阅读说明：本技术 光学发射光谱系统及其校准方法和制造半导体器件的方法 (Optical emission spectroscopy system, method of calibrating the same, and method of manufacturing semiconductor device ) 是由 文丁一 李衡周 宣钟宇 于 2019-07-11 设计创作，主要内容包括：一种光学发射光谱系统可以包括：参考光源；分析器,用于接收和分析从参考光源发射的光；以及校准器,用于校准从参考光源发射的光。校准器可以根据光的入射角改变校准比率。(An optical emission spectroscopy system can include: a reference light source; an analyzer for receiving and analyzing light emitted from a reference light source; and a collimator for collimating the light emitted from the reference light source. The collimator may change the collimating ratio according to the incident angle of the light.)

1. An optical emission spectroscopy system comprising:

a reference light source;

an analyzer for receiving and analyzing light emitted from the reference light source; and

a collimator for collimating light emitted from the reference light source,

wherein the collimator changes a light receiving ratio according to an incident angle of the light.

2. The system of claim 1, wherein the collimator calibrates the intensity of light incident on the analyzer.

3. The system of claim 2, wherein the calibrator comprises:

a first filter transmitting light at a first incident angle; and

a second filter transmitting light at a second angle of incidence,

wherein a transmittance of the first filter is different from a transmittance of the second filter.

4. The system of claim 2, wherein the calibrator comprises:

a first opening allowing light to be incident therethrough at a first incident angle; and

a second opening through which light is allowed to be incident at a second angle of incidence,

wherein the size of the first opening is different from the size of the second opening.

5. The system of claim 2, wherein the calibrator comprises:

a first liquid crystal transmitting light incident at a first incident angle; and

a second liquid crystal transmitting light incident at a second incident angle,

wherein a transmittance of the first liquid crystal is different from a transmittance of the second liquid crystal.

6. The system of claim 2, wherein the calibrator is located between the reference light source and the analyzer.

7. The system of claim 2, further comprising a sub-calibration component between the reference light source and the analyzer.

8. The system of claim 7, wherein the sub-calibration component comprises a mask.

9. The system of claim 7, wherein the sub-calibration component comprises a shutter.

10. The system of claim 7, further comprising: a controller for controlling the sub-calibration section to obtain a calibration factor according to an incident angle of light.

11. The system of claim 10, wherein the analyzer uses the calibration factor to calibrate the light according to an angle of incidence of the light incident on the analyzer.

12. The system of claim 10, wherein the analyzer obtains a final calibration factor from the calibration factor.

13. A method of calibrating an optical emission spectroscopy system, the method comprising:

emitting light from a reference light source;

calibrating light emitted from the reference light source;

the light after the calibration is analyzed and,

wherein calibrating the light emitted from the reference light source comprises: the calibration factor is obtained from the angle of incidence of the light.

14. The method of claim 13, further comprising: the light is further calibrated based on the calibration factor.

15. The method of claim 13, wherein calibrating the light emitted from the reference light source further comprises: and obtaining a final calibration factor according to the calibration factor.

16. The method of claim 13, wherein calibrating the light emitted from the reference light source comprises: the light intensity is calibrated according to the incident angle of the light.

17. The method of claim 15, further comprising: a collimator is arranged to collimate light from the reference light source.

18. A method of manufacturing a device, the method comprising:

calibrating the optical emission spectroscopy system;

performing an inspection process on a process chamber using the optical emission spectroscopy system;

loading a substrate in the process chamber; and

performing a plasma process on the substrate,

wherein calibrating the optical emission spectroscopy system comprises: the intensity of the light is controlled according to the incident angle of the light.

19. The method of claim 18, wherein calibrating the optical emission spectroscopy system comprises: and obtaining a calibration factor according to the incidence angle.

20. The method of claim 18, wherein the plasma process comprises at least one of an etch process, a chemical vapor deposition process, an ashing process, or a cleaning process.

Technical Field

The present disclosure relates to an optical emission spectroscopy system, and more particularly, to an optical emission spectroscopy system for measuring a state of plasma generated in a process chamber and a calibration method thereof.

Background

As the demand for advanced processes for manufacturing semiconductor devices or flat panel display devices is increasing, plasma processing systems are used to perform various processes. In a plasma processing system, Radio Frequency (RF) power is applied to a platen or electrode to generate an electromagnetic field in a plasma chamber, and plasma generated by the electromagnetic field is used to process a substrate.

Disclosure of Invention

According to an embodiment, an optical emission spectroscopy system may include: a reference light source; an analyzer for receiving and analyzing light emitted from the reference light source; and a collimator for collimating the light emitted from the reference light source. The collimator may change a light receiving ratio according to an incident angle of the light.

According to an embodiment, a method of calibrating an optical emission spectroscopy system may comprise: emitting light from a reference light source; calibrating light emitted from the reference light source; and analyzing the calibrated light. Calibrating the light emitted from the reference light source may include obtaining a calibration factor according to an incident angle of the light.

According to an embodiment, a method of manufacturing a device may include: calibrating the optical emission spectroscopy system; performing an inspection process on a process chamber using the optical emission spectroscopy system; loading a substrate in the process chamber; and performing a plasma process on the substrate. Calibrating the optical emission spectroscopy system can include controlling an intensity of the light as a function of an angle of incidence of the light.

Drawings

Features will become apparent to those skilled in the art by describing in detail exemplary embodiments with reference to the attached drawings, wherein:

fig. 1 shows a typical plasma processing system and optical emission spectroscopy system.

Fig. 2 illustrates an enlarged view of light incident on the light receiving part of fig. 1.

Fig. 3 shows a graph demonstrating data obtained by an optical emission spectroscopy system.

FIG. 4 illustrates an optical emission spectroscopy system according to some embodiments.

Fig. 5 shows the plasma processing system and the optical emission spectroscopy system of fig. 4.

FIG. 6 illustrates the sub-calibration component of FIG. 4 according to some embodiments.

FIG. 7 illustrates a flow chart for fabricating a semiconductor device using the plasma processing system and optical emission spectroscopy system of FIG. 5.

Fig. 8A-8C illustrate stages in a process of obtaining the calibration factor of fig. 7, according to some embodiments.

Fig. 9A-9C illustrate stages in a process of obtaining the calibration factor of fig. 7, according to some embodiments.

FIG. 10 illustrates an optical emission spectroscopy system according to some embodiments.

Fig. 11 shows the plasma processing system and the optical emission spectroscopy system of fig. 10.

FIG. 12 shows a flow chart for fabricating a semiconductor device using the plasma processing system and optical emission spectroscopy system of FIG. 11.

Fig. 13A illustrates the calibration component of fig. 10 according to some embodiments.

FIG. 13B illustrates the calibration component of FIG. 10 according to some embodiments.

Detailed Description

In the optical emission spectroscopy system according to example embodiments, Optical Emission Spectroscopy (OES), which is an optical inspection technique used in a plasma process for manufacturing a device, may be used to measure physical characteristics of plasma generated in a process chamber. In this specification, the substrate may be, for example, a semiconductor wafer for manufacturing a semiconductor device, a glass substrate for manufacturing a flat display device, or the like. The plasma process on the substrate may be, for example, an etching process, a chemical vapor deposition process, an ashing process, a cleaning process, or the like.

The physical characteristics of the plasma in the process chamber (e.g., electron density or ion density) may be parameters that affect the process characteristics of the plasma process (e.g., process rate, homogeneity, uniformity, and wafer-to-wafer repeatability). For example, electron density in the process chamber can affect the excitation, ionization, and dissociation of electrons. Therefore, in order to effectively perform the plasma process, it is important to check the internal state of the process chamber and to know the physical characteristics of the plasma generated in the process chamber.

Fig. 1 shows an optical emission spectroscopy system 50 disposed in a plasma processing system. Referring to fig. 1, a stage 20 and a showerhead 30 may be disposed in the process chamber 10 to face each other. RF power from the RF power component 40 may be supplied to the showerhead 30 to generate plasma P in the process chamber 10. An exemplary optical emission spectroscopy system 50 may include a light receiving component 54 and an analysis component 56. A window 11 may be disposed in a sidewall of the process chamber 10, and the light receiving part 54 may receive the plasma light PL (fig. 2) through the window 11. The plasma light PL received by the light receiving part 54 may be transmitted to the analyzing part 56 to be analyzed.

Fig. 2 shows plasma light PL incident on the light receiving part 54 of fig. 1. Referring to fig. 1 and 2, the plasma light PL incident on the light receiving part 54 may include a plurality of light beams at a plurality of incident angles. The difference between the incident angles may be small. In practice, the plasma light PL may be a single beam, but in this specification, the plasma light PL will be described as a plurality of beams. In addition, the angle of the plasma light PL shown in the drawing may be different from the angle of the actual light. As an example, the plasma light PL incident on the light receiving part 54 may include a first plasma light beam PL1, a second plasma light beam PL2, and a third plasma light beam PL 3. The first plasma light beam PL1 may have a first incident angle θ 1, and the second plasma light beam PL2 may have a second incident angle θ 2. The third plasma light beam PL3 may be incident on the light-receiving part 54 at an incident angle of 0 ° (i.e., vertically).

The light intensities of the plasma light beams PL1, PL2, and PL3 incident on the light-receiving part 54 may be different from each other, for example, the distribution of the plasma P in the process chamber 10 may vary between different regions. Further, when a plurality of process chambers are provided, a difference in characteristics (for example, model or position) between optical emission spectroscopy systems respectively provided for the process chambers may cause a difference in damping ratio of light amount between the optical emission spectroscopy systems at each of the incident angles θ 1, θ 2, and θ 3. Therefore, in order to realize a more accurate optical emission spectroscopy system, the damping ratio of light intensity between the optical emission spectroscopy systems at each of the incident angles θ 1, θ 2, and θ 3 may be considered.

Multiple process chambers may perform the same plasma process. For example, in multiple process chambers, plasma processes may be performed under the same process conditions (e.g., process time, process gases, etc.). In an embodiment, after the plasma process in each process chamber, the OES spectrum may be measured by a plurality of optical emission spectroscopy systems provided for the respective process chambers.

Although no difference between measurements may be expected, as shown in FIG. 3, there may be an intensity difference between the OES spectra of curves ① and ②. As shown in FIG. 3, such a difference between OES spectra may result from various causes.

FIG. 4 illustrates an optical emission spectroscopy system 500 according to some embodiments. Fig. 5 shows the plasma processing system 1 and the optical emission spectroscopy system 500 of fig. 4.

The plasma processing system 1 may include a process chamber 100, a platen 200, a showerhead 300, and RF power components 400. For example, the plasma processing system 1 may be a Capacitively Coupled Plasma (CCP) system, an Inductively Coupled Plasma (ICP) system, a microwave plasma system, or any other plasma processing system.

The process chamber 100 may have an inner space in which a plasma process with respect to a substrate is to be performed. That is, plasma for processing a substrate may be generated in the inner space. The process chamber 100 may be hermetically sealed such that the process chamber 100 is in a vacuum state. The process chamber 100 may include an upper chamber and a lower chamber coupled to each other, and may have a hollow hexahedral shape, a hollow cylindrical shape, or any other shape.

The window 110 may be disposed in the process chamber 100, for example, in a sidewall thereof. The window 110 may be formed of glass, quartz, or other optically transparent material (e.g., transparent to the wavelength of light to be detected and analyzed). The window 110 may transmit infrared light, ultraviolet light, or visible light. The opening provided with the window 110 may be sealed to prevent foreign materials from entering the process chamber 100 or to maintain a vacuum state of the process chamber 100. In some embodiments, the window 110 may be disposed in a top surface or gas exhaust of the process chamber 100, rather than in a sidewall of the process chamber 100. In some embodiments, a plurality of windows 110 may be disposed in the process chamber 100. The window 110 may be coated with an anti-reflective material and may have uniform transmission characteristics regardless of the wavelength of incident light.

The process chamber 100 may include a gas supply hole and a gas exhaust hole. Process gases may be supplied into the process chamber 100 through the gas supply holes, and unreacted source gases and byproducts may be exhausted from the process chamber 100 through the gas exhaust holes. In addition, a deposition shield or the like may also be provided in the opening including the window 110.

A stage 200 may be disposed in the inner space of the process chamber 100 to support a substrate. The platen 200 may be located on the inner bottom surface of the process chamber 100. The platform 200 may have a plate shape. As an example, the stage 200 may include an electrostatic chuck to hold the substrate using electrostatic force. The platen 200 may include a heater, such as a heater wire embedded in the platen 200 for heating the substrate to the temperature of the plasma process.

The showerhead 300 may be located in an interior volume of the process chamber 100, such as an interior upper surface. Showerhead 300 may face a platen 200, such as a surface of platen 200 that holds a substrate. The showerhead 300 may uniformly supply the process gas onto the substrate. The showerhead 300 may be used as the upper electrode 300 and may be referred to herein as the upper electrode 300.

The RF power part 400 may apply Radio Frequency (RF) power to the upper electrode 300 to generate or control plasma. RF power component 400 may include one or more power components. In some embodiments, the RF power component 400 may apply RF power to another component instead of the upper electrode 300. As an example, the RF power part 400 may apply RF power to the lower electrode in the platform 200 when the lower electrode is buried in the platform 200.

When RF power is applied to the process chamber 100, an electric field between the platen 200 and the upper electrode 300 may be formed by a potential difference between the platen 200 and the upper electrode 300. Accordingly, a plasma may be generated in the process chamber 100. The density of the plasma generated on the substrate may be controlled by varying the potential difference between the stage 200 and the upper electrode 300. The plasma conditions in the process chamber 100 may be controlled by adjusting the RF power from the RF power component 400.

Referring to fig. 4 and 5, the optical emission spectroscopy system 500 may include a reference light source 520, a calibrator (e.g., sub-calibration part 530), a light receiving part 540, an analyzing part 560, and a controller 580. The components making up the optical emission spectroscopy system 500 may be divided into internal and external components depending on whether they are located inside or outside the process chamber 100. As an example, the reference light source 520 and the sub-calibration part 530 may be located inside the process chamber 100, and the light receiving part 540, the analysis part 560, and the controller 580 may be located outside the process chamber 100. When the calibration process on the optical emission spectroscopy system 500 is complete, the reference light source 520 and the sub-calibration component 530 may be unloaded from the process chamber 100.

The optical emission spectroscopy system 500 may be disposed adjacent to the window 110. The optical emission spectroscopy system 500 may collect light generated in a region between the stage 200 and the upper electrode 300 through the window 110.

The reference light source 520 may emit reference light L for calibrating the optical emission spectroscopy system 500. Hereinafter, the reference light L may be referred to as light L for convenience of description. The reference light source 520 may emit, for example, ultraviolet light. Although fig. 4 illustrates an example in which the reference light source 520 has a cylindrical body, any particular shape of the reference light source 520 may be used. For example, the reference light source 520 may emit light radially. The reference light source 520 may emit multi-wavelength light, but the following description will refer to an example in which the reference light source 520 emits monochromatic light.

In practice, the light L may be a single light beam, but in the present specification, it will be described that the light L includes a plurality of light beams. Further, the ratio and/or angle of the light L shown in the drawings may be different from the ratio and/or angle of the actual light. As an example, the light L incident on the light receiving part 540 may include a first light beam L1, a second light beam L2, and a third light beam L3. As described above, the first light beam L1 may have the first incident angle θ 1, and the second light beam L2 may have the second incident angle θ 2. The third light beam L3 may have an incident angle of 0 ° or may be perpendicularly incident on the light receiving part 540.

The light receiving part 540 may receive the light L emitted from the reference light source 520. The light receiving part 540 may be adjacent to the window 110. The light receiving part 540 may include an optical fiber. The light receiving part 540 may transmit the received light L to the analyzing part 560. The analysis component 560 or analyzer may be an Optical Emission Spectroscopy (OES) system to analyze the plasma state in the process chamber 100. For example, the analysis component 560 may convert the received light L into an electrical signal, wherein the received light L contains information related to a reaction between the plasma P and the substrate in the process chamber 100, e.g., the analysis component 500 may comprise a photodetector, and may analyze the electrical signal, e.g., may comprise a processor, to obtain information about the reaction between the plasma P and the substrate. The analysis component 560 may include a display. The light may be directly incident on the analysis component 560, for example on its photodetector.

The sub-calibration part 530 may be between the reference light source 520 and the light receiving part 540. The sub-calibration component 530 may be adjacent to the reference light source 520, e.g., without an intermediate element. The sub-calibration member 530 may have a size corresponding to the reference light source 520, for example, may be large enough to have all light output from the reference light source 520 incident thereon. The reference light source 520, the sub-calibration part 530, and the light receiving part 540 may be coaxial with the central axis a.

FIG. 6 illustrates the sub-calibration component of FIG. 4 according to some embodiments. The sub-alignment feature 530 may include a mask. Referring to fig. 6, the sub-alignment part 530 may include a first shield 531, a second shield 533, a third shield 535, a first slit 532, a second slit 534, and a third slit 536. As an example, the sub-calibration member 530 may be provided in the form of a plate, for example, a flat rectangular shape. The slits 532, 534, 536 may extend further in a first direction than a second direction, both orthogonal to the central axis a, and the shields 531, 533, 535 may correspond to the slits. If the first shield 531 is opened, the first slit 532 transmits light incident thereon. If the second shield 533 is open, the second slit 534 transmits light incident thereon. If the third shield 535 is opened, the third slit 536 transmits light incident thereon. Otherwise, each shutter prevents light from being transmitted by the corresponding slit. When closed, each shield may be between the reference light source 520 and the corresponding slit, or may be between the corresponding slit and the light receiving part 540, so that light is not transmitted from the slit. As shown in fig. 6, a separate shield may be provided for each slit. Alternatively, a mask with a single opening may be used to selectively allow individual slits to transmit light.

The first and second slits 532 and 534 may be symmetrical about the central axis a. Hereinafter, it is assumed that the first slit 532 and the second slit 534 receive the same light intensity if the first slit 532 and the second slit 534 are symmetrical with respect to the central axis a or if the first slit 532 and the second slit 534 have the same incident angle with respect to the light receiving part 540. Specifically, the first slit 532 may include an upper first slit and a lower first slit with respect to the central axis a, and may receive light of the first incident angle t (or the first incident angle- θ n). Similarly, the second slit 534 may include an upper second slit and a lower second slit with respect to the central axis a, and may receive light of the second incident angle h2 (or the second incident angle- θ n). Alternatively, only one of the upper and lower first slits and only one of the upper and lower second slits may be used or provided. The third slit 536 may be a single central slit.

The controller 580 may control the shutters 531, 533, and 535 of the sub-alignment member 530 to block some of the slits 532, 534, and 536 and open others. The controller 580 may selectively open and close each of the shutters 531, 533 and 535. As an example, shutters 531, 533, and 535 may open and close in a sliding manner, such as sliding from side to side or up and down. Alternatively, the sub-alignment feature 530 may include a shutter (e.g., a circular shutter), an electronic shield (e.g., liquid crystal), or the like to control the transmission of light through the slits. As shown in fig. 6, if the first shutter 531 is opened, a portion of the light L emitted from the reference light source 520 (e.g., the first light beam L1 having a first incident angle) is transmitted through the first slit 532 and is incident on the light receiving part 540.

Referring back to fig. 4 and 5, the controller 580 may control the reference light source 520, the sub-calibration part 530, the light receiving part 540, and the analysis part 560. For example, the controller 580 may control the reference light source 520, the sub-calibration component 530, the light receiving component 540, and the analysis component 560 to calibrate the optical emission spectroscopy system 500.

The optical emission spectroscopy system 500 can measure light in the process chamber 100 to monitor plasma conditions in the process chamber 100. The plasma state in the process chamber 100 may be analyzed by an optical emission spectroscopy system 500 disposed outside the process chamber 100. Accordingly, the optical emission spectroscopy system 500 may not affect the process environment of the process chamber 100.

Fig. 7 is a flow chart for fabricating a semiconductor device using the plasma processing system 1 and optical emission spectroscopy system 500 of fig. 5. Referring to fig. 7, the optical emission spectroscopy system 500 may be calibrated (in S10). Calibration of the optical emission spectroscopy system 500 can be performed to check and maintain the process environment of the optical emission spectroscopy system 500. Calibration of the optical emission spectroscopy system 500 may include obtaining a calibration factor (in S12) and/or obtaining a final calibration factor (in S14). In certain embodiments, calibration of the optical emission spectroscopy system 500 can include elements that improve the process environment, such as cleaning and/or changing components (e.g., windows, etc.).

Fig. 8A-8C illustrate stages in a process of obtaining a calibration factor (e.g., S12 of fig. 7) according to some embodiments. The reference light source 520 of fig. 8A to 8C may emit light radially, but only a portion of the light incident on the light receiving part 540 is illustrated in fig. 8A to 8C for convenience of explanation.

Referring to fig. 8A, the first light beam L1 emitted from the reference light source 520 may be incident on the light receiving part 540 through the first slit 532 of the sub-collimating part 530. Here, the controller 580 may control the sub-calibration member 530 to open only the first slit 532 and close the second and third slits 534 and 536 such that only the first light beam L1 passes through the sub-calibration member 530. In other words, only the first light beam L1 emitted from the reference light source 520 and having the first incident angle θ 1 is incident on the light receiving part 540. The controller 580 may obtain a calibration factor of the first light beam L1 using the light receiving part 540 and the analyzing part 560. Hereinafter, in the present specification, the terms "incident angle" and "angle" may be used in the same meaning. Further, in this specification, for convenience of description, the first light, the second light, and the third light have been mentioned, but the light may be a substantially continuous light, such as a single light beam, and it may be further divided into the first light, the second light, the.

Referring to fig. 8B, the second light beam L2 emitted from the reference light source 520 may be incident on the light receiving part 540 through the second slit 534 of the sub-collimating part 530. Here, the controller 580 may control the sub-calibration member 530 to open only the second slit 534 and close the first slit 532 and the third slit 536 such that only the second light beam L2 passes through the sub-calibration member 530. In other words, only the second light beam L2 emitted from the reference light source 520 and having the second incident angle θ 2 is incident on the light receiving part 540. The controller 580 may obtain a calibration factor of the second light beam L2 using the light receiving part 540 and the analyzing part 560.

Referring to fig. 8C, the third light beam L3 emitted from the reference light source 520 may be incident on the light receiving part 540 through the third slit 536 of the sub-collimating part 530. Here, the controller 580 may control the sub-calibration member 530 to open only the third slit 536 and close the first slit 532 and the second slit 534 so that the third light beam L3 passes through the sub-calibration member 530. In other words, only the third light beam L3 emitted from the reference light source 520 and vertically incident on the light receiving part 54 is incident on the light receiving part 540. The controller 580 may obtain a calibration factor of the third light beam L3 using the light receiving part 540 and the analyzing part 560.

The calibration factor may be obtained by performing a plurality of measurement procedures and setting reference data based on the obtained measurement data. As an example, the calibration factor may be obtained by comparing values of OES intensity obtained from the first process chamber and the second process chamber under the same conditions. Table 1 below shows calibration factors obtained by the method according to the example.

[ TABLE 1 ]

Table 1 shows OES spectral intensity of light emitted from the first process chamber at various incident angles (e.g., first to third incident angles) and OES spectral intensity of light emitted from the second process chamber at various incident angles (e.g., first to third incident angles). Here, the OES intensity obtained from the first process chamber may be set as a reference value, and the OES intensities obtained from the first process chamber and the second process chamber may be used to obtain the calibration factor. As an example, each calibration factor may be given as a corresponding ratio of the OES intensity obtained from the second process chamber to a reference value (i.e., the OES intensity obtained from the first process chamber). The calibration factor may be used to calibrate OES intensities obtained from multiple process chambers. Which process chamber is used to set the reference value may vary, for example, the reference value may be set based on the OES intensity obtained from the second process chamber instead of the first process chamber.

The controller 580 may calibrate the measured intensity of the light incident on the light receiving part 540 based on a calibration factor that is given to vary with the incident angle of the light. As an example, each obtained OES intensity may be calibrated by dividing the OES intensity obtained from the second process chamber by a respective one of the calibration factors. The calibration factor may be input to the analysis component 560 and may be applied to calibrate OES intensity. Once the calibration factor is obtained, the reference light source 520 may be unloaded from the process chamber 100.

Fig. 9A-9C illustrate stages of obtaining the calibration factor of fig. 7 (e.g., S12 of fig. 7), according to some embodiments. Unlike the reference light source 520 having a cylindrical shape, the reference light source 520a may be provided to have a limited light emitting portion, and may be a point light source, for example.

Referring to fig. 9A to 9C, the position of the reference light source 520a may be changed to obtain the calibration factor. Under the control of the controller 580, the reference light source 520a may be positioned to provide the light receiving part 540 with the first light beam L1 having the first incident angle θ 1 with respect to the central axis of the light receiving part 540, and then the calibration factor of the first light beam L1 may be obtained (for example, see fig. 9A). Under the control of the controller 580, the reference light source 520a may be positioned to provide the first light beam L2 having the second incident angle θ 2 with respect to the central axis of the light receiving part 540, and then the calibration factor of the second light beam L2 may be obtained (for example, see fig. 9B). Under the control of the controller 580, the reference light source 520a may provide the third light beam L3 having the third incident angle n3 to the light receiving part 540 (e.g., the reference light source 520a may be coplanar with the light receiving part 540), and then a calibration factor of the third light beam L3 may be obtained (e.g., see fig. 9C). In this case, the calibration factor can be obtained even if the above-described sub-calibration part 530 is not provided. After obtaining the calibration factor, the reference light source 520a may be unloaded from the process chamber 100.

Referring back to fig. 7, the controller 580 may obtain a final calibration factor from the calibration factor (in S14). Obtaining the final calibration factor may include multiplying the calibration factor by a corresponding weight. Each weight may correspond to a relative ratio of the amount of plasma generated to the total amount of plasma in the area specified by each incident angle. As an example, in the case where the amount of plasma in the region specified by the first incident angle θ 1 is greater than the amount of plasma in the region specified by the third incident angle θ 3, and the amount of plasma in the region specified by the third incident angle θ 3 is again greater than the amount of plasma in the region specified by the second incident angle θ 2, the weight of the third angle may be greater than the weight of the first angle, and the weight of the second angle may be greater than the weight of the third angle. Thus, to equalize the plasma volume, weights may be assigned for the various angles. The weights for the various angles may be determined by various methods (e.g., using a simulation process or optimization algorithm).

Table 2 below shows the light amount of plasma light according to the incident angle in the example.

[ TABLE 2 ]

First plasma light beam PL1 having a first incident angle	15
		Second plasma light beam PL2 having second incident angle	50
Third plasma light beam PL3 having a third incident angle	35

The controller 580 may use the calibration factor and the weights to obtain a final calibration factor. As an example, the final calibration factor may be obtained by multiplying the calibration factors by the respective weights and summing them. That is, the final calibration factor may be expressed as a single constant. As shown in table 2, the weights of the first, second, and third plasma lights are 0.15, 0.5, and 0.35, respectively. Meanwhile, in the case of performing the same plasma process, there may be no difference in plasma distribution between process chambers, and thus the weight of plasma light may be considered to be the same between chambers. Thus, as can be seen from tables 1 and 2, the final calibration factor can be given as 1.3875 (i.e., 0.15 × 0.9166667+0.5 × 1.1+0.35 × 2). Once the final calibration factor is obtained, the OES intensities obtained from the plurality of process chambers can be calibrated immediately without individually calibrating the OES intensities according to the respective incident angles of light. Calibrating the OES intensity using the final calibration factor can include dividing the OES intensity obtained from the second process chamber by the final calibration factor. Table 2 above is a set of examples, but the inventive concept is not limited thereto.

Once the calibration of the optical emission spectroscopy system 500 is completed, an inspection process on the process chamber 100 may be performed (in S20). An inspection process may be performed to inspect or inspect the internal state of the process chamber 100, thereby allowing the plasma process to be more efficiently performed. In the optical emission spectroscopy system 500, the inspection process of the process chamber 100 may be performed using the light receiving part 540, the analyzing part 560, and the controller 580 without the reference light source 520 and the sub-calibration part 530. In an embodiment, the inspection process on the process chamber 100 may include generating plasma in the process chamber 100 and measuring and inspecting plasma light.

When the inspection of the process chamber is completed, the plasma process on the substrate may be performed (in S30). For example, a substrate may be loaded on the stage 200 in the process chamber 100, and then a plasma process may be performed on the substrate. In this specification, the substrate may be a semiconductor wafer for manufacturing a semiconductor device, a glass substrate for manufacturing a flat panel display device, or the like. The plasma process on the substrate may be an etching process, a chemical vapor deposition process, an ashing process, a cleaning process, or the like.

Fig. 7 shows an example in which the plasma process is performed after the OES calibration, but in an embodiment, the OES calibration may be performed after the plasma process. In an embodiment, the plasma process on the substrate may be performed twice, for example before and after OES calibration.

According to some embodiments, the optical emission spectroscopy system and the method of calibrating it may be different. The calibration factor may be considered to compensate for the difference between light intensities caused by the difference between incident angles, wherein the calibration factor is given in terms of incident angles. Therefore, the optical emission spectroscopy system can be calculated more accurately. Furthermore, when calibrating the optical emission spectroscopy system based on the final calibration factor, the optical emission spectroscopy system can be calibrated more simply.

FIG. 10 is an optical emission spectroscopy system 500a according to some embodiments. Fig. 11 shows the plasma processing system 1 and optical emission spectroscopy system 500a of fig. 10. In the following description of the optical emission spectroscopy system 500a of fig. 10, elements that are substantially the same as the elements of the optical emission spectroscopy system 500 described with reference to fig. 4 will be identified with the same reference numerals, and will not be described in detail with repeated description. The optical emission spectroscopy system 500a may also include a calibrator, such as a calibration component 550. The calibration component 550 may simultaneously calibrate light incident thereon at different angles, as compared to the sub-calibration component 530, which may separately account for light incident at different angles.

The calibration part 550 may be between the reference light source 520 and the light receiving part 540. The calibration part 550 may be on the same central axis a as the reference light source 520, the sub-calibration part 530, and the light receiving part 540. Although the sub-calibration component 530 is shown between the reference light source 520 and the calibration component 550, in some embodiments, the sub-calibration component 530 may be omitted or the calibration component 550 may be between the reference light source 520 and the sub-calibration component 530. The calibration member 550 may be provided to have a size corresponding to that of the reference light source 520, for example, so that all light emitted from the reference light source 520 may be incident on the calibration member 520.

The calibration part 550 may calibrate optical characteristics (e.g., intensity) of the light L incident on the light receiving part 540 such that the light receiving ratio varies according to the incident angle of the light L. As an example, the calibration part 550 may calibrate the light amount thereof according to the incident angle of the light L incident on the light receiving part 540. The calibration component 550 may be manufactured in consideration of the aforementioned weights. For example, the calibration member 550 may be manufactured such that the transmittance of a region having a higher weight is higher than that of another region having a lower weight. In an embodiment, the collimating part 550 may be placed in front of the reference light source 520 in the propagation direction of the light L to allow the light amount distribution of the light L incident on the light receiving part 540 to become similar to the distribution of plasma. The calibration member 550 may be manufactured to include a plurality of regions having different transmittances, and the structure of the calibration member 550 may be variously changed.

Fig. 12 shows a flowchart of a process for manufacturing a semiconductor device using the plasma processing system 1 and the optical emission spectroscopy system 500a of fig. 11. Fig. 13A illustrates the calibration component 550a of fig. 10 according to some embodiments. Fig. 13B illustrates the calibration component 550B of fig. 10 according to some embodiments. Steps S12, S20, and S30 (e.g., obtaining a calibration factor, performing an inspection process, and performing a plasma process) in fig. 12 may be performed in the same or similar manner as in fig. 7, and thus a detailed description thereof will be omitted. The calibration of the optical emission spectroscopy system 500a may further include setting the calibration component 550 (in S16) using the obtained calibration factor.

Referring to fig. 13A, the calibration part 550a may include a first filter 552a, a second filter 554a, and a third filter 556 a. The first filter 552a may be positioned at a first angle θ 1 from the central axis a of fig. 10, the second filter 554a may be positioned at a second angle θ 2 from the central axis a, and the third filter 556a may be located on a plane that includes the central axis a. In other words, the first light beam L1 passing through the first filter 552a may have a first incident angle θ 1 on the light receiving part 540, the second light beam L2 passing through the second filter 554a may have a second incident angle θ 2 on the light receiving part 540, and the third light beam L3 passing through the third filter 556a may be perpendicularly incident on the light receiving part 540. The transmittances of the first filter 552a, the second filter 554a, and the third filter 556a may be different from each other. As an example, the transmittance of the first filter 552a may be lower than the transmittance of the second filter 554a, and the transmittance of the second filter 554a may be lower than the transmittance of the third filter 556 a.

Referring to fig. 13B, the calibration member 550B may include a first opening 552B, a second opening 554B, and a third opening 556B. The first opening 552b may be positioned at a first angle θ 1 relative to the central axis a of fig. 10, the second opening 554b may be positioned at a second angle θ 2 relative to the central axis a, and the third opening 556b may be positioned on a plane including the central axis a. In other words, the first light beam L1 passing through the first opening 552b may have a first incident angle θ 1 on the light receiving part 540, the second light beam L2 passing through the second opening 554b may have a second incident angle θ 2 on the light receiving part 540, and the third light beam L3 passing through the third opening 556b may be perpendicularly incident on the light receiving part 540. In some embodiments, the first opening 552b, the second opening 554b, and the third opening 556b may have different sizes from one another. As an example, the size of the first opening 552b may be smaller than the size of the second opening 554b, and the size of the second opening 554b may be smaller than the size of the third opening 556 b. Examples in which the opening is provided to have a hole or a circular shape have been described, but the opening may be provided to have a slit shape or any other shape.

The alignment member may include a first liquid crystal, a second liquid crystal, and a third liquid crystal. The alignment member including the first liquid crystal, the second liquid crystal, and the third liquid crystal may have the same shape as the alignment member 550a of fig. 13A. The first liquid crystal may be positioned to have a first angle with the central axis, the second liquid crystal may be positioned to have a second angle with the central axis, and the third liquid crystal may be positioned on a plane including the central axis. In other words, the first light passing through the first liquid crystal may be incident on the light receiving part 540 at a first incident angle, the second light passing through the second liquid crystal may be incident on the light receiving part 540 at a second incident angle, and the third light passing through the third liquid crystal may be perpendicularly incident on the light receiving part 540. The controller 580 may apply different voltages to the liquid crystals so that the first liquid crystal, the second liquid crystal, and the third liquid crystal may have different transmittances from each other. As an example, the transmittance of the first liquid crystal may be lower than that of the second liquid crystal, and the transmittance of the second liquid crystal may be lower than that of the third liquid crystal.

According to some embodiments, the calibration member 550, 550a, or 550b may be configured in such a manner that the light amount distribution of the light emitted from the reference light source 520 of the optical emission spectroscopy system 500a becomes similar to the distribution of the plasma. Since the optical emission spectroscopy system 500a includes the calibration part 550, 550a, or 550b, in order to realize the transmittance difference according to the incident angle difference, the intensity of light incident on the light receiving part 540 may be controlled according to the incident angle of the light. Therefore, an additional calibration process for improving the reliability of the inspection process may be omitted.

The methods, processes, and/or operations described herein may be performed by code or instructions to be executed by a computer, processor, controller, or other signal processing device. A computer, processor, controller or other signal processing device may be an element described herein or an element other than an element described herein. Because algorithms forming the basis of a method (or the operation of a computer, processor, controller or other signal processing device) are described in detail, the code or instructions for carrying out the operations of the method embodiments may transform the computer, processor, controller or other signal processing device into a special purpose processor for performing the methods described herein.

The computing components and other processing features of the disclosed embodiments may be implemented in logic, which may include hardware, software, or both, for example. When implemented at least partially in hardware, the computing unit, control unit, and other processing features can be, for example, any of a variety of integrated circuits including, but not limited to, an application specific integrated circuit, a field programmable gate array, a combination of logic gates, a system on a chip, a microprocessor, or another type of processing or control circuit.

When implemented at least partially in software, the components and other processing features may include, for example, a memory or other memory device for storing code or instructions to be executed by, for example, a computer, processor, microprocessor, controller or other signal processing device. A computer, processor, microprocessor, controller or other signal processing device may be or be an element other than those described herein. Because algorithms forming the basis of a method (or the operation of a computer, processor, microprocessor, controller or other signal processing device) are described in detail, the code or instructions for carrying out the operations of the method embodiments may transform the computer, processor, controller or other signal processing device into a special purpose processor for performing the methods described herein.

According to some embodiments, an optical emission spectroscopy system and a method of calibrating an optical emission spectroscopy system may be provided with improved accuracy and reliability.

Example embodiments have been disclosed herein, and although specific terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purposes of limitation. In some instances, features, characteristics, and/or elements described in connection with a particular embodiment may be used alone or in combination with features, characteristics, and/or elements described in connection with other embodiments, unless expressly stated otherwise, as would be recognized by one of ordinary skill in the art upon review of the present application. It will, therefore, be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as set forth in the appended claims.