge voltage during this time was measured. Afterward, the vacuum chamber... 1 The experiment was conducted by repeatedly increasing the amount of oxygen in the device (2) and discharging for another 5 minutes until the oxygen flow rate caused a rapid increase in the discharge voltage.

[0055] Figure 3 shows the vacuum chamber in the second embodiment. 1 This graph shows the relationship between the oxygen flow rate and oxygen partial pressure introduced into the vacuum chamber. The oxygen partial pressure was measured using a diaphragm pressure gauge (manufactured by MKS). 1 The oxygen partial pressure was calculated by multiplying the total pressure inside the chamber by the oxygen flow rate and then dividing by the total gas flow rate (argon + oxygen). As shown in Figure 3, it can be seen that the oxygen partial pressure changes almost linearly with respect to the oxygen flow rate.

[0056] Figures 4 and 5 are graphs showing the relationship between oxygen partial pressure and discharge voltage in Example 2. Figure 4 shows the results when the arc current is 100 A, and Figure 5 shows the results when the arc current is 150 A. Both Figures 4 and 5 show experiments with two levels of argon gas introduction (150 sccm or 450 sccm).

[0057] As shown in Figures 4 and 5, the discharge voltage increases with the oxygen partial pressure, and the increase in discharge voltage in response to the increase in oxygen partial pressure becomes rapid between 0.3 and 0.4 Pa. This phenomenon suggests that, from the perspective of discharge voltage, it is desirable to keep the discharge voltage below 20 V in the system used in this experiment. Therefore, in order to maintain a stable discharge during film deposition, a vacuum chamber is necessary.1 It was found that it is necessary to control the oxygen partial pressure inside 2 to less than 0.4 Pa at most.

[0058] <Example 3> Next, Example 3 will be described. In Example 3 as well, a target 20 (100 mm in diameter) made of metal Y is attached to the arc evaporation source of an arc ion plating apparatus (Figure 1) to which an arc power supply 22 consisting of a DC power supply is connected, and after vacuum evacuation and preheating, a vacuum chamber is used. 1 150 sccm of argon gas was introduced into chamber 2. At this time, a vacuum chamber was installed. 1 The pressure (total pressure) inside the chamber was adjusted to approximately 2 Pa. Then, pure oxygen gas was introduced, and the arc evaporation source was discharged with a current of 125 A to form a yttrium oxide film on the Si substrate (workpiece W) with a target thickness of 3 μm. During film formation, a pulse bias (voltage -10V, frequency 200 kHz, pulse width 2.8 μS) was applied. The surface roughness (Ra) of the formed film was then measured using a stylus-type surface roughness meter (Tokyo Seimitsu SURFCOM TOUCH550).

[0059] Figure 6 is a graph showing the surface roughness of the yttrium oxide film formed in Example 3 by varying the oxygen partial pressure. As shown in Figure 6, the surface roughness increases with decreasing oxygen partial pressure. Since high surface roughness necessitates polishing during practical use, it is desirable that the surface roughness be kept below 0.4 μm. For this reason, it is desirable to set the oxygen partial pressure (x) = 0.17 Pa, obtained by substituting Ra(y) = 0.4 into the regression equation (y = -1.7628x + 0.6961) based on the results in Figure 6, as the lower limit of this partial pressure. Thus, it is desirable to set the oxygen partial pressure during film formation to 0.17 Pa or higher.

[0060] <Example 4> Next, Example 4 will be described. In Example 4 as well, a target 20 (100 mm in diameter) made of metal Y is attached to the arc evaporation source of an arc ion plating apparatus (Figure 1) connected to an arc power supply 22 consisting of a DC power supply, and after vacuum evacuation and preheating, a vacuum chamber is used. 1450 sccm of argon gas was introduced into chamber 2. During this process, a vacuum chamber was installed. 1 The pressure inside chamber 2 (total pressure) was introduced to approximately 2 Pa. Then, 50 sccm of pure oxygen gas was introduced, and the arc evaporation source was discharged with a current of 100 A for 400 minutes, creating a vacuum chamber. 1 The changes in oxygen partial pressure and discharge voltage within the device 2 were measured.

[0061] Figure 7 is a graph showing the change in oxygen partial pressure during long-term discharge in Example 4. Figure 8 is a graph showing the change in discharge voltage during long-term discharge in Example 4.

[0062] As shown in Figures 7 and 8, vacuum chamber 1 It can be seen that by controlling the oxygen partial pressure inside 2 to less than 0.4 Pa, the discharge voltage stabilizes (below 20 V), enabling long-term discharge. Note that Examples 2 and 4 above were for the purpose of evaluating discharge characteristics, and no actual film deposition was performed.

[0063] As described above, in a vacuum chamber where the discharge current (arc current) is between 100A and 150A, and the amount of argon gas introduced is between 150 sccm and 450 sccm, 1 By adjusting the oxygen partial pressure within 2 to a range of less than 0.4 Pa, it became possible to maintain stable discharge.

[0064] <Example 5> Next, Example 5 will be described. In Example 5, a target 20 (100 mm in diameter) made of metal Y was attached to the arc evaporation source of an arc ion plating apparatus (Figure 1) connected to an arc power supply 22 consisting of a DC power supply. After vacuum evacuation and preheating, bombardment was performed with argon gas ions. After this gas bombardment, pure oxygen gas was introduced at a flow rate of approximately 240 sccm at a Pa of approximately 1 Pa, or a mixed gas of argon and pure oxygen (Ar 450 sccm, oxygen 50-75 sccm) was introduced into the vacuum chamber. 1The system was introduced to a total pressure of approximately 2 Pa. A yttrium oxide film was deposited on the workpiece W by discharging electricity using a metal target 20 (metal Y) as the cathode. During deposition, the temperature of the workpiece W was approximately 300°C, the arc current was between 100 and 150 A, and the voltage applied to the workpiece W was a unipolar pulse with a frequency of 200 kHz and a duty cycle of 56% or 300 kHz and a duty cycle of 60%, with the average voltage varied between 10 and 50 V. The thickness of the formed film was approximately 5 to 100 μm. A6061 Al (20 × 20 square-shaped) was used as the substrate for the workpiece W. The amount of oxygen in the yttrium oxide film was measured in the vacuum chamber. 1 This was controlled by changing the partial pressure of oxygen (oxygen flow rate) inside the device.

[0065] Figure 9 is a graph showing the O / Y ratio of yttrium oxide films formed by varying the oxygen partial pressure in Example 5. The method for calculating the O / Y ratio is the same as described above. As shown in Figure 9, it can be confirmed that yttrium oxide films formed in the range of oxygen partial pressure less than 0.4 Pa have an O / Y ratio of 1.5 or less (1.51 or less).

[0066] The embodiments of the present invention have been described in detail above. The yttrium oxide film obtained by the film formation method according to the present invention can be widely applied to components exposed to plasma, such as semiconductor manufacturing equipment. In particular, by forming the yttrium oxide film by the arc ion plating method, it is possible to form a film that is denser and has higher plasma resistance compared to the case of film formation by thermal spraying.

[0067] The present invention relates to a film deposition method for depositing a yttrium oxide film on a substrate to be deposited on by an arc ion plating method, and comprises a vacuum chamber 1 2 involves placing a target 20 made of yttrium and a workpiece W (substrate) inside, and a vacuum chamber 1 Introducing at least oxygen into 2, applying a predetermined bias voltage to the workpiece W, evaporating the surface of the target 20 in oxygen to form a yttrium oxide film on the workpiece W, and the vacuum chamber during the evaporation.1 The device comprises setting the oxygen partial pressure within 2 to a pressure of less than 0.4 Pa such that the O / Y ratio, which is the ratio of oxygen to yttrium in the yttrium oxide film on the workpiece W, is 1.5 or less.

[0068] According to this film deposition method, the vacuum chamber used during film deposition... 1 By controlling the oxygen partial pressure within 2 and changing the amount of oxygen in the yttrium oxide film, the electrical resistance of the film can be reduced, and a conductive yttrium oxide film can be obtained. In particular, since the oxygen partial pressure is set to less than 0.4 Pa, oxide is less likely to form on the surface of target 20, and it is possible to suppress the increase in discharge voltage that would make it difficult to sustain the discharge.

[0069] In the above method, the vacuum chamber during evaporation is set such that the O / Y ratio is less than 1.4. 1 It is desirable to further provide a setting for the oxygen partial pressure within 2. According to this method, the electrical resistance of the film can be further reduced, and a conductive yttrium oxide film can be stably obtained.

[0070] In the above method, the electrical resistance of the yttrium oxide film is set to 10,000 Ω or less, in a vacuum chamber 1 It is desirable to further provide a method for setting the partial pressure of oxygen within the film. According to this method, by controlling the partial pressure of oxygen during film formation and changing the amount of oxygen in the film, a conductive yttrium oxide film with an electrical resistance of 10,000 Ω or less can be stably obtained.

[0071] In the above method, it is desirable to further include setting the oxygen partial pressure so that the discharge voltage during film formation is 20V or less. According to this method, the oxygen partial pressure suppresses the increase in the rate of increase of the discharge voltage caused by a high discharge voltage, and the discharge during film formation can be stably maintained.

[0072] In the above method, it is desirable that the oxygen partial pressure be 0.17 Pa or higher. This method makes it possible to suppress the increase in film roughness as the oxygen partial pressure decreases.

[0073] In the above method, vacuum chamber 1 It is desirable to further provide argon in addition to oxygen in step 2. This method makes it possible to lower the discharge voltage during film formation and stabilize the discharge during film formation.

[0074] In the above method, it is desirable to further include applying a pulse voltage as the bias voltage to the workpiece W. According to this method, even if the resistance of the film formed on the workpiece W is relatively high, charge buildup caused by incident ions can be suppressed.

[0075] Furthermore, it is desirable to obtain a yttrium oxide film with a high electrical resistance, having an O / Y ratio of 1.4 or more and 1.5 or less. In this case, as described above, a vacuum chamber 1 Excellent discharge stability can be obtained by setting the oxygen partial pressure inside 2 to a pressure of less than 0.4 Pa, such that the O / Y ratio of the yttrium oxide film is 1.5 or less.

[0076] Furthermore, if the oxygen flow rate (oxygen partial pressure) is high during film formation, oxides will form on the surface of the metal target 20, causing the discharge voltage to rise and making it difficult to sustain the discharge. As in the previous example, the rate of increase in discharge voltage tends to increase as the discharge voltage rises, so it is desirable to adjust the oxygen flow rate (oxygen partial pressure) so that the discharge voltage is 20V or less, more preferably 18V or less. Also, the vacuum chamber 1 As the oxygen partial pressure inside 2 decreases, the roughness of the formed film increases; therefore, it is preferable to keep the oxygen partial pressure at 0.17 Pa or higher.

[0077] These are merely illustrative examples, and the present invention is not to be interpreted in any way as being limited by the above-described embodiments. In the present invention, the substrate is not limited to an insulating material, but may also be made of a conductive material. In the present invention, the manner in which a negative bias voltage and a positive bias voltage are alternately applied is not limited to the pulsed manner described in the above embodiments, but may be sinusoidal, for example. Furthermore, if the arc current is too small, the discharge may not be stable, and if it is too large, the target may overheat, so for a target with a diameter of about 100 mm, it is desirable to set it in the range of 50 A or more and 200 A or less. [Explanation of symbols]

[0078] 10 Film deposition equipment 12 Vacuum Chamber 14 Rotating Table 16. Base material holder 18 Bias power supply 20 Targets 22 Arc power supply 24 Heater 30 argon tanks 32 oxygen tanks 50 Controllers W Work W (Base Material)

Claims

1. A method for forming a yttrium oxide film on a substrate by an arc ion plating method, comprising the steps of: placing a target made of yttrium and the substrate in a chamber; introducing at least oxygen into the chamber; applying a predetermined bias voltage to the substrate; evaporating a surface of the target in oxygen to form a yttrium oxide film on the substrate; setting an oxygen partial pressure in the chamber during the evaporation to a pressure less than 0.4 Pa such that an O / Y ratio, which is a ratio of oxygen to yttrium in the yttrium oxide film on the substrate, is 1.5 or less; The film forming method comprises:

2. 2. The method for forming an yttrium oxide film according to claim 1, The film forming method further comprises setting an oxygen partial pressure in the chamber during the evaporation so that the O / Y ratio is less than 1.

4.

3. 3. The method for forming an yttrium oxide film according to claim 2, The film forming method further comprises setting an oxygen partial pressure in the chamber so that the electrical resistance of the yttrium oxide film is 10,000 Ω or less.

4. 2. The method for forming an yttrium oxide film according to claim 1, The film forming method further comprises setting the oxygen partial pressure so that a discharge voltage during film formation is 20 V or less.

5. 2. The method for forming an yttrium oxide film according to claim 1, The film forming method further comprises: the oxygen partial pressure being 0.17 Pa or more.

6. A method for forming an yttrium oxide film according to any one of claims 1 to 5, The method further comprises introducing argon into the chamber in addition to oxygen.

7. A method for forming an yttrium oxide film according to any one of claims 1 to 5, The film forming method further comprises applying a pulse voltage to the substrate as the bias voltage.

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