JP5778893B2 - End point detection apparatus, plasma processing apparatus, and end point detection method - Google Patents

Description

  The present invention relates to an end point detection apparatus, a plasma processing apparatus, and an end point detection method.

Dry processes using plasma (hereinafter referred to as plasma treatment) are utilized in a wide range of technical fields such as semiconductor device manufacturing, surface hardening of metal parts, surface activation of plastic parts, and non-chemical sterilization. For example, for the manufacture of semiconductor devices and flat panel displays, plasma processing is performed in various processes such as ashing, etching, thin film deposition, and surface modification.
Here, when etching, thin film deposition, or the like is performed by plasma processing, reaction products and the like are deposited as deposits in the processing container. When such deposits are peeled off, particles are generated, which causes a decrease in product yield. In addition, the presence of deposits may cause a change in processing characteristics such as a processing rate. Therefore, removal (cleaning) of the deposit accumulated in the processing container is performed according to the amount of the deposit or periodically. In such cleaning, deposit removal (so-called dry cleaning) is performed by plasma treatment. Plasma treatment is advantageous in that it is low-cost, high-speed, and can reduce environmental pollution because it does not use chemicals.

  In such plasma processing, a technique for detecting an end point of plasma processing has been proposed in order to perform appropriate processing. For example, if the chemical composition of the layer removed by etching changes, the spectrum of light emitted from the plasma changes, and this change is detected using optical emission spectroscopy (OES) and plasma processing is performed. A technique for detecting the end point of the system has been proposed (see, for example, Patent Document 1).

  However, as in the technique disclosed in Patent Document 1, a change index, a change rate, an inflection point, and the like of the emission intensity at one type of wavelength (for example, the wavelength of light related to the removal target) are used for determining the end point. If this is the case, there is a possibility that precise end point detection cannot be performed. In addition, since it is impossible to eliminate the influence of individual differences in light emission intensity between the plasma processing apparatuses, there is a possibility that the end point detection error may increase.

JP 2001-250812 A

  The present invention provides an end point detection apparatus, a plasma processing apparatus, and an end point detection method capable of performing accurate end point detection.

According to one aspect of the present invention, a spectroscopic analysis unit that spectroscopically analyzes light generated when plasma processing is performed, information on emission intensity for a plurality of wavelengths provided from the spectroscopic analysis unit,
Based on information on emission intensity for a plurality of wavelengths at the end point of the plasma processing, a principal component calculation unit that determines a residual, and an end point determination unit that determines the end point of the plasma processing based on the obtained residual There is provided an end point detection device characterized by comprising the above.

According to another aspect of the present invention, a processing container, an electrode for generating plasma in the processing container, a spectroscopic analysis unit that spectrally analyzes light generated when the plasma processing is performed, Based on the information on the emission intensity for the plurality of wavelengths provided from the spectroscopic analysis unit and the information on the emission intensity for the plurality of wavelengths at the end point of the plasma processing, a principal component calculation unit for obtaining a residual, and the obtained residual There is provided a plasma processing apparatus comprising: an end point determination unit that determines an end point of plasma processing based on the difference.

A step of sequentially obtaining the emission intensity for the plurality of wavelengths in the plasma processing, the sought
Based on the information on the emission intensity for a plurality of wavelengths and the information on the emission intensity for a plurality of wavelengths at the end point of the plasma treatment, the end point of the plasma treatment is determined based on the procedure for obtaining the residual and the obtained residual. And an end point detecting method characterized by comprising the following:

  ADVANTAGE OF THE INVENTION According to this invention, the end point detection apparatus, plasma processing apparatus, and end point detection method which can perform exact end point detection are provided.

The schematic diagram for demonstrating the plasma processing apparatus which concerns on this Embodiment. The schematic diagram for demonstrating a mode that the spectrum of light changes. The schematic diagram for demonstrating a mode that the spectrum of light changes. The schematic diagram for demonstrating the calculation of the main component score which is a main component, and a residual. The schematic diagram for demonstrating the calculation of the main component score which is a main component, and a residual. The schematic diagram for illustrating construction of the end point detection model based on a residual. The schematic diagram for demonstrating the mode of the end point detection based on a residual. The flowchart for demonstrating about the end point detection method which concerns on this Embodiment.

Hereinafter, embodiments of the present invention will be illustrated with reference to the drawings.
FIG. 1 is a schematic diagram for illustrating an end point detection apparatus according to the present embodiment.
FIG. 1 shows a case where the plasma processing apparatus 40 provided with the end point detection apparatus 1 according to the present embodiment is a so-called parallel plate type reactive ion etching (RIE) apparatus. However, the plasma processing apparatus is not limited to the parallel plate type reactive ion etching apparatus, and can be changed as appropriate.

First, the plasma processing apparatus 40 is illustrated.
As shown in FIG. 1, the plasma processing apparatus 40 is provided with a processing vessel 42, a plasma generation unit 43, a power supply unit 44, a decompression unit 50, a gas supply unit 53, a control unit 41, and the like.
The processing container 42 has a substantially cylindrical shape with both ends closed, and has an airtight structure capable of maintaining a reduced-pressure atmosphere.

A plasma generator 43 that generates plasma P is provided inside the processing vessel 42. The plasma generating unit 43 is provided with a lower electrode 48 and an upper electrode 49.
The lower electrode 48 is provided below the region in the processing container 42 where the plasma P is generated. The lower electrode 48 is provided with a holding portion (not shown) for holding the workpiece W. The holding unit (not shown) can be, for example, an electrostatic chuck. Therefore, the lower electrode 48 also serves as a placement unit that places and holds the workpiece W on the upper surface (mounting surface).

  The upper electrode 49 is provided so as to face the lower electrode 48. A power supply 45 is connected to the lower electrode 48 via a blocking capacitor 46, and the upper electrode 49 is grounded. Therefore, the plasma generator 43 can generate the plasma P by supplying electromagnetic energy to a region where the plasma P is generated.

The power supply unit 44 is provided with a power supply 45 and a blocking capacitor 46.
The power supply 45 applies high frequency power of about 100 KHz to 100 MHz to the lower electrode 48. The blocking capacitor 46 is provided to prevent movement of electrons generated in the plasma P and reaching the lower electrode 48.

  A decompression unit 50 such as a turbo molecular pump (TMP) is connected to the bottom surface of the processing vessel 42 via a pressure control unit (Auto Pressure Controller: APC) 51. The decompression unit 50 decompresses the inside of the processing container 42 to a predetermined pressure. The pressure control unit 51 controls the internal pressure of the processing container 42 to be a predetermined pressure based on the output of a vacuum gauge (not shown) that detects the internal pressure of the processing container 42. That is, the processing vessel 42 has a region for generating the plasma P inside, and can maintain an atmosphere that is depressurized from the atmospheric pressure.

  A gas supply unit 53 is connected to the upper portion of the side wall of the processing vessel 42 via a flow rate control unit (Mass Flow Controller: MFC) 52. A gas G (e.g., an etching gas or a cleaning gas) can be supplied from the gas supply unit 53 to the region where the plasma P in the processing container 42 is generated via the flow rate control unit 52. Further, the supply amount of the gas G can be adjusted by controlling the flow rate control unit 52 by the control unit 41.

A window 54 is provided on the upper side wall of the processing vessel 42. The window 54 is made of a transparent material such as quartz so that light can pass therethrough. The position where the window 54 is provided is not limited to the upper part of the side wall of the processing vessel 42 and can be changed as appropriate.
The control unit 41 performs plasma processing by controlling the decompression unit 50, the gas supply unit 53, the power source 45, the pressure control unit 51, the flow rate control unit 52, and the like. Further, the plasma processing end operation is controlled based on an end point detection signal from an end point determination unit 5 described later.

Next, the end point detection apparatus 1 according to the present embodiment is illustrated.
As shown in FIG. 1, the end point detection apparatus 1 includes a light receiving unit 2, a spectroscopic analysis unit 3, a principal component calculation unit 4, and an end point determination unit 5.
The light receiving unit 2 is provided so as to face the window 54. The light receiving unit 2 and the spectroscopic analysis unit 3 are optically connected by an optical cable or the like. Therefore, the light incident on the light receiving unit 2 through the window 54 can be transmitted to the spectroscopic analysis unit 3.

Further, the spectroscopic analysis unit 3 and the principal component calculation unit 4 are electrically connected, and the principal component calculation unit 4 and the end point determination unit 5 are electrically connected.
The spectroscopic analysis unit 3 spectroscopically analyzes light generated when the plasma processing is executed. In other words, the spectroscopic analysis unit 3 analyzes light transmitted from the light receiving unit 2 (light generated inside the processing container 42) using emission spectroscopy (OES). Further, the light emission intensities for a plurality of wavelengths obtained by the emission spectroscopic analysis method are sequentially converted into electric signals, which are provided to the principal component calculation unit 4.

The principal component calculation unit 4 obtains the principal component score PC or the residual Q based on the information regarding the emission intensity for a plurality of wavelengths provided from the spectroscopic analysis unit 3. That is, the principal component calculation unit 4 is based on the information on the emission intensity for the plurality of wavelengths provided from the spectroscopic analysis unit 3 and the information on the emission intensity for the plurality of wavelengths at the end point of the target plasma processing. The score PC or residual Q is obtained. Then, information regarding the obtained principal component score PC or residual Q is provided to the end point determination unit 5. Information on the emission intensity for a plurality of wavelengths at the end point of the target plasma treatment may be stored in advance in a storage unit (not shown) provided in the principal component calculation unit 4 or provided from the outside. You may make it do.
The end point determination unit 5 determines the end point of the plasma processing based on the information on the principal component score PC or the residual Q provided from the principal component calculation unit 4.

Here, the end point determination performed in the end point determination unit 5 is further illustrated.
If the amount of change, change rate, inflection point, etc. of the emission intensity with respect to one type of wavelength (for example, the wavelength of light related to the removal object) is used as a determination index for end point detection, there is a possibility that precise end point detection cannot be performed. is there. In addition, since the influence of individual differences in light emission intensity between the processing apparatuses cannot be excluded, there is a possibility that the end point detection error may increase.
Therefore, the end point determination unit 5 determines the end point in consideration of the change in the emission intensity with respect to a plurality of wavelengths.

Hereinafter, as an example, a case where the end point is determined in consideration of a change in emission intensity with respect to two types of wavelengths (wavelength X1, wavelength X2) will be described.
FIG. 2 is a schematic diagram for illustrating how the spectrum of light changes.
FIG. 2 shows a case where the spectrum changes while the correlation between the wavelength and the emission intensity in the light spectrum is substantially constant.
For example, this is a case where the spectrum S1 at the end point of the plasma processing and the spectrum S2 at the start of the plasma processing are as shown in FIG.
In such a case, the relationship between the emission intensity at wavelength X1 and the emission intensity at wavelength X2 is as shown in FIG. In this case, the relationship between the emission intensity of the wavelength X1 and the emission intensity of the wavelength X2 in the spectrum S1 is indicated by a point P1, and the relationship between the emission intensity of the wavelength X1 and the emission intensity of the wavelength X2 in the spectrum S2 is indicated by a point P2. .
In such a case, the point P2 is on a line passing through the origin and the point P1. As the plasma processing proceeds and approaches the end point, the point P2 moves toward the point P1 on a line passing through the origin and the point P1. That is, the value of the principal component score PC2 shown in FIG. 2B changes so as to approach the value of the principal component score PC1. However, in such a case, the residual Q described later hardly occurs. In this case, the principal component score PC and the residual Q can be obtained by principal component analysis (PCA). The calculation of the principal component score PC and the residual Q by the principal component analysis will be described later.

FIG. 3 is also a schematic diagram for illustrating how the spectrum of light changes.
FIG. 3 shows a case where the spectrum changes while the correlation between the wavelength and the emission intensity in the light spectrum varies.
For example, this is a case where the spectrum S1 at the end point of the plasma processing and the spectrum S3 at the start of the plasma processing are as shown in FIG.
In such a case, the relationship between the emission intensity at the wavelength X1 and the emission intensity at the wavelength X2 is as shown in FIG. In this case, the relationship between the emission intensity of the wavelength X1 and the emission intensity of the wavelength X2 in the spectrum S1 is indicated by a point P1, and the relationship between the emission intensity of the wavelength X1 and the emission intensity of the wavelength X2 in the spectrum S3 is indicated by a point P3. .
In such a case, there is no point P3 on the line passing through the origin and the point P1, and a residual Q is generated. Then, as the plasma processing proceeds and approaches the end point, the point P3 moves so as to approach the point P1. That is, the value of the residual Q shown in FIG.

  As illustrated above, when the end point is detected in consideration of changes in emission intensity with respect to a plurality of wavelengths, either the main component score PC or the residual Q can be used as a determination index. Then, the value of the principal component score PC (the difference between the sequentially obtained principal component score PC ′ and the principal component score PC ″ obtained in advance), and the time point when the residual Q value falls within a predetermined range. In this case, in general, the spectrum often changes while the correlation between the wavelength and the emission intensity in the light spectrum varies. More preferably, the residual Q is used as a determination index.

Next, the calculation of the principal component score PC by the principal component analysis and the calculation of the residual Q will be exemplified.
By performing the principal component analysis, it becomes possible to express information on a plurality of wavelengths by a principal component score PC and a residual Q which are one type of comprehensive determination index. Note that when performing principal component analysis, the principal component, which is a comprehensive index, is determined under the condition that the loss of information is minimized but the loss of information is minimized.

4 and 5 are schematic diagrams for illustrating the calculation of the principal component score PC, which is the principal component, and the residual Q. FIG.
4 and 5 show a case where the residual Q is obtained using information on four types of wavelengths (wavelengths X1 to X4).
First, as shown in FIG. 4, the temporal change of the emission intensity at four types of wavelengths (wavelengths X1 to X4) is obtained.
At this time, it is preferable to perform measurement at each wavelength a plurality of times.
Here, in the case of light related to deposits and reaction products, the amount of decomposition of the deposits and reaction products increases from the start of processing, so the emission intensity increases accordingly. Then, as the process proceeds, the amount of deposits and reaction products decreases, so the emission intensity also decreases accordingly. That is, the wavelengths X1 to X3 in FIG.
On the other hand, in the case of light related to a gas used for processing (for example, an etching gas or a cleaning gas), the light emission intensity increases from the start of the processing. That is, as shown by the wavelength X4 in FIG. 4, the light emission intensity increases without decreasing even if processing proceeds. This is because the amount of deposits and reaction products decreases as the process proceeds, and the amount of gas consumed and lost in the reaction with them decreases.

  As described above, depending on the wavelength, the emission intensity may decrease or increase as the process proceeds. Here, the residual Q is an evaluation index representing a difference from the final state (end point) of the process. For this reason, the residual Q decreases as it approaches the final state (end point) regardless of the increase or decrease in the emission intensity at an arbitrary time. The principal component score PC "at the end point is an evaluation index representing the final state (end point) of the process. Therefore, as the final state (end point) is approached regardless of the increase or decrease in the emission intensity at an arbitrary time point, The difference between the principal component score PC ′ obtained sequentially and the principal component score PC ″ at the end point obtained in advance will decrease.

  In this case, the end point may be detected by obtaining the principal component score PC or the residual Q based only on the light emission intensity that decreases as the process proceeds, such as light related to the deposits and reaction products. it can. However, the detection accuracy of the end point can be improved by combining the light emission intensity increasing as the process proceeds, such as the light related to the gas used for the process.

Next, as shown in FIG. 5A, the emission intensity at the end point is obtained for each wavelength.
In addition, when measuring the emitted light intensity in each wavelength in multiple times, as shown in FIG.5 (b), the calculated | required emitted light intensity is averaged and it is set as the emitted light intensity in the end point for every wavelength.
Here, when the emission intensity at the end point of the wavelength X1 is a1, the emission intensity at the end point of the wavelength X2 is a2, the emission intensity at the end point of the wavelength X3 is a3, and the emission intensity at the end point of the wavelength X4 is a4, the emission intensity at the end point Information X can be expressed by the following equation (1).

X = (a1, a2, a3, a4) (1)

Next, a principal component score PC "at the end point is obtained.
In this case, the principal component score PC ″ at the end point can be obtained by the following equation (2).

PC "= a1.b1 + a2.b2 + a3.b3 + a4.b4 (2)

  Here, b1 to b4 are coefficients (coupling coefficients) determined so that the loss of information is minimized in the principal component analysis.

Next, the light emission intensity at an arbitrary time point of the wavelength X1 is a11, the light emission intensity at an arbitrary time point of the wavelength X2 is a12, the light emission intensity at an arbitrary time point of the wavelength X3 is a13, and the light emission intensity at an arbitrary time point of the wavelength X4 is a14. Then, the light emission intensity information X10 at an arbitrary time can be expressed by the following equation (3).

X10 = (a11, a12, a13, a14) (3)

Here, when the principal component score PC is used as a determination index for end point detection, the principal component score PC ′ at an arbitrary time is obtained by the following equation (4). Next, the principal component score PC is obtained by the difference between the principal component score PC "at the end point and the principal component score PC 'at an arbitrary time point shown in the following equation (5). The principal component score PC is within a predetermined range. The predetermined range can be arbitrarily set by the user, for example, 3σ of the main component score at the time of manufacturing a non-defective product is set as the predetermined range.

PC ′ = a11 · b1 + a12 · b2 + a13 · b3 + a14 · b4 (4)

PC = │PC ''-PC'│ (5)

On the other hand, when the residual Q is used as a determination index for end point detection, information X20 obtained by projecting light emission intensity information X10 at an arbitrary time point on the principal component axis is obtained by the following equation (6).

X20 = (PC ′ · b1 + PC ′ · b2 + PC ′ · b3 + PC ′ · b4) (6)

In this case, the residual Q is obtained by the following equation (7). A time point when the value of the residual Q falls within a predetermined range can be set as the end point. The predetermined range can be arbitrarily set by the user. For example, the residual 3σ at the time of manufacturing a good product is set as a predetermined range.

Q = (X10−X20) ² (7)

Here, if the emission intensity at each wavelength is sequentially obtained and the residual Q at each time point is obtained, an end point detection model based on the residual Q can also be constructed.
FIG. 6 is a schematic diagram for illustrating the construction of the end point detection model based on the residual.
As shown in FIG. 6A to FIG. 6D, the temporal change of the emission intensity at each wavelength is sequentially obtained, and the residual Q at each time point is obtained by the above-described procedure. Then, an end point detection model as shown in FIG. 6E can be constructed based on the residual Q at each time point.

FIG. 7 is a schematic diagram for illustrating how the end point is detected based on the residual Q.
Note that T1 in the figure is the end point in the end point detection model constructed in advance as described above. In this case, the end point T1 is an end point in the average process.
When cleaning the inside of the processing container 42, the cleaning can be terminated based on the end point T1 of the end point detection model obtained in advance. In this way, more appropriate cleaning can be performed than when the cleaning is terminated based on the end point obtained from an empirical rule.

However, in the case of etching or the like directly related to the product, it is preferable to detect the end point more precisely. Even when cleaning is performed, the end point may change greatly depending on the internal state of the processing container 42 and the like. For example, as shown in FIGS. 7A to 7E, the end point T2 may be shorter than the end point T1, or the end point T3 may be longer than the end point T1.
In such a case, for example, if the cleaning is ended at the end point T1, the cleaning is excessive at the end point T2, and the cleaning is insufficient at the end point T3.

Therefore, in the present embodiment, the emission intensity at each wavelength is sequentially obtained, the residual Q at each time point is obtained by the equation (4), and when the residual Q falls within a predetermined range, the time point is determined as the end point. And so on.
By doing so, the plasma processing can be terminated at an appropriate time according to the actual situation. That is, accurate end point detection can be performed. In this case, it is possible to eliminate the influence of individual differences in emission intensity between the plasma processing apparatuses.

Next, the operation of the end point detection device 1 according to this embodiment will be illustrated.
As an example, a case where the inside of the processing container 42 is cleaned is illustrated. First, the inside of the processing container 42 is decompressed to a predetermined pressure by the decompression unit 50. At this time, the pressure inside the processing container 42 is adjusted by the pressure control unit 51.
Next, a gas G having a predetermined flow rate is supplied from the gas supply unit 53 through the flow rate control unit 52 to a region where the plasma P inside the processing container 42 is generated. The gas G to be supplied can be a so-called cleaning gas (for example, a gas containing oxygen or an inert gas such as Ar (argon)).

  On the other hand, high frequency power of about 100 kHz to 100 MHz is applied to the lower electrode 48 from the power supply unit 44. Then, since the lower electrode 48 and the upper electrode 49 constitute a parallel plate electrode, discharge occurs between the electrodes and plasma P is generated. The gas G is excited and activated by the generated plasma P, and plasma products such as neutral active species, ions, and electrons are generated. The inside of the processing vessel 42 is cleaned by the generated plasma product. That is, the deposits are physically removed by collision of ions or electrons with the deposits accumulated in the processing container 42. Further, the deposit and the neutral active species react to cause chemical decomposition and removal of the deposit.

  When cleaning is started, light of multiple wavelengths is emitted according to the components of the deposit, the components of the reaction product generated by the reaction between the deposit and the neutral active species, the components of the cleaning gas, etc. The The emitted light enters the light receiving unit 2 through the window 54, and the light incident on the light receiving unit 2 is transmitted to the spectroscopic analysis unit 3 through an optical cable or the like. The light transmitted to the spectroscopic analysis unit 3 is subjected to spectroscopic analysis, and light emission intensities for a plurality of wavelengths are converted into electric signals. The converted electric signal is transmitted to the principal component calculation unit 4. In the principal component calculation unit 4, a principal component score is obtained based on the information on the emission intensity for the plurality of wavelengths provided from the spectroscopic analysis unit 3 and the information on the emission intensity for the plurality of wavelengths at the end point of the target plasma processing. PC or residual Q is determined. The obtained principal component score PC or residual Q is transmitted to the end point determination unit 5 to determine the end point.

For example, the principal component score PC ′ and the residual Q at each time point are sequentially obtained based on the emission intensity at each wavelength obtained sequentially, and the principal component score PC ′ obtained sequentially and the principal component at the end point obtained in advance. When the difference from the score PC "or the residual Q falls within a predetermined range, the time point is determined as the end point. When the end point determination unit 5 determines that the end point is reached, the control unit 41 is directed to. An end point detection signal is output.
When the end point detection signal is input to the control unit 41, the cleaning end operation is performed and the cleaning ends. That is, the application of high-frequency power and the supply of gas G are stopped, and the residue is discharged by exhausting the inside of the processing vessel 42. Thereafter, the inside of the processing container 42 is returned to the atmospheric pressure state, and the cleaning is completed.

  According to the end point detection apparatus 1 according to the present embodiment, the emission intensity at each wavelength is sequentially obtained to obtain the residual Q at each time point, and when the residual Q falls within a predetermined range, that point is determined as the end point. It can be. Further, the emission intensity at each wavelength is sequentially obtained to obtain the principal component score PC ′ at each time point, and the difference between the sequentially obtained principal component score PC ′ and the principal component score PC ″ obtained in advance at the end point is within a predetermined range. If it becomes inside, the end point can be set as the end point, so that the plasma processing can be terminated at an appropriate point according to the actual situation, that is, the end point can be accurately detected. In this case, it is possible to eliminate the influence of individual differences in emission intensity between the plasma processing apparatuses.

Next, the end point detection method according to the present embodiment will be exemplified.
FIG. 8 is a flowchart for illustrating the end point detection method according to the present embodiment.
First, the emission intensity at the end point of the target plasma treatment is obtained in advance.
That is, first, a temporal change in the emission intensity for a plurality of wavelengths is obtained in advance (step S10).
The emission intensity can be determined using, for example, emission spectroscopy (OES).
Next, the emission intensity at the end point is obtained for each wavelength (step S11).
In this case, it is preferable that the measurement at each wavelength is performed a plurality of times in step S10, and the obtained light emission intensities are averaged in step S11 to obtain the light emission intensity at the end point for each wavelength.
Next, a principal component score PC "at the end point is obtained (step S12).

Next, the end point in plasma processing is detected.
That is, first, the emission intensity for a plurality of wavelengths is sequentially obtained in the plasma processing (step S21).
Next, the principal component score PC or the residual Q is obtained based on the information regarding the emission intensity obtained sequentially (step S22).
That is, the principal component score PC ′ and the residual Q at each time point are obtained based on the emission intensity at the end point obtained in advance and the principal component score PC ″ and the emission intensity obtained sequentially in the plasma processing.
Note that when the end point is detected using the principal component score PC, the procedure for obtaining the residual Q can be omitted.

Next, the end point of the plasma processing is determined based on the obtained principal component score PC or residual Q (step S23).
For example, when the residual Q at each time point obtained sequentially falls within a predetermined range, the time point can be determined as the end point. Further, when the difference between the principal component score PC ′ obtained at each time point sequentially obtained and the principal component score PC ″ obtained at the end point in advance is within a predetermined range, that point is determined as the end point. be able to.

  According to the end point detection method according to the present embodiment, the emission intensity at each wavelength is sequentially obtained to obtain the residual Q at each time point, and when the residual Q falls within a predetermined range, that time point is set as the end point. can do. Further, the emission intensity at each wavelength is sequentially obtained to obtain the principal component score PC ′ at each time point, and the difference between the sequentially obtained principal component score PC ′ and the principal component score PC ″ obtained in advance at the end point is within a predetermined range. If it becomes inside, the end point can be set as the end point, so that the plasma processing can be terminated at an appropriate point according to the actual situation, that is, the end point can be accurately detected. In this case, it is possible to eliminate the influence of individual differences in emission intensity between the plasma processing apparatuses.

Next, the end point detection program according to this embodiment will be exemplified.
The end point detection program according to the present embodiment causes a computer to execute the end point detection described above.
In order to execute a series of end point detection methods, the end point detection program according to the present embodiment is stored, for example, in a storage unit (not shown) provided in the end point determination unit 5. For example, the end point detection program is supplied to the end point determination unit 5 while being stored in a recording medium (not shown), and is read and stored in a storage unit (not shown) of the end point determination unit 5. In addition, it can be stored in a storage unit (not shown) of the end point determination unit 5 via a MES (Manufacturing Execution System) system LAN (Local Area Network) or the like.

That is, a program that executes the following procedures (1) to (5) is stored in a storage unit (not shown) of the end point determination unit 5.
In the case where end point detection is performed using the principal component score PC, the procedure for obtaining the residual Q shown in (4) can be omitted.
(1) A procedure for collecting the emission intensity at the end point obtained in advance.
(2) A procedure for sequentially collecting emission intensities for a plurality of wavelengths in plasma processing.
(3) A procedure for obtaining the principal component score PC or the residual Q based on information on the emission intensity collected sequentially.

  (4) A procedure for determining the end point of plasma processing based on the obtained principal component score PC or residual Q.

  (5) A procedure for outputting an end point detection signal.

In this case, it may be executed in time series according to the above-described order, or may be executed in parallel or selectively without necessarily being executed in time series.
Further, the end point detection program according to the present embodiment may be processed by a single calculation means, or may be distributedly processed by a plurality of calculation means.
Since the contents of each procedure are the same as those described above, detailed description thereof is omitted.

  According to the end point detection program according to the present embodiment, the emission intensity at each wavelength is sequentially obtained to obtain the residual Q at each time point, and when the residual Q falls within a predetermined range, that time point is set as the end point. can do. Further, the emission intensity at each wavelength is sequentially obtained to obtain the principal component score PC ′ at each time point, and the difference between the sequentially obtained principal component score PC ′ and the principal component score PC ″ obtained in advance at the end point is within a predetermined range. If it becomes inside, the end point can be set as the end point, so that the plasma processing can be terminated at an appropriate point according to the actual situation, that is, the end point can be accurately detected. In this case, it is possible to eliminate the influence of individual differences in emission intensity between the plasma processing apparatuses.

Next, a method for manufacturing the microstructure according to this embodiment is illustrated.
As a manufacturing method of the fine structure, for example, a manufacturing method of a semiconductor device can be exemplified. Here, in the manufacturing process of the semiconductor device, a process of forming a pattern on the substrate (wafer) surface by film formation, resist coating, exposure, development, etching, resist removal, etc., inspection process, cleaning process, heat treatment process, impurity introduction There are a process, a diffusion process, a planarization process, and the like. In these steps, plasma treatment is widely used.
Therefore, in the process in which the plasma processing is used, the plasma processing can be terminated using the end point detection apparatus 1, the end point detection method, and the end point detection program according to the above-described embodiment. In addition, since the technique in each known process can be applied to those other than the end point detection device 1, the end point detection method, and the end point detection program according to the present embodiment described above, detailed description thereof will be omitted.

  In addition, as an example, the method for manufacturing a fine structure according to the present embodiment has been described using a method for manufacturing a semiconductor device, but the method is not limited thereto. For example, in the manufacture of electronic devices such as flat panel displays and solar cells, the manufacture of precision components such as phase shift masks and optical elements, and the manufacture of precision components in the MES (Micro-Electro-Mechanical Systems) and microchemical fields. Also plasma processing is widely used. Therefore, it can be applied to manufacture of a fine structure including a process in which plasma treatment is used.

  According to the manufacturing method of the microstructure according to the present embodiment, the plasma processing can be terminated at an appropriate time according to the actual situation. That is, accurate end point detection can be performed. In this case, it is possible to eliminate the influence of individual differences in emission intensity between the plasma processing apparatuses. Therefore, it is possible to improve productivity and product quality.

Heretofore, the present embodiment has been illustrated. However, the present invention is not limited to these descriptions.
As long as the features of the present invention are provided, those skilled in the art appropriately modified the design of the above-described embodiments are also included in the scope of the present invention.
For example, the shape, size, material, arrangement, number, and the like of each element included in the end point detection device 1 are not limited to those illustrated, but can be changed as appropriate.

  In the above-described embodiment, either the principal component score PC or the residual Q is used as a determination index. However, using both the principal component score PC and the residual Q as a determination index, the value of the principal component score PC and The point in time when both of the residual Q values are within a predetermined range can be determined as the end point in the plasma processing. Thereby, the end point in plasma processing can be determined more accurately.

Moreover, although the parallel plate type reactive ion etching apparatus has been exemplified as the plasma processing apparatus, the present invention is not limited to this. For example, various plasma processing apparatuses such as a microwave excitation type plasma processing apparatus can be used.
Moreover, although cleaning was illustrated as plasma processing, it is not necessarily limited to this. For example, in various plasma treatments such as etching, ashing, thin film deposition (film formation), and surface modification, endpoint detection is performed by emission spectroscopy, and various plasmas are detected by emission spectroscopy. It can be applied to processing.
Moreover, each element with which each embodiment mentioned above is combined can be combined as much as possible, and what combined these is also included in the scope of the present invention as long as the characteristics of the present invention are included.

  DESCRIPTION OF SYMBOLS 1 ... End point detection apparatus, 2 ... Light-receiving part, 3 ... Spectral analysis part, 4 ... Main component calculating part, 5 ... End point determination part, 40 ... Plasma processing apparatus, 41 ... Control part, 42 ... Processing container, 43 ... Plasma generation , 44 ... power supply part, 50 ... decompression part, 53 ... gas supply part, 54 ... window, G ... gas, P ... plasma, PC ... principal component score, Q ... residual, S1 to S3 ... spectrum, W ... covered Processed product, X1-X4 ... Wavelength

Claims (3)

A spectroscopic analyzer that sequentially spectroscopically analyzes the light generated when the plasma processing is performed;
Information on emission intensity for a plurality of wavelengths provided from the spectroscopic analysis unit;
Based on the information about the emission intensity for a plurality of wavelengths at the end of the pre-determined plasma treatment, the principal component analysis, information about the emission intensity for a plurality of wavelengths provided from the spectral analyzer, the end point of the pre-determined plasma processing A principal component calculation unit for obtaining a residual which is an evaluation index representing a difference from information on emission intensity for a plurality of wavelengths in
Wherein on the basis of the residual obtained by principal component calculating unit includes a determining end point determination unit end point of the plasma treatment, a,
The end point determination unit is characterized in that when the residual obtained by the principal component calculation unit falls within a predetermined range, it is determined as an end point of plasma processing . A processing vessel;
An electrode for generating plasma in the processing vessel;
A spectroscopic analyzer that sequentially spectroscopically analyzes the light generated when the plasma processing is performed;
Information on emission intensity for a plurality of wavelengths provided from the spectroscopic analysis unit;
Based on the information about the emission intensity for a plurality of wavelengths at the end of the pre-determined plasma treatment, the principal component analysis, information about the emission intensity for a plurality of wavelengths provided from the spectral analyzer, the end point of the pre-determined plasma processing A principal component calculation unit for obtaining a residual which is an evaluation index representing a difference from information on emission intensity for a plurality of wavelengths in
Wherein on the basis of the residual obtained by principal component calculating unit includes a determining end point determination unit end point of the plasma treatment, a,
The plasma processing apparatus , wherein the end point determination unit determines that the end point of the plasma processing is the end point when the residual obtained by the principal component calculation unit falls within a predetermined range . A procedure for obtaining information on the emission intensity for a plurality of wavelengths at the end point of the plasma treatment;
A procedure for sequentially obtaining emission intensities for a plurality of wavelengths in plasma processing;
Information about the emission intensity with respect to the emission intensity of the plurality of wavelengths obtained by the procedure sequentially determining the, on the basis of the information about the emission intensity for a plurality of wavelengths at the end of the plasma treatment, the principal component analysis, the obtained plurality A procedure for obtaining a residual that is an evaluation index representing a difference between information on emission intensity with respect to the wavelength of light and information on emission intensity with respect to a plurality of wavelengths at the end point of the plasma treatment ;
Based on the residual determined in procedure to determine the residual comprises a procedure for determining the end point of the plasma treatment, a,
An end point detection method, comprising: determining an end point of plasma processing when the residual obtained in the procedure for obtaining the residual falls within a predetermined range .

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