Target joining state detection method and film forming apparatus

Abstract

The invention provides a target material joint state detection method and a film forming apparatus which can detect peeling even if the peeling of a target material is small. The film forming apparatus (1) determines the bonding state of the target material (231) on the basis of the pattern of the temperature change of the target material (231) at the predetermined time (T1) and the predetermined time (T2). Temperature sensors (237b, 238b) detect the temperature of the target (231) and / or the target base (232) at a predetermined time (T1) from the start of film formation or at a predetermined time (T2) from the end of film formation. On the basis of the detected temperature of the target and / or the target susceptor, the calculation unit (45) calculates a temperature change over time over a predetermined period of time. A joining state determination unit (46) determines the joining state of the target material (231) on the basis of temperature changes over time at predetermined times (T1, T2).

Description

Technical Field

[0001] The present invention relates to a method for detecting the bonding state of a target and a film forming apparatus. Background Art

[0002] In the manufacturing processes of various products such as semiconductors, displays, and optical discs, a thin film such as an optical film is sometimes formed on a workpiece such as a wafer or a glass substrate. The thin film can be produced by repeatedly performing film formation of a film such as a metal on the workpiece and film processing such as etching, oxidation, or nitridation of the formed film.

[0003] Such film formation and film processing can be performed by various methods. As one of them, there is a method using plasma. During film formation, an inert gas is introduced into a vacuum chamber, which is a vacuum container in which a target is disposed, and a DC voltage is applied. Ions of the plasmaized inert gas collide with the target, and the material ejected from the target accumulates on the workpiece to perform film formation. In film processing, a process gas is introduced into a chamber in which an electrode is disposed, and a high-frequency voltage is applied to the electrode. Ions of the plasmaized process gas collide with the film on the workpiece, thereby performing film processing.

[0004] There is known a sputter-down type film forming apparatus that, during film formation processing, disposes a target bonded to the lower surface of a target base via an adhesive material on the upper surface inside a vacuum container, generates plasma by forming an electric field on the lower surface side of the target, and sputters the target by ions of the plasma. The target is cooled by a cooling mechanism via the target base.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-166032 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] In a film forming apparatus, due to reasons such as excessive power supply to the target, insufficient cooling of the target base by the cooling mechanism, or poor compatibility between the target material and the adhesive material, the target may peel off and fall off from the target base. Particularly in the case of a sputter-down type film forming apparatus, the fallen target may cause a long-term operation stop or a malfunction of the apparatus.

[0010] As a method for detecting the detachment of a target, a method using a cooling mechanism for cooling the target can be considered. In the case of a water-cooled cooling mechanism using a coolant, the following method can be considered: detecting the temperature Te_out on the discharge side of the cooling water for cooling the target, and determining that the target has detached when the temperature exceeds a threshold value.

[0011] However, in the case where the target is slowly peeled off, etc., the temperature Te_out on the discharge side of the cooling water does not change beyond the threshold value, and thus small detachment of the target cannot be detected.

[0012] An embodiment of the present invention is proposed to solve the above problems, and an object thereof is to provide a method for detecting the bonding state of a target and a film forming apparatus that can detect the detachment even when small detachment of the target occurs.

[0013] Technical means for solving the problem

[0014] The film forming apparatus according to an embodiment of the present invention forms a film on a workpiece using plasma, and the film forming apparatus includes: a sealed container into which the workpiece is carried; a target provided in the sealed container; a target base that holds the target on one surface; a temperature detection unit that detects the temperature of the target and / or the target base at a specified time after the film forming process ends or at a specified time from the start of the film forming process after a specific time has elapsed since the film forming process ended; a calculation unit that calculates the temperature change over time at the specified time based on the detected temperature of the target and / or the target base; and a bonding state determination unit that determines the bonding state of the target based on the temperature change over time at the specified time.

[0015] In addition, the bonding state detection method according to an embodiment of the present invention is a method for detecting the bonding state of a target in a film forming apparatus that forms a film on a workpiece using plasma, and the target bonding state detection method includes: a temperature detection step of detecting the temperature of the target and / or the target base at a specified time after the film forming process ends or at a specified time from the start of the film forming process after a specific time has elapsed since the film forming process ended; a calculation step of calculating the temperature change over time at the specified time based on the detected temperature of the target and / or the target base; and a bonding state determination step of determining the bonding state of the target based on the temperature change over time.

[0016] Effects of the invention

[0017] According to the film forming apparatus according to an embodiment of the present invention, even when small detachment of the target occurs, the detachment can be detected. Description of the drawings

[0018] Figure 1 is a schematic diagram of the film forming apparatus showing the first embodiment.

[0019] Figure 2 is a perspective view (A) and a bottom view (B) of the cooling plate showing the first embodiment.

[0020] Figure 3 is a block diagram showing the structure of the control device of the first embodiment.

[0021] Figure 4 is a graph showing the inlet / outlet temperature difference of the cooling water of the good target stored in the reference temperature storage unit of the first embodiment.

[0022] Figure 5 is a graph showing the inlet / outlet temperature difference of the cooling water when the target reaches a stable state during stable operation over a certain period of time.

[0023] Figure 6 is a graph showing the change patterns of the inlet / outlet temperature difference of the cooling water in the good target and the damaged target.

[0024] Figure 7 is a flowchart showing the target bonding state detection process in the first embodiment.

[0025] Figure 8 is a graph (A) showing the change patterns of the inlet / outlet temperature difference of the cooling water in the good target and the damaged target, and a graph (B) showing the on / off of the applied voltage based on the power supply device corresponding to the change pattern of the inlet / outlet temperature difference of the cooling water in (A). Figure 8 (A) The change pattern of the inlet / outlet temperature difference of the cooling water in, and a graph (B) showing the on / off of the applied voltage based on the power supply device corresponding to the change pattern of the inlet / outlet temperature difference of the cooling water in (A).

[0026] Figure 9 is a schematic diagram of the film forming apparatus showing a modification of the first embodiment.

[0027] Figure 10 is a graph showing the change patterns of the cumulative heat dissipation of the good target and the damaged target at a specified time.

[0028] Figure 11 is a block diagram showing the structure of the control device of a modification of the first embodiment.

[0029] Figure 12 is a block diagram showing the structure of the control device of a modification of the first embodiment.

[0030] Figure 13 is a graph showing the heat dissipation ratio with respect to the elapsed time since the heat supply stopped in a modification of the first embodiment.

[0031] ​​​​​​​​​​​​​​Figure 14 is a schematic diagram showing a film forming apparatus according to a second embodiment.

[0032] Figure 15 is a block diagram showing the structure of a control device according to a second embodiment.

[0033] Figure 16 is a graph obtained by simulating the correlation between the temperature of a target using Cr and the temperature of a target base over time after film formation processing in a film forming apparatus according to a second embodiment.

[0034] Figure 17 is a flowchart showing a target bonding state detection process in a second embodiment.

[0035] Figure 18 is a graph showing the correlation between the target temperature and the target base temperature. Detailed Embodiments

[0036] Embodiments of the present invention will be specifically described with reference to the drawings (hereinafter referred to as the present embodiment). In addition, the drawings are schematic diagrams, and dimensions, ratios, etc. of each part include parts exaggerated for easy understanding.

[0037] [1. First Embodiment]

[0038] [1-1. Structure]

[0039] A first embodiment of the present invention will be described with reference to the accompanying drawings.

[0040] A film forming apparatus 1 is a film forming apparatus that forms a film on a workpiece W using plasma. As Figure 1 shown, the film forming apparatus 1 is provided with a stage 21 for placing the workpiece W near the bottom of a chamber 2 that is a sealed container. The type of the workpiece W is not limited to a specific type, and for example, it is a glass substrate.

[0041] The stage 21 is disk-shaped, connected to and supported by a shaft 22 extending from the bottom surface of the chamber 2. The shaft 22 penetrates the bottom surface of the chamber 2 airtightly and communicates with the outside. An exhaust device 25 and a pressure gauge 26 are provided in the chamber 2. The exhaust device 25 is, for example, a pump, and always exhausts the inside of the chamber 2 to maintain a reduced pressure state. The pressure gauge 26 measures the pressure inside the chamber 2.

[0042] ​​​​An inlet / outlet 20 for loading and unloading the workpiece W is provided in the chamber 2. The inlet / outlet 20 is connected to a load lock chamber (not shown), and the workpiece W is carried into the interior of the chamber 2 from the outside of the film forming apparatus 1 via the load lock chamber. An exhaust device is also provided in the load lock chamber. When the workpiece W is carried into the chamber 2, after the workpiece W is carried into the interior of the load lock chamber, the load lock chamber is depressurized to a preset pressure. After depressurizing to the preset pressure, the inlet / outlet 20 of the chamber 2 is opened, and the workpiece W is carried into the chamber 2. By opening the inlet / outlet 20 after depressurizing to the preset pressure, an increase in the pressure of the chamber 2 can be reduced.

[0043] A sputtering source 23 is disposed above the chamber 2. The sputtering source 23 is a supply source of a film forming material that accumulates on the workpiece W to form a film. The sputtering source 23 includes a target 231, a target base 232, an adhesive portion 233, a cooling plate 235, an anode portion 236, a water supply portion 237, a drainage portion 238, and a magnet portion 239. In addition, a power supply device 24 is connected to the sputtering source 23.

[0044] The target 231 is disposed below the sputtering source 23 and is arranged such that its surface faces the stage 21 provided near the bottom of the chamber 2. That is, the target 231 is disposed inside the chamber 2. The target 231 contains a film forming material, and all well-known film forming materials can be applied. In the present embodiment, the target 231 is made of chromium (Cr). The shape of the target 231 is, for example, a cylindrical shape. However, it may also be other shapes such as an elliptical cylindrical shape or a prismatic shape.

[0045] The upper surface of the target 231 is held on one surface of the target base 232 via the adhesive portion 233. The target base 232 and the target 231 together form a cathode. The target base 232 is, for example, a copper plate. The surface of the target base 232 opposite to the stage 21 is held by the cooling plate 235. The adhesive portion 233 is an adhesive layer that bonds the target 231 and the target base 232 using an adhesive such as In or an In alloy.

[0046] When sputtering starts, ions in the plasma collide with the target 231. Due to the collision of the ions, particles of the film forming material fly out from the target 231 and accumulate on the workpiece W as the film forming substrate, thereby forming a thin film. By applying a DC voltage to the target 231 during film formation, the sputtering gas is plasmaized to become a heat source 234. During sputtering operation, the surface of the target 231 becomes high temperature due to the influence of the heat source 234. The target 231 is cooled by the cooling plate 235 to prevent melting of the adhesive portion 233, stress caused by the difference in thermal expansion between the target 231 material and the adhesive portion 233, and peeling of the target 231 from the target base 232 accompanying this.

[0047] The cooling plate 235 functions to cool the target 231. The cooling plate 235 indirectly cools the object to be cooled, for example, using a coolant as a medium. In the present embodiment, the cooling plate 235 has cooling water e flowing inside it as a coolant, and cools the target 231 uniformly via the target base 232. The cooling plate 235 is, for example, a cylindrical shape with one end closed. A surface for holding the other surface of the target base 232 is provided on the end face of one end. A flange 235c, a water supply port 235d, and a discharge port 235e are provided at the other end of the cooling plate 235.

[0048] The flange 235c is formed to extend outward at the other end of the cooling plate 235. The flange 235c is hermetically connected to the thick wall portion 236a1 of the TS interval adjustment portion 236a, which will be described later, via an insulating member (not shown). The water supply port 235d is a water supply port connected to the water supply portion 237 for introducing the cooling water e into the inside of the cooling plate 235. The discharge port 235e is a discharge port connected to the drainage portion 238 for discharging the cooling water e supplied to the inside of the cooling plate 235.

[0049] The surface (the surface) of the cooling plate 235 that holds the target base 232 is larger than the surface of the target 231. As shown in (A) and (B) of Figure 2 , concave grooves 235b are formed on the surface of the cooling plate 235. The grooves 235b are formed on the surface of the cooling plate 235 in a range at least larger than the area of the surface of the target 231 and smaller than the area of the surface of the cooling plate 235. The grooves 235b have an inlet 235b1 and an outlet 235b2. The inlet 235b1 is connected to the water supply port 235d, and the outlet 235b2 is connected to the discharge port 235e. The grooves 235b surround the above-mentioned range on the surface of the cooling plate 235 without omission and communicate from the inlet 235b1 to the outlet 235b2. When the grooves 235b are provided on the surface of the cooling plate 235, a sealing material 235a such as an O-ring is provided on the surface of the cooling plate 235 so as to surround the grooves 235b. The cooling plate 235 is fixed to the target base 232 via a sealing material 235a such as an O-ring. A flow path 235f for the cooling water e is formed by the grooves 235b and the fixed target base 232. Since the formed flow path 235f is sealed by the sealing material 235a, the cooling water e does not leak from the connection portion and flows in the flow path 235f. In addition, in the present embodiment, the flow path 235f is formed by the grooves 235b of the cooling plate 235 and the target base 232, but this case is also included in the case where the flow path 235f is provided in the cooling plate 235.

[0050] Alternatively, the flow path 235f may be provided inside the cooling plate 235. In such a case, the cooling water e does not leak from the connection portion with the target base 232, and thus the target base 232 and the cooling plate 235 may be connected without using the sealing material 235a.

[0051] The anode portion 236 suppresses the generation of plasma other than the surface of the target 231 and functions as an anode for the target 231 and the target base 232. The anode portion 236 includes a TS distance adjustment portion 236a and an anode ring 236b.

[0052] The TS distance adjustment portion 236a is a member capable of adjusting the distance (TS distance) between the target 231 and the workpiece W. The TS distance adjustment portion 236a has, for example, a cylindrical shape. One end of the TS distance adjustment portion 236a is inserted through the opening on the upper surface of the chamber 2 into the interior of the chamber 2. One end of the TS distance adjustment portion 236a has a thick-walled portion 236a1 with a thickness throughout the entire circumference of the inner periphery. The flange 235c of the cooling plate 235 is hermetically connected to the thick-walled portion 236a1 via an insulating member (not shown). With such a structure, the target 231, the target base 232, the cooling plate 235, and the magnet portion 239 are disposed inside the anode portion 236. The other end of the TS distance adjustment portion 236a is provided outside the chamber 2. The other end of the TS distance adjustment portion 236a has a flange 236a2 protruding in a ring shape so as to expand outward in diameter. The TS distance adjustment portion 236a is hermetically connected to the chamber 2 via the flange 236a2.

[0053] The TS distance adjustment portion 236a can change the TS distance by changing the length between the thick-walled portion 236a1 and the flange 236a2. For example, a plurality of TS distance adjustment portions 236a with different lengths between the thick-walled portion 236a1 and the flange 236a2 are prepared in advance. By separately using the TS distance adjustment portions 236a with different lengths between the thick-walled portion 236a1 and the flange 236a2, the TS distance can be changed to any value. Alternatively, the TS distance can also be changed by providing a spacer (not shown) between the flange 236a2 of the TS distance adjustment portion 236a and the chamber 2. For example, by changing the thickness of the spacer (not shown), the TS distance can be changed. In addition, the TS distance adjustment portion 236a is grounded.

[0054] The anode ring 236b suppresses the generation of plasma other than the surface of the target 231 and functions as an anode for the target 231 and the target base 232. The anode ring 236b has, for example, a ring shape. The anode ring 236b is connected to one end of the TS distance adjustment portion 236a and is arranged to surround the periphery of the target 231. Thereby, the case where argon molecules collide with the target base 232 or the like is shielded.

[0055] The water supply unit 237 supplies cooling water e to the flow path 235f of cooling water e formed in the cooling plate 235. The drainage unit 238 discharges the cooling water e flowing in the flow path 235f of cooling water e. That is, the water supply unit 237 and the drainage unit 238 are connected to the flow path 235f of the cooling plate 235. The water supply unit 237 and the drainage unit 238 are respectively provided with a temperature sensor 237b and a temperature sensor 238b. The temperature sensor 237b and the temperature sensor 238b are equivalent to the temperature detection unit and are connected to the control device 4. The detected temperature (temperature Te of cooling water e) detected by the temperature sensor 237b and the temperature sensor 238b is transmitted to the control device 4 as the supply side temperature Te_in of cooling water e and the discharge side temperature Te_out of cooling water e. In addition, the supply side temperature Te_in of the cooling water e may be referred to as the temperature Te_in of the cooling water e or the temperature Te_in, and the discharge side temperature Te_out of the cooling water e may be referred to as the temperature Te_out of the cooling water e or the temperature Te_out.

[0056] The magnet part 239 has the function of enclosing electrons in a magnetic field and forming a space with a high electron density near the surface of the target material 231. The magnet part 239 includes a magnet 239a and a motor 239b. The magnet 239a generates a magnetic field near the surface of the target material 231. The magnet 239a is rotated eccentrically relative to the rotation axis of the motor 239b by the motor 239b. The magnet 239a is arranged on the back of the target material 231 across the cooling plate 235 and is a permanent magnet that generates a rotating magnetic field. The motor 239b is a driving source for rotating the magnet 239a. The motor 239b is connected to a power supply device not shown in the figure to rotate the magnet 239a eccentrically, thereby changing the magnetic field near the surface of the target material 231. By changing the magnetic field near the surface of the target material 231, the plasma density near the surface of the target material 231 can also be changed. As a result, the erosion area based on sputtering on the surface of the target material 231 can be moved, thereby suppressing excessive erosion or heating of one part of the target material 231.

[0057] The power supply device 24 is a structural part that applies voltage to the target 231 via the target base 232. That is, the power supply device 24 plasma-forms the sputtering gas introduced into the periphery of the target 231 by applying voltage to the target 231, and deposits the film-forming material on the workpiece W. The power supply device 24 in this embodiment is, for example, a direct current (DC) power supply that applies a high voltage. In this embodiment, the power supply device 24 is connected to the cooling plate 235. Thus, the power supply device 24 is connected to the target base 232 via the cooling plate 235. In addition, in the case of a device that performs high-frequency sputtering, the power supply device 24 can also be set to a radio frequency (RF) power supply.

[0058] In addition, a sputtering gas introduction part 27 is provided in the chamber 2. A sputtering gas is introduced into the interior of the chamber 2 from the sputtering gas introduction part 27. The sputtering gas is not limited to a specific gas, but in the present embodiment, for example, an inert gas such as argon can be used. The sputtering gas introduction part 27 includes an argon gas introduction part 271a and a flow controller 271b. The argon gas introduction part 271a is a supply source of argon gas such as a gas cylinder. The flow controller 271b measures and controls the flow rate of argon gas, and introduces argon gas into the interior of the chamber 2 at a predetermined flow rate.

[0059] [Control device]

[0060] The control device 4 controls the operations of the respective parts of the film forming apparatus 1. The control device 4 can include, for example, a dedicated electronic circuit or a computer operating according to a prescribed program. In the control device 4, the control contents for each part are programmed and executed by a processing device such as a Programmable Logic Controller (PLC) or a Central Processing Unit (CPU). Therefore, it is possible to cope with a variety of film forming specifications.

[0061] In addition, the control device 4 has the following function: based on the change over time of the temperature of the target 231 and / or the target base 232 at a prescribed time T2 after the film forming process ends or at a prescribed time T1 starting from the start of the film forming process after a specific time Tsp has elapsed since the film forming process ended, that is, the mode of the temperature change of the target 231 and / or the target base 232, the bonding state of the target 231 is judged. Refer to Figure 3 The structure of such a control device 4 will be described. The control device 4 includes a film forming processing part 41, a reference temperature storage part 43, a storage part 44, a calculation part 45, a bonding state determination part 46, a notification part 47, and an input / output control part 48.

[0062] The film forming processing part 41 is a processing part that controls the mechanisms of the respective parts of the film forming apparatus 1 and performs a film forming process. As the control contents, for example, the opening and closing of the load lock chamber and the control of the pressure inside the load lock chamber; the control of the pressure inside the chamber 2; the opening and closing of the loading / unloading port 20, the exhaust speed of the exhaust device 25, the introduction timing and introduction amount of the sputtering gas introduction part 27; the voltage application timing and the supply power amount control in the power supply device 24; the control of the timing for detecting the change over time of the temperature in the target 231 and / or the target base 232, etc. can be cited.

[0063] The film forming processing unit 41 obtains the pressure inside the chamber 2 from the pressure gauge 26 and confirms whether the pressure inside the chamber 2 has reached the base pressure. The base pressure is the pressure inside the chamber 2 where sputtering gas can be introduced. Specifically, after the workpiece W is loaded into the chamber 2 and the loading / unloading port 20 is closed, the chamber 2 is evacuated by the evacuation device 25 for a preset time, thereby reducing the pressure inside the chamber 2 to the base pressure. After reaching the base pressure, the sputtering gas introduction unit 27 controls the flow rate controller 271b of argon and introduces argon into the chamber 2 at a preset flow rate. As a result, an arbitrary pressure is formed inside the chamber 2.

[0064] The reference temperature storage unit 43 is a storage component such as a memory. The reference temperature storage unit 43 stores the temperature change of the good target material corresponding to the elapsed time t for a specified time T1 starting from the start of the film forming process after a specific time Tsp has elapsed since the end of the film forming process, or for a specified time T2 starting from the end of the film forming process. Here, a good target material refers to a target material in a state where no melting or peeling due to stress occurs at the bonding portion 233 and no peeling of the target material 231 is caused.

[0065] In addition, the peeling of the target material 231 refers to either or both of the peeling of the target material 231 from the bonding portion 233 and the peeling of the target base 232 from the bonding portion 233. In the above case, the "peeling of the target material 231" includes peeling from a very small peeling (very small peeling at the initial stage) as the initial stage of peeling to a large peeling that causes the target material 231 to fall off. In addition, the small peeling before the target material 231 falls off, which will be described later, is a peeling that is larger than the very small peeling at the initial stage and smaller than the large peeling that causes the target material 231 to fall off.

[0066] As a value used as an index for judging the small peeling before the target material 231 falls off, it is preferably set to a value with a certain margin relative to the value used as an index for judging the large peeling that causes the target material 231 to fall off. That is, if the value as an index for small peeling is reached before the value as an index for large peeling is reached, it can be judged as peeling. For example, the absolute value of the "slope of the temperature curve" at the time of large peeling is obtained in advance through experiments, and a value with a margin compared to the above value and a large value when compared in absolute value is set as the value used as an index for small peeling. Thus, as long as peeling is detected at the time point when the value as an index for small peeling is reached, the falling off of the target material 231 can be prevented. In addition, the difference between the value used as an index for small peeling and the absolute value of the slope of the temperature curve of the good target material can be obtained, and if the slope difference is within the above value, it is determined that no peeling has occurred.

[0067] In addition, the specified time T1 is a time determined in advance from the start of the film formation process after a specific time Tsp has elapsed since the end of the film formation process, and the specified time T2 is a time determined in advance from the end of the film formation process. The specified time T1 and the specified time T2 are times that can be appropriately determined according to the film formation conditions or the raw material of the target. In addition, in the present embodiment, the so-called "specified" means preset in the storage component of the control device 4 or the like, and the so-called "specified time" can be replaced with a "set time" preset in advance. In addition, the specific time Tsp is the time until the heated target 231 is cooled to room temperature. The specific time Tsp is, for example, 180 seconds (s) or more, and in the present embodiment, the specific time Tsp is 180 s. The specific time Tsp is also preset in the storage component of the control device 4 or the like.

[0068] The temperature change of the good target can be obtained by directly measuring the temperature of the target 231 or indirectly measuring the temperature of the target 231. As a method for indirectly measuring the temperature change of the good target, a method using the temperatures Te of the cooling water e before and after cooling the target 231, that is, the temperature Te_in and the temperature Te_out, can be adopted. For example, a method of calculating the temperature difference between the temperature Te_in and the temperature Te_out (inlet / outlet temperature difference of the cooling water e) can be adopted. That is, the temperature sensor 237b and the temperature sensor 238b detect the temperature of the target 231 and / or the target base 232 at the specified time T2 from the end of the film formation process or at the specified time T1 from the start of the film formation process after a specific time Tsp has elapsed since the end of the film formation process. In addition, in the following description, the inlet / outlet temperature difference of the cooling water e may sometimes be referred to as the cooling water inlet / outlet temperature difference or the inlet / outlet temperature difference. Figure 4 It is a graph showing the inlet / outlet temperature difference of the cooling water e of the good target stored in the reference temperature storage unit 43. Figure 4 It shows the inlet / outlet temperature difference of the cooling water e during the period from shortly after the start of the film formation process of the good target to 180 seconds after the end of the film formation process. In the graph, the period from the start of the film formation process to 80 seconds (0 s to 80 s) is set as the specified time T1, and the period from the end of the film formation process to 180 seconds (710 s to 890 s) is set as the specified time T2.

[0069] In addition, Figure 4 The film formation process in shows a case where film formation is performed on a plurality of workpieces W in a short film formation time. The time required for one film formation at this time is 65 seconds. In addition, the case of a short film formation time means that the target 231 is not in a stable state.

[0070] In addition, as Figure 4As shown, in the case of performing film formation multiple times repeatedly, it means repeatedly performing the entire film formation process multiple times, which is referred to as "film formation treatment". In this case, in one film formation among the multiple repeated film formations, the start of film formation is called "film formation start", and the end of film formation is called "film formation end". In addition, in the multiple repeated film formations, the start of the first film formation is called "film formation treatment start", and the end of the last film formation is called "film formation treatment end". In addition, film formation treatment means dividing the states between film formations according to a specific time Tsp. Therefore, sometimes only one film formation is performed in one film formation treatment, and sometimes "film formation treatment start" is called "film formation treatment start after a specific time Tsp has elapsed since film formation treatment end".

[0071] The storage unit 44 is a storage unit that stores the temperature of the target 231 to be determined. In the case of indirectly measuring the temperature of the target 231, it stores the temperature Te_in and the temperature Te_out detected by the water supply unit 237 and the drainage unit 238. When film formation treatment starts, the temperature Te_in and the temperature Te_out are transmitted from the temperature sensor 237b and the temperature sensor 238b to the control device 4. The storage unit 44 stores the temperature Te_in and the temperature Te_out during a specified time (during the specified time T1 or the specified time T2) after the start or end of film formation treatment. In addition, the storage unit 44 may store the temperature Te_in and the temperature Te_out detected by the water supply unit 237 and the drainage unit 238 during the period from the start of film formation treatment to the end of film formation treatment. Or, the storage unit 44 may store the temperature Te_in and the temperature Te_out detected by the water supply unit 237 and the drainage unit 238 during the period when the film formation apparatus 1 is operating.

[0072] The calculation unit 45 is a calculation unit for calculating the temperature difference between the inlet and outlet of the cooling water e based on the temperature Te_in and the temperature Te_out stored in the storage unit 44 and arranging them according to the elapsed time t. That is, the calculation unit 45 calculates the temperature change over time at a specified time T1 (T2) based on the temperature Te_in and the temperature Te_out (the detected temperature of the target 231 and / or the target base 232). The temperature difference between the inlet and outlet calculated by the calculation unit 45 may be only the specified time T1 or the specified time T2, but for the sake of explanation below, it is assumed that the temperature difference between the inlet and outlet from shortly after the start of film formation treatment to 300 seconds after the end of film formation treatment is calculated for explanation.

[0073] The joint state determination unit 46 is a determination unit that compares the temperature difference between the inlet and outlet of the cooling water e of the good target stored in the reference temperature storage unit 43 with the temperature difference between the inlet and outlet of the cooling water e in the target 231 installed in the film forming apparatus 1, and determines the joint state of the target 231. That is, the joint state determination unit 46 is a determination unit that determines the joint state of the target 231 based on the temperature change over time at a specified time T1 (T2). For example, as Figure 6 shown, the joint state determination unit 46 compares and determines the slopes of the plots (temperature curves) of the temperature difference between the inlet and outlet of the cooling water e of the good target and the temperature difference between the inlet and outlet of the cooling water e of the target 231 installed in the film forming apparatus 1 at the specified time T1 or the specified time T2 of the temperature difference between the inlet and outlet of the cooling water e. The specific determination method will be described later.

[0074] In the case of detecting a small peel before the target 231 falls off, the notification unit 47 notifies the output device 62 described later. The input / output control unit 48 is an interface that controls the conversion or input / output of signals between the respective units to be controlled.

[0075] Furthermore, an input device 61 and an output device 62 are connected to the control device 4. The input device 61 is an input component such as a switch, a touch screen, a keyboard, or a mouse for a user to operate the film forming apparatus 1 via the control device 4.

[0076] The output device 62 is an output component such as a display, a lamp, an instrument, etc. that makes the information for confirming the state of the film forming apparatus 1 visible to the user, or a speaker, a buzzer, etc. that enables the user to recognize the state by hearing.

[0077] [1-2. Function]

[0078] Next, the operation and film forming method of the film forming apparatus 1 of the present embodiment will be described. The operation of the film forming apparatus 1 described below is controlled by the film forming processing unit 41 of the control device 4. Hereinafter, a Cr target of φ150 mm × t10 mm will be used. Figure 7 The workpiece W is carried into a load lock chamber (not shown) from the outside of the atmosphere. After the load lock chamber is depressurized to a preset pressure, the carry-in / carry-out port 20 is opened, and the workpiece W is carried into the inside of the chamber 2. The carried-in workpiece W is placed on the stage 21. The carrying-in of the workpiece W into the chamber 2 is performed by a carrying device (not shown). After the workpiece W is placed on the stage 21, the carry-in / carry-out port 20 is closed and the chamber 2 is sealed. Since the chamber 2 is always evacuated by the evacuation device 25, the chamber 2 is depressurized by closing the carry-in / carry-out port 20.

[0079]

[0080] ​After the control device 4 closes the loading and unloading port 20, at the time point when the elapsed time of the timing has passed a predetermined exhaust time, it obtains the pressure value inside the chamber 2 from the pressure gauge 26. When the pressure inside the chamber 2 is equal to or lower than the base pressure, the film forming unit 41 introduces argon gas into the chamber 2.

[0081] Specifically, the film forming unit 41 controls the flow rate controller 271b of the sputtering gas introduction unit 27 to introduce argon gas with a predetermined flow rate into the chamber 2. As a result, an arbitrary pressure is formed inside the chamber 2.

[0082] After the above steps, film formation is started (S01: film formation start step). Argon gas is introduced into the chamber 2 from the sputtering gas introduction unit 27. After the pressure inside the chamber 2 becomes an arbitrary pressure, a DC voltage is applied to the target 231 from the power supply device 24. By applying the DC voltage, the sputtering gas is plasmaized and ions are generated. When the generated ions collide with the target 231, particles of the film forming material of the target 231 fly out and film formation starts. The flying particles accumulate on the workpiece W placed on the stage 21, and thus a thin film is formed on the workpiece W.

[0083] After film formation starts, the storage unit 44 starts storing the temperature Te_in and temperature Te_out of the cooling water e (S02). That is, after film formation starts, the temperature Te of the cooling water e measured (temperature detection step) by the temperature sensor 237b and the temperature sensor 238b is periodically transmitted to the control device 4. The storage unit 44 stores at least the temperature Te_in and temperature Te_out of the cooling water e for a predetermined time T1 and a predetermined time T2 transmitted from the temperature sensor 237b and the temperature sensor 238b.

[0084] For example, if the control device 4 determines that the film formation to be executed now is the first film formation, it stores the temperature Te_in and temperature Te_out of the cooling water e during the period from the time when the film formation process is determined to start until the time when a predetermined time T1 has elapsed. In addition, if the control device 4 determines that the film formation to be executed now is the last film formation, it stores the temperature Te_in and temperature Te_out of the cooling water e during the period from the time when the film formation process is determined to end until the time when a predetermined time T2 has elapsed.

[0085] The control device 4 extracts from the storage unit 44 the temperature Te_in and temperature Te_out of the cooling water e for a predetermined time T2 from the time point when the film formation process is determined to end, or for a predetermined time T1 from the time point when the film formation process is determined to start.

[0086] The calculation unit 45 calculates the temperature difference between the inlet and outlet of the cooling water (S03: calculation step). The temperature difference between the inlet and outlet of the cooling water is calculated based on the difference between the temperature Te_out and the temperature Te_in retrieved from the storage unit 44. The difference is calculated based on the temperature Te_out and the temperature Te_in when the elapsed time t is the same. The calculated temperature difference between the inlet and outlet of the cooling water is arranged according to the elapsed time t. Thereby, a change pattern of the temperature difference over time at a specified time T1 (T2) can be obtained.

[0087] Incidentally, the target 231 receives heat from the heat source 234 (generated plasma). For example, the ions generated from the plasma have energy. By colliding with the target 231 through the energy, heat is transferred to the target 231 as heat, and the temperature of the target 231 rises. In order to reduce the temperature of the rising target 231, the cooling water e cools the target 231 via the target base 232 and the bonding portion 233. The temperature of the cooling water e rises corresponding to the heat taken from the target 231. Therefore, when film formation starts, the temperature of the cooling water e rises. That is, when film formation starts, the temperature Te_out of the cooled cooling water e rises. For example, as Figure 4 shown in the specified time T1, the temperature difference between the inlet and outlet of the cooling water gradually increases with the film formation time.

[0088] At the beginning of the film formation process, the heat obtained from the heat source 234 (heat supply to the target 231) is greater than the cooling amount based on the cooling water e (heat discharge amount based on the cooling water e). Therefore, the temperature of the target 231 increases. When the temperature of the target 231 becomes high, the cooling amount based on the cooling water e also increases. When the target 231 reaches a certain temperature, the heat supply to the target 231 balances with the heat discharge amount based on the cooling water e. That is, the target 231 becomes a stable state. As a result, the temperature difference between the inlet and outlet of the cooling water becomes constant.

[0089] Figure 5 is a graph showing the temperature difference between the inlet and outlet of the cooling water in a stable operation for a certain time, where the target 231 becomes a stable state. Figure 5 shows the temperature difference between the inlet and outlet of the cooling water when film formation (film formation process) is continuously performed for 120 seconds. As Figure 5 shown, the temperature difference between the inlet and outlet of the cooling water becomes constant 100 seconds after the start of the film formation process. That is, the target 231 becomes a stable state 100 seconds after the start of the film formation process. As described above, the case where the film formation time is short means the case where the target 231 does not become a stable state. Therefore, the case where the film formation time is short is, for example, the case where film formation ends within 100 seconds or less from the start of film formation. In addition, the conditions for the target 231 to become a stable state vary depending on the material of the target 231 or the film formation conditions. Therefore, the case where the target 231 does not become a stable state even when it is more than 100 seconds from the start of film formation is also included in the case where the film formation time is short.

[0090] After the film formation is completed, the plasma disappears. Therefore, the heat source 234 disappears, and thus the heat introduced into the target 231 disappears. The cooling water e continuously cools the target 231 via the target base 232 and the bonding portion 233. Therefore, due to the heat dissipation based on the cooling water e, the temperature of the target 231 decreases. As the temperature of the target 231 decreases, the temperature of the cooled cooling water e also decreases. That is, after the film formation is completed, the temperature Te_out of the cooling water e decreases. For example, as Figure 4 shown by the specified time T2, as time elapses after the film formation process ends, the temperature difference between the inlet and outlet of the cooling water gradually becomes smaller.

[0091] The joint state determination unit 46 compares the change pattern of the calculated temperature difference between the inlet and outlet of the cooling water e with the change pattern of the temperature difference between the inlet and outlet of the cooling water e in a good target, and determines the joint state of the target 231 (S04: joint state determination step). Figure 6 is a graph showing the change patterns of the temperature differences between the inlet and outlet of the cooling water e in good targets and damaged targets. In addition, a damaged target is a target in which peeling has occurred. As Figure 6 shown by the graph in the part surrounded by the frame of, it can be seen that at the specified time T1 and the specified time T2, the slope of the temperature curve in the good target becomes larger, whereas the slope of the temperature curve in the damaged target is small. The joint state determination unit 46 calculates the slope of the temperature curve of the calculated temperature difference between the inlet and outlet, and calculates to what extent the slope is approximated to the slope of the good target. Then, if the difference in slopes is within a certain value, it is determined that no large peeling that causes the target 231 to fall off has occurred.

[0092] Here, a case where the target 231 is in a stable state during stable operation for a certain period of time is studied. For example, the case where the target 231 is in a stable state means the state of the temperature difference between the inlet and outlet of the cooling water e 100 seconds after the start of the film formation process in Figure 5 . At this time, if peeling occurs in the bonding portion 233, the thermal resistance of the bonding portion 233 increases, and thus the temperature difference between the inlet and outlet of the cooling water e temporarily decreases. In the case of stable operation for a certain period of time, if the temporarily decreased temperature is set as a threshold value, the peeling of the bonding portion 233 can be detected.

[0093] However, it is difficult to set a threshold value shortly after the start of operation or when the film formation time is short even during stable operation. For example, as Figure 4As shown, even when the film formation is stable and the film formation time is short, the temperature difference between the inlet and outlet of the cooling water e decreases during the period from the end of film formation of a certain film formation to the start of the next film formation. Regarding the reason for the decrease in the temperature difference between the inlet and outlet of the cooling water e, it is difficult to distinguish whether the film formation has ended or the bonding portion 233 has peeled off by using the method of setting a threshold value.

[0094] [1-3. Effects]

[0095] (1) The film formation apparatus 1 of the present embodiment includes: a chamber 2 into which a workpiece W is carried; a target 231 provided in the chamber 2; a target base 232 that holds the target 231 on one of its surfaces; a temperature detection unit (temperature sensors 237b, 238b) that detects the temperature of the target 231 and / or the target base 232 at a specified time T2 after the film formation process ends or at a specified time T1 from the start of the film formation process after a specific time Tsp has elapsed since the film formation process ends; a calculation unit 45 that calculates the temperature change over time at a specified time based on the detected temperature of the target 231 and / or the target base 232; and a bonding state determination unit 46 that determines the bonding state of the target 231 based on the temperature change over time at a specified time.

[0096] In the present embodiment, the bonding state of the target 231 is determined based on the temperature change pattern of the target 231 at the specified times T1 and T2. That is, the state of the thermal resistance of the bonding portion 233 that fixes the target 231 and the target base 232 is indirectly monitored based on the temperature of the target 231. When the target 231 peels off, the thermal resistance of the target 231 increases. In addition, since the detection of peeling is not based on the state of the target 231 at a certain time, but on the temperature change pattern over time during a certain period of the specified times T1 and T2, it is possible to detect extremely small peeling in the initial stage.

[0097] In addition, since minute peeling in the initial stage can be detected, information on the bonding state of the target 231 can be managed. For example, information on the bonding state of the target 231 can be recorded in recording media such as barcodes, Quick Response (QR) codes, and Integrated Circuit (IC) tags provided in a Front Opening Unified Pod (FOUP). By managing information using the recording media provided in the FOUP, even if there are defective conditions such as deterioration in the quality of the film formed on the workpiece W or non-uniformity in the film thickness, the cause can be quickly identified and eliminated. In addition, by managing information on the bonding state of the target 231, minute peeling in the initial stage where no defective conditions occur and minute peeling in the initial stage where defective conditions occur can be discriminated. Therefore, in the case of minute peeling in the initial stage where defective conditions occur, the film forming apparatus 1 can be stopped, thus improving the yield of the workpiece W.

[0098] When detecting peeling only using the state change of the target 231, for example, the temperature of the target 231 at a certain time, due to some reasons, the bonding portion 233 starts to melt or peel off, and small peeling of the target 231 caused by the melting or peeling cannot be detected. In such a case, during the continued use of the target 231, the peeling of the target 231 gradually progresses and often leads to the detachment of the target 231. Therefore, even if a problem occurs at the time point when the target 231 detaches, it is often impossible to determine the true cause of the peeling. In the present embodiment, the state of the target 231 to be monitored is compared with the measurement result after a certain period of time in a non-defective target, that is, the mode of temperature change. Since the peeling of the target 231 is caused by the melting of the bonding portion 233 or peeling due to stress, the thermal resistance of the target 231 increases. Since the bonding state of the target 231 is detected using the temperature change difference during a specified time T1 (T2) generated by the increase in the thermal resistance of the target 231, minute peeling before the detachment of the target 231 can be detected. In addition, since minute peeling before the detachment of the target 231 can be detected, the timing of replacing the target 231 can be predicted, and the user can be notified of the period when maintenance is required.

[0099] In addition, even though the target 231 is not heated to the temperature at which the bonding portion 233 melts, peeling of the target 231 sometimes occurs. It is considered that this is caused by stress generated by the difference in thermal expansion between the target 231 and the bonding portion 233, or between the target base 232 and the bonding portion 233. In the present embodiment, when peeling of the target 231 occurs, it is manifested as the temperature change of the target 231 at the specified time T1 and the specified time T2, so peeling caused by stress can also be detected.

[0100] In addition, in the present embodiment, the temperature change patterns of the good target and the target 231 are compared. Therefore, even when it is difficult to determine a threshold value for the measured value (for example, shortly after the start of operation or when the film formation time is short even during stable operation), it is possible to detect a small peel before the target 231 detaches. In addition, since it is possible to determine whether the peel occurs within the specified time T1 and the specified time T2, it is easy to determine the true cause leading to the start of peeling of the target 231.

[0101] (2) In the present embodiment, a cooling plate 235 that is in contact with another surface of the target base 232 and has a flow path 235f for cooling water e is provided, and temperature detection units are temperature sensors 237b and 238b provided in a water supply unit 237 and a drainage unit 238 that are connected to the flow path 235f of the cooling plate 235. The temperature detection unit detects the temperature of the target 231 and / or the target base 232 as the temperature of the cooling water e before and after cooling (temperature Te_in and temperature Te_out), a calculation unit 45 calculates the change over time of the temperature difference between the temperature of the cooling water e before and after cooling at the specified time T1 and the specified time T2, and a joint state determination unit 46 determines the joint state of the target 231 based on the change over time of the temperature difference between the temperature of the cooling water e before and after cooling at the specified time T1 and the specified time T2.

[0102] Instead of directly measuring the temperature of the target 231, it is indirectly measured by measuring the temperatures Te_in and Te_out of the cooling water e. Therefore, there is no need to newly install temperature measurement equipment for the target 231 or the target base 232. Therefore, the occurrence of measurement defects caused by the installation of temperature measurement equipment can be suppressed, and it can be introduced without imposing a burden on the user associated with the installation.

[0103] [1-4. Modification Example]

[0104] (1) In the above-described embodiment, the bonding state determination unit 46 detects the bonding state of the target 231 by comparing the slopes of the cooling water inlet / outlet temperature differences at the specified time T1 and the specified time T2 with the slope of the cooling water inlet / outlet temperature difference for a non-defective target. By performing the determination of the bonding state of the target in two steps, namely the specified time T1 and the specified time T2, it is easier to further narrow down the period during which the target 231 starts to peel off, and it is easier to identify the true cause leading to the start of peeling. On the other hand, instead of determining the bonding state of the target 231 in the two intervals of the specified time T1 and the specified time T2, the bonding state can also be determined only at the specified time T1 or only at the specified time T2. Depending on the film formation conditions or the type of target, sometimes the difference between a non-defective target and a damaged target appears only in one of the specified time T1 and the specified time T2. In such a case, the bonding state can also be determined not in the two intervals but only at one of the specified times. In particular, by determining the bonding state at the specified time T1, the bonding state of the target 231 can be determined shortly after the start of the film formation process. Therefore, in the case of detecting a small peel before the target 231 falls off, the film formation process can be immediately stopped. Thus, it is possible to prevent the target 231 from falling off during the film formation process.

[0105] In addition, during the periods of S01 and S02, the control device 4 can also store in parallel whether the power supply device 24 applies a voltage to the target 231 with respect to the elapsed time t. As a method for the control device 4 to recognize the "end of the film formation process" and the "start of the film formation process" after a specific time Tsp has elapsed since the end of the film formation process, there is a method of monitoring the interval of the voltage application from the power supply device 24 to the target 231. Figure 8 (A) is a graph showing the change patterns of the cooling water e inlet / outlet temperature differences for non-defective and damaged targets. Figure 8 (B) is related to Figure 8 (A) and shows a graph representing the ON / OFF (turn-on / turn-off) of the applied voltage based on the power supply device 24. For example, as shown in Figure 8 (B), it is only necessary to determine whether the time (off-time) from when the power supply device 24 stops applying a DC voltage to the target 231 until it starts applying a DC voltage to the next target 231 has passed a specific time Tsp or more. In the present embodiment, the specific time Tsp is 180 s. Therefore, when 180 s or more have passed after stopping the application of the DC voltage to the target 231, the film formation end just before the specific time Tsp is about to pass is determined as the end of the film formation process. Similarly, if film formation starts after 180 s or more have passed since the state of stopping the application of the DC voltage to the target 231, it is determined that the film formation process has started.

[0106] Alternatively, instead of the slopes of the temperature differences between the inlet and outlet of the cooling water at the specified times T1 and T2, a value obtained by setting the difference when comparing the temperature difference between the inlet and outlet of the cooling water e for the damaged target with the temperature difference between the inlet and outlet of the cooling water e for the non-defective target as a threshold value (first threshold value) may be used, and it may be confirmed whether the time during which the difference during the comparison is equal to or greater than the first threshold value continues for a specified time or longer, thereby determining the bonding state of the target 231.

[0107] For example, at the specified time T1, the value of the temperature difference between the inlet and outlet of the cooling water e in the non-defective target is greater than the value of the temperature difference between the inlet and outlet of the cooling water e in the damaged target. Therefore, the difference between the temperature difference between the inlet and outlet of the cooling water e in the non-defective target and the temperature difference between the inlet and outlet of the cooling water e in the damaged target is obtained. It may also be determined that a small peel before the detachment of the target 231 has occurred when the time during which the obtained difference is equal to or greater than the first threshold value continues for an arbitrary specified time or longer.

[0108] Alternatively, at the specified time T2, the value of the temperature difference between the inlet and outlet of the cooling water e in the non-defective target is smaller than the value of the temperature difference between the inlet and outlet of the cooling water e in the damaged target. Therefore, the difference between the temperature difference between the inlet and outlet of the cooling water e in the non-defective target and the temperature difference between the inlet and outlet of the cooling water e in the damaged target is obtained. It may also be determined that a small peel before the detachment of the target 231 has occurred when the time during which the obtained difference is equal to or greater than the first threshold value continues for an arbitrary specified time or longer. In addition, different first threshold values may be used for the specified time T1 and the specified time T2.

[0109] (2) In the above-described embodiment, the bonding state determination unit 46 compares the calculated temperature difference between the inlet and outlet of the cooling water e of the target 231 with the temperature difference between the inlet and outlet of the cooling water e of the non-defective target, and determines the bonding state of the target 231. However, the method for determining the bonding state of the target in the bonding state determination unit 46 is not limited to the above description.

[0110] For example, as Figure 9As shown, a flowmeter 53 for measuring the flow rate of the cooling water e flowing in the flow path 235f is preset, and the temperature of the inlet of the cooling water e (temperature Te_in), the temperature of the outlet (temperature Te_out), and further the flow rate of the cooling water e are measured. Based on the measured temperature of the inlet of the cooling water e (temperature Te_in), the temperature of the outlet (temperature Te_out), and the flow rate of the cooling water e, the heat dissipation amount J of the target 231 is calculated. The cumulative value (cumulative heat dissipation amount G) of the heat dissipation amount J at a specified time T1 and / or a specified time T2 can also be calculated based on the calculated heat dissipation amount J, and compared with the cumulative value at the same time of a good target, thereby determining the bonding state. In addition, in the present embodiment, the flowmeter 53 is provided in the water supply unit 237, but it may also be provided in the drainage unit 238, or may be provided in both the water supply unit 237 and the drainage unit 238.

[0111] Refer to Figure 9 , Figure 10 and Figure 11 A case of determining the bonding state of the target 231 based on the cumulative value of the heat dissipation amount J at a specified time T2 will be described. The storage unit 44a stores not only the temperature Te_in and the temperature Te_out of the cooling water e, but also the flow rate of the cooling water e from the flowmeter 53. The calculation unit 45 includes a heat dissipation amount calculation unit 451 and a heat dissipation amount accumulation unit 452. The heat dissipation amount calculation unit 451 calculates the heat dissipation amount J of the target 231 at an elapsed time t based on the temperature change of the target 231 over time at a specified time T2 and the flow rate of the cooling water e. The temperature change of the target 231 over time at a specified time T2 is calculated based on the temperature Te_in and the temperature Te_out of the cooling water e at a specified time T2. Further, in the heat dissipation amount accumulation unit 452, the heat dissipation amount J is accumulated, and the cumulative heat dissipation amount G for the elapsed time t is calculated, and the cumulative heat dissipation amount GT2 (GT1) at a specified time T2 (T1) is calculated. That is, the heat dissipation amount calculation unit 451 calculates the change over time of the cumulative heat dissipation amount G at a specified time T1 and / or a specified time T2.

[0112] The reference value storage unit 43a stores in advance the cumulative heat dissipation amount GT2 (GT1) of a good target at a specified time T2 (T1). The bonding state determination unit 46a determines the bonding state by comparing the cumulative heat dissipation amount GT2 (GT1) of a good target at a specified time T2 (T1) with the cumulative heat dissipation amount GT2 (GT1) calculated from the target 231. That is, the bonding state determination unit 46a determines the bonding state of the target 231 based on the change over time of the cumulative heat dissipation amount G at a specified time T1 and / or a specified time T2.

[0113] Figure 10It is a graph showing the change pattern of the cumulative heat dissipation GT2 of the good target and the damaged target at the specified time T2. In Figure 10 , the start time tT2b of the specified time T2 is set to zero, and the end time tT2e of the specified time T2 is set to 180 s. Additionally, at the start time tT2b of the specified time T2, the cumulative heat dissipation GT2 is set to the same value as the heat dissipation J at the start time tT2b of the specified time T2. In this embodiment, the cumulative heat dissipation GT2 at the specified time T2 for determining the bonding state is set to the cumulative heat dissipation GT2 at the end time tT2e of the specified time T2. When determining the bonding state of the target 231 based on the cumulative heat dissipation GT2 at the specified time T2, the heat dissipation J at the specified time T2 is accumulated, and the cumulative heat dissipation GT2 at the specified time T2 is calculated. In the above case, the value of the cumulative heat dissipation GT2 at the time of large peeling is obtained in advance through experiments, and a small cumulative heat dissipation G value with a margin compared to the above value is set as the value of the index for small peeling before the target 231 falls off. Thus, as long as peeling is detected at the time point of the value of the index for small peeling before the target 231 falls off, the falling off of the target 231 can be prevented.

[0114] The bonding state determination unit 46a determines the bonding state by comparing the cumulative heat dissipation GT2 of the good target at the specified time T2 pre-stored in the reference value storage unit 43a with the cumulative heat dissipation GT2 calculated from the target 231. For example, it is possible to detect the peeling of the target 231 by whether the difference between the cumulative heat dissipation GT2 calculated from the target 231 and the cumulative heat dissipation GT2 of the good target is higher or lower than a threshold value (second threshold value). The same can be done at the specified time T1. However, even if the material of the target 231 is the same, if the film formation conditions are different, the cumulative heat dissipation GT2 will also be different. It is preferable to perform the determination using the above method under the same film formation conditions.

[0115] (3) Additionally, instead of directly comparing the cumulative heat dissipations G with each other, taking the cumulative heat dissipation Gt after the specified time tc that is the reference as the reference, the heat dissipation ratio, which is the relative value of the cumulative heat dissipation G with respect to the cumulative heat dissipation Gt according to the elapsed time t, is obtained, and the bonding state is determined based on the heat dissipation ratio. As Figure 12As shown, the calculation unit 45 further includes a relative cumulative heat dissipation amount calculation unit 454. The relative cumulative heat dissipation amount calculation unit 454 sets the cumulative heat dissipation amount Gt 180 seconds after the film formation process ends to "1", and calculates the relative value (heat dissipation ratio) of the cumulative heat dissipation amount G with respect to the elapsed time t after the film formation process (the elapsed time t after the heat supply stops). That is, the relative cumulative heat dissipation amount calculation unit 454 uses the cumulative heat dissipation amount Gt after a specified time tc calculated by the heat dissipation amount accumulation unit 452 as a reference to find the relative value of the cumulative heat dissipation amount G with respect to the elapsed time t.

[0116] Figure 13 is a graph showing the heat dissipation ratio with respect to the elapsed time t after the heat supply stops. In Figure 13 the solid line represents the change in the heat dissipation ratio of the good target with respect to the elapsed time t after the heat supply stops, and the dashed line represents the change in the heat dissipation ratio of the target 231 (damaged target) with peeling occurring at the bonding portion 233 with respect to the elapsed time t after the heat supply stops. It can be seen that in the case of the good target, 30 seconds after the film formation process (heat supply stop), the heat dissipation ratio exceeds 0.8. In contrast, in the target 231 with peeling occurring at the bonding portion 233, the value of the heat dissipation ratio 30 seconds after the film formation process (heat supply stop) is lower than 0.8.

[0117] For example, the heat dissipation ratio 30 seconds after the film formation process (heat supply stop) can also be calculated, and whether its value is higher or lower than 0.8 (the second threshold) can be used to detect the peeling of the target 231. Regarding the second threshold, for example, the heat dissipation ratio 30 seconds after the film formation process (heat supply stop) at the time of large peeling is obtained in advance through experiments, and a large value with a margin compared to the above value is set as the value indicating small peeling. Thus, as long as the peeling is detected at the time point of the value indicating small peeling, the detachment of the target 231 can be prevented.

[0118] In this modification, the joint state determination unit 46a determines the joint state of the target 231 based on the relative value calculated by the relative cumulative heat dissipation amount calculation unit 454. Since the joint state is determined based on the heat dissipation ratio, the detection of peeling can be determined by comparing with the second threshold. Therefore, the effort in creating a program for determining the joint state can be reduced. In addition, even when the film formation conditions are different and the values of the cumulative heat dissipation amount GT2 of the good target and the cumulative heat dissipation amount GT2 of the target 231 are different, the comparison based on the heat dissipation ratio (relative value) can be performed. Therefore, it is easy to compare the cumulative heat dissipation amounts G of targets with different film formation conditions with each other.

[0119] [2. Second Embodiment]

[0120] [2-1. Structure]

[0121] A second embodiment of the present invention will be described with reference to the accompanying drawings. Components identical to those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

[0122] As Figure 14 shown, the film forming apparatus 1 of the present embodiment includes a temperature sensor 231a that detects the temperature TTGT of the target 231, which corresponds to a temperature detection unit, and a temperature sensor 232a that detects the temperature Tbase of the target base 232. As the temperature sensor 231a and the temperature sensor 232a, thermocouples can be used. The temperature sensor 231a and the temperature sensor 232a detect the temperatures of the target 231 and the target base 232 at a specified time T2 after the film forming process ends or at a specified time T1 starting from the start of the film forming process after a specific time Tsp has elapsed since the film forming process ended. In addition, the temperature TTGT of the target 231 is sometimes referred to as the temperature TTGT, and the temperature Tbase of the target base 232 is sometimes referred to as the temperature Tbase.

[0123] Referring to Figure 15 a virtual functional block diagram, the structure of the control device 4 will be described. The control device 4 has a film forming processing unit 41, a reference temperature storage unit 43b, a storage unit 44b, a calculation unit 45b, a bonding state determination unit 46b, a notification unit 47, and an input / output control unit 48. In addition, as in the first embodiment, the control device 4 is connected to the input device 61 and the output device 62.

[0124] The reference temperature storage unit 43b calculates and stores in advance the process of the temperature drop of the target 231 and the target base 232, which are good target materials, from the state (stable state) where heat supply and heat dissipation are balanced with respect to the good target material until the heat supply disappears. For example, it stores in advance the temperature Tbase of the target base 232 with respect to the temperature TTGT of the target 231 according to the elapsed time t from the end of the film forming process of the good target material to 300 seconds later.

[0125] Figure 16 is a graph obtained by simulating the correlation between the temperature TTGT of the target 231 and the temperature Tbase of the target base 232 over time after the film forming process using a Cr target of φ150 mm × t10 mm. In other words, Figure 16 is a graph obtained by simulating the correlation between the temperature TTGT of the target 231 and the temperature Tbase of the target base 232 at the specified time T2. In Figure 16Among them, the temperature TTGT of the target 231 is taken as the X-axis, and the temperature Tbase of the target base 232 is taken as the Y-axis. The solid line represents the result when simulating the temperature Tbase of the target base 232 with respect to the temperature TTGT of the target 231, which is a non-peeling good target, by changing the applied power and the flow rate of the cooling water e. In addition, the dashed line represents the temperature Tbase of the target base 232 with respect to the temperature TTGT of the target 231, assuming that peeling occurs and the thermal resistance increases, and the thermal resistance of the target 231 is 10 times that of the original. Regarding these, the simulation was also carried out by changing the applied power and the flow rate of the cooling water e.

[0126] As Figure 16 shown, it can be seen that in the plot assuming peeling (dashed line), at any flow rate of the cooling water e, the temperature TTGT of the target 231 is higher than the temperature Tbase of the target base 232 compared with the good target. The reason is considered to be that the thermal resistance of the target 231 with peeling increases due to peeling, so it is difficult to transfer the heat supply from the heat source 234 to the target base 232. That is, by obtaining the slope of the temperature change from the plot of the temperature Tbase of the target base 232 with respect to the temperature TTGT of the target 231 that changes with time during the specified time T2 after the film formation process and comparing it with the good target, the bonding state of the target 231 can be determined.

[0127] The storage unit 44b stores the temperature TTGT of the target 231 and the temperature Tbase of the target base 232 detected by the temperature sensor 231a and the temperature sensor 232a. When film formation starts, the temperature TTGT of the target 231 and the temperature Tbase of the target base 232 are transmitted to the control device 4. The storage unit 44b stores the temperature TTGT of the target 231 and the temperature Tbase of the target base 232 that change with time during the specified time T1 and the specified time T2. In addition, the storage unit 44b may also store the temperature TTGT of the target 231 and the temperature Tbase of the target base 232 during the period from the start to the end of the film formation process. Or, the storage unit 44b may store the temperature TTGT of the target 231 and the temperature Tbase of the target base 232 during the operation of the film forming apparatus 1.

[0128] The calculation unit 45b calculates the temperature Tbase of the target substrate 232 with respect to the temperature TTGT of the target 231 based on the temperature TTGT and the temperature Tbase stored in the storage unit 44b. That is, the calculation unit 45b correlates the temperature TTGT of the target 231 that changes with time at a specified time T2 (T1) with the temperature Tbase of the target substrate 232. Thereby, the value of the temperature Tbase of the target substrate 232 with respect to the temperature TTGT of the target 231 within the specified time T2 (T1) can be obtained. The value of the temperature Tbase of the target substrate 232 with respect to the temperature TTGT of the target 231 within the specified time T2 (T1) is also included in the temperature change with time at the specified time T2 (T1). The temperature Tbase of the target substrate 232 with respect to the temperature TTGT of the target 231 calculated by the calculation unit 45b over time t can also be obtained using either or both of the specified time T1 or the specified time T2. However, for the sake of explanation below, it is assumed that the temperature Tbase of the target substrate 232 with respect to the temperature TTGT of the target 231 at the specified time T2 (from the end of the film formation process until 300 seconds have elapsed) is calculated for explanation.

[0129] The bonding state determination unit 46b determines the bonding state of the target 231 based on the correlation between the temperature TTGT of the target 231 that changes with time at the specified time T2 and the temperature Tbase of the target substrate 232. That is, the bonding state determination unit 46b is a determination unit that compares the temperature Tbase of the target substrate 232 with respect to the temperature TTGT of the target 231 over time t at the specified time T2 calculated from the target 231 with the temperature Tbase of the target substrate 232 with respect to the temperature TTGT of the target 231 over time t at the specified time T2 of the non-defective target stored in the reference temperature storage unit 43b, and determines the bonding state of the target.

[0130] [2-2. Function]

[0131] Next, according to Figure 17 The operation of the film forming apparatus 1 and the film forming method of the present embodiment will be described.

[0132] After the film formation process ends (S21: film formation process end step), the temperature TTGT and the temperature Tbase are stored (S22: temperature detection step). The temperature TTGT and the temperature Tbase detected by the temperature sensor 231a and the temperature sensor 232a are periodically transmitted to the control device 4. The storage unit 44 stores the temperature TTGT and the temperature Tbase.

[0133] The calculation unit 45 correlates the temperature Tbase at the specified time T2 with the temperature TTGT (S23: calculation step). That is, although there is heat supply to and heat dissipation from the target 231 during film formation, since the target 231 is no longer heated after the film formation process ends, the target 231 and the target base 232 gradually cool down. The calculation unit 45 arranges the temperature Tbase and the temperature TTGT according to the elapsed time t, thereby obtaining the pattern of the change in the temperature Tbase with respect to the temperature TTGT at the specified time T2.

[0134] The joint state determination unit 46 compares the calculated pattern of the change in the temperature Tbase of the target base 232 with respect to the temperature TTGT of the target 231 with the pattern of the change in the temperature Tbase of the target base 232 with respect to the temperature TTGT of the target 231 as a non-defective target, and determines the joint state of the target 231 (S24: joint state determination step). Figure 18 It is a graph showing the correlation between the temperature TTGT of the target 231 and the temperature Tbase of the target base 232. Figure 18 It shows the temperature Tbase of the target base 232 with respect to the temperature TTGT of each target 231 in different states. If Figure 18 is compared with Figure 16 the pattern of the change in the temperature Tbase of the target base 232 with respect to the temperature TTGT of the target 231 is the same. Based on this, it is considered that the temperature change of the target 231 and the target base 232 is caused by an increase in the thermal resistance of the target 231. In addition, as shown in the graph of Figure 18 in the case of a non-defective target, the absolute value of the slope of the temperature curve in the graph becomes larger. In contrast, in the case of a damaged target, the absolute value of the slope in the temperature curve becomes smaller.

[0135] The bonding state determination unit 46b calculates the slope of the temperature Tbase of the target base 232 with respect to the temperature TTGT of the target 231, and calculates to what extent the slope approximates the slope of a good target. And if the difference in slopes is within a certain value, it is determined that no peeling has occurred. For example, the absolute value of the "slope of the temperature curve" at the time of large peeling is obtained in advance through experiments, and a value that has a margin compared to the above value and becomes a large value when compared in absolute value is set as the value that becomes an index for small peeling. Thus, as long as peeling is detected at the time point that becomes the value as an index for small peeling, the detachment of the target 231 can be prevented. In addition, the difference between the value that becomes an index for small peeling and the absolute value of the slope of the temperature curve of a good target can also be obtained, and if the difference in slopes is within the above value, it is determined that no peeling has occurred. In addition, although the method of calculating the slope of the temperature Tbase of the target base 232 with respect to the temperature TTGT of the target 231 at the specified time T2 has been described, even if the slope of the temperature Tbase of the target base 232 with respect to the temperature TTGT of the target 231 at the specified time T1 is calculated, the bonding state determination unit 46b can determine the bonding state of the target 231.

[0136] [2-3. Effect]

[0137] (1) In the present embodiment, based on the correlation between the temperature Tbase and the temperature TTGT that change with time at the specified time T1 and the specified time T2, the bonding state of the target 231 is determined. That is, by directly measuring the temperature Tbase and the temperature TTGT, the state of the thermal resistance of the bonding portion 233 that fixes the target 231 and the target base 232 is monitored. When peeling occurs in the target 231, the thermal resistance of the target 231 becomes large. Therefore, similar to the first embodiment, instead of detecting peeling based on the state of the target 231 at a certain time, the bonding state is determined based on the correlation between the temperature Tbase and the temperature TTGT that change with time within a certain period from the specified time T1 to the specified time T2, that is, the mode of temperature change. Therefore, extremely small peeling in the initial stage can be detected.

[0138] In addition, since extremely small peeling in the initial stage can be detected, the information on the bonding state of the target 231 can be recorded in the recording medium provided in the FOUP, and the information on the bonding state of the target 231 can be managed. Therefore, even if there are defective conditions such as deterioration of the quality of the film formed on the workpiece W and unevenness of the film thickness, the cause can be quickly grasped and eliminated. In addition, since the quality of the thin film formed on the workpiece W can be managed, the yield of the workpiece W can be increased. In addition, by managing the information on the bonding state of the target 231, the timing of replacing the target 231 can be predicted, and the user can be notified of the period when maintenance is required.

[0139] [3. Other Embodiments]

[0140] The embodiments of the present invention and the modification examples of each part have been described above. However, the above-described embodiments or the modification examples of each part are only presented as examples and are not intended to limit the scope of the invention. These novel embodiments described above can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments or their modifications are included in the scope or gist of the invention and are included in the invention described in the claims.

[0141] Explanation of Reference Numerals in the Drawings

[0142] 1: Film Forming Apparatus

[0143] 2: Chamber

[0144] 4: Control Device

[0145] 20: Loading / Unloading Port

[0146] 21: Stage

[0147] 22: Shaft

[0148] 23: Sputtering Source

[0149] 231: Target

[0150] 231a: Temperature Sensor

[0151] 232: Target Base

[0152] 232a: Temperature Sensor

[0153] 233: Bonding Part

[0154] 234: Heat Source

[0155] 235: Cooling Plate

[0156] 235a: Sealing Material

[0157] 235b: Groove

[0158] 235b1: Inlet

[0159] 235b2: Outlet

[0160] 235c: Flange

[0161] 235d: Water Supply Port

[0162] 235e: Drain Port

[0163] 235f: Flow Path

[0164] 236: Anode Part

[0165] 236a: TS distance adjustment section

[0166] 236a1: Thick wall section

[0167] 236a2: Flange

[0168] 236b: Anode ring

[0169] 237: Water supply section

[0170] 237b: Temperature sensor

[0171] 238: Drainage section

[0172] 238b: Temperature sensor

[0173] 239: Magnet section

[0174] 239a: Magnet

[0175] 239b: Motor

[0176] 24: Power supply device

[0177] 25: Exhaust device

[0178] 26: Pressure gauge

[0179] 27: Sputtering gas introduction section

[0180] 271a: Argon gas introduction section

[0181] 271b: Flow controller

[0182] 41: Film formation processing section

[0183] 43, 43b: Reference temperature storage section

[0184] 43a: Reference value storage section

[0185] 44, 44a, 44b: Storage section

[0186] 45, 45b: Calculation section

[0187] 451: Heat dissipation amount calculation section

[0188] 452: Heat dissipation amount accumulation section

[0189] 454: Relative cumulative heat dissipation amount calculation section

[0190] 46, 46a, 46b: Joint state determination section

[0191] 47: Notification section

[0192] 48: Input / output control section

[0193] 53: Flowmeter

[0194] 61: Input device

[0195] 62: Output device

[0196] J: Heat rejection

[0197] G, Gt, GT2: Cumulative heat rejection

[0198] t: Elapsed time

[0199] T1, T2: Specified time

[0200] Tbase: Temperature of the target substrate

[0201] Tsp: Specific time

[0202] TTGT: Temperature of the target

[0203] Te: Temperature of the cooling water

[0204] W: Workpiece

Claims

1. A film forming device that uses plasma to form a film on a workpiece. The film forming device is characterized by comprising: A closed container into which the workpiece is loaded; A target material is disposed in the sealed container; a target base, holding the target on one of its faces; A temperature detection unit detects the temperature of the target and / or the target base at a predetermined time after the film forming process is completed or at a predetermined time after the film forming process is started after a specific time has passed since the film forming process is completed; a calculation unit that calculates a temperature change over time at the predetermined time based on the detected temperature of the target and / or the target base; as well as The bonding state determination unit determines the bonding state of the target based on the temperature change over time at the predetermined time.

2. The film forming device according to claim 1, characterized in that A cooling plate is provided, the cooling plate is connected to the other surface of the target base and is provided with a flow path for cooling water, The temperature detection unit is a temperature sensor provided in a water supply unit and a water discharge unit connected to the flow path of the cooling plate. The temperature detection unit detects the temperature of the target and / or the target base as the temperature before and after cooling of the cooling water. The calculation unit calculates a change over time in the temperature difference between the cooling water before and after cooling for a predetermined period of time. The bonding state determination unit determines the bonding state of the target material based on a temporal change in a temperature difference between before and after cooling of the cooling water at the predetermined time.

3. The film forming apparatus according to claim 2, comprising a flow meter for detecting a flow rate of cooling water flowing in the flow path. The calculation unit includes: a heat dissipation calculating unit for calculating the heat dissipation amount of the target material over time based on a temperature change of the target material over time and a flow rate of the cooling water; and The heat dissipation accumulating unit accumulates the heat dissipation and calculates the accumulated heat dissipation in a predetermined time. The calculation unit calculates the change over time of the cumulative heat output in a predetermined time. The bonding state determination unit determines the bonding state of the target based on the temporal change in the cumulative heat output in the predetermined time.

4. The film forming device according to claim 3, wherein: The calculation unit includes a relative cumulative heat output calculation unit, which calculates a relative value of the cumulative heat output with respect to the elapsed time, based on the cumulative heat output after a predetermined time calculated by the heat output accumulation unit. The bonding state determination unit determines the bonding state of the target based on the relative value calculated by the relative cumulative heat amount calculation unit.

5. The film forming device according to claim 1, wherein: The temperature detection unit detects the temperature of the target and the target base at a predetermined time after the film forming process is completed or at a predetermined time after the film forming process is started after a specific time has passed since the film forming process is completed. The calculation unit correlates the temperature of the target material that changes with time at the predetermined time with the temperature of the target material base, The bonding state determination unit determines the bonding state of the target based on a correlation between a temperature of the target and a temperature of the target base that change with time.

6. A target material bonding state detection method, which is a target material bonding state detection method in a film forming device that forms a film on a workpiece using plasma, The target material bonding state detection method is characterized by comprising: a temperature detection step of detecting the temperature of the target and / or the target base at a specified time after the film forming process is completed or at a specified time after the film forming process is started after a specific time has passed since the film forming process is completed; A calculation step of calculating a temperature change over time at the predetermined time based on the detected temperature of the target and / or the target base; as well as The bonding state determination step determines the bonding state of the target based on the temperature change over time.

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