Method of diagnosing chamber condition

Abstract

The objective of this invention is to provide a technique for diagnosing the condition of a chamber. This invention is a method for diagnosing the condition of a chamber in a substrate processing apparatus for processing substrates, and includes the following steps: cleaning the interior of the chamber; generating a plasma containing helium or a gas composed of helium mixed with one or more inert gases that do not contain argon inside the chamber; measuring the luminescence intensity of fluorine inside the chamber; and diagnosing the condition of the chamber based on the luminescence intensity.

Description

technical field

[0001] The invention relates to a method for diagnosing chamber conditions. prior art

[0002] For example, Patent Document 1 discloses a method of restoring a substrate processing apparatus that can determine an abnormality of the substrate processing apparatus without reducing the operating rate of the substrate processing apparatus. [Prior Art Literature] [Patent Document]

[0003] [Patent Document 1] Japanese Patent Laid-Open No. 2006-140237 Contents of the invention

[0004] [Problem to be solved by the invention]

[0005] The present invention provides a technique for diagnosing the condition of a chamber. [Technical means to solve the problem]

[0006] According to one aspect of the present invention, there is provided a method for diagnosing the state of a chamber, which is a method for diagnosing the state of a chamber of a substrate processing apparatus for processing product substrates, and includes the following steps: cleaning the inside of the chamber; Generating a plasma of helium or a mixture of one or more inert gases not including argon in the above-mentioned chamber; measuring the luminous intensity of fluorine inside the above-mentioned chamber; and based on the above Luminous intensity to diagnose the condition of the above chamber. [Effect of Invention]

[0007] The present invention provides a technique for diagnosing the condition of a chamber. Brief description of the diagram

[0008] FIG. 1 is a cross-sectional view showing a schematic configuration of a substrate processing apparatus using the method for diagnosing the state of a chamber according to this embodiment. FIG. 2 is a flow chart of the method for diagnosing the state of the chamber in this embodiment. FIG. 3 is a flow chart of the method for diagnosing the state of the chamber in this embodiment. FIG. 4 is a flow chart of the method for diagnosing the condition of the chamber in this embodiment. FIG. 5 is a conceptual diagram of device diagnosis with respect to a time axis using the method for diagnosing the condition of a chamber according to this embodiment. FIG. 6 is a diagram showing time-series data of luminous intensity using the method for diagnosing the condition of the chamber according to this embodiment. FIG. 7 is a graph showing time-series data of the in-plane average value of the polysilicon etching rate using the method for diagnosing the state of the chamber according to the present embodiment. FIG. 8 is a graph showing the relationship between the in-plane average value of the polysilicon etching rate and the luminous intensity using the method for diagnosing the state of the chamber according to the present embodiment. Fig. 9 is a graph showing the relationship between the generated plasma and the luminous intensity at a predetermined wavelength. Fig. 10 is a graph showing the relationship between the generated plasma and the luminous intensity at a predetermined wavelength. FIG. 11 is a diagram showing time-series data of luminous intensity using the method for diagnosing the state of the chamber according to this embodiment. FIG. 12 is a graph showing the relationship between the in-plane average value of the polysilicon etching rate and the luminous intensity using the method for diagnosing the state of the chamber according to this embodiment. Implementation

[0009] Hereinafter, modes for implementing the present invention will be described with reference to the drawings. In addition, in this specification and drawings, the description of repetition is abbreviate|omitted by attaching the same code|symbol to the structure which is substantially the same. In addition, for easy understanding, the reduced scale of each part in the drawing may be different from the actual one. Parallel, right-angled, orthogonal, horizontal, vertical, up-down, left-right, etc., deviations are allowed to the extent that the effects of the embodiments are not impaired. The shape of the corners is not limited to right angles, and can also be arc-shaped with arcs. Parallel, right angles, orthogonal, horizontal, and vertical may also include approximately parallel, approximately right angles, approximately orthogonal, approximately horizontal, and approximately vertical.

[0010] <Overall Configuration of Substrate Processing Apparatus 1> First, an example of the overall configuration of a substrate processing apparatus 1 will be described with reference to FIG. 1 . FIG. 1 is a cross-sectional view showing a schematic configuration of a substrate processing apparatus 1 using a method for diagnosing the state of a chamber according to this embodiment. In addition, in the present embodiment, an example in which the substrate processing apparatus 1 is a microwave plasma processing apparatus using a slot antenna will be described. The microwave plasma processing apparatus as the substrate processing apparatus 1 is, for example, an apparatus for performing plasma etching of polysilicon.

[0011] As shown in FIG. 1 , a substrate processing apparatus 1 is airtightly configured and includes a grounded chamber 2 . The chamber 2 is made of metal, such as aluminum or stainless steel.

[0012] A ceramic spray film can also be formed on the inner surface of the chamber 2 . The ceramic spray film preferably includes any one of alumina, yttrium oxide, yttrium fluoride, and yttrium fluoride oxide. Furthermore, the inner surface of the chamber 2 may also be formed of a material including any one of alumina, yttrium oxide, yttrium fluoride, and yttrium fluoride oxide.

[0013] The mounting table 10 includes a main body 8 and an annular member (edge ​​ring) 4 . The main body portion 8 has a central region 8 a for supporting the substrate W, and an annular region 8 b for supporting the annular member 4 . The substrate W is arranged on the central region 8a of the main body 8, and the annular member 4 is arranged on the annular region 8b of the main body 8 so as to surround the substrate W on the central region 8a of the main body 8. The main body 8 includes a base and an electrostatic chuck. The base includes a conductive member (lower electrode). The electrostatic chuck is arranged on the abutment. In addition, although not shown, the stage 10 may also include a temperature adjustment module configured to adjust at least one of the electrostatic chuck and the substrate W to a target temperature. The temperature regulation module may also include heaters, flow paths, or a combination thereof. The temperature-regulating fluid such as refrigerant and heat transfer gas flows in the flow path.

[0014] The lower electrode of the main body 8 is electrically connected to the high-frequency power source 21 via the power supply bar and the matching unit. The high-frequency power supply 21 supplies a high-frequency bias voltage to the lower electrode. The frequency of the high-frequency bias voltage generated by the high-frequency power supply is a predetermined frequency suitable for controlling the energy of ions fed to the substrate W, for example, 13.56 MHz. The matching unit accommodates a matching device 22 for matching between the impedance of the high-frequency power supply side and the impedance of the load side of the main electrodes, plasma, and chamber 2 . The matching unit 22 includes, for example, a blocking capacitor for self-bias voltage generation.

[0015] The mounting table 10 includes substrate support pins (not shown) for supporting and lifting the substrate W. As shown in FIG. The substrate support pins are provided so as to protrude and sink from the surface of the mounting table 10 .

[0016] The substrate processing apparatus 1 is provided with an exhaust port 11 opened at the bottom of the chamber 2 . Exhaust port 11 is connected to TMP (Turbo Molecular Pump, turbomolecular pump) or DP (Dry Pump, dry pump) (both not shown) via APC (Automatic Pressure Control, automatic pressure control) valve (not shown) . TMP or DP exhausts the gas in the chamber 2, and the APC valve controls the pressure in the chamber 2.

[0017] The chamber 2 has, on the side wall, an loading / unloading port 25 for loading and unloading the substrate W between a transfer chamber (not shown) adjacent to the substrate processing apparatus 1 , and a gate valve for opening and closing the loading / unloading port 25 . 26.

[0018] The upper part of the chamber 2 becomes an opening part. The substrate processing apparatus 1 includes a microwave plasma source 20 facing the opening.

[0019] The microwave plasma source 20 includes an antenna unit 30 and a microwave transmission unit 35 .

[0020] The antenna unit 30 includes a microwave transmission plate 28 , a slot antenna 31 , and a slow wave material 33 .

[0021] The microwave transmission plate 28 is made of a dielectric, for example, ceramics such as quartz or alumina (Al 2 O 3 ). The microwave transparent plate 28 is embedded in the upper part of the side wall of the chamber 2 in such a manner as to block the opening of the chamber 2 . The substrate processing apparatus 1 includes a seal ring between the chamber 2 and the microwave transmission plate 28 . The inside of the chamber 2 is kept airtight by providing a sealing ring.

[0022] The slot antenna 31 has a disk shape corresponding to the microwave transmission plate 28 . The slot antenna 31 is provided in close contact with the microwave transmission plate 28 . The slot antenna 31 is locked on the upper end of the side wall of the chamber 2 . The slot antenna 31 is formed of a conductive material.

[0023] The slot antenna 31 is made of, for example, a silver-plated or gold-plated copper or aluminum plate. The slot antenna 31 has a plurality of slots 32 for radiating microwaves. The slot 32 is formed to penetrate the slot antenna 31 in a predetermined pattern.

[0024] The pattern of the slots 32 is appropriately set in such a manner that microwaves are radiated uniformly. For example, as an example of a pattern, two slots 32 arranged in a T shape may be regarded as a pair, and plural pairs of slots 32 may be arranged concentrically. The length or arrangement interval of the slots 32 is determined according to the effective wavelength (λg) of the microwave. For example, the slots 32 are arranged at equal intervals of λg / 4, λg / 2, or λg.

[0025] Furthermore, the slot hole 32 may also be in other shapes such as a circle shape, an arc shape, or the like. Furthermore, the arrangement form of the slots 32 is not particularly limited, and other than concentric circles, for example, they may be arranged in a helical or radial form. The pattern of the slots 32 is appropriately set so as to obtain the desired microwave radiation characteristics of the plasma density distribution.

[0026] The slow wave material 33 is closely attached to the upper surface of the slot antenna 31 . The slow wave material 33 is formed of a dielectric body with a larger dielectric constant than vacuum, such as quartz, ceramics (Al 2 O 3 ), polytetrafluoroethylene, polyimide and other resins. The slow wave material 33 has the function of making the wavelength of the microwave shorter than that in vacuum and making the slot antenna 31 smaller.

[0027] The thickness of the microwave transparent plate 28 and the slow wave material 33 is adjusted in such a way that the equivalent circuit formed by the slow wave material 33, the slot antenna 31, the microwave transparent plate 28 and the plasma satisfies the resonance condition. By adjusting the thickness of the slow wave material 33, the phase of the microwave can be adjusted.

[0028] The thickness is adjusted so that the joint portion of the slot antenna 31 becomes an "antinode" of a standing wave by adjusting the phase of the microwave. Also, by adjusting the thickness so that the junction of the slot antenna 31 becomes the "antinode" of the standing wave, the reflection of microwaves is minimized and the radiated energy of microwaves is maximized. Furthermore, by making the slow wave material 33 and the microwave transmission plate 28 the same material, the interface reflection of microwaves can be prevented.

[0029] Furthermore, the space between the slot antenna 31 and the microwave transmission plate 28 , and between the slow wave material 33 and the slot antenna 31 can also be arranged at intervals.

[0030] The antenna unit 30 includes a shield cover 34 made of a metal material such as aluminum, stainless steel, or copper to cover the slot antenna 31 and the slow wave material 33 . The shield cover 34 has a cooling water flow path 34a formed inside. Cooling water flows through the cooling water channel 34a, so that the shielding cover 34 cools the shielding cover 34, the slow wave material 33, the slot antenna 31, and the microwave transmission plate 28. Furthermore, the shield cover 34 is grounded.

[0031] The microwave transmission unit 35 includes a coaxial waveguide 37 , a mode converter 38 , a waveguide 39 , a microwave oscillator 40 , and a tuner 41 .

[0032] The coaxial waveguide 37 is inserted from above the opening 36 formed in the center of the upper wall of the shield cover 34 . The coaxial waveguide 37 includes a hollow rod-shaped inner conductor 37a and a cylindrical outer conductor 37b. The inner conductor 37a and the outer conductor 37b are arranged concentrically. The inner conductor 37 a and the outer conductor 37 b respectively extend upward from the shielding cover 34 . The inner conductor 37a is provided with a tapered connector 43 at the lower end. The tapered connector 43 is connected to the slot antenna 31 . The cone connector 43 has a metal cover 44 at the front end.

[0033] The mode converter 38 is connected to the upper end of the coaxial waveguide 37 . A waveguide 39 is connected to the mode converter 38 . The shape of the waveguide 39 is rectangular in cross section. One end of the waveguide 39 is connected to the mode converter 38 and the other end is connected to the microwave oscillator 40 .

[0034] The microwave oscillator 40 includes a signal generator 45 and an amplifier 46 . The signal generator 45 outputs a signal of a predetermined frequency to the amplifier 46 . The amplifier 46 amplifies the signal waveform from the signal generator 45 and oscillates microwaves of a predetermined power. Also, the amplifier 46 performs frequency modulation. For example, when the center frequency is 2450 MHz (2.45 GHz), the amplifier 46 can modulate the frequency between 2400~2500 MHz (2.4~2.5 GHz). Furthermore, the central frequency of the microwave is not limited to 2450 MHz, and various frequencies such as 8.35 GHz, 1.98 GHz, 860 MHz, and 915 MHz can be used.

[0035] The tuner 41 is provided in the middle of the waveguide 39 . The tuner 41 matches the impedance of the load (plasma) in the chamber 2 to the characteristic impedance of the power source of the microwave oscillator 40 .

[0036] The microwave oscillated by the microwave oscillator 40 propagates in the waveguide 39 in a TE (transverse magnetic, transverse magnetic) mode. The mode converter 38 converts the microwave propagation mode from TE mode to TEM (transverse electromagnetic, transverse electromagnetic) mode. Furthermore, the mode converter 38 outputs the microwave converted into the TEM mode to the coaxial waveguide 37 . The microwave output to the coaxial waveguide 37 is guided to the slot antenna 31 .

[0037] Furthermore, even if the mode conversion is performed by the mode converter 38, there may be cases where microwaves in the TE mode remain slightly. Even if the microwaves of the TE mode remain, the remaining microwaves of the TE mode component during propagation through the coaxial waveguide 37 are also converted into the TEM mode.

[0038] The inner conductor 37a of the coaxial waveguide 37 has a hole 47 reaching from the upper part to the tapered connector 43 at the center. In the hole 47, the first thermocouple 51 as a temperature detector is inserted into the position of the conical connector 43. The temperature of the central portion of the antenna portion 30 is detected by the first thermocouple 51 . On the other hand, a second thermocouple 52 is provided at the end of the shielding cover 34 as a temperature detector. The temperature at the end of the antenna unit 30 is detected by the second thermocouple 52 .

[0039] The signal of the temperature (Tcent) at the center of the antenna part detected by the first thermocouple 51 and the signal of the temperature (Tedge) at the end of the antenna part detected by the second thermocouple 52 are input to the frequency controller for controlling the microwave frequency. device 50. Both the first thermocouple 51 and the second thermocouple 52 are inserted from the outside of the antenna unit 30 and placed in the atmosphere.

[0040] The frequency controller 50 gives instructions to the microwave oscillator 40 so as to optimize the density distribution of plasma based on the temperature Tcent detected by the first thermocouple 51 and the temperature Tedge detected by the second thermocouple 52 . The microwave oscillator 40 controls the oscillation frequency of the output microwave based on the instruction from the frequency controller 50 .

[0041] The temperature Tcent and the temperature Tedge are respectively related to the temperatures of the central portion and the edge portion of the lower surface of the microwave transmission plate 28 in the chamber 2 . Also, by manipulating the distribution of the electric field radiated from the slot antenna 31 by varying the oscillation frequency of the microwave, the plasma density distribution can be controlled with high precision.

[0042] The microwave plasma source 20 is provided with a plurality of stub members 42 at the lower part of the coaxial waveguide 37 . A plurality of short wire members 42 are provided in the circumferential direction. Each of the stub members 42 can extend from the outer conductor 37b to the inner conductor 37a. The short wire member 42 can adjust the propagation of the microwave in the circumferential direction by adjusting the distance between its front end and the inner conductor 37a.

[0043] The substrate processing apparatus 1 further includes a gas supply unit 60 that supplies gas into the chamber 2 through the side wall of the chamber 2 . The gas supply unit 60 includes a gas supply source 61 , a pipe 62 , a buffer chamber 63 , a gas flow path 64 , and a gas discharge port 65 .

[0044] The gas supply source 61 supplies an appropriate gas according to the plasma treatment. The pipe 62 connects the gas supply source 61 and the chamber 2 . The piping 62 is provided between the gas supply source 61 and the chamber 2 . The buffer chamber 63 is annularly arranged along the side wall of the chamber 2 . The gas flow path 64 connects the pipe 62 and the buffer chamber 63 . A plurality of gas ejection ports 65 are horizontally provided so as to face the inside of the chamber 2 at equal intervals from the buffer chamber 63 .

[0045] An appropriate gas is supplied from the gas supply unit 60 according to the plasma treatment. As the plasma treatment, polysilicon etching treatment is exemplified. As the processing gas at this time, for example, gas such as chlorine gas (Cl2 gas), hydrogen bromide gas (HBr gas) and nitrogen trifluoride gas (NF3 gas) or helium gas ( He gas) and other inert gases.

[0046] A plurality of gas supply sources 61 are provided according to the quantity of gas (kind of gas). The piping 62 extends from each gas supply source 61 . Flow controllers such as valves and mass flow controllers (both are not shown) are provided on the piping 62 .

[0047] A glass window 55 is provided on the side wall of the chamber 2 . A beam splitter 56 is provided at a position facing the glass window 55 . The beam splitter 56 receives light radiated from the plasma inside the chamber 2 through the glass window 55 . Furthermore, the spectrometer 56 measures the luminous intensity (spectral intensity) of a specific wavelength from the received light.

[0048] The substrate processing apparatus 1 includes a control unit 70 . The control unit 70 controls each component of the substrate processing apparatus 1, such as the microwave oscillator 40, the valve of the gas supply unit 60, the spectrometer 56, the flow controller, and the like. The control unit 70 includes a main control unit having a CPU (Central Processing Unit, central processing unit) (computer), an input device (keyboard, mouse, etc.), an output device (printer, etc.), a display device (monitor, etc.), a memory device (memory medium).

[0049] Parameters of various processes performed by the substrate processing apparatus 1 are stored in the memory device. In addition, the memory device is provided with a memory medium for storing a program for controlling the processing executed by the substrate processing apparatus 1, that is, a processing recipe. The main control unit performs control by calling a predetermined processing recipe stored in the storage medium, and performing predetermined processing by the substrate processing apparatus 1 based on the processing recipe.

[0050] In the substrate processing apparatus 1 , first, the gate valve 26 is opened, and the substrate W to be processed is carried into the chamber 2 and placed on the stage 10 . Then, in the substrate processing apparatus 1, the processing gas (for example, Cl gas, HBr gas, etc.) is introduced into the chamber 2 at a predetermined flow rate and flow ratio from the gas supply part 60, and the chamber is opened by the APC valve. The pressure in 2 is the specified value.

[0051] Furthermore, in the substrate processing apparatus 1 , microwaves are supplied from the microwave oscillator 40 to the chamber 2 . Moreover, high-frequency power is supplied to the mounting table from the high-frequency power supply 21 . The processing gas ejected from the gas ejection port 65 is plasmaized, and the substrate W is etched by free radicals or ions in the plasma.

[0052] <Diagnostic method of chamber condition> A method of diagnosing the state of the chamber 2 (chamber state) of the substrate processing apparatus 1 will be described. FIG. 2 is a flow chart of the method for diagnosing the state of the chamber in this embodiment.

[0053] The method for diagnosing the state of the chamber in this embodiment focuses on the fluorine originating from the inner surface of the chamber to diagnose the state of the chamber. The fluorine originating from the inner surface of the chamber refers to the fluorine contained in the process gas that adheres to or penetrates into the sprayed film forming the inner surface of the chamber, or the fluorine originally contained in the sprayed film itself. The amount of fluorine originating from the inner surface of the chamber affects the condition of the chamber. The method for diagnosing the state of the chamber in this embodiment diagnoses the state of the chamber by the luminous intensity (spectral intensity) of fluorine when plasma is generated using helium gas.

[0054] (step S10) First, the control unit 70 performs a cleaning process of cleaning the inside of the chamber 2 . In the cleaning step, for example, fluorine etc. adhering to the inside of the chamber 2 during substrate processing is removed. By cleaning the inside of the chamber 2, the inside of the chamber is brought into an initial state.

[0055] (step S20) Next, the control unit 70 performs a plasma generating step of generating a plasma of one or more inert gases containing helium gas but not argon gas inside the chamber 2 . In other words, a plasma generating step is performed to generate plasma of helium gas or a gas obtained by mixing one or more inert gases not including argon gas in the helium gas inside the chamber 2 .

[0056] In the plasma generation process, for example, a dummy substrate different from the product substrate formed of silicon may be placed on the central region 8a of the main body portion 8 . Furthermore, the control part 70 controls so that one or more types of inert gas containing helium gas and not containing argon gas may be supplied from the gas supply part 60 to the inside of the chamber 2 . In a state where one or more inert gases containing helium but not argon are supplied to the chamber 2, the control unit 70 supplies microwaves from the microwave oscillator 40 to the chamber 2 and supplies the stage from the high-frequency power supply 21. It is controlled by supplying high-frequency power.

[0057] As described above, the plasma of one or more inert gases containing helium but not argon is generated inside the chamber 2 . In other words, generate plasma of helium or a gas in which helium is mixed with one or more inert gases not including argon.

[0058] In the method for diagnosing the state of the chamber in this embodiment, one or more inert gases including helium but not argon are used to generate plasma. The reason for using helium is that, as described below, the time from plasma generation to stabilization is short. Also, the reason is that, compared with argon gas, the sputtering rate is lower and the damage to the chamber is smaller.

[0059] Furthermore, since the emission wavelength of argon and the emission wavelength of fluorine overlap more, in the case of the mixed gas, an inert gas other than argon is used. Examples of the inert gas include xenon gas, neon gas, krypton gas and the like. One or more inert gases containing helium but not argon, such as helium alone, or a mixture of helium and xenon, neon, krypton and other inert gases other than argon.

[0060] (step S30) Next, the control unit 70 performs a luminous intensity measurement step of measuring the luminous intensity of fluorine inside the chamber. The control unit 70 performs control so that the beam splitter 56 measures the light emission intensity of the plasma inside the chamber 2 . Specifically, the control unit 70 performs control so that the spectrometer 56 measures the emission intensity of fluorine. For example, the control unit 70 controls the spectroscope 56 so as to measure the emission intensity at 686 nm, which is the emission wavelength of fluorine.

[0061] (step S40) Next, the control unit 70 diagnoses the state of the chamber 2 (chamber state) based on the luminous intensity measured in step S30.

[0062] For example, when the luminous intensity of fluorine measured in step S30 is not less than the first threshold and not more than the second threshold that is greater than the first threshold, the control unit 70 determines that the state in the chamber 2 (chamber state) is normal state (normal state).

[0063] In addition, when the luminous intensity of fluorine measured in step S30 does not reach the first threshold value, the control unit 70 diagnoses that the state in the chamber 2 (chamber condition) is a state in which the fluorine on the inner surface of the chamber 2 is insufficient. (fluorine deficiency state).

[0064] Furthermore, when the luminous intensity of fluorine measured in step S30 is greater than the second threshold value, the control unit 70 diagnoses that the state in the chamber 2 (chamber condition) is excessively present on the inner surface of the chamber 2. state (excess fluorine state).

[0065] In addition, when the luminous intensity of fluorine measured in step S30 does not reach the third threshold which is lower than the first threshold, or when the luminous intensity is diagnosed to be greater than the fourth threshold which is greater than the second threshold, it is diagnosed as The state in the chamber 2 (chamber status) is the state in which the parts in the chamber 2 are degraded and must be replaced (deteriorated state of the parts).

[0066] The specific processing flow will be described. FIG. 3 is a flow chart of the method for diagnosing the state of the chamber in this embodiment. Specifically, it is a flowchart of the state estimation process of step S40.

[0067] First, in step S41, the control unit 70 determines whether or not the luminescence intensity of fluorine measured in step S30 is equal to or greater than a first threshold. When the luminous intensity of fluorine measured in step S30 is greater than the first threshold (Yes in step S41), the control unit 70 determines whether the luminous intensity of fluorine measured in step S30 is greater than the first threshold. That is, it is determined that it is not more than the second threshold (step S42). When the luminous intensity of fluorine measured in step S30 is greater than the first threshold but not greater than the second threshold (Yes in step S42), the control unit 70 estimates the state of the chamber 2 of the substrate processing apparatus 1 (chamber state). ) is a normal state (step S43).

[0068] In step S41, when the luminous intensity of fluorine measured in step S30 does not reach the first threshold (No in step S41), the control unit 70 determines whether the luminous intensity of fluorine measured in step S30 is less than The value of the first threshold is determined to be greater than or equal to the third threshold (step S44). When the luminous intensity of fluorine measured in step S30 is equal to or greater than the third threshold (Yes in step S44), the control unit 70 estimates that the state (chamber state) of the chamber 2 of the substrate processing apparatus 1 is a fluorine-deficient state. (step S45).

[0069] In step S42, when the luminous intensity of fluorine measured in step S30 is greater than the second threshold (No in step S42), the control unit 70 determines whether the luminous intensity of fluorine measured in step S30 is greater than the second threshold. 2. Determination that the value of the threshold is equal to or less than the fourth threshold (step S46). When the luminous intensity of fluorine measured in step S30 is equal to or less than the fourth threshold (Yes in step S46), the control unit 70 estimates that the state (chamber state) of the chamber 2 of the substrate processing apparatus 1 is a fluorine-excess state. (step S47).

[0070] In step S44, when the luminous intensity of fluorine measured in step S30 does not reach the third threshold (No in step S44), the control unit 70 estimates the state of the chamber 2 of the substrate processing apparatus 1 (chamber state ) is the deterioration state of the part (step S48). In addition, in step S46, when the luminous intensity of fluorine measured in step S30 is greater than the fourth threshold value (No in step S46), the control unit 70 estimates the state of the chamber 2 of the substrate processing apparatus 1 (chamber state) is the state of component degradation (step S48). In the state of parts degradation, even if the processing of step S53 and step S54 of the following post-processing process is performed, it is judged that the normal state cannot be achieved, and replacement of parts is instructed.

[0071] Also, for example, based on the luminescence intensity of fluorine measured in step S30, the polysilicon etching rate when etching the substrate W may be estimated as follows, and the control unit 70 estimates whether the state of the chamber 2 is capable of producing the desired polysilicon Etching rate The state of etching.

[0072] (step S50) Next, the control unit 70 performs a post-processing process based on the diagnosis result in step S40. The details of the processing of step S50 will be described. FIG. 4 is a flow chart of the method for diagnosing the condition of the chamber in this embodiment. Specifically, FIG. 4 is a flow chart of the processing steps after step S50.

[0073] In the processing steps after step S50, in step S51, the control unit 70 performs processing based on the estimation result of the state estimation step in step S40.

[0074] In step S51, when the state estimation process in step S40 is estimated to be a normal state ("normal state" in step S51), in particular, no processing is performed in the post-processing process (step S52), and the post-processing process is ended.

[0075] In step S51, when the state estimation step in step S40 is estimated to be a fluorine-deficient state ("fluorine-deficient state" in step S51), the control unit 70 controls to perform plasma processing using a gas containing fluorine. (step S53). Performing plasma treatment using a gas containing fluorine, such as attaching fluorine to or adding fluorine to the sprayed film, or increasing the amount of fluorine on the inner surface of the chamber by fluorinating the sprayed film. The gas containing fluorine is, for example, a gas containing CF 4 gas or NF 3 gas, but is not limited thereto. After the plasma treatment is completed, the control unit 70 ends the post-treatment process.

[0076] In step S51, when it is estimated that the fluorine-excess state is in the state estimation process of step S40 ("the fluorine-excess state" of step S51), the control part 70 controls so that plasma processing using the gas containing oxygen may be performed (step S54). Plasma treatment with a gas containing oxygen is performed, for example, to relatively reduce the amount of fluorine on the inner surface of the chamber by oxidizing the sprayed film. The gas containing oxygen is, for example, a gas containing O 2 gas, but is not limited thereto. After the plasma treatment is completed, the control unit 70 ends the post-treatment process.

[0077] In step S51, when the state estimation process in step S40 estimates that the state of the parts is degraded ("deteriorated state of parts" in step S51), the control unit 70 displays (instructs) that the parts should be replaced (step S55) . After the display processing ends, the control unit 70 ends the post-processing step.

[0078] Furthermore, the method for diagnosing the state of the chamber in this embodiment is implemented, for example, after the substrate processing device 1 is started, after the substrate processing device 1 is maintained, or before and after processing a product substrate in the substrate processing device 1 .

[0079] [Device diagnosis using the diagnosis method of chamber condition] Next, device diagnosis using the method for diagnosing the condition of the chamber according to this embodiment will be described. FIG. 5 is a conceptual diagram of device diagnosis with respect to a time axis using the method for diagnosing the condition of a chamber according to this embodiment.

[0080] The process from the center to the left side of Fig. 5 shows the process when starting the device. The process from the center to the right side of FIG. 5 shows the process of processing the substrate (substrate processing) after the device is activated. Furthermore, the time axis passes from left to right.

[0081] When starting up the device, after performing maintenance such as assembling or replacing parts, the temperature in the chamber is raised while evacuating. Furthermore, it is checked whether there is no leakage in the chamber, and the state of the chamber is checked (health check). Then, adjustment processing is performed. Through the above process, confirm the normality of the assembly of parts, etc., or check whether there is air leakage, or check whether there is degassing or moisture. In addition, by adjusting, oxidation and fluorination of the inner surface of the chamber, or deposition (deposition) of a desired film, etc. are performed. By starting the device, the state inside the chamber is set to the initial state.

[0082] Next, the quality of the substrate processing device is finally investigated, and a QC (quality control, quality control) substrate for judging the normality of the device state is placed on the stage to measure the polysilicon etching rate. In addition, a dummy substrate is placed on the mounting table to obtain the reference luminescence data. Furthermore, the measurement conditions of the standard luminescence data are, for example, chamber pressure 80 mT, microwave (2.45 GHz) 2000 W, high-frequency power 100 W, He=300 sccm, 30 sec. The measurement conditions of polysilicon etching rate are, for example, chamber pressure 120 mT, microwave (2.45 GHz) 2000 W, high-frequency power 300 W, HBr / O2 / He=800 / 6 / 1000 sccm, 60 sec.

[0083] Next, the actual substrate processing is carried out. While processing the substrate, the polysilicon etching rate is measured by placing the QC substrate on the stage at fixed time intervals. By measuring the polysilicon etching rate at fixed time intervals, for example, during the processing time of 0 hours to 200 hours, the change data of the polysilicon etching rate (polysilicon etching rate variation) is obtained at prescribed intervals. Also, immediately before or immediately after the measurement of the polysilicon etching rate, a dummy substrate is placed on the stage to obtain luminescence data at a predetermined wavelength, which is the luminescence wavelength of fluorine in this embodiment. By obtaining the luminescence data of fluorine, for example, during the processing time of 0 hours to 200 hours, the change data of the luminescence data is obtained through the spectrometer at predetermined intervals (the spectroscope luminescence data change). In FIG. 5, as an example, it is schematically shown that the luminescence data of fluorine becomes smaller with the passage of time. The luminescence data of the background of the chamber (chamber background) is quantified by obtaining the change of the luminescence data of the beam splitter.

[0084] Furthermore, after the polysilicon etching rate change and the beam splitter luminescence data change are obtained once, the polysilicon etching rate can be estimated according to the obtained beam splitter luminescence data. That is, the measurement of the polysilicon etching rate using the QC substrate can be omitted. That is, the use of a QC substrate can be omitted. In addition, since the QC substrate is not used, the cost can be suppressed, and further, device diagnosis, such as diagnosis of normal stability of the device, can be performed efficiently. By improving the efficiency of device diagnosis, the productivity of substrate processing using the device can be improved.

[0085] The results of the actual measurements will be described. FIG. 6 is a diagram showing time-series data of luminous intensity using the method for diagnosing the condition of the chamber according to this embodiment. FIG. 7 is a graph showing time-series data of the in-plane average value of the polysilicon etching rate using the method for diagnosing the state of the chamber according to the present embodiment. The polysilicon etch rate is the polysilicon etch rate when the QC substrate is etched with plasma containing fluorine gas.

[0086] The horizontal axis of FIG. 6 represents the cumulative time during which high-frequency power is applied to the substrate processing apparatus 1 . The vertical axis of Fig. 6 is the luminous intensity at a wavelength of 686 nm. The wavelength of 686 nm is the emission wavelength of fluorine. Therefore, the vertical axis of FIG. 6 represents the luminescence intensity of fluorine. In addition, the luminous intensity at a wavelength of 686 nm is the luminous intensity (average value of 3 seconds) after 25 seconds after the generation of plasma after the application of high-frequency power is started. The horizontal axis of FIG. 7 represents the cumulative time for applying high-frequency power in the substrate processing apparatus 1 . The vertical axis of Fig. 7 is the in-plane average value of polysilicon etching rate.

[0087] According to Fig. 6 and Fig. 7, if the application time of high-frequency power becomes longer, the etching rate of polysilicon and the luminous intensity (spectral intensity) of fluorine become smaller. Here, the relationship between the polysilicon etching rate and the luminous intensity (spectral intensity) of fluorine will be described. FIG. 8 is a graph showing the relationship between the in-plane average value of the polysilicon etching rate and the luminous intensity using the method for diagnosing the state of the chamber according to the present embodiment.

[0088] According to the results in FIG. 8, it can be seen that there is a correlation between the etching rate of polysilicon and the luminous intensity (spectral intensity) of the luminous wavelength of fluorine. That is, by obtaining either one of the polysilicon etching rate and the emission intensity (spectral intensity) of the emission wavelength of fluorine, the other can be estimated. For example, by measuring the luminous intensity (spectral intensity) of fluorine, the etching rate of polysilicon can be estimated.

[0089] [About plasma treatment using helium] In this embodiment, helium gas is used when measuring the luminous intensity (spectral intensity) of fluorine. Plasma treatment using helium gas will be described. Fig. 9 is a graph showing the relationship between the generated plasma and the luminous intensity at a predetermined wavelength. The horizontal axis of FIG. 9 represents the time after application of high-frequency power, ie, generation of plasma. The vertical axis of Fig. 9 represents the luminous intensity at a wavelength of 288.5 nm. The wavelength of 288.5 nm is the emission wavelength of silicon or carbon monoxide. Line L_He is the luminescence intensity at a wavelength of 288.5 nm in plasma treatment using helium gas. Line L_Ar is the luminescence intensity at a wavelength of 288.5 nm in plasma treatment using argon gas.

[0090] Comparing the line L_He with the line L_Ar, the luminous intensity in the plasma treatment using helium converges faster than the luminous intensity in the plasma treatment using argon gas. For example, the luminous intensity in the plasma treatment using helium stabilizes after about 1 second. On the other hand, it takes more than 10 seconds for the luminous intensity to stabilize in the plasma treatment using argon gas. Therefore, the plasma treatment using helium gas can obtain stable luminous intensity immediately after plasma generation, and can shorten the measurement time (diagnosis time).

[0091] Fig. 10 is a graph showing the relationship between the generated plasma and the luminous intensity at a predetermined wavelength. The horizontal axis of FIG. 10 represents the time after application of high-frequency power, that is, generation of plasma. The vertical axis of Fig. 10 represents the luminous intensity at a wavelength of 686 nm. The wavelength of 686 nm is the emission wavelength of fluorine. Line L_He is the luminescence intensity at a wavelength of 686 nm in plasma treatment using helium gas. Among the luminous intensity at a wavelength of 686 nm, the luminous intensity in the plasma treatment using helium is also stabilized after about 1 second after plasma luminescence. Thus, the luminous intensity in the plasma treatment using helium converges faster. Furthermore, in the case of performing plasma treatment using argon gas, argon gas itself has a peak at a wavelength of 686 nm. Since argon itself has a peak at a wavelength of 686 nm, it is impossible to measure the luminous intensity using fluorine.

[0092] Next, it shows the results of measurements performed under changing conditions. FIG. 11 is a diagram showing time-series data of luminous intensity using the method for diagnosing the state of the chamber according to this embodiment. FIG. 12 is a graph showing the relationship between the in-plane average value of the polysilicon etching rate and the luminous intensity using the method for diagnosing the state of the chamber according to this embodiment.

[0093] The horizontal axis of FIG. 11 represents the cumulative time during which high-frequency power is applied to the substrate processing apparatus 1 . The vertical axis of Fig. 11 is the luminous intensity at a wavelength of 686 nm. The wavelength of 686 nm is the emission wavelength of fluorine. Therefore, the vertical axis of FIG. 11 represents the luminous intensity of fluorine. In addition, the luminous intensity at a wavelength of 686 nm is the luminous intensity (average value of 3 seconds) after 9 seconds after the generation of plasma after the application of high-frequency power is started.

[0094] It can be seen from FIG. 12 that there is a correlation between the polysilicon etching rate and the luminous intensity (spectral intensity) of the luminous wavelength of fluorine even if the time from plasma generation to measurement of luminous intensity is short. That is, even if the time from plasma generation to the measurement of the luminous intensity is short, the polysilicon etching rate can be estimated by measuring the luminous intensity. Furthermore, the time required for diagnosis can be shortened, so that the efficiency of diagnosis can be improved.

[0095] It should be considered that the method for diagnosing the state of the chamber of the substrate processing apparatus of the present embodiment disclosed this time is illustrative and not restrictive in all respects. The above-mentioned embodiment can be changed and improved in various forms without departing from the scope of the patent application and its gist. The matters described in the above-mentioned plural embodiments may be configured in other ways within the scope of no contradiction, and may be combined within the scope of no contradiction.

[0096] The method for diagnosing the condition of the chamber of the substrate processing apparatus of the present invention is described by taking an apparatus that generates plasma by microwaves as an example, but it is not limited thereto. It can also be applied to capacitively coupled plasma (Capacitively Coupled Plasma, CCP), inductively coupled plasma (Inductively Coupled Plasma, ICP), electron cyclotron resonance plasma (Electron Cyclotron Resonance Plasma, ECR), and helicon wave plasma (Helicon Wave Plasma, HWP) and any other type.

[0097] 1: Substrate processing device 2: chamber 4: ring member 8: Main body 8a: Central area 8b: Ring area 10: Carrying table 11:Exhaust port 20: Microwave plasma source 21: High frequency power supply 22: Matcher 25: Import and export 26: Gate valve 28:Microwave transparent plate 30: Antenna 31: Slot antenna 32: slot 33: slow wave material 34: shielding cover 34a: cooling water flow path 35:Microwave transmission department 36: Opening 37: Coaxial waveguide 37a: inner conductor 37b: Outer conductor 38: Mode Converter 39: Waveguide 40:Microwave oscillator 41: Tuner 42: short line components 43: Tapered connector 44: cover 45: Signal generator 46: Amplifier 47: hole 50: Frequency controller 51: 1st thermocouple 52: The second thermocouple 55: glass window 56: Optical splitter 60: Gas supply part 61: Gas supply source 62: Piping 63: buffer room 64: Gas flow path 65: Gas outlet 70: Control Department S10, S20, S30, S40, S41, S42, S43, S44, S45, S46, S47, S48, S50, S51, S52, S53, S54, S55: steps W: Substrate

Claims

1. A method for diagnosing the condition of a chamber, comprising the steps of: cleaning the interior of the chamber; generating a plasma of helium or a gas of helium mixed with one or more inert gases that do not contain argon inside the chamber; measuring the luminescence intensity of fluorine inside the chamber; and diagnosing the condition of the chamber based on the luminescence intensity; wherein the inert gas is xenon, neon, or krypton.

2. The method for diagnosing the condition of the chamber as described in claim 1, wherein the process of generating the aforementioned plasma is performed by placing a dummy substrate on a mounting stage.

3. The diagnostic method for the chamber condition as requested in item 1 or 2 is performed after starting the substrate processing apparatus, after maintaining the substrate processing apparatus, or before or after processing the product substrate in the substrate processing apparatus.

4. The method for diagnosing the condition of the chamber as claimed in claim 1 or 2 further includes the following steps: In the step of diagnosing the condition of the chamber, when it is diagnosed that the luminous intensity has not reached the first threshold, plasma treatment is performed by means of a gas containing fluorine.

5. The method for diagnosing the condition of the chamber as claimed in claim 1 or 2 further includes the following steps: In the step of diagnosing the condition of the chamber, when it is diagnosed that the luminous intensity is greater than the second threshold, plasma treatment with an oxygen-containing gas is performed.

6. The method for diagnosing the condition of a cavity as claimed in claim 1 or 2 further comprises the following steps: in the step of diagnosing the condition of the cavity, when it is diagnosed that the luminous intensity has not reached the first threshold, plasma treatment using a gas containing fluorine is performed; and in the step of diagnosing the condition of the cavity, when it is diagnosed that the luminous intensity is greater than a second threshold that is greater than the first threshold, plasma treatment using a gas containing oxygen is performed.

7. The method for diagnosing the condition of the cavity as described in claim 6 further includes the following steps: In the step of diagnosing the condition of the cavity, when it is diagnosed that the light intensity is not less than the third threshold of the first threshold, or when it is diagnosed that the light intensity is greater than the fourth threshold of the second threshold, the method instructs to replace the part.

8. A diagnostic method for the condition of a cavity as claimed in claim 1 or 2, wherein a ceramic melt-cast film is formed on the surface of the cavity.

9. The diagnostic method for the chamber condition as described in claim 8, wherein the aforementioned ceramic melt-cast film comprises any one of alumina, yttrium oxide, yttrium fluoride, or yttrium fluoride oxide.

10. A substrate processing apparatus comprising: a chamber into which a substrate to be processed is placed; a gas supply unit that supplies gas to the chamber; a plasma generation unit that generates plasma inside the chamber; a luminescence intensity measuring unit that measures the luminescence intensity inside the chamber; and a control unit that controls the gas supply unit, the plasma generation unit, and the luminescence intensity measuring unit; wherein the control unit performs the following steps: controlling the gas supply unit and the plasma generation unit to clean the interior of the chamber; controlling the gas supply unit to supply the interior of the chamber with helium or a gas formed by mixing helium with one or more inert gases that do not contain argon, and controlling the plasma generation unit to generate plasma; controlling the luminescence intensity measuring unit to measure the luminescence intensity of fluorine inside the chamber; and diagnosing the condition of the chamber based on the luminescence intensity; wherein the inert gas is xenon, neon, or krypton.

Images