Sputtering device and support program used for same

Abstract

In order to form a film by sputtering at an optimum inclination angle according to film formation conditions, the present invention comprises a depressurizable chamber (12) for forming a film on a substrate (2), and an electrode unit (13) that is provided inside the chamber and that includes a sputtering electrode (131), wherein the electrode unit is supported by a shaft (14) via a tilt unit (15), the shaft is movable with respect to the chamber in a first axis direction (X) parallel to a surface of the substrate at a film formation position and in a second axis direction (Z) perpendicular to the surface of the substrate at the film formation position, and the tilt unit can adjust the inclination angle (θ) formed between the surface of the substrate at the film formation position and a surface of a target (132) mounted on the sputtering electrode.

Description

Sputtering apparatus and support program used therein

[0001] This invention relates to a sputtering apparatus and a support program used therein.

[0002] A sputtering apparatus is known in which the surface of the substrate holder that holds the substrate and the surface of the target holder that holds the target are arranged to be non-parallel (Patent Document 1). It is said that by arranging the surface of the substrate holder and the surface of the target to be non-parallel, the deposition rate can be reduced and an ultra-thin MgO film can be deposited accurately and reproducibly (see

[0013] of the same document).

[0003] Japanese Patent Publication No. 2010-77452

[0004] However, in the conventional technology described above, the inclination angle between the surface of the substrate holder and the surface of the target is fixed, making it impossible to perform sputter deposition at an optimal inclination angle according to the material and other deposition conditions.

[0005] The problem that this invention aims to solve is to provide a sputtering apparatus and a support program used therefor that can perform sputtering film deposition at an optimal inclination angle according to the film deposition conditions.

[0006] The present invention solves the above problem with a sputtering apparatus comprising: a housing; a vacuum chamber provided inside the housing for forming a film on a substrate; and an electrode unit provided inside the chamber for including a sputtering electrode, wherein the electrode unit is supported by a tilt unit on a shaft that is movable relative to the housing in a first axial direction parallel to the surface of the substrate in the film formation position and in a second axial direction perpendicular to the surface of the substrate in the film formation position, and the tilt unit is capable of adjusting the inclination angle between the surface of a target attached to the sputtering electrode and the surface of the substrate in the film formation position.

[0007] According to the present invention, sputter deposition can be performed at an optimal inclination angle according to the deposition conditions.

[0008] This is a longitudinal cross-sectional view of a main part of a sputtering apparatus according to one embodiment of the present invention. This is a cross-sectional view along the line II-II in Figure 1. This is a perspective view of the tilt unit in Figure 1. This is a side view of the tilt unit in Figure 1. This is a diagram showing the cam slide mechanism of the tilt unit in Figure 1. This is a longitudinal cross-sectional view of a main part illustrating the movable range of the electrode unit in Figure 1. This is a flowchart showing the procedure for determining the optimal values ​​of the center coordinates and tilt angle of the sputtering electrode using a support program according to one embodiment of the present invention.

[0009] Embodiments of the present invention will be described below with reference to the drawings. Figure 1 is a longitudinal cross-sectional view of the main part of a sputtering apparatus according to one embodiment of the present invention, and Figure 2 is a cross-sectional view along the line II-II in Figure 1. The sputtering apparatus 1 of this embodiment has a housing 11 consisting of a frame (skeletal member of the housing, not shown) and panels, as shown in Figure 1, and the inside of this housing 11 is a chamber 12 that can be set to a predetermined vacuum level. The chamber 12 is airtight and can be set to a predetermined vacuum level by an exhaust device 112 provided at the exhaust port 111 of the housing 11.

[0010] The chamber 12 according to this embodiment includes a deposition chamber 121 facing a target 132 mounted on a sputtering electrode 131 and a substrate 2 mounted on a susceptor 16. The deposition chamber 121 in this embodiment is partitioned by four side wall panels 113 that constitute the side of the chamber 12, a bottom panel 114 attached to the frame of the housing 11, and a ceiling panel 115 also attached to the frame of the housing 11. As will be described later, the electrode unit 13 in this embodiment is movable in the X-axis and Z-axis directions via a shaft 14 and is also tiltable by a tilt unit 15. A movable panel 133 is rotatably provided on the electrode unit 13, whose opening degree follows the range of motion of the electrode unit 13. By providing the movable panel 133, the scattering of sputtering particles to the outside of the deposition chamber 121 is suppressed.

[0011] In this embodiment, the chamber 12 is provided with a porous quartz plate 122 and a porous metal plate 123. As shown in Figure 1, the porous quartz plate 122 and the porous metal plate 123 in this embodiment are provided on the inner wall of the deposition chamber 121, in front of the target 132, with the porous quartz plate 122 positioned in front of the porous metal plate 123. The porous metal plate 123 is electrically coupled to the plasma and supplies electrons to the plasma. At this time, the potential of the porous metal plate 123 may be ground, or a controlled negative potential may be supplied to more actively supply electrons. Furthermore, in order to increase the power efficiency of the actual sputtering phenomenon from the high-frequency power supplied to the target 132, the surface area of ​​the porous metal plate 123 may be increased by stacking multiple plates. The porous quartz plate 122 has the function of preventing the deposition of sputtered particles on the porous metal plate 123 and maintaining a constant supply of electrons. Furthermore, the porous quartz plate 122 also has the function of preventing the reverse deposition of the material of the porous metal plate 123, which is sputtered, onto the substrate 2 when a negative potential is supplied.

[0012] The sputtering apparatus 1 of this embodiment further includes a gas supply device 124 that supplies argon gas, oxygen gas, etc., to the film deposition chamber 121 as a process gas during film deposition.

[0013] The sputtering electrode 131 of this embodiment supplies high-frequency power to a target 132 attached to its tip. The diameter of the sputtering electrode 131 of this embodiment is not particularly limited, but it is preferable to apply it to heavy objects with a diameter of 190 mm or more. The frequency of the high-frequency power of this embodiment is not particularly limited, but it may include a frequency of 13.56 MHz. Furthermore, the material of the target 132 is not particularly limited, and targets made of various materials can be used.

[0014] The susceptor 16 of this embodiment is made of a conductive material, holds the substrate 2, and can be rotated at a predetermined rotational speed by a drive device 162 connected to a rotating shaft 161. The susceptor 16 may be configured to allow deposition on multiple substrates 2 in a single process. The material constituting the susceptor 16 is not particularly limited, but examples include Inconel, silicon carbide, graphite, and silicon. The conductivity of the susceptor 16 does not necessarily have to be exhibited at room temperature, and may be exhibited when the substrate 2 is heated to below 450°C.

[0015] Furthermore, a heater 163 is provided at the bottom of the susceptor 16 to heat the substrate 2 to a predetermined temperature. The heating method of the heater 163 is not limited, but examples include a resistance heating method using graphite or silicon carbide as a resistor, and a photothermal heating method using a halogen lamp. Note that the heater 163 is not an essential component in this invention and may be provided as needed.

[0016] In this embodiment, the electrode unit 13 is attached to the shaft 14 via a tilt unit 15. The shaft 14 extends upward through the ceiling panel 115 of the housing 11 (chamber 12) and is movable in the X-axis direction as will be described later, so an elongated hole (not shown) is formed in the ceiling panel 115 through which the shaft 14 passes. A slide plate 116 is provided on the upper surface of the ceiling panel 115 to close and seal this elongated hole and through which the shaft 14 passes airtightly.

[0017] The slide plate 116 is slidably supported on a linear rail (not shown) that extends in the X-axis direction from the frame of the housing 11. An X-axis drive mechanism, including a lead screw mechanism for moving in the X-axis direction, is provided between the slide plate 116 and the linear rail. For example, by turning a handle, the position of the slide plate 116 in the X-axis direction (and consequently the position of the shaft 14 and electrode unit 13) can be adjusted.

[0018] Further, as shown in FIG. 2, the shaft 14 is fixed to the lifting plate 141, and a Z-axis drive mechanism including a feed screw mechanism 142 for moving the lifting plate in the vertical direction in the Z-axis direction is provided between the slide plate 116 and the lifting plate 141. By turning the handle, for example, to rotate the feed screw mechanism 142, the position of the lifting plate 141 in the Z-axis direction with respect to the slide plate 116 (and as a result, the positions of the shaft 14 and the electrode unit 13) can be adjusted.

[0019] In the sputtering apparatus 1 of the present embodiment, as shown in FIG. 1, when the rotation center point of the susceptor 16 is C1 and the center point of the target 132 mounted on the sputtering electrode 131 is C2, the distance in the Z-axis direction from the rotation center point C1 of the susceptor 16 to the center point C2 of the target 132 is defined as the height Z, and the distance in the X-axis direction from the rotation center point C1 of the susceptor 16 to the center point C2 of the target 132 is defined as the offset length X. Although the movable range of the shaft 14 in this embodiment is not particularly limited, for example, it is preferably movable in the range where the height Z is 0 to 350 mm and the offset length X is 0 to 590 mm.

[0020] FIG. 3 is a perspective view showing an example of the tilt unit 15 in FIG. 1, and is a perspective view looking obliquely upward from below the tilt unit 15. FIG. 4 is a side view of the tilt unit 15. FIGS. 3 and 4 show a state in which the electrode unit 3 is tilted at an inclination angle θ = 45°. FIG. 5 is a view showing the cam slide mechanism of the tilt unit 15 in FIG. 1. In this embodiment, as shown in FIG. 5, a bellows tube 17 is provided between the first plate 151 of the tilt unit 15 and the sputtering electrode 131, and a cable 18 for supplying high-frequency power to the sputtering electrode 131 is inserted through the inside of the shaft 14 and the bellows tube 17 from the outside of the housing 11 and connected to the sputtering electrode 131. The upper end of the bellows tube 17 is fixed to the first plate 151 of the tilt unit 15, and the lower end of the bellows tube 17 is fixed to the sputtering electrode 131.

[0021] The tilt unit 15 of the present embodiment is a mechanical structural member that enables adjustment of the inclination angle θ formed by the surface of the target 132 mounted on the sputtering electrode 131 with respect to the surface of the substrate 2 at the film formation position. Here, as shown in FIG. 1, in the sputtering apparatus 1 of the present embodiment, when the plane parallel to the surface of the substrate 2 is PL1, the plane parallel to the surface of the target 132 is PL2, the rotation center point of the susceptor 16 is C1, and the center point of the target 132 mounted on the sputtering electrode 131 is C2, the angle θ formed by the plane PL1 parallel to the surface of the substrate 2 and the plane PL2 parallel to the surface of the target 132 is defined as the inclination angle of the electrode unit 3. The range of the inclination angle θ of the tilt unit 15 of the present embodiment is not particularly limited, but for example, it is more preferable that the inclination angle θ can be adjusted in the range of 0° to 90° (including both ends).

[0022] As shown in FIGS. 3 and 4, the tilt unit 15 of the present embodiment includes a first plate 151 fixed to the lower end of the shaft 14, a pair of second plates 152, 152 fixed to both ends of the first plate 151 so as to be spaced apart from each other, and a third plate 153 fixed across the pair of second plates 152, 152. In FIG. 4, one of the pair of second plates 152, 152 on the front side is shown. A first cam hole 154 and a second cam hole 155 are formed at corresponding positions on each of the pair of second plates 152. As shown in FIGS. 3 and 4, in the tilt unit 15 of the present embodiment, the first cam hole 154 is linear and extends in the vertical direction, and the second cam hole 155 is formed in a substantially arc shape.

[0023] A pair of spaced-apart support plates 134 are fixed to the sputtering electrode 131. A first pin 135, which serves as the center of rotation and engages with the first cam hole 154, and a second pin 136, which engages with the second cam hole 155, are fixed to each support plate 134. In Figure 4, the first pin 135 and the second pin 136 are fixed extending perpendicular to the plane of the paper. These first pins 135 and 136 engage with the first cam hole 154 and the second cam hole 155 formed in the pair of second plates 152, 152, respectively. As a result, the sputtering electrode 131, including the support plates 134, is supported so as to be tiltable along the direction of the first cam hole 154 and the second cam hole 155 on the pair of second plates 152.

[0024] As shown in Figure 3, the tilt unit 15 of this embodiment has a feed screw mechanism comprising a feed screw 156 rotatably supported between a first plate 151 and a third plate 153, and a bush 157 including a nut that screws onto the feed screw 156. When the feed screw 156 is rotated in one direction by turning a handle (not shown), the bush 157 descends, while when the feed screw 156 is rotated in the opposite direction, the bush 157 rises. A link plate 158 is attached between the bush 157 and the sputter electrode 131. When the feed screw 156 is rotated in one direction, the bush 157 descends and the link plate 158 pushes one end of the sputter electrode 131, causing the electrode unit 13 to rotate clockwise around the first pin 135 in Figure 4. Conversely, turning the lead screw 156 in the opposite direction causes the bush 157 to rise, and the link plate 158 pulls one end of the sputter electrode 131, causing the electrode unit 13 to rotate counterclockwise around the first pin 135 in Figure 4.

[0025] Here, the tilt angle θ of the sputtering electrode 131 is said to be variable between 0 and 90°. When the tilt angle θ of the sputtering electrode 131 is 0°, the bellows tube 17, which has both ends fixed to the first plate 151 and the sputtering electrode 131, hangs vertically as shown by the dashed line in Figure 5. In contrast to this state, as the tilt angle θ of the sputtering electrode 131 approaches 90°, the bellows tube 17, which has both ends fixed to the first plate 151 and the sputtering electrode 131, does not tilt in a straight line, but rather curves at the tilt unit 15, because it is a flexible pipe. When the bellows tube 17 curves, as shown in Figure 5, the length of the bellows tube 17 becomes longer compared to when it is tilted in a straight line, and the cable 18 inserted inside is also pulled, causing the high-frequency inductance to change. In other words, when the tilt angle θ changes, the properties of the discharge plasma from the sputtering electrode 131 also change. Therefore, the tilt unit 15 of this embodiment includes a cam slide mechanism that ensures the length of the bellows tube 17 (and consequently the length of the cable 18) remains constant regardless of the adjustable tilt angle θ.

[0026] Figure 5 shows the operation of the cam slide mechanism of the tilt unit 15 in this embodiment. The cam slide mechanism of the tilt unit 15 in this embodiment consists of a first cam hole 154 and a second cam hole 155 formed in the second plate 152 of the tilt unit 15, and a first pin 135 and a second pin 136 provided on the support plate 134 of the sputtering electrode 131. As described above, the first pin 135 and the second pin 136 engage with the first cam hole 154 and the second cam hole 155 formed in each of the pair of second plates 152, 152, respectively, thereby allowing the sputtering electrode 131, including the support plate 134, to be tiltably supported on the pair of second plates 152 along the direction of the first cam hole 154 and the second cam hole 155.

[0027] More specifically, when the inclination angle θ of the sputtering electrode 131 is 0°, the bellows tube 17 hangs vertically as shown by the dashed line in Figure 5. In this case, the first pin 135 that engages with the first cam hole 154 is located at position M1 as shown in Figure 5, the second pin 136 that engages with the second cam hole 155 is located at position M1 as shown in Figure 5, and the length of the bellows tube 17 is L. In contrast, when the inclination angle θ of the sputtering electrode 131 is 90°, the bellows tube 17 is curved at a right angle as shown by the dashed line in Figure 5. In this case, the first pin 135 that engages with the first cam hole 154 is located at position M2 as shown in Figure 5, the second pin 136 that engages with the second cam hole 155 is located at position M2 as shown in Figure 5, and the length of the curved bellows tube 17 is L. Furthermore, when the inclination angle θ of the sputtering electrode 131 is between 0° and 90°, the bellows tube 17 gradually bends as the inclination angle θ increases. However, as the second pin 136 moves from position M1 to M2, the first pin 135 moves from position M1 to M2, thereby maintaining the length of the bellows tube 17 at all times at L.

[0028] As a result, tensile stress acting on the cable 18 inserted inside the bellows tube 17 is suppressed, and fluctuations in high-frequency inductance can be suppressed. In other words, even if the inclination angle θ changes, the properties of the discharge plasma from the sputter electrode 131 can be kept constant. In addition, since the length L of the bellows tube 17 is kept constant and no unnecessary load is applied, the lifespan of the bellows tube 17 can be extended. Figure 6 is a longitudinal cross-sectional view of the main part to explain the movable range of the electrode unit 13 in Figure 1. The electrode unit 13 of this embodiment is movable in the range of inclination angle θ from 0° to 90°, height Z from 0 to 350 mm, and offset length X from 0 to 590 mm. In Figure 6, the cases when the inclination angle θ = 0°, height Z = 350 mm, and offset length X = 0 mm, and the cases when the inclination angle θ = 90°, height Z = 50 mm, and offset length X = 590 mm are shown by dashed lines.

[0029] Next, a method for obtaining the optimum values of the offset length X, height Z, and tilt angle θ of the sputtering electrode 131 when forming a thin film on the substrate 2 using the sputtering apparatus 1 of the present embodiment described above will be described. FIG. 7 is a flowchart showing a procedure for determining the optimum values of the center coordinates (X, Z) and tilt angle θ of the sputtering electrode 131 using the support program according to an embodiment of the present invention.

[0030] The program of the present embodiment utilizes the Monte Carlo method (a method of performing simulations and numerical calculations using random numbers) that tracks and simulates the behavior of sputtering particles flying from the target to the substrate to obtain the film thickness distribution. On the premise that the pressure (vacuum degree) in the chamber 12 is kept constant and the material of the target 132 is set to a predetermined material, using the sputtering apparatus 1 of the present embodiment described above, with arbitrary center coordinates (X ０ , Z ０ ) and tilt angle θ ０ , when sputtering is performed, based on the measured value of the film thickness distribution of the film formed on the substrate 2, parameters including the center coordinates (X ０ , Z ０ ), tilt angle θ ０ and variables A, B, n, m of the emission angle distribution model of sputtering particles are obtained, and based on the obtained parameters, the flight of sputtering particles is simulated to predict the film thickness distribution of the film formed on the substrate 2.

[0031] Specifically, as shown in step ST1 of FIG. 7, using the sputtering apparatus 1 of the present embodiment described above, the pressure (vacuum degree) in the chamber 12 is kept constant and the material of the target 132 is set to a predetermined material, with arbitrary center coordinates (X ０ , Z ０ ) and tilt angle θ ０Sputtering is performed. Then, the film thickness distribution of the film formed on the substrate 2 under these film formation conditions is measured. The definition of the film thickness distribution of the film formed on the substrate is not particularly limited. For example, if the substrate is a circular substrate such as a silicon wafer, it can be defined as the film thickness at predetermined pitches along the radial direction of the circular substrate. If the substrate is a rectangular substrate, it can be defined as the film thickness at predetermined pitches along a straight line passing through the center point of the rectangular substrate. This measured film thickness distribution is also called the measured value of the film thickness distribution. Generally, a small film thickness distribution, that is, small variation in in-plane film thickness, is considered preferable for film formation quality.

[0032] In the following step ST2, the center coordinates (X) of the sputtering electrode 131 set in step ST1 are determined. ０ , Z ０ ) and inclination angle θ ０ Then, the measured values ​​of the film thickness distribution are input into the program of this embodiment.

[0033] In the subsequent step ST3, the center coordinates (X) of the sputtering electrode 131 set in step ST1 are determined. ０ , Z ０ ) and inclination angle θ ０ Based on the measured film thickness distribution, the variables of the sputtering particle emission angle distribution model are calculated using Bayesian optimization. Bayesian optimization is a method that quickly arrives at the optimal solution by sequentially sampling points with a high probability of obtaining the optimal solution, and it is a method of estimating the shape of a black-box function y = f(x) from limited observed data. In this example, the variables of the sputtering particle emission angle distribution model are used as the search range for the Bayesian optimization process, and the variables of the emission angle distribution model that minimize the difference between the measured film thickness distribution and the calculated film thickness distribution are calculated.

[0034] Here, the probability distribution equation for the sputtering particle emission angle distribution model is P(θ) = A・cos ｎ (θ) - B・cos ｍIt is expressed as (θ), where A, B, n, and m are the variables to be determined. The film thickness distribution of sputtering particles is determined from the central coordinates (X, Z) and tilt angle θ of the sputtering electrode 131, and the emission angle distribution of the sputtering particles. Therefore, the measured film thickness distribution and the arbitrarily set central coordinates (X ０ , Z ０ ) and inclination angle θ ０ If and are known, then the probability distribution formula P(θ) = A・cos ｎ (θ) - B・cos ｍ The variables A, B, n, and m of (θ) can be determined.

[0035] Then, in the following step ST4, the probability distribution formula P(θ) = A・cos of the sputtering particle emission angle distribution model is obtained by substituting the variables A, B, n, and m obtained in step ST3. ｎ (θ) - B・cos ｍ Using (θ), the optimal values ​​for the center coordinates (X, Z) and tilt angle θ of the sputtering electrode 131 are calculated using Bayesian optimization. That is, the center coordinates (X, Z) and tilt angle θ of the sputtering electrode 131 are set as the search range for Bayesian optimization, and the center coordinates (X, Z) and tilt angle θ that result in the smallest calculated value of the film thickness distribution (minimum variation in film thickness distribution) are calculated. As described above, the film thickness distribution of sputtering particles is obtained from the center coordinates (X, Z) and tilt angle θ of the sputtering electrode 131 and the emission angle distribution of the sputtering particles. Here, the probability distribution formula for the emission angle distribution of sputtering particles is P(θ) = A・cos ｎ (θ) - B・cos ｍ The variables A, B, n, and m of (θ) were determined in step ST3, and the ideal form of the film thickness distribution is when there is no variation in film thickness, that is, when the film thickness distribution is at its minimum value. From this, the center coordinates (X, Z) and the tilt angle θ of the sputtering electrode 131 can be determined, and the center coordinates (X １ , Z １ ) and inclination angle θ １ This represents the optimal value in the simulation.

[0036] In the following step ST5, the center coordinates (X) obtained in step ST4 are used.１ , Z １ ) and inclination angle θ １ Display it on a computer screen or similar device.

[0037] In the subsequent step ST6, using the sputtering apparatus 1 of this embodiment described above, the pressure (vacuum level) of the chamber 12 is set to the same pressure as in step ST1, and the material of the target 132 is made the same as in step ST1, and the center coordinate (X) displayed on a computer display or the like is set. １ , Z １ ) and inclination angle θ １ The sputtering process is performed. Then, the film thickness distribution of the film formed on substrate 2 under these film formation conditions is measured.

[0038] In the following step ST7, it is determined whether the measured value of the film thickness distribution measured in step ST6 is satisfactory. If it is satisfactory, the process proceeds to step ST12; otherwise, the process proceeds to step ST8. In step ST12, the center coordinates (X) of the sputtering electrode 131 obtained in step ST4 are determined. １ , Z １ ) and inclination angle θ １ The sputtering apparatus 1 of this embodiment is set to this value, and actual production is carried out. This eliminates the need for complicated, time-consuming, and labor-intensive trial-and-error experiments, and allows for the determination of the optimal center coordinate (X) of the sputtering electrode 131. １ , Z １ ) and inclination angle θ １ This can be obtained by conducting at least one experiment.

[0039] In step ST7, if the measured value of the film thickness distribution measured in step ST6 is not a satisfactory value, in step ST8, the center coordinate (X) of the sputter electrode 131 obtained in step ST4 is used. １ , Z １ ) and inclination angle θ １ Then, the measured values ​​of the film thickness distribution obtained in step ST6 are input into the program of this embodiment.

[0040] In the following steps ST9 to ST10, the same process as described in steps ST3 to ST4 is performed. Then, in step ST11, the center coordinates (X) obtained in step ST10 are used. ２ , Z ２ ) and inclination angle θ ２ After displaying the results on a computer screen or similar, proceed to step ST6. Subsequently, in step ST7, repeat steps ST8 to ST11 and ST6 to ST7 until the measured value of the film thickness distribution measured in step ST6 is satisfactory.

[0041] The Monte Carlo method used in the program of this embodiment is a method that uses random numbers to simulate the behavior of sputtered particles flying from the target to the substrate, and therefore includes a step of generating random number samples to represent the emission angle distribution model of sputtering particles. Specifically, this step of generating random number samples involves setting the emission angle range to 0 to π / 2 radians (corresponding to a tilt angle θ of 0 to 90°) and generating an angle list for each arbitrary angle within this emission angle range. Then, the probability distribution formula P(θ) = A・cos ｎ (θ) - B・cos ｍ Based on (θ), calculate the probability density for each angle in the angle list, and then normalize the calculated probability density.

[0042] Next, in order to generate random number samples, angles are randomly selected according to a uniform distribution within the emission angle range of 0 to π / 2 radians. The normalized probability density corresponding to the selected angle is compared with the uniform random number, and the angle is accepted as a sample if its probability density is greater than that of the uniform random number. The above steps are repeated until a predetermined number of samples are obtained.

[0043] Furthermore, the probability distribution formula P(θ) = A・cos for the sputtering particle emission angle distribution model is ｎ (θ) - B・cos ｍ (θ) is adjusted by parameters A and B, and the shape of the distribution is determined by parameters n and m. Furthermore, the selection of angle samples is performed using the acceptance / rejection method, and sampling is carried out based on the maximum probability value obtained by normalizing the probability density.

[0044] In the sputtering apparatus 1 of this embodiment, when a circular target is used as the target 132, it is known that the annular region (donut-shaped region) on the surface of the target 132 becomes the source of sputtering particles. Therefore, the program of this embodiment includes a step of generating the sputtering particle source as a point source within the annular region.

[0045] The step of generating point sources within this annular region involves receiving (inputting) the inner radius, outer radius, and density of multiple annular regions, calculating the area of ​​each annular region, determining the number of point sources to be generated based on the area and density of each annular region, dividing the angles into equal intervals to evenly distribute the point sources, generating random radii, calculating the coordinates of the point sources based on the radii and angles, and setting the coordinates of a specific axis of the point source to a unique value.

[0046] 1...Sputtering apparatus 11...Housing 111...Exhaust port 112...Exhaust device 113...Side wall panel 114...Bottom panel 115...Ceiling panel 116...Slide plate 12...Chamber 121...Film deposition chamber 122...Porous quartz plate 123...Porous metal plate 124...Gas supply device 13...Electrode unit 131...Sputtering electrode 132...Target 133...Movable panel 134...Support plate 135...First pin 136...Second pin 137...Bracket 14...Shaft 141...Lifting plate 142...Lead screw mechanism 15...Tilt unit 151...First plate 152...Second plate 153...Third plate 154...First cam hole 155...Second cam hole 156...Lead screw 157...Bush 158...Link plate 16... Susceptor 161... Rotating shaft 162... Drive unit 163... Heater 17... Bellows tube 18... Cable 2... Substrate C1... Susceptor center point C2... Target center point X... Offset length (distance in the X-axis direction from susceptor center point C1 to target center point C2) Z... Height (distance in the Z-axis direction from susceptor center point C1 to target center point C2) PL1... Plane parallel to the surface of the substrate PL2... Plane parallel to the surface of the target θ... Inclination angle (angle between PL1 and PL2)

Claims

1. A sputtering apparatus comprising: a chamber capable of reducing pressure for forming a film on a substrate; and an electrode unit provided inside the chamber and including a sputtering electrode, wherein the electrode unit is supported by a shaft via a tilt unit, the shaft is movable relative to the chamber in a first axial direction parallel to the surface of the substrate in the film formation position, and is also movable in a second axial direction perpendicular to the surface of the substrate in the film formation position, and the tilt unit is capable of adjusting the inclination angle of the surface of a target mounted on the sputtering electrode with respect to the surface of the substrate in the film formation position.

2. The sputtering apparatus according to claim 1, wherein a bellows tube is fixed between the shaft and the sputtering electrode, a cable supplying high-frequency power to the sputtering electrode is connected to the sputtering electrode from outside the chamber, through the inside of the shaft and the bellows tube, and the tilt unit includes a cam slide mechanism such that the length of the cable remains constant regardless of the adjustable tilt angle.

3. The sputtering apparatus according to claim 1 or 2, wherein the diameter of the sputtering electrode is 190 mm or more, the tilt unit is adjustable in inclination angle in the range of 0° to 90°, the shaft is movable in the second axial direction in the range of 0 to 350 mm with respect to the surface of the substrate where the film is deposited, and the center coordinates of the sputtering electrode are movable in the first axial direction in the range of 0 to 590 mm with respect to the center coordinates of the surface of the substrate where the film is deposited.

4. A program for assisting in determining the optimal values ​​of the center coordinates and tilt angle of the sputtering electrode in a sputtering apparatus according to any one of claims 1 to 3, the program causing a computer to perform the following steps: determine parameters including the center coordinates, the tilt angle, and variables of the sputtering particle emission angle distribution model based on measured values ​​of the film thickness distribution of a film formed on a substrate when a predetermined vacuum and predetermined target material are sputtered using the sputtering apparatus at arbitrary center coordinates and tilt angle; simulate the flight of sputtering particles based on the determined parameters; and predict the film thickness distribution of the film formed on the substrate.

5. The program according to claim 4, which includes the steps of: calculating the variables of the emission angle distribution model that minimize the difference between the measured value of the film thickness distribution and the calculated value of the film thickness distribution by Bayesian optimization with the variables of the emission angle distribution model of the sputtering particles as the search range; and using the calculated variables of the emission angle distribution model, calculating the center coordinates and the tilt angle that minimize the calculated value of the film thickness distribution by Bayesian optimization with the center coordinates and the tilt angle as the search range.

6. The step includes generating a random number sample to represent the emission angle distribution model of the sputtering particles, the step of generating the random number sample includes setting the emission angle range to 0 to π / 2 radians, generating an angle list for each arbitrary angle within the emission angle range, and the probability distribution formula P(θ) = A・cos ｎ (θ) - B・cos ｍ The program according to claim 4 or 5, which calculates the probability density for each angle in the angle list based on (θ), normalizes the calculated probability density, randomly selects an angle in the emission angle range according to a uniform distribution in order to generate the random number sample, compares the probability density calculated and normalized by the probability distribution formula based on the selected angle with a uniform random number, accepts the angle as a sample if the normalized probability density is greater than the uniform random number, and repeats the above steps until a predetermined number of samples is obtained.

7. The program according to claim 6, wherein the probability distribution formula is adjusted by parameters A and B, the shape of the distribution is determined by parameters n and m, a sample of the angle is selected using an acceptance / rejection method, and sampling is performed based on the maximum probability value obtained by normalizing the probability density.

8. A program according to any one of claims 4 to 7, comprising the step of generating the sputtering particle emission sources as point sources in annular regions, the step of generating as point sources comprising: receiving the inner radius, outer radius and density of a plurality of annular regions; calculating the area of ​​each annular region; determining the number of point sources to be generated based on the area and density of each annular region; dividing the angles into equal intervals to evenly distribute the point sources; generating random radii; calculating the coordinates of the point sources based on the radii and angles; and setting the coordinates of a particular axis of the point sources to a unique value.

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