KR20160089262A - Plasma processing method and plasma processing device - Google Patents

Plasma processing method and plasma processing device Download PDF

Info

Publication number
KR20160089262A
KR20160089262A KR1020150126202A KR20150126202A KR20160089262A KR 20160089262 A KR20160089262 A KR 20160089262A KR 1020150126202 A KR1020150126202 A KR 1020150126202A KR 20150126202 A KR20150126202 A KR 20150126202A KR 20160089262 A KR20160089262 A KR 20160089262A
Authority
KR
South Korea
Prior art keywords
light
wavelengths
intensity
detected
spectrum
Prior art date
Application number
KR1020150126202A
Other languages
Korean (ko)
Other versions
KR101750001B1 (en
Inventor
시게루 나카모토
다테히토 우스이
사토미 이노우에
고스케 후쿠치
Original Assignee
가부시키가이샤 히다치 하이테크놀로지즈
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 가부시키가이샤 히다치 하이테크놀로지즈 filed Critical 가부시키가이샤 히다치 하이테크놀로지즈
Publication of KR20160089262A publication Critical patent/KR20160089262A/en
Application granted granted Critical
Publication of KR101750001B1 publication Critical patent/KR101750001B1/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
    • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
    • H01L21/302—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to change their surface-physical characteristics or shape, e.g. etching, polishing, cutting
    • H01L21/306—Chemical or electrical treatment, e.g. electrolytic etching
    • H01L21/3065—Plasma etching; Reactive-ion etching
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02107—Forming insulating materials on a substrate
    • H01L21/02296—Forming insulating materials on a substrate characterised by the treatment performed before or after the formation of the layer
    • H01L21/02299—Forming insulating materials on a substrate characterised by the treatment performed before or after the formation of the layer pre-treatment
    • H01L21/02312—Forming insulating materials on a substrate characterised by the treatment performed before or after the formation of the layer pre-treatment treatment by exposure to a gas or vapour
    • H01L21/02315—Forming insulating materials on a substrate characterised by the treatment performed before or after the formation of the layer pre-treatment treatment by exposure to a gas or vapour treatment by exposure to a plasma
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
    • H05H1/00—Generating plasma; Handling plasma
    • H05H1/24—Generating plasma
    • H05H1/46—Generating plasma using applied electromagnetic fields, e.g. high frequency or microwave energy

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Plasma & Fusion (AREA)
  • Drying Of Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Manufacturing & Machinery (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Plasma Technology (AREA)
  • Electromagnetism (AREA)
  • Spectroscopy & Molecular Physics (AREA)

Abstract

A method and apparatus for processing semiconductor wafers capable of stable end point detection are provided.
A plasma processing apparatus or process for treating a film layer to be processed of a film structure including a plurality of film layers previously formed on the surface of a wafer placed on a sample table disposed in a treatment chamber inside a vacuum container by using plasma formed in the treatment chamber The intensity of the light of a plurality of wavelengths is detected by using data obtained by synthesizing the results obtained by receiving light of a plurality of wavelengths from the inside of the treatment chamber during a plurality of periods of the light receiving unit .

Figure P1020150126202

Description

TECHNICAL FIELD [0001] The present invention relates to a plasma processing method and a plasma processing apparatus,

The present invention relates to a plasma processing apparatus for processing a sample of a substrate shape such as a semiconductor wafer in a semiconductor integrated circuit or the like by using a plasma formed in the processing chamber by disposing a sample in a processing chamber in a vacuum chamber, The present invention relates to a plasma processing apparatus for detecting an end point of a process or detecting a state or a process characteristic in a process chamber during a process using the result of detection of light emission.

BACKGROUND OF THE INVENTION In the manufacture of semiconductor wafers, dry etching is widely used in the removal or patterning of layers of various materials formed on the surface of wafers and in particular layers of dielectric materials. In this dry etching apparatus, an etching gas introduced into a vacuum processing chamber is converted into an ion or a radical by plasma, and the ion or radical is reacted with a film to be treated on the wafer, thereby etching the film to be processed.

During the dry etching process of the semiconductor wafer, the emission intensity of the specific wavelength in the plasma light changes with the progress of the etching of the film to be treated. As a method of detecting the end point of etching of a semiconductor wafer, there has heretofore been known a method of detecting a change in the light emission intensity of a specific wavelength from a plasma during a dry etching process, and detecting, based on the detection result, There is a method of detecting an etching end point.

In a dry etching process for a low-aperture-ratio wafer having a small exposed area of a material to be etched, the change of the light emission intensity at the etching end point becomes weak. Further, at the etching end point, the emission intensity of the wavelength of the reaction product generated by etching the etched material is reduced.

On the other hand, the emission intensity of the wavelength of the etching gas (etchant) increases. A method of increasing the slight intensity change at the etching end point by dividing the emission intensity of the wavelength of the reaction product and the emission intensity of the wavelength of the etchant is known in Patent Document 1 and the like.

In this prior art 1, in the etching process in which the change of the light emission intensity at the etching end point of the low opening ratio wafer or the like is weak, a signal in which the light emission intensity increases at the etching end point and a signal in which the light emission intensity decreases are divided, Is increased.

Japanese Unexamined Patent Publication No. 2011-9546

However, in the above-mentioned prior art, problems have arisen due to insufficient consideration of the following points. That is, when a signal having a small intensity level of light emission is compared with a large signal, the component of the noise included in the signal indicating the spectrum at an arbitrary wavelength or frequency is relatively large for electrons. Therefore, when the difference between the signal intensity at which the light emission intensity increases at the end point of the etching and the signal intensity at which the light emission intensity decreases is remarkably large, for example, in the light emission at the time of etching the low- A change in the intensity of the light emission adversely affects the noise, and it becomes difficult to accurately detect this.

It is an object of the present invention to provide a semiconductor wafer processing method capable of accurately detecting a weak signal intensity change at an etching end point and performing stable end point detection even when the difference in light emission intensity is large, And to provide a processing apparatus.

The object of the present invention can be achieved by a plasma processing method for processing a film layer to be processed of a film structure including a plurality of film layers formed on a surface of a wafer placed on a sample table in a treatment chamber inside a vacuum chamber, And a detector for detecting the intensity of the light of the plurality of wavelengths from the output of the light receiver, wherein the plurality of different photodetectors And detecting the intensity of the light of the plurality of wavelengths by using the data obtained by synthesizing the results of the light reception in each of the periods.

It is also possible to place a wafer on a sample table disposed in a treatment chamber inside a vacuum chamber and form a plasma in the treatment chamber to treat a film layer of a film structure including a plurality of film layers formed in advance on the surface of the wafer The intensity of the light having a plurality of wavelengths is detected using data obtained by synthesizing the results obtained by receiving light of a plurality of wavelengths from the inside of the treatment chamber during a plurality of periods And the like.

In the etching using light emission of two or more wavelengths at the end point detection, end point can be stably detected at a high S / N even when the difference in light emission intensity is large.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram schematically showing a configuration of a plasma processing apparatus according to an embodiment of the present invention. Fig.
Fig. 2 is a diagram showing the setting of the time shown in Fig. 1 and the prior art spectroscope receiving light from the inside of the processing chamber. Fig.
Fig. 3 is a graph showing a spectrum detected using light from inside the treatment chamber in the embodiment shown in Fig. 1; Fig.
Fig. 4 is a flow chart schematically showing the flow of processing for synthesizing the detected spectra in the embodiment shown in Fig. 1;
5 is a graph showing an example of a spectrum obtained as a result of the processing shown in Fig.
Fig. 6 is a graph schematically showing optical waveforms of a plurality of wavelengths before and after the end point of the treatment obtained in the conventional technique. Fig.
Fig. 7 is a graph schematically showing optical waveforms of a plurality of wavelengths before and after the end point of the process obtained by using the synthesis process related to the embodiment shown in Fig.
8 is a longitudinal sectional view schematically showing the outline of the configuration of a plasma processing apparatus according to another embodiment of the present invention.
Fig. 9 is a graph schematically showing the optical waveforms before and after the end point of the process for the light of a certain wavelength in the spectrum detected by the plasma processing apparatus according to the embodiment shown in Fig. 8;

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

[Example 1]

Hereinafter, the present invention will be described based on the embodiment shown in Figs. 1 to 7. Fig.

The plasma processing apparatus according to this embodiment is shown in Fig. Fig. 1 is a schematic view schematically showing a configuration of a plasma processing apparatus according to an embodiment of the present invention.

The plasma processing apparatus 1 of the present embodiment has a vacuum processing chamber 2 disposed inside a vacuum container and a substrate 4 in the form of a substrate such as a semiconductor wafer to be processed, And a sample bed (5).

The etching gas introduced from the gas introducing means (not shown) in the vacuum processing chamber 2 is an electric field such as a microwave generated by electric field forming means such as waveguide, flat plate or coil antenna, Or by a magnetic field generating means such as a solenoid coil and excited by a magnetic field supplied into the treatment chamber to separate or decompose the plasma 3 to form a plasma 3. A plurality of masks including a mask previously formed on the upper surface of the object to be processed 4 such as a semiconductor wafer on the sample bed 5 by charged particles in the plasma 3 formed in the vacuum processing chamber 2 and particles having high activity excited by the sample Is subjected to an etching treatment.

Light emitted from the excited particles in the plasma 3 passes through a window made of a transparent member arranged in a vacuum container constituting a side wall of the vacuum processing chamber 2 and is received by an externally disposed light receiver, Passes through the optically connected optical fiber 11, and is introduced into the spectroscope 12. In the spectroscope 12, the light emission of the incident plasma is, for example, spectroscopically measured at a predetermined interval in the range of 200 nm to 800 nm, and then transmitted by a light sensor (not shown) receiving light for each divided wavelength And converted into a digital signal representing the intensity of the light of that wavelength.

These signals indicating the intensity of light for each of a plurality of wavelengths are transmitted to the spectrum synthesizer 14 and are calculated by synthesizing the intensities of light of a specific wavelength spectrum using the intensities of a plurality of wavelengths. A signal indicating the intensity of the spectrum of the plurality of wavelengths including the intensity of the calculated light of the wavelength is transmitted to the wavelength decider 15 and a plurality of wavelengths used for detecting the end point determined in advance from the recipe or the like are extracted therefrom. The signal output as the sampling signal in the wavelength determiner 15 is stored as a time-series data yi in a storage device such as a RAM (not shown).

The time series data yi is smoothed by the digital filter 16 and stored as a smoothed time series data Yi in a storage device such as a RAM. The smoothed time-series data Yi is converted by the differentiator 17 into time-series data di of unmeasured values (primary differential values or secondary differential values) and stored in a storage device such as a RAM.

Here, the calculation of the non-coefficient time series data di will be described. As the digital filter circuit 16, for example, a low-pass filter of the second-order Butterworth type is used. The smoothed time-series data Yi is obtained by the second-order Butterworth-type low-pass filter by Expression (1).

Yi = b1.multidot.yi + b2.multidot.yi-1 + b3.multidot.yi-2- [a2.multidot.Yi-1 + a3.multidot.Yi-2] (One)

Here, the coefficients an and bn (n = 1 to 3) are multipliers whose numerical values differ depending on the sampling frequency and the cutoff frequency. For example, in the case of a sampling frequency of 10 Hz and a cutoff frequency of 1 Hz in this example, a2 = -1.143, a3 = 0.4128, b1 = 0.067455, b2 = -0.013491 and b3 = 0.067455.

The time series data di of the second order coefficient value is calculated from the equation (2) using the polynomial fitting smoothing differentiation method of the time series data Yi of, for example, five points in the differentiator 17 as follows.

Figure pat00001

In the above example, the weighting coefficients wj (j = -2 to 2) are w-2 = 2, w-1 = -1, w0 = -2, w1 = -1, w2 = 2. In the above example, the calculations of the differentiator 17 use a polynomial smoothing differentiation method, but a difference method may also be used.

It is judged by the end point judging device 18 whether or not the secondary differential value (or the first differential value) obtained by the differentiator 17 satisfies a predetermined condition such as a recipe or the like. When it is judged that the condition is satisfied, the display unit 19 displays the detection of the end point and is communicably connected with each of the detectors and the movable parts provided in the plasma processing apparatus 1 to control the operation of the movable part To the controller (7). The controller 7 that has received the communication calculates the command signal necessary for terminating the next processing step of the subject 4 or the processing of the subject 4 and supplies it to the gas introducing means, To a plasma forming means such as a solenoid coil.

In the process of etching the film structure on the wafer having the low opening ratio as the object to be processed 4, the change in the intensity of the light emission from the plasma at the end point of the etching becomes relatively small. In some cases, the ratio of intensity to noise (SN ratio) becomes as small as to make it difficult to detect a change in intensity of light emission.

Also, at the end point of the etching, the intensity of the light emission of the wavelength of the reaction product generated by etching the film material symmetrical to the etching treatment on the object to be processed 4 is also reduced. On the other hand, the emission intensity of the wavelength of the etching gas (etchant) increases. It is generally known that the waveform change at the etching end point can be increased by dividing the emission intensity of the wavelength of the reaction product and the emission intensity of the wavelength of the etchant.

Here, a configuration for detecting the end point in the conventional technique will be described with reference to Figs. 2, 3, and 6. Fig. Fig. 2 is a view showing the setting of the time when the spectroscope of the embodiment shown in Fig. 1 and the prior art receives light from the inside of the processing chamber. Fig. 3 is a graph showing an example of spectra detected by the embodiment shown in Fig. 1 and the light from the inside of the treatment chamber of the conventional spectroscope. FIG. 6 is a graph schematically showing optical waveforms of a plurality of wavelengths before and after the end point of the process obtained in the conventional technique. FIG.

FIG. 2B is a diagram showing the setting of the time for the conventional spectroscope to receive light from the inside of the processing chamber. That is, in the conventional technique, data relating to light emission obtained as a result of continuous reception of spectral data of emission in the spectroscope 12 by dividing the period is detected, and Fig. 2 (b) (Referred to as " accumulation time " in the figure) as a unit in which the light receiving sensor of the spectroscope receives the light emission, which fluctuates with the elapse of the processing time during the processing of FIG.

As shown in FIG. 2 (b), in the conventional technique, the light emission is continuously received at the same accumulation time B, and the emission spectrum is continuously acquired at the accumulation time B to detect a change in the emission spectrum of the plasma. Here, the accumulation time of a multi-channel spectroscope using a CCD sensor or the like will be described.

In the multi-channel spectroscope 12, the light sensor receives light at a predetermined wavelength of light emitted from the spectroscopic plasma during the accumulation time, so that charges are accumulated inside the sensor or the circuit, It is output after the end of time. The predetermined amount of charge for each wavelength can be represented by, for example, a wavelength as a luminescence spectrum shown in Figs. 3 (a) and 3 (b). The relationship between the accumulation time and the amount of charge output is approximately proportional to the accumulation time, and the amount of output charge doubles when the accumulation time is doubled.

Fig. 3 (b) shows an example of the spectrum obtained from the light emission during the etching process in the prior art. In Fig. 3 (b), the emission intensity increases at wavelength 1 at the etching end point and the emission intensity decreases at the wavelength 2 at the etching end point.

Fig. 6 is a graph schematically showing optical waveforms of a plurality of wavelengths before and after the end point of the process obtained in the conventional technique shown in Figs. 2 and 3. Fig. In these drawings, the graph on the left is a graph showing the values of the light emission intensity, and the graph on the right is a graph showing the values obtained by second differentiating the data in the graph on the left.

As shown in Fig. 6 (a), the light intensity of the spectrum of wavelength 1 includes noise and increases or decreases with time, and the value slightly increases at the end point of etching. On the other hand, as shown in Fig. 6 (b), the intensity of the spectrum of the wavelength 2 decreases and decreases with the change of time including the noise and decreases slightly at the etching end point.

A temporal change in the intensity of light of these two wavelengths divided by time is shown in the left drawing of Fig. 6 (c). For the sake of convenience, the divided data is normalized to 30000 counts as shown in Fig. 6 (c). The second-order differential value of the divided data is shown on the right-hand side of FIG. 6 (c).

In these drawings, it can be considered that the change of the etching end point occurs at 10 seconds as indicated by the line of the smoothed arrow. If the maximum value of the second derivative at this etching end point is defined as a signal, the signal is 273.9. The value before 10 seconds can be defined as the noise amount, and the noise amount is 170.6. Therefore, the S / N (SN ratio) of the secondary differential value in this etching process is 1.6.

These parameters are summarized in FIG. 6 (d) and shown in the table. Normally, according to the examination by the inventors, the criterion of S / N (SN ratio) that can stably perform end point detection is 4.0 or more. According to this standard, it is impossible to detect such a stable end point in the conventional technique.

Next, the structure of the detection of the end point of the etching process in this embodiment will be described with reference to Figs. 2A, 3, 4, 5, and 7. Fig.

3 (b) shows the spectrum detected from the plasma emission during the etching process. In Fig. 3 (b), the emission intensity increases at wavelength 1 at the etching end point and the emission intensity decreases at the wavelength 2 at the etching end point. Further, the emission intensity at wavelength 1 is high and the wavelength 2 is relatively low. Since the noise in the circuit in the spectroscope 12 does not depend on the intensity of the emission of the plasma, the ratio of the noise to the signal of the wavelength spectrum detected by the optical sensor and outputted in the spectroscope 12, It is known that the S / N ratio is low.

Thus, in this example, in order to increase the light emission intensity of the wavelength 2, the accumulation times of other plural values are alternately repeated to detect the intensity of light emission in the spectroscope 12. 2 (a), in the spectroscope 12, the relatively long accumulation time A and the short accumulation time B are alternately repeated in succession to receive light from the processing chamber by the optical sensor.

Fig. 3 (a) shows the result of detecting light emission using the light receiving pattern shown in Fig. 2 (a). As shown in Fig. 3 (a), the intensity of the emitted light is high at the wavelength 2, and the S / N ratio is good. However, if the period of the accumulation time A becomes longer than the predetermined value, as shown in the same figure, the value of the spectrum of the wavelength 1 exceeds the limit of the charge that can be accumulated in the photosensor, there was.

As shown in the figure, the saturated output is the data of the frequency or wavelength region representing a constant value at the maximum value on the output data, and the intensity of the light having the wavelength which is higher than the maximum value The value is not displayed and is not displayed. In the present embodiment, the data that are detected by using the result of spectroscoping the output of the unrepresented output or the output of the non-output value of the light received by the spectroscope 12 at a different accumulation time, for example, a shorter period of time , Or by synthesizing them.

Thus, in the present embodiment, the accumulation time A and the accumulation time B are alternately repeated, and light is continuously received and detected, and the distribution of the intensity of the spectrum corresponding to each accumulation time is acquired. That is, the data of the spectrum distribution shown in each of FIGS. 3A and 3B is detected.

In the present embodiment, in the spectrum synthesizer 14, from the data of the spectrum of the intensity of light emission in the other period obtained during this same process, the spectrum of each of the other wavelengths such as the wavelength 1 with high emission intensity and the wavelength 2 with high emission intensity A signal having a different intensity of light emission in the same process is detected. Further, by using these emission spectra, a synthesized spectrum synthesized by supplementing the saturated region of the emission spectrum (spectrum A) in which the signal of the intensity of the wavelength 1 is saturated in the accumulation time A is calculated.

The calculation algorithm of the synthesis spectrum will be described with reference to Fig. Fig. 4 is a flow chart schematically showing the flow of processing for synthesizing the spectrum detected in the embodiment shown in Fig.

First, after the process starts in step 401, the light emission from the plasma in the process chamber in the accumulation time A is received by the light receiver and the light emission spectrum A is detected (step 402). Next, the emission spectrum B is detected in the accumulation time B following the accumulation time A (step 403).

Next, the saturated regions in the emission spectra A and B are detected (Step 404). Thereafter, in step 405, the spectral ratios of both of them are obtained from the emission spectra A and B. [

As a method of calculating the spectral ratio, a ratio of a peak having a high emission intensity which is not saturated in the emission spectra A and B is used. Alternatively, the ratio of the average value of all or a part of the respective light emission intensities of the regions not saturated in the light emission spectra A and B may be used.

The intensity of the emission spectrum intensities A and B is compared at step 406 and the saturated spectrum of the stronger intensity spectrum is synthesized into a value obtained by multiplying the spectrum ratio obtained at step 405 by the spectrum having a lower intensity, (Steps 407 and 408).

Fig. 7 shows the intensities of the luminescence of a plurality of wavelengths in the synthesis spectrum and their ratios. 7 is a graph schematically showing optical waveforms of a plurality of wavelengths before and after the end point of the process obtained by synthesizing the spectrum related to the embodiment shown in Fig. 7A is a graph showing a temporal change (left figure) of the intensity value of the light emission of wavelength 1, FIG. 7B of wavelength 2, and FIG. 7C of wavelength 1 / Time derivative of the differential value (right drawing).

7 (a right side view of FIG. 7A), a second-order differential value of wavelength 2 (the right-side view of FIG. 7B), a second-order differential value of wavelength 1 / wavelength 2 (Right drawing of Fig. 7 (c)). In the left drawing and the right drawing of Fig. 7 (c), the change of the etching end point occurs at 10 seconds. If the maximum value of the second derivative at this etching end point is defined as a signal, the signal is 236.2. The value before 10 seconds can be defined as the noise amount, and the noise amount is 45.3. Therefore, the S / N of the second derivative value at this etching is 5.2.

These parameters are summarized in the table as (d) in Fig. As described above, it is understood that the standard of the S / N capable of stably performing the end point detection is 4.0 or more, and the present etching can stably detect the end point.

In the above embodiment, the spectrum of the light emission is detected in the spectroscope 12, but the present invention is not limited to this configuration, and a signal indicating the amount of charge accumulated by the optical sensor of the spectroscope 12 The spectrum synthesizer 14 that has received the signal may have a function of detecting the spectrum before synthesis based on this. Even if the user of the plasma processing apparatus 1 can arbitrarily set using a pointing device such as a computer terminal having a display device (not shown), the accumulation time can be set by the device controller 7 ) May be set according to data such as a predetermined algorithm or table.

As described above, when the end point detection is performed using two or more wavelengths having different light emission intensities, the multiplication times of the CCD sensors are set so that the light emission intensity of each wavelength becomes large (more than half of the saturation capacity) The S / N ratio (SN ratio) in the temporal change of the emission intensity of the wavelength is improved and the end point can be detected at a high S / N ratio (SN ratio) by dividing them.

Further, by synthesizing and calculating spectra, the emission spectra A and B during the etching process can be combined into one spectrum. This makes it possible to reduce the storage area in the main storage device such as the HD (not shown).

[Example 2]

Next, another embodiment of the present invention will be described with reference to Figs. 8 and 9. Fig. 8 is a longitudinal sectional view schematically showing the outline of the configuration of a plasma processing apparatus according to another embodiment of the present invention. Fig. 9 is a graph schematically showing the optical waveforms of a plurality of wavelengths before and after the end point of the process obtained by synthesizing the spectrum related to the embodiment shown in Fig.

The plasma processing apparatus 801 shown in Fig. 8 has the same configuration as that of the plasma processing apparatus 1 shown in Fig. In the embodiment shown in Fig. 1, the output from the spectrum synthesizer 14 is transmitted to the wavelength determiner 15, and the result that the transmitted data is differentiated is transmitted to the end point judging device 18 to determine the end point, The present invention is not limited to this. In the present embodiment, a removable disk drive such as a hard disk drive or CD-ROM or a removable disk drive such as a RAM or a flash ROM, which is communicably connected to the spectrum synthesizer 14, And a data storage device 802 having a storage device such as a device. The output from the spectrum synthesizer 14 is transmitted to the data storage device 802, and the data of the received signal is stored in the internal storage device.

Also in this example, in the spectrum synthesizer 14, one synthesis spectrum is calculated using the spectrum of a plurality of wavelengths detected by receiving the light or the signal indicating the intensity thereof at different times. The data retainer 802 that has received the signal indicating the synthesized spectrum output from the spectrum synthesizer 14 stores the data of the signal in a storage device such as an auxiliary storage device such as a hard disk or a RAM or the like.

In this example, data obtained by acquiring time-series data of a plurality of wavelengths from the spectroscope 12 is referred to as OES data, and data of a predetermined spectrum of the composite spectrum in the OES data is used to determine An analysis is made on the characteristics and conditions of the processing using the state or the plasma. The area (opening) of the object to be processed on the semiconductor wafer gradually decreases with the high integration and complexity of the semiconductor device, and the area of the object to be processed on the semiconductor wafer The change in the intensity of the light and the distribution of the wavelengths becomes very small. Under such conditions, particularly in the case of analyzing the OES data to detect minute changes, the S / N ratio of the light emission data of each wavelength is very important in increasing the accuracy thereof.

In this example as well, as in the embodiment shown in Fig. 1, the spectroscope 12 outputs the amount of charge occupied by the spectroscopic plasma light for the specified accumulation time. This charge quantity is shown, for example, as an emission spectrum shown in Figs. 3 (a) and 3 (b).

The relationship between the accumulation time and the output charge amount is approximately proportional to each other, and when the accumulation time is doubled, the output charge amount is also doubled. In this example as well, the accumulation times A and B of different lengths are received repeatedly for a predetermined number of times for each of a plurality of wavelengths of light obtained by spectroscopy in the spectroscope 12, and spectra A and B corresponding thereto are detected do. 3, the spectrum A detected is that the intensity of the light of the wavelength 1 is saturated, the wavelength 2 is not saturated, and the spectrum B is that the intensity of the light is not saturated in both the wavelengths 1 and 2.

With reference to FIG. 9, a temporal change of data indicating the intensity of light of wavelength 2 among a plurality of wavelengths constituting the spectrum detected by this embodiment will be described. Fig. 9 is a graph schematically showing an example of optical waveforms before and after the end point of the processing in which the plasma processing apparatus according to the embodiment shown in Fig. 8 detects light of a certain wavelength in the spectrum. Fig.

An example of the temporal change in the intensity of the light of the predetermined wavelength 2 received at the accumulation time A is shown on the left side of Fig. The temporal change in the intensity of the light of the wavelength 2 received at the accumulation time B is shown on the right. 9 (a) and 9 (b) are graphs showing the intensity of light emission of the plasma and graphs showing the secondary differential values thereof, respectively.

In these figures, the change in the vicinity of 10 seconds on the horizontal axis is the end point (end point) of etching. The secondary differential was calculated in order to evaluate the change of the light emission in the preceding and succeeding periods including the end point and the ratio of the shaking (noise) component before 10 seconds. The result of calculating the S / N using the noise component and the change after 10 seconds as a signal component in the second derivative is shown in Tables 901 and 902 in the left and right sides of FIG. 9C, respectively Lt; / RTI > As shown in Tables 901 and 902 in the figure, the S / N ratio of the data related to the accumulation time A was 2.6, and the S / N ratio at the accumulation time B was 1.6.

Consider the case of using wavelength 1 and wavelength 2 for analysis. Since the noise of the circuit in the spectroscope 12 does not depend on the light emission intensity, a signal having a low light emission intensity has a large noise ratio and a low S / N ratio. Thus, in order to increase the emission intensity of the wavelength 2, when the emission spectrum A is obtained by increasing the accumulation time of the spectroscope, the emission intensity of the wavelength 2 is increased and the S / N ratio is improved compared with the wavelength 2 of the emission spectrum B, May be saturated.

2 (a), the accumulation time A and the accumulation time B are repeated to obtain two emission spectra A and emission spectra A corresponding to the respective accumulation times, as shown in Fig. 3, B is detected. Thus, it is possible to detect the OES data having both the data of the wavelength 1 having the strong light emission intensity and the data of the wavelength 2 having the high S / N.

When the two OES data acquired as described above are respectively stored as data, the storage data capacity is doubled. In the case where analysis is performed on the characteristics or conditions of the processing using the state or the plasma inside the vacuum processing chamber 2 during the processing using the data of the predetermined wavelength of the synthesized spectrum in the OES data, It is necessary to interpret data relating to the same intensity range.

Thus, in the present embodiment, one synthesized OES data is created from two or more OES data detected in different accumulation times in the spectroscope 12 as described above. The flow of processing for calculating such synthesized OES data is the same as the flowchart shown in Fig.

That is, after the process starts in step 401, the light emission from the plasma in the treatment chamber in the accumulation time A is received by the light receiver and the light emission spectrum A is detected (step 402). Next, the emission spectrum B is detected in the accumulation time B following the accumulation time A (step 403).

Next, the saturated regions in the emission spectra A and B are detected (Step 404). Thereafter, in step 405, the spectral ratios of both of them are obtained from the emission spectra A and B. [

As a method of calculating the spectral ratio, a ratio of a peak having a high emission intensity which is not saturated in the emission spectra A and B is used. Alternatively, the ratio of the average value of all or a part of the respective light emission intensities of the regions not saturated in the light emission spectra A and B may be used.

The intensity of the emission spectrum intensities A and B is compared at step 406 and the saturated spectrum of the stronger intensity spectrum is synthesized into a value obtained by multiplying the spectrum ratio obtained at step 405 by the spectrum having a lower intensity, (Steps 407 and 408).

As described above, when two or more wavelengths having different intensities of plasma emission are used to analyze the characteristics of processing and the state inside the processing chamber, it is preferable that the light emission intensity of the plurality of wavelengths is increased A plurality of emission spectrum intensities in which the accumulation time of the CCD sensor is set are acquired. With this configuration, a composite spectrum in which S / N is improved in temporal change of the light emission intensity of a plurality of wavelengths used for analysis is recorded as OES data.

By performing the luminescence analysis using this synthesis spectrum, analysis results with better accuracy can be obtained. By recording the synthesized spectrum as OES data, it is possible to reduce the storage area in a storage device such as a hard disk not shown.

1: plasma processing apparatus 2: vacuum processing chamber
3: Plasma 4:
5: sample bed 7: controller
11: optical fiber 12: spectroscope
13: Accumulation time setter 14: Spectrum synthesizer
15: wavelength determiner 16: digital filter
17: differentiator 18: end point determination device
19: Indicator
601: S / N result of the second derivative in the conventional method
701: S / N result of the second derivative value in the present invention

Claims (8)

There is provided a plasma processing apparatus for processing a film layer to be processed of a film structure including a plurality of film layers previously formed on the surface of a wafer placed on a sample table disposed in a treatment chamber inside a vacuum container using plasma formed in the treatment chamber ,
A photodetector for receiving light of a plurality of wavelengths from the inside of the processing chamber during the processing; a detector for detecting the intensity of light of the plurality of wavelengths from the output of the photodetector, And the intensity of light of the plurality of wavelengths is detected using data obtained by synthesizing the results. The method according to claim 1,
Wherein the detector detects a portion not detected from an output obtained from the light receiver in a long period of the plurality of periods from an output obtained from the light receiver in a short period of the plurality of periods, And the intensity of the light of the plurality of wavelengths is detected using the data obtained by synthesizing the detected result from the output obtained from the light receiver. 3. The method according to claim 1 or 2,
Wherein the light receiving unit receives light without saturating each of the lights of the plurality of wavelengths in one of the plurality of periods and receives light in the other period without saturating only one of the lights of the plurality of wavelengths. 3. The method according to claim 1 or 2,
And a determiner for determining an end point of the process using the intensity of the light of the plurality of wavelengths detected by the detector. A plasma processing method for processing a film layer of a film structure including a plurality of film layers formed in advance on the surface of the wafer by placing a wafer on a sample table disposed in a processing chamber inside a vacuum chamber and forming a plasma in the processing chamber In this case,
And a step of detecting the intensity of the light of a plurality of wavelengths by using the data obtained by synthesizing the results obtained by the light-receiving devices receiving light of a plurality of wavelengths from the inside of the treatment chamber during a plurality of different periods Plasma processing method. 6. The method of claim 5,
In this process, a portion not detected from an output obtained from the light receiver in a long period of the plurality of periods is detected from an output obtained from the light receiver in a short period of the plurality of periods, And detecting the intensity of the light of the plurality of wavelengths by using the data obtained by synthesizing the detection result from the output obtained from the light receiver. The method according to claim 5 or 6,
Wherein the light receiving unit receives light without saturation representing each of the lights of the plurality of wavelengths in one of the plurality of periods and receives light in the other period without saturating only one of the lights of the plurality of wavelengths. The method according to claim 5 or 6,
And determining an end point of the process using the detected intensity of the light of the plurality of wavelengths.
KR1020150126202A 2015-01-19 2015-09-07 Plasma processing method and plasma processing device KR101750001B1 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JPJP-P-2015-007360 2015-01-19
JP2015007360 2015-01-19
JPJP-P-2015-113580 2015-06-04
JP2015113580A JP6560909B2 (en) 2015-01-19 2015-06-04 Plasma processing method and plasma processing apparatus

Publications (2)

Publication Number Publication Date
KR20160089262A true KR20160089262A (en) 2016-07-27
KR101750001B1 KR101750001B1 (en) 2017-06-22

Family

ID=56513113

Family Applications (1)

Application Number Title Priority Date Filing Date
KR1020150126202A KR101750001B1 (en) 2015-01-19 2015-09-07 Plasma processing method and plasma processing device

Country Status (3)

Country Link
JP (1) JP6560909B2 (en)
KR (1) KR101750001B1 (en)
TW (1) TWI584376B (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10215704B2 (en) * 2017-03-02 2019-02-26 Tokyo Electron Limited Computed tomography using intersecting views of plasma using optical emission spectroscopy during plasma processing
JP6832800B2 (en) * 2017-06-21 2021-02-24 東京エレクトロン株式会社 Plasma processing equipment
WO2021181545A1 (en) * 2020-03-11 2021-09-16 株式会社日立ハイテク Plasma processing device or plasma processing method

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011009546A (en) 2009-06-26 2011-01-13 Toppan Printing Co Ltd Endpoint detecting device, dry etching device, and dry etching method

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57128823A (en) * 1981-02-02 1982-08-10 Shimadzu Corp Spectrum measuring device
JPS6111622A (en) * 1984-06-27 1986-01-20 Hitachi Ltd Spectrophotometer
JP3217581B2 (en) * 1994-02-25 2001-10-09 東京エレクトロン株式会社 Etching end point detection method
JP4227301B2 (en) * 1998-02-03 2009-02-18 東京エレクトロンＡｔ株式会社 End point detection method in semiconductor plasma processing
KR100426988B1 (en) * 2001-11-08 2004-04-14 삼성전자주식회사 end point detector in semiconductor fabricating equipment and method therefore
TW560080B (en) * 2002-09-12 2003-11-01 Winbond Electronics Corp A method for detecting the end point of plasma etching process by using matrix
US6982175B2 (en) * 2003-02-14 2006-01-03 Unaxis Usa Inc. End point detection in time division multiplexed etch processes
US8158526B2 (en) * 2006-10-30 2012-04-17 Applied Materials, Inc. Endpoint detection for photomask etching
JP2009231718A (en) * 2008-03-25 2009-10-08 Renesas Technology Corp Method for detecting dry etching endpoint

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011009546A (en) 2009-06-26 2011-01-13 Toppan Printing Co Ltd Endpoint detecting device, dry etching device, and dry etching method

Also Published As

Publication number Publication date
JP2016136607A (en) 2016-07-28
KR101750001B1 (en) 2017-06-22
TWI584376B (en) 2017-05-21
JP6560909B2 (en) 2019-08-14
TW201628086A (en) 2016-08-01

Similar Documents

Publication Publication Date Title
KR101123171B1 (en) Method and apparatus for measuring process parameters of a plasma etch process
KR100912748B1 (en) Method and apparatus for endpoint detection using partial least squares
US6969619B1 (en) Full spectrum endpoint detection
JP4724795B2 (en) End point detection method in time division multiplexed etch process
US6586262B1 (en) Etching end-point detecting method
US20130016344A1 (en) Method and Apparatus for Measuring Process Parameters of a Plasma Etch Process
KR101750001B1 (en) Plasma processing method and plasma processing device
KR101656745B1 (en) Plasma processing apparatus and driving method of plasma processing apparatus
TWI615901B (en) Plasma processing apparatus and plasma processing method
KR101901328B1 (en) Plasma processing device and plasma processing method
JP2015532544A (en) Plasma endpoint detection using multivariate analysis
US9865439B2 (en) Plasma processing apparatus
KR101582208B1 (en) Plasma processing device and plasma processing method
US20040200718A1 (en) Plasma processing method and apparatus
JP6804694B1 (en) Etching equipment, etching methods and detectors
TW540095B (en) Emission spectroscopic processing apparatus and plasma processing method using it
CN113646874B (en) Plasma processing apparatus and plasma processing method
KR102429079B1 (en) Plasma treatment method and wavelength selection method used for plasma treatment
JPH05172638A (en) Photo array sensor and image intensifier for spectral analyzer
JP3117355B2 (en) End point detection method for plasma processing
JP6177513B2 (en) Plasma processing equipment
JP2005340547A (en) Plasma treatment apparatus
KR20090046583A (en) Process monitoring method and proces monitoring apparatus
Ma et al. An analysis of noise on optical emission spectroscopy measurements
Westerman et al. Endpoint detection method for time division multiplex etch processes

Legal Events

Date Code Title Description
A201 Request for examination
E902 Notification of reason for refusal
E701 Decision to grant or registration of patent right
GRNT Written decision to grant