JP3927780B2 - Circuit board manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of manufacturing a circuit board such as a semiconductor substrate or a liquid crystal substrate, and in particular, fine particles suspended in a processing chamber (vacuum processing chamber) that performs processing such as thin film generation (film formation) and etching, The present invention relates to a circuit board manufacturing method having a function of performing in-situ measurement.
[0002]
[Prior art]
Starting with an etching apparatus, a process using plasma is widely applied to a semiconductor manufacturing process and a liquid crystal display substrate manufacturing process.
[0003]
As an example of a processing apparatus using plasma, there is a parallel plate type plasma etching apparatus shown in FIG. As shown in FIG. 26, this type of apparatus modulates the output voltage of the power amplifier 84 by a high frequency signal from a signal generator 83, distributes the high frequency voltage by a distributor 85, and arranges them in parallel in the processing chamber. For example, a semiconductor substrate (wafer) as an object to be processed with the active species is generated between the upper electrode 81 and the lower electrode 82, and plasma 71 is generated from the etching gas by discharge between the electrodes 81 and 82. W is etched. For example, a frequency of about 400 kHz is used as the high frequency signal.
[0004]
In the plasma etching apparatus, it is known that a reaction product generated by an etching reaction by plasma processing is deposited on the wall surface or electrode of the plasma processing chamber, and is peeled off to become floating fine particles with time. Yes. These floating fine particles fall on the wafer and become adhering foreign matter at the moment when the etching process is finished and the plasma discharge is stopped, causing circuit characteristic defects and pattern appearance defects. Ultimately, this causes a decrease in yield and a decrease in device reliability.
[0005]
A number of devices for inspecting foreign matter adhering to the wafer surface have been reported and put into practical use. However, these devices are used to inspect the wafer once extracted from the plasma processing apparatus, and it has been found that many foreign matters are generated. At that time, the processing of other wafers has already progressed, and there is a problem of a decrease in yield due to a large number of defects. Further, in the evaluation after the processing, the distribution of the generation of foreign matters in the processing chamber and the change with time are not known.
[0006]
Accordingly, there is a demand in the fields of semiconductor manufacturing, liquid crystal manufacturing, and the like for techniques for real-time monitoring of the contamination status in the processing chamber in-situ.
[0007]
The size of fine particles floating in the processing chamber is in the range of submicron to several hundred μm, but in the field of semiconductors that are highly integrated into 256 Mbit DRAM (Dynamic Random Access Memory) and 1 Gbit DRAM, circuit patterns The minimum line width of 0.25 to 0.18 μm continues to be miniaturized, and the size of foreign matter to be detected is also required to be on the order of submicrons.
[0008]
As conventional techniques for monitoring fine particles floating in a processing chamber (vacuum processing chamber) such as a plasma processing chamber, Japanese Patent Laid-Open Nos. 57-118630 (prior art 1) and Japanese Patent Laid-Open No. 3-25355 (prior art). 2), JP-A-3-147317 (Prior Art 3), JP-A-6-82358 (Prior Art 4), JP-A-6-124902 (Prior Art 5), JP-A-10-213539 ( The technique disclosed in the prior art 6) is mentioned.
[0009]
The prior art 1 includes means for irradiating the reaction space with parallel light having a spectrum different from the spectrum of the self-emission light in the reaction space, and fine particles generated in the reaction space upon receiving the parallel light. A vapor deposition apparatus having a means for detecting scattered light is disclosed.
[0010]
Further, in the prior art 2, in a fine particle measuring apparatus for measuring fine particles adhering to a substrate surface for a semiconductor device and floating fine particles using scattering by laser light, the wavelength is the same and the mutual positions are the same. A laser beam phase modulation unit that generates two laser beams modulated at a predetermined frequency having a phase difference, and an optical system that intersects the two laser beams in a space including the fine particles to be measured; A light detection unit that receives light scattered by fine particles to be measured in a crossed region of the two laser beams and converts the light into an electric signal, and the laser beam phase in the electric signal by the scattered light A fine particle measuring apparatus comprising: a signal processing unit that extracts a signal component whose frequency is the same as or twice as high as that of a phase modulation signal in a modulation unit and whose phase difference from the phase modulation signal is temporally constant. It is shown.
[0011]
Further, the prior art 3 includes a step of generating light scattered in the reaction vessel by scanning irradiation with coherent light, and a step of detecting light scattered in the reaction vessel, thereby A technique for measuring the contamination status in the reaction vessel by analyzing the scattered light is described.
[0012]
The prior art 4 includes laser means for generating laser light, scanner means for scanning an area in a reaction chamber of a plasma processing tool containing particles to be observed with the laser light, and particles in the area. A particle detector is described having a video camera for generating a video signal of scattered laser light and means for processing and displaying an image of the video signal.
[0013]
The prior art 5 includes a camera device for observing a plasma generation region in a plasma processing chamber, a data processing unit for processing images obtained by the camera device to obtain target information, and the data processing unit. A plasma processing apparatus comprising: a control unit that controls at least one of exhaust means, process gas introduction means, high-frequency voltage application means, and purge gas introduction means so as to reduce particles based on the information obtained in Are listed.
[0014]
The prior art 6 also includes a light transmitter for transmitting a light beam that irradiates across a measurement volume, a light detector and scattered light from the measurement volume and condensing the light to the light detector. And a detector configured to generate a signal representative of the intensity of light directed to the photodetector and to analyze the signal from the photodetector. A pulse detector connected to detect a pulse in the signal from the light detector, and corresponding to a plurality of irradiations with the beam a plurality of times while the fine particle moves in the measurement volume corresponding to the fine particle; A fine particle sensor is described that includes signal processing means including an event detector that identifies a series of pulses due to light scattered by the fine particles.
[0015]
[Problems to be solved by the invention]
Each of the above-described conventional techniques irradiates laser light from an observation window provided on the side surface of the processing apparatus, and from an observation window different from the laser irradiation observation window provided on the opposite side surface or other side surface, Laser forward scattered light and side scattered light are detected. Therefore, in the method for detecting the forward scattered light and the side scattered light, the irradiation optical system and the detection optical system are formed by different units, and two observation windows for attaching them are necessary. Axis adjustment and the like must also be performed by the irradiation / detection optical system, and handling is troublesome.
[0016]
Usually, an observation window on the side of a processing chamber such as a plasma processing chamber is provided in most models for monitoring plasma emission, etc., but only one observation window is provided. Not a few. Therefore, there is a problem that the conventional method that requires two observation windows cannot be applied to a manufacturing apparatus having a processing chamber that has only one observation window.
[0017]
Furthermore, in the conventional method for detecting the forward scattered light and the side scattered light, the irradiation beam irradiated to the processing chamber is rotated and scanned so as to observe the generation state of fine particles on the entire surface of the object to be processed such as a wafer. In some cases, a large number of observation windows and detection optical systems are required, which causes a significant cost increase. In addition, it is actually very difficult to provide a large number of observation windows and detection optical systems due to space factor limitations. Have difficulty.
[0018]
On the other hand, in the field of semiconductors that have been highly integrated into 256 Mbit DRAMs, and further to 1 Gbit DRAMs, the minimum line width of circuit patterns has been continually miniaturized to 0.25 to 0.18 μm, and the size of foreign matter to be detected Submicron orders are also required. However, in the prior art, since it is difficult to separate the fine particle scattered light and the plasma emission, the application is limited to observation of relatively large fine particles, and it is difficult to detect submicron-order fine particles.
[0019]
[Means for Solving the Problems]
The present invention has been made in view of the above points. According to the technology disclosed in the embodiments of the present invention, for example, a method for manufacturing a circuit board includes: generating plasma in a processing chamber; A step of performing a process of forming a thin film on or processing a thin film formed on the object to be processed, and generating intensity of plasma at a desired frequency while processing the object to be processed by generating plasma in the processing chamber Scanning and irradiating the processing chamber with laser light having a desired wavelength through the observation window, and receiving backscattered light that has been scattered by fine particles floating in the processing chamber by the irradiation and passed through the observation window. A step of detecting the frequency component from the received light signal obtained by receiving the light; a number of fine particles present in the region irradiated with the laser light in the processing chamber using the detected signal; , Step obtain information on the size and 該得 was the number of fine particles were constituted by the step of outputting information about the size.
[0020]
In addition, according to the technique disclosed in the embodiments of the present invention, a circuit board manufacturing method includes a step of applying a resist on a substrate, a step of exposing the resist applied on the substrate, and developing the exposed resist. An etching process comprising: forming a pattern on the substrate by etching the substrate on which the resist has been developed using a plasma etching apparatus; and performing an ashing process on the substrate on which the pattern has been formed. In the step of performing plasma etching, a plasma beam is generated through a window of the plasma etching processing apparatus when plasma is generated by the plasma etching processing apparatus and the substrate on which the resist is developed is etched. Scan and irradiate inside the processing equipment, And backscattered scattered light to be detected through the window portion by the fine particles suspended in the interior of the serial plasma etching apparatus.
[0021]
Further, according to the technique disclosed in the embodiments of the present invention, a circuit board manufacturing method includes a step of forming a thin film on a substrate, a step of applying a resist on the substrate on which the thin film is formed, and an exposure apparatus. A step of transferring a pattern formed on a mask by exposing the resist coated on the substrate to the resist, a step of developing the exposed resist using a developing device, and a substrate on which the resist is developed. In the step of forming the hole pattern in the thin film formed on the substrate by performing an etching process using a plasma etching apparatus, and the step of performing an ashing process on the substrate on which the hole pattern has been formed, A substrate on which the resist is developed by generating plasma in a plasma etching processing apparatus During the etching process, a laser beam is scanned and irradiated inside the plasma etching processing apparatus, and scattered light from fine particles floating inside the plasma etching processing apparatus is reflected from the wall surface of the plasma etching processing apparatus. Detection was performed separately from light.
[0022]
Furthermore, according to the technique disclosed in the embodiments of the present invention, a circuit board manufacturing method includes a step of loading a substrate having a resist pattern formed on a surface thereof in a plasma etching apparatus, and the step of loading the substrate. A step of evacuating the inside of the plasma etching apparatus to introduce a processing gas under a controlled flow rate and setting the pressure to a desired pressure; applying high-frequency power to the electrode of the plasma etching apparatus to generate plasma in the plasma etching apparatus; A step of etching a substrate having a resist pattern formed on the surface by the generated plasma, and a window portion of the plasma etching apparatus during etching of the substrate by the plasma. A laser beam is scanned and irradiated into the plasma etching apparatus. The step of detecting backscattered light from fine particles floating inside the plasma etching apparatus through the window, and the introduction of the processing gas is stopped and the processing gas is exhausted from the plasma etching apparatus. After that, the substrate is unloaded from the plasma etching apparatus.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to FIGS.
Each embodiment of the present invention described below shows an application example to a parallel plate type plasma etching apparatus used in a plasma dry etching apparatus, but the scope of the present invention is not limited to this. However, the present invention can be applied to thin film production (film formation) devices such as sputtering devices and CVD devices, or various thin film processing devices such as ECR etching devices, microwave etching devices, and ashing devices.
[0024]
First, a plasma etching apparatus according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a diagram showing a configuration of an etching processing apparatus 1 having a plasma suspended fine particle measuring apparatus according to the first embodiment.
[0025]
As shown in FIG. 1, in the etching processing apparatus 1, the output voltage of the power amplifier 84 is modulated by the high frequency signal from the signal generator 83, and this high frequency voltage is distributed by the distributor 85 to be parallel to each other in the processing chamber 5. Is applied between the upper electrode 81 and the lower electrode 82 disposed on the substrate, and plasma 71 is generated from the etching gas by the discharge between the electrodes 81 and 82. Wafer) W is etched. For example, 400 kHz is used as the high-frequency signal.
[0026]
The apparatus for measuring suspended fine particles in plasma is mainly composed of a laser illumination optical system 2000, a scattered light detection optical system 3000, and a signal processing system 6000, and an irradiation light exit in the laser illumination optical system 2000 and the scattered light detection optical system 3000. The detector / detection light entrance is disposed so as to face the observation window 10 provided on the side surface of the processing chamber 5.
[0027]
In the laser illumination optical system 2000, first, an S-polarized beam 101 emitted from a laser light source 21 (for example, a YAG second harmonic laser; wavelength 532 nm) is incident on an AO (Acousto-Optical) modulator 22. For example, a rectangular wave signal having a frequency of 170 kHz, preferably a duty of 50%, output from the oscillator 23 is applied to the AO modulator 22, and the intensity of the laser beam (S-polarized beam) 101 is modulated with the frequency. Here, in this embodiment in which the high-frequency voltage applied to the electrode of the etching processing apparatus is 400 kHz, the laser intensity modulation frequency may be 400 kHz and the frequency 170 kHz different from the harmonic components 800 kHz, 1.2 MHz, etc. The reason will be described later.
[0028]
The intensity-modulated beam 102 is reflected by the polarization beam splitter 24 and the galvanometer mirror 25 and guided into the processing chamber 5 through the observation window 10 provided on the side surface of the processing chamber 5. Here, by rotating the galvanometer mirror 25 and scanning the beam in a plane parallel to the wafer surface, it becomes possible to detect fine particles on the entire surface immediately above the wafer.
[0029]
As shown in FIG. 2A, the observation window 10 is provided with an inclination that forms the Brewster angle θB1 with respect to the incident beam 102 that is P-polarized light. It becomes zero for the incident beam 102 which is the upper P-polarized light. Here, the Brewster angle θB1 is expressed by θB1 = tan˜1 (n2 / n1) (n1: air refractive index, n2: refractive index of the glass material of the observation window), and the laser wavelength is 532 nm. When the glass material of the window 10 is synthetic quartz (refractive index of 1.46 at 532 nm), θB1 = 55.6 °. Similarly, θB2 = 34.4 ° for θB2. In addition, as shown in FIG. 2B, the observation window 10 has a curved shape so as to always have the same inclination with respect to the incident beam 102 when the incident beam 102 is rotated and scanned by the rotation of the galvanometer mirror 25. Is formed.
[0030]
The beam 103 guided into the processing chamber 5 is scattered by the floating fine particles 72 in the plasma. Of the fine particle scattered light, the back scattered light propagating on the same optical axis as the beam 103 passes through the observation window 10 and is reflected by the galvanometer mirror 25 and travels toward the polarization beam splitter 24. Of this backscattered light, only the P-polarized light component transmitted through the polarization beam splitter 24 is collected by the imaging lens 31.
[0031]
The collected scattered light is separated into two beams 201 and 202 by the beam splitter 42 and specified by the CCD camera 41 and the bundle fiber 33 in order to specify the size and generation position of the fine particles.
[0032]
The beam 201 that has passed through the beam splitter 42 passes through the interference filter 40 having the transmission center wavelength at the laser wavelength (532 nm), and after the wavelength separation of the fine particle scattered light from the plasma emission, is imaged by the CCD camera 41. FIG. 3 is a simplified representation of how the scattered light is imaged by the CCD camera 41. As shown in FIG. 3A, the image forming relationship between 73a in front of the wafer and the incident surface of the CCD camera 41 is shown. Since the image of the scattered light from the wafer center 73b and the wafer depth 73c is defocused, as shown in FIG. 3B, the image obtained for the scattered light from the same fine particles The size is different. Therefore, information serving as a clue to know where the fine particles are generated can be obtained from the captured image. However, it cannot be distinguished from fine particles having different sizes. Therefore, the fine particle size is determined from the signal obtained by the method described below and the imaging signal.
[0033]
The beam 202 reflected by the beam splitter 42 is condensed on the incident surface of the bundle fiber 33 by the imaging lens 31. As shown in FIG. 4, the center 73b of the wafer and the incident surface of the bundle fiber 33 are in an imaging relationship, but the fiber bundle region (light receiving region) of the incident end surface is from the defocused wafer ends 73a and 73c. The size of the scattered light is also detectable. Therefore, backscattered light from fine particles from the front to the back of the wafer can be detected with the same sensitivity. Further, since the scattered light generated on the inner wall of the processing chamber 5 forms an image in front of the light receiving surface of the bundle fiber 33, a spatial filter 36 is installed at the image forming position to shield the light. The output end of the bundle fiber 33 is connected to a spectroscope 34 such as a monochromator or an interference filter set to a laser wavelength, and after wavelength separation of backscattered light from fine particles from plasma emission, the photoelectric conversion element 35 performs photoelectric separation. Converted.
[0034]
The photoelectrically converted detection signal is amplified by the amplifier 50 having a band sufficiently wider than the laser modulation frequency, and then the frequency of 170 kHz output from the oscillator 23 used for intensity modulation of the laser light by the lock-in amplifier 51, and the duty Synchronous detection is performed using a 50% rectangular wave signal as a reference signal, and a backscattered light component from a fine particle having a frequency of 170 kHz is extracted from the detection signal.
[0035]
The inventors of the present application have verified by experiment that the intensity of plasma emission is synchronized with the plasma excitation frequency. For example, the intensity of plasma emission is separated from the emission of plasma generated by the high-frequency power having the plasma excitation frequency of 400 Khz. The fine particle signal obtained by modulation and synchronous detection at a frequency of 170 kHz, which is different from the plasma excitation frequency and its integral multiple, is separated and detected from plasma emission in two regions of wavelength and frequency as shown in FIG. The The inventors of the present application have experimentally confirmed that back-scattered light from weak fine particles can be detected with high sensitivity from plasma emission by this modulation / synchronous detection method.
[0036]
That is, as shown in FIG. 5, the plasma emission is continuously distributed in the wavelength region, but discretely exists in the frequency region, and there is an empty region in the frequency region. Accordingly, for example, a laser beam having a wavelength of 532 nm is incident on the plasma processing chamber after being intensity-modulated at a frequency of 170 kHz, for example, different from the frequency of the plasma emission, and a wavelength of 532 nm component, a frequency of 170 kHz component, that is, a peak signal is detected. If only this is taken out, it becomes possible to detect the backscattered light from the fine particles separately from the plasma emission.
[0037]
Thus, in this embodiment, the influence of the reflected light from the surface of the observation window and the processing room wall scattered light, which can be a large noise in the backscattered light detection, is substantially eliminated, and further, by the modulation / synchronous detection method, It is possible to detect weak fine particle scattering signals with high sensitivity from plasma emission noise, which is a problem in detecting fine particles in plasma. In addition, by using the backscattered light detection, the laser illumination optical system and the scattered light detection optical system can be configured by one unit, and can be applied even to a processing apparatus having only one observation window 10. Compared with the case where the illumination optical system and the detection optical system are separated from each other, the optical axis adjustment and the like are facilitated, and the total optical system becomes compact.
[0038]
Here, it is said that many floating fine particles are present at the plasma-sheath interface, but the position of the plasma-sheath interface varies depending on processing conditions such as electrode spacing, and there are fine particles other than the plasma-sheath. Therefore, the laser illumination optical system 2000 and the scattered light detection optical system 3000 configured as one unit can be moved up and down obliquely in parallel with the inclination of the observation window 10 as shown in FIG. It is configured. By adopting such a configuration, it is possible to detect fine particles in different height regions in the plasma.
[0039]
The output of the lock-in amplifier 51 is sent to the computer 61. In the computer 61, the captured signal is displayed on the display one by one, for example, in the form as shown in FIG. Here, since the detection signal includes electrical noise NE generated by the amplifier 50, the lock-in amplifier 51, etc., threshold processing is performed at the time of display, and a signal equal to or lower than NE as shown in FIG. 7B. If 0 is set to 0 mV and only signals having a magnitude greater than NE are displayed, it is easy to determine the detection signal of the backscattered light from the fine particles.
[0040]
In the signal processing system 6000, the size, number, and generation position of the fine particles are determined from the detection signal intensity of the backscattered light from the obtained fine particles and the captured image of the CCD camera 41. Therefore, for the image captured by the CCD camera 41, a threshold value Ith is set for the lock-in amplifier output, and only when the signal intensity exceeds the threshold value Ith, fine particles are generated and an image is recorded. .
[0041]
Next, the computer 61 compares the signal intensity and captured image data for the particle diameter obtained by experiments in advance with the detected signal intensity and captured image of the backscattered light from the detected fine particles, and determines the size of the fine particles. Then, the occurrence position and the number of occurrences are determined, and the result is displayed on the display as shown in FIG.
[0042]
In this embodiment, since the beam can be scanned over the entire surface of the wafer by the galvanometer mirror 25, the computer 61 sends a scanning signal to the galvanometer mirror 25 via the galvano driver 29, and scans the beam while scanning the beam. If the detection signal and the image of the backscattered light from the fine particles at the position are captured in synchronism with the galvanomirror operation, in addition to the fine particle generation position before and after the wafer, as shown in FIG. The dimensional distribution can be grasped.
[0043]
Further, the computer 61 counts the number of generated fine particles to determine the contamination status in the processing chamber. When the total number of generated fine particles exceeds a preset reference value, the etching process is terminated. Further, if this is notified to the operator by an alarm or the like, the operator can perform operations such as cleaning the processing chamber based on the information.
[0044]
As described above, according to the present embodiment, the influence of reflected light from the surface of the observation window and scattered light from the processing room wall can be substantially eliminated in backscattered light detection, and further, the modulation / synchronous detection method is used. , By separating and detecting weak fine particle scattering signals from plasma emission noise, which is a problem in the detection of fine particles in plasma, detection sensitivity is improved, and it is expected to be difficult to detect with conventional methods. It is possible to detect fine particles of the order.
[0045]
In addition, according to the present embodiment, it is possible to detect weak fine particle scattered light in two regions of wavelength and frequency separately from the plasma emission, and the floating fine particles in the plasma as compared with the conventional wavelength separation-only method. The effect that the particle detection sensitivity is greatly improved is obtained, and the minimum detection sensitivity obtained in the case of only conventional wavelength separation is limited to about φ1 μm at most, but according to the method of the present invention, The minimum detection sensitivity can be improved to φ0.2 μm, and the effect of enabling stable fine particle detection over the entire wafer surface is produced. Note that the detection sensitivity can be further improved by shortening the laser wavelength, increasing the laser output, or simultaneously shortening the wavelength and increasing the output in order to increase the scattering intensity.
[0046]
In addition, according to the present embodiment, since the backscattered light detection is performed, the irradiation / detection optical system can be configured as a single unit, and can be easily installed and adjusted, and a small fine particle detection device can be configured. It becomes. In addition, since the backscattered light is detected, the irradiation beam can be rotated and scanned in the horizontal direction, and the two-dimensional distribution of fine particles can be easily grasped.
[0047]
Furthermore, in this embodiment, since the irradiation / detection optical system is configured to be able to slide obliquely up and down, different plasma regions can be observed and the vertical distribution of fine particles can be known. At this time, since the irradiation optical system and the detection optical system are constituted by one unit, the optical axis for irradiation / detection is not shifted even if it is slid, and readjustment is not necessary.
[0048]
Furthermore, according to the present embodiment, since the fine particle detection is performed on the entire surface of the wafer and the number, size, and distribution of the fine particles are determined, the operator can check the information on the display in real time.
[0049]
In addition, according to the present embodiment, the contamination status in the processing chamber can be determined in real time based on the information on the number of generated fine particles, the size, and the distribution, so that the cleaning time is optimized and the throughput is improved. As a result, it is possible to prevent the occurrence of defective defects (occurrence of a large number of defects at a time), thereby improving the yield. In addition, since the processing can proceed while constantly monitoring the number of fine particles in the processing chamber, the semiconductor substrates and liquid crystal substrates manufactured in this way are of high quality manufactured in an environment that does not contain fine particles above the reference value. This makes it a highly reliable product.
[0050]
Further, according to the present embodiment, it is not necessary to judge the contamination status of the processing chamber using the dummy wafer or to determine the contamination status by sampling inspection, so that the cost of the dummy wafer can be reduced and the throughput can be improved.
[0051]
Next, 2nd Embodiment of this invention is described based on FIG. 9 and FIG.
FIG. 9 is a diagram showing a configuration of an etching processing apparatus 2 having a plasma suspended fine particle measuring apparatus according to the second embodiment.
[0052]
The plasma suspended fine particle measuring apparatus according to the present embodiment is assumed to be mounted on an etching processing apparatus already provided with an observation window 11 for the purpose of plasma emission observation and the like, and a Brewster angle is set on the observation window. This is an embodiment of an apparatus for measuring suspended fine particles in plasma, which is effective even when it has no special structure such as being provided, that is, when a large amount of reflected light is generated from the surface of the observation window.
[0053]
In the present embodiment, the irradiation / detection optical system of the plasma suspended fine particle measuring apparatus is mounted on the etching processing apparatus by attaching an attachment such as a base plate in the vicinity of the observation window 11 and mounting it via the attachment. Take measures such as. Further, similarly to the first embodiment described above, the illumination / detection optical system can move in the vertical direction on the attachment and can detect fine particles in plasma regions having different heights.
[0054]
Moreover, in the said 1st Embodiment, it became the structure which irradiates with P polarization | polarized-light and detects the S polarization component orthogonal to irradiation light among the backscattered light from a fine particle. However, in general, scattered light has the same polarization direction as incident light. Therefore, in the present embodiment, a configuration for extracting the same polarization direction component as the incident light is realized. Further, the polarization of the incident beam to the observation window is not limited to the P-polarized light as in the first embodiment.
[0055]
Since the plasma processing chamber and the processing method are the same as those in the first embodiment, description thereof will be omitted. Similarly to the first embodiment, using a modulation / synchronous detection technique, fine particle scattered light is detected separately from two regions of wavelength and frequency from the plasma emission, and the scattered light from the inner wall of the plasma processing chamber is Light is shielded by a spatial filter.
[0056]
The plasma suspended fine particle measuring apparatus in this embodiment is mainly composed of a laser illumination optical system 2001, a scattered light detection optical system 3001, and a signal processing system 6000.
[0057]
Since the signal processing system 6000 is the same as that of the first embodiment, the description thereof is omitted.
[0058]
In the second embodiment, the intensity-modulated P-polarized beam 102 passes through the polarization beam splitter 24, passes through the slit portion of the half-wave plate 27 provided with the slit, and then passes through the galvano mirror 25. It is guided into the processing chamber 5 through the observation window 11. The slit direction of the half-wave plate 27 is the direction shown in FIG. 10, in which the optical path of the observation window reflected light and the state of receiving scattered light are simplified.
[0059]
Backscattered light generated by the floating fine particles 72 in the plasma 71 passes through the observation window 11 and travels toward the half-wave plate 27 via the galvanometer mirror 25. Among them, the scattered light that has passed through the half-wave plate 27 shown by hatching in FIG. 10 is rotated by 90 ° to become S-polarized light, and is reflected by the polarization beam splitter 24 and detected by the scattered light detection optical system. The On the other hand, the directly reflected light from the front and back surfaces of the observation window 11 passes through the slit portion of the half-wave plate 27 and remains as P-polarized light, and is reflected by the polarization beam splitter 24. In the scattered light detection optical system, Not detected.
[0060]
Here, on the laser incident side of the observation window 11, it is possible to reduce the reflected light by applying an antireflection coating that minimizes reflection with respect to the wavelength, polarization, and incident angle of the incident beam. Become. Since the reception and imaging of the scattered light are the same as in the first embodiment, description thereof is omitted.
[0061]
The computer 61 includes a terminal for outputting the obtained information to a plasma processing apparatus and the like, and an input terminal for obtaining operation information such as a cumulative discharge time from the plasma processing apparatus, as in the first embodiment. The plasma processing apparatus can be monitored and controlled based on information obtained from the suspended fine particle measuring apparatus in plasma.
[0062]
As described above, according to the present embodiment, not only the same effects as those of the first embodiment can be obtained, but also when reflected light is generated in an observation window having no special structure, it is affected. Without being able to detect fine particle scattered light.
[0063]
Moreover, according to this embodiment, the fine particle scattered light of the same polarization direction as irradiation light can be detected, and the backscattered light signal from a fine particle can be detected more efficiently.
[0064]
Next, 3rd Embodiment of this invention is described based on FIG. 11 and FIG.
FIG. 11 is a diagram showing a configuration of an etching processing apparatus 2 having a plasma suspended fine particle measuring apparatus according to the third embodiment.
[0065]
As in the second embodiment, the apparatus for measuring suspended fine particles in plasma according to the present embodiment is assumed to be mounted on an etching processing apparatus that already has an observation window 11 for the purpose of plasma emission observation or the like. An embodiment of a device for measuring suspended fine particles in plasma that is effective even when there is no special structure such as providing a Brewster angle on the observation window, that is, when there is reflected light from the surface of the observation window It is.
[0066]
In the present embodiment, as in the second embodiment, the irradiation / detection optical system in the plasma suspended fine particle measuring apparatus is mounted on the etching processing apparatus by attaching an attachment such as a base plate to the observation window 11. A means such as mounting through the attachment is taken. Further, similarly to the first embodiment described above, the illumination / detection optical system can move in the vertical direction on the attachment and can detect fine particles in plasma regions having different heights.
[0067]
This embodiment is different from the second embodiment in that circularly polarized illumination and circularly polarized light are detected.
[0068]
Since the plasma processing chamber and the processing method are the same as those in the first embodiment, description thereof will be omitted. Similarly to the first embodiment, using the modulation / synchronous detection technique, the backscattered light from the fine particles is detected separately from the plasma emission in two regions of wavelength and frequency, and scattered from the inner wall of the processing chamber. Light is blocked by a spatial filter.
[0069]
The plasma suspended fine particle measuring apparatus according to the present embodiment mainly includes a laser illumination optical system 2002, a scattered light detection optical system 3002, and a signal processing system 6000.
[0070]
Since the signal processing system 6000 is the same as that of the first embodiment, the description thereof is omitted.
[0071]
Similar to the first and second embodiments, the intensity-modulated P-polarized beam 102 passes through the polarization beam splitter 24, becomes a circularly polarized beam 104 by the quarter-wave plate 26, and is observed through the galvanometer mirror 25. It is guided into the processing chamber 5 through the window 11.
[0072]
FIG. 12 is a simplified representation of the optical path of the observation window reflected light and the state of scattered light reception.
As shown in FIGS. 11 and 12, the backscattered light generated by the suspended fine particles 72 in the plasma 71 passes through the observation window 11 and travels toward the quarter-wave plate 26 via the galvanometer mirror. The scattered light that has passed through the quarter-wave plate 26 again is rotated by 90 ° and becomes S-polarized light. Therefore, the scattered light is reflected by the polarization beam splitter 24 and detected by the scattered light detection optical system. On the other hand, the directly reflected light from the front and back surfaces of the observation window also passes through the quarter-wave plate 26, becomes S-polarized light, is reflected by the polarization beam splitter 24, and travels toward the scattered light detection optical system. Therefore, the spatial filter 36 is installed in front of or behind the imaging lens 31 to shield the observation window reflected light.
[0073]
Here, on the laser incident side of the observation window 11, as in the first and second embodiments, an antireflection coating 15 is applied so as to minimize reflection with respect to the wavelength and incident angle of the incident beam. Yes, the reflected light can be reduced.
[0074]
As described above, in the present embodiment, the suspended microparticle measurement apparatus in plasma similar to the second embodiment can be configured by circularly polarized illumination and circularly polarized light detection.
[0075]
Also in this embodiment, as in the second embodiment, operation information such as terminals for outputting information obtained by the signal processing system to the plasma processing apparatus and the like, and cumulative discharge time from the plasma processing apparatus are also obtained. If the input terminal for obtaining is provided, the plasma processing apparatus can be monitored and controlled by the suspended fine particle measuring apparatus in plasma.
[0076]
As described above, according to the present embodiment, similarly to the second embodiment, even when reflected light is generated in an observation window having no special structure, the circularly polarized illumination / circle is not affected by the reflected light. Fine particle scattered light can be detected by polarization detection.
[0077]
Moreover, according to this embodiment, since circularly polarized illumination and circularly polarized light detection are performed, fine particle scattered light can be detected more efficiently than in the first embodiment.
[0078]
Next, 4th Embodiment of this invention is described based on FIG. 13 and FIG.
FIG. 13 is a diagram showing a configuration of an etching processing apparatus 2 having a plasma suspended fine particle measuring apparatus according to the fourth embodiment.
[0079]
The plasma suspended fine particle measuring apparatus in the present embodiment is mainly composed of a laser illumination optical system 2003, a scattered light detection optical system 3003, and a signal processing system 6000.
[0080]
This embodiment differs from the third embodiment in that, in the third embodiment, the reflected light from the observation window is shielded by using a spatial filter, whereas in the present embodiment, a straight line is used. The light is shielded by using a polarizing plate. Since this embodiment has exactly the same effect as the third embodiment, only portions different from the third embodiment will be described.
[0081]
Similar to the third embodiment, the intensity-modulated P-polarized beam passes through the polarization beam splitter 24, passes through the linearly polarizing plate 28 installed so as to pass the P-polarized light, and then enters the quarter wavelength plate 26. Becomes circularly polarized light and is guided into the processing chamber 5 through the observation window 11 through the galvanometer mirror 25.
[0082]
FIG. 14 is a simplified representation of the optical path of observation window reflected light and the state of scattered light reception.
[0083]
As shown in FIGS. 13 and 14, the backscattered light generated by the suspended fine particles 72 in the plasma 71 passes through the observation window 11 and travels toward the quarter-wave plate 26 through the galvanometer mirror. The scattered light that has passed through the quarter-wave plate 26 is rotated by 90 ° and becomes S-polarized light, and is reflected by the polarizing beam splitter 24 except for a small area that is shielded by the linearly polarizing plate 28. It is detected by the scattered light detection optical system.
[0084]
On the other hand, the directly reflected light from the front and back surfaces of the observation window 11 passes through the quarter-wave plate 26 and becomes S-polarized light and is shielded by the linearly polarizing plate 28. Therefore, also in the present embodiment, the observation window reflected light is not detected as in the third embodiment.
[0085]
Also in this embodiment, as in the second and third embodiments, a terminal for outputting information obtained by the signal processing system to a plasma processing apparatus, a cumulative discharge time from the plasma processing apparatus, etc. If an input terminal for obtaining the operation information is provided, the plasma processing apparatus can be monitored and controlled by the plasma suspended fine particle measuring apparatus.
[0086]
As described above, according to the present embodiment, similarly to the second and third embodiments, even if the reflected light is generated in the observation window without having a special structure, it is fine without being affected. Backscattered light from particles can be detected.
[0087]
Moreover, according to this embodiment, since circularly polarized illumination and circularly polarized light detection are performed, backscattered light from fine particles can be detected more efficiently than in the first embodiment.
[0088]
Next, as a fifth embodiment of the present invention, FIG. 15 to FIG. 23, FIG. 29, and FIG. 15 show the detection method and apparatus configuration in consideration of the influence of the reflected light from the inner wall surface of the processing chamber. 30 will be used for explanation.
[0089]
FIG. 15 shows an etching apparatus 1006 and a suspended fine particle measuring apparatus in plasma according to the fifth embodiment. The plasma suspended fine particle measuring apparatus includes a laser irradiation optical system 2000, a scattered light detection optical system 3000, and a signal processing / control system 6000.
[0090]
As shown in FIG. 15, in the etching apparatus 1006, the output voltage of the power amplifier 84 is modulated by the high frequency signal from the signal generator 83, this high frequency voltage is distributed by the distributor 85, and parallel to each other in the plasma processing chamber 86. Applied between the arranged upper electrode 81 and lower electrode 82, plasma 71 is generated from the etching gas by discharge between both electrodes, and the semiconductor wafer 70 as an object to be processed is etched by the active species.
[0091]
As the high frequency signal, for example, about 400 kHz is used. In the etching process, the progress of etching is monitored, the end point thereof is detected as accurately as possible, and the etching process is performed for a predetermined pattern shape and depth. When the end point is detected, the output of the power amplifier 83 is stopped, and the semiconductor wafer 70 is discharged from the plasma processing chamber 86.
[0092]
In the laser illumination optical system 2000, first, the S-polarized beam 101 emitted from the laser 21 (for example, YAG second harmonic laser; wavelength 532 nm) 21 is expanded by the collimating lens 16 and then the semiconductor by the focusing lens 17. The light is condensed at the center of the wafer 70. For example, as shown in FIG. 18, when the incident light aperture to the focusing lens 17 is 3 mm and the focal length of the focusing lens 17 is 2000 mm, the beam spot at the center on the φ300 mm wafer is obtained by a well-known geometrical optical equation. Can generate a focused beam with a focal depth of 602 mm, with a diameter of 452 μm and a beam spot diameter of 565 μm at the front and back, and irradiates fine particles with a substantially uniform light energy density on a φ300 mm wafer It becomes possible.
[0093]
The condensed S-polarized beam 102 is reflected by the polarizing beam splitter 24, then converted to a circularly polarized beam 103 by passing through a quarter-wave plate 26, and then reflected by a galvano mirror 25 that is driven at a high speed. The light passes through the window 10 and enters the plasma processing chamber 87 to scan the entire surface of the semiconductor wafer 70. By scanning with the long focal depth beam, it is possible to irradiate the entire upper surface of the semiconductor wafer 70 with a substantially uniform energy density. The circularly polarized beam 103 is scattered by the suspended fine particles 72 in the plasma 71.
[0094]
Of the scattered light 201 from the fine particles, the backscattered light 202 scattered in the backward direction along the same optical axis as the incident beam is reflected by the galvanometer mirror 25, and the circularly polarized light component, which is a regular reflection component, is again a quarter wavelength plate. 26 is converted to P-polarized light, passes through the polarization beam splitter 24, and is focused on the incident end face of the optical fiber 33 by the imaging lens 31.
[0095]
Here, as shown in FIG. 16, by shifting the imaging lens 31 from the principal ray of the propagation optical axis of the backscattered light, the backscattering from the fine particles from the front a1, the center a2 and the back a3 of the semiconductor wafer 70. Light is not imaged on the same optical axis, but is imaged at different positions 1b, 2b and 3b. At this time, the light receiving end face of the bundle fiber 33 is formed in a multistage shape corresponding to the imaging points 1b, 2b, and 3b, so that the fine points from different points a1, a2, and a3 above the wafer 70 in the optical axis direction of the irradiation light can be obtained. It becomes possible to distinguish and detect the particle scattered light.
[0096]
Here, the size of the light receiving surface b1 of the multistage bundle fiber 33 is an area in which backscattered light from the defocused fine particles from the region 1A before and after the point 1a on the wafer can also be detected. Similarly, the sizes of the light receiving surfaces b2 and b3 of the multistage bundle fiber are respectively determined by backscattering from defocused fine particles from the region 2A before and after the point 2a on the wafer and the region 3A before and after the point 3a on the wafer. The area can detect light. Accordingly, along with high-speed scanning with a long focal beam, fine particle detection can be performed over the entire surface of the semiconductor wafer 70, and the fine particle generation region can be specified in three regions having different optical axis directions.
[0097]
As in this embodiment, when the laser wavelength is 532 nm and the fine particle diameter is smaller than about 10 μm, most of the polarization component of the backscattered light becomes equal to the polarization component of the incident light. Therefore, in the S-polarized illumination / P-circle light detection (P-polarized illumination / S-polarized light detection) widely known as the polarization separation method, the detection scattering intensity is remarkably lowered and the detection sensitivity is lowered. Thus, it becomes possible to suppress the fall of the detection sensitivity accompanying the reduction | decrease in a fine particle diameter by setting it as circularly polarized illumination and circularly polarized light detection. Note that the direct reflected light and scattered light from the irradiation point 4a on the processing chamber wall surface 86 are not detected because they are imaged on the point 4b outside the light receiving surface of the multistage bundle fiber 33 by shifting the detection optical axis.
[0098]
This is also one of the features of the present invention. As shown in FIG. 17, when the detection optical axis is not shifted, the imaging point 4c of directly reflected light or scattered light from the irradiation point 4a of the processing chamber inner wall 86 is The spatial filter 36 is used to shield the directly reflected light and scattered light from the irradiation point 4a of the processing chamber inner wall 86 because it is located in the light beam of backscattered light from fine particles from the sky 1a or the like of the semiconductor wafer 70 to be detected. Etc. at the same time, part of the backscattered light from the fine particles is shielded and the detection sensitivity is lowered, but when the detection optical axis is shifted as in the present invention, the detection sensitivity There is no reduction in One of the features of the present invention is that the direct reflected light from the fine particle observation window 10 is not incident on the optical fiber by tilting the observation window 10 and shifting the reflection optical axis from the detection optical axis.
[0099]
It is also possible to reduce the reflected light intensity by applying an antireflection coating to the observation window. The exit end of the fiber 33 corresponds to the light receiving end face of the multi-stage bundle fiber 33 and is similarly divided. The output end of the multi-stage bundle fiber 33 is connected to the interference filter 40, and the same wavelength component (532 nm) as the laser light is extracted, and the three-dimensional one-dimensional sensor 37 distinguishes the detection light from each output end face to generate an electrical signal. Therefore, it is possible to specify fine particle generation regions in three regions having different irradiation optical axis directions.
[0100]
Instead of the three-channel one-dimensional sensor 37, a three-channel parallel output type photodiode array may be used. Also, as shown in FIG. 29 and FIG. 30, the light that has passed through the interference filter 40 is not directly received by the multistage bundle fiber, but is directly received by the three-channel one-dimensional sensor 37 or the three-channel parallel output type photodiode array. It is also good. Detection signals from the respective channels of the three-channel one-dimensional sensor are amplified by the three-channel amplifier unit 37 in the signal processing / control system 6000 and then sent to the computer 62. In the computer 61, a scanning control signal 401 is sent to the galvanometer mirror 25 via the galvano driver 29, and the intensity of backscattering from fine particles at each scanning position is displayed on the display 62 while scanning the beam 103.
[0101]
19 to 21 show display examples on the display 62. FIG. FIG. 19 shows the change of the detection signal for each scan, that is, the change of time, in the central region of the wafer, with 9 lines of irradiation light on a 300 mm wafer. When scattered light is generated by suspended fine particles in the plasma, a large signal on the pulse appears as shown at three points in the figure. The size of the fine particles can be determined from the intensity of these pulse signals.
[0102]
As shown in FIG. 20, when the difference between the output at the n-th scanning and the output at the (n-1) -th scanning is taken at each detection position, the DC component of the background noise is canceled, and always Similarly, it is possible to reduce the fluctuation of the background noise that is fluctuating, and the determination of the fine particle signal is facilitated. When the etching is finished and the wafer 70 is discharged from the processing chamber, the measurement is finished. Measurement data is recorded on a wafer basis. It is also possible to output measurement data to the outside and sequentially monitor the contamination status of the processing chamber plasma processing chamber 87 using the external output signal 402.
[0103]
In the present embodiment, the multistage bundle fiber has three stages, but the number of stages is not limited to three, and an arbitrary number of stages of two or more can be selected. The position resolution in the direction of the optical axis is, for example, 100 mm for a φ300 mm wafer when the number of stages is three in the performance of this embodiment, but is 30 mm if the number of bundle fiber stages is 10 and the number of signal processing channels is 10, for example. Thus, the position resolution in the optical axis direction can be improved by increasing the number of stages.
[0104]
If the number of stages is increased and the position resolution in the optical axis direction is increased, as shown in FIG. 21, the generation position of fine particles is specified from the position data of the scanning illumination beam and the fine particle generation position data in the irradiation optical axis direction, It is also possible to determine the size of the fine particles based on the signal intensity and to map the fine particle generation distribution and size on the wafer. It is possible to estimate the behavior of fine particles from the fine particle mapping data for each scan, and it is possible to obtain information for specifying the fine particle generation position in the processing chamber based on the data. Furthermore, it is possible to take measures for reducing fine particles in the processing chamber based on the information.
[0105]
Further, the bundle number and the bundle shape of the bundle fiber 33 are not limited to the shape and the number shown in FIG. 16, and it is obvious that any shape and number can be selected.
[0106]
Furthermore, in the present embodiment, as shown in FIG. 16, the case where the imaging lens 31 is shifted upward with respect to the wafer has been described, but it is obvious that the imaging lens 31 can also be shifted downward. Furthermore, as shown in FIG. 22, when the imaging lens 31 is shifted in a direction parallel to the wafer surface, the same effect can be obtained, and the direction in which the axis of the imaging lens 31 is shifted is arbitrary. Direction can be selected. Also, it is possible to obtain the same effect as that of shifting the axis by tilting the imaging lens.
[0107]
Furthermore, as in the present embodiment, by performing backscattered light detection, irradiation and scattered light detection can be performed through one observation window, so it is possible to configure the irradiation optical system and the detection optical system in one unit, It is also one of the features of the present invention that a small optical system can be configured. Conversely, by shifting the irradiation optical axis and the detection optical axis, the illumination optical system and the scattered light detection optical system can be configured separately as shown in FIG.
[0108]
According to the present invention, by using a long-focus beam scanning, an off-axis imaging optical system, and a multistage bundle fiber, it is possible not only to realize substantially uniform energy illumination and uniform sensitivity detection over the entire wafer surface, but also over the entire wafer surface. The effect that it becomes possible to specify the generation | occurrence | production position of a fine particle is acquired.
[0109]
This enables real-time monitoring of the contamination status in the etching apparatus processing chamber, thereby reducing the occurrence of defective wafers due to adhering foreign matter and the effect of accurately grasping the apparatus cleaning time.
[0110]
Moreover, since the frequency of the advance check work using the dummy wafer can be reduced, the effects of cost reduction and productivity improvement are born.
[0111]
Furthermore, since the position where the fine particles are generated can be specified, the fine particle generation source can be specified by estimating the behavior of the fine particles, so that it is possible to obtain effective information for measures for reducing the fine particles.
[0112]
A sixth embodiment of the present invention will be described with reference to FIG. In this embodiment, in the signal processing control system, a gain adjuster is provided at the subsequent stage of each output of the three-channel synchronous detection unit. Since the configuration and function of the optical system are the same as those in the fifth embodiment, description thereof is omitted.
[0113]
According to the present embodiment, the same effect as the fifth embodiment described above can be obtained,
As described in the first embodiment, it is possible to separate and detect backscattered light from weak fine particles in two regions of wavelength and frequency from the plasma emission, and the conventional method using only wavelength separation. In comparison, the detection sensitivity of floating fine particles in plasma can be greatly improved, and fine particles with a diameter of about 0.2 μm, which could not be detected by the conventional method, can be detected.
[0114]
Furthermore, according to the present embodiment, a decrease in detection intensity due to a decrease in energy density accompanying an increase in the diameter of the beam spot of the illumination light at the point 1a in front of the wafer over the wafer 70 and the point 2a at the back of the wafer is corrected. This makes it possible to detect fine particles with uniform sensitivity over the entire wafer surface.
Next, a seventh embodiment of the present invention will be described based on FIG. 25, FIG. 26 and FIG.
[0115]
First, the concept of a method for manufacturing a semiconductor integrated circuit device according to the present invention will be described with reference to FIGS.
[0116]
Step 1001 is a film forming step for forming a film to be processed 601 such as a silicon oxide film on the wafer W, and step 1002 is a film thickness measuring step for inspecting the thickness of the formed film. Step 1003 is a resist coating step for applying a resist 602 to the wafer W, and step 1004 is a pattern transfer step for transferring the mask pattern 603 onto the wafer. Step 1005 is a developing step for removing the resist in the processed portion. Step 1006 uses the resist pattern 604 as a mask to etch the processed film 601 in the resist removing portion 605 to form wiring grooves and contact holes 606. Etching process. Step 1007 is an ashing step for removing the resist pattern 604, and step 1008 is a cleaning step for cleaning the front surface and the back surface of the wafer. The series of steps is applied to the formation of contact holes, for example.
[0117]
In a normal semiconductor integrated circuit device, a multilayer structure is formed by repeating the series of steps.
[0118]
Next, the defect which arises when the fine particle which generate | occur | produced during the etching adheres to a wafer using FIG. FIG. 28 is a diagram illustrating an example of defects generated in, for example, contact hole etching.
A fine particle 701 indicates a fine particle attached to the contact hole opening during etching. In this case, since the etching reaction is stopped by the attached fine particles (foreign matter), the contact hole where the fine particles are attached becomes non-open and becomes a fatal defect.
[0119]
A fine particle 702 indicates a fine particle attached to the inside of the contact hole during the etching. Also in this case, since the etching reaction is stopped by the attached fine particles (foreign matter), the contact hole where the fine particles are attached becomes non-open and becomes a fatal defect.
[0120]
The fine particles 703 and the fine particles 704 indicate foreign matters attached to the inside of the contact hole after completion of etching. Foreign matter adhering to a portion with a high aspect ratio such as a contact hole is often difficult to remove even if it is washed. If the size is large, such as fine particles 703, contact failure occurs. It becomes a fatal defect.
[0121]
The fine particles 705 indicate foreign matters attached to the resist pattern 604 during the etching. In this case, the etching reaction is not affected at all by the attached fine particles 705, and no fatal defect is generated by the attached fine particles 705.
[0122]
In this way, even if fine particles are attached, if the size of the fine particles is not large enough to cause a defect, or if the attached portion is a non-etched region, it does not become a fatal defect, and the fine particles are not attached to the wafer. Not all of them will cause fatal defects. In addition, the fine particles 701 and 705 are foreign matters that are relatively easy to remove by cleaning, whereas foreign matters that fall into contact holes with a high aspect ratio, such as fine particles 602, fine particles 703, and fine particles 704. Is difficult to remove by washing.
[0123]
In the present invention, in the etching step 1006, the fine particles generated in the processing chamber during the etching are detected in real time by the plasma floating fine particle measuring apparatus 1100, and the processed wafer is next processed based on the fine particle detection result. It is selected whether to proceed to the next process and proceed with the processing of the remaining wafers sequentially, to perform an appearance inspection before sending to the next process, or to stop the process and perform cleaning (maintenance) in the processing chamber. Here, the process to be performed next was selected by comparing the size and number of detected fine particles with a preset standard value (fine particle management standard).
[0124]
Then, next, the example of the calculation method of the said standard value (fine particle management reference | standard) in a present Example is demonstrated. As already explained, even if fine particles adhere to the wafer, not all of them cause fatal defects. The probability of a fatal defect occurring due to the attached fine particles (foreign matter) can be obtained by calculation from the relationship between the opening ratio and pattern density of the etching pattern, the wiring width, and the size and number of attached fine particles. . Therefore, the correlation between the size and number of fine particles detected during the etching process and the size and number of fine particles (foreign matter) adhering to the wafer is obtained in advance through experiments, so that the fine particles detected during etching are obtained. The probability of causing a fatal defect can be obtained.
[0125]
The standard value (fine particle management standard) is set based on the value obtained by the above means. In the following, an example of setting a standard value in the present embodiment is shown.
[0126]
The standard value 1 is set so that the probability that a fatal defect will occur is very low (for example, the fatal defect occurrence probability is 1% or less) if the number of detected fine particles of a certain size or more is less than the specified value 1. To do. For example, the standard value 1 is 10 fine particle diameters of 0.4 μm or more.
[0127]
The standard value 2 is such that if the number of detected fine particles of a certain size or more is greater than the standard value 1 and smaller than the specified value 2, the value of which a critical defect is likely to occur (for example, a critical defect is generated). Probability 5% or less). For example, the standard value 2 is 30 fine particle diameters of 0.4 μm or more.
[0128]
If the number of detected fine particles of a certain size or more is the specified value 2 or more, many fatal defects are generated (for example, a fatal defect occurrence probability of 5% or more).
[0129]
On the basis of the standard value, if the number of fine particles detected during the etching process is smaller than the specified value 1, the probability that a fatal defect will occur is low. I do.
[0130]
If the number of fine particles detected during the etching process is greater than or equal to the specified value 1 but smaller than the specified value 2, an appearance inspection is performed after the etching process is completed. If no fatal defect is confirmed as a result of the visual inspection, the wafer is sent to the next ashing step 1007. If a fatal defect is confirmed as a result of the visual inspection, it is determined whether the fatal defect is a remedyable defect. If it is determined that the defect can be repaired (eg, using a repair circuit) based on the determination result, the wafer is sent to the next ashing step 1007. If it is determined that the defect cannot be repaired based on the determination result, the defect is recorded, and then the wafer is sent to the next ashing step 1007. Thereafter, for example, when each chip is cut out by dicing, the chip including the irreparable defect is eliminated.
[0131]
If the number of fine particles detected during the etching process is larger than the specified value 2, it is highly possible that a large number of fatal defects will occur on the wafer to be processed thereafter. The operator of the etching apparatus is displayed on the monitor screen or notified by an alarm so that the etching process is interrupted and the plasma processing chamber is cleaned (maintenance).
[0132]
In an etching processing apparatus that does not include a plasma suspended fine particle measuring apparatus, the processing chamber is not necessarily cleaned in an appropriate time. Therefore, cleaning is performed at a time when it is not necessary to clean, and the operation rate of the apparatus is reduced, or conversely, processing is continued even when the time to be cleaned has passed, resulting in a large amount of defective products and yield. It may be reduced.
[0133]
There is also a method of performing a prior work with a dummy wafer for checking fine particles in the processing chamber and determining the cleaning time from the result. In this case, extra work is performed during a series of steps, resulting in a decrease in throughput and a cost for dummy wafers. However, with the increase in wafer diameter, the cost of dummy wafers is inevitably increased, and the reduction of prior work by dummy wafers for checking fine particles in the processing chamber is also a big problem.
[0134]
On the other hand, according to the present embodiment, since the object to be processed can be processed while monitoring the contamination status in the processing chamber in real time, the cleaning time is optimized, and no prior work with a dummy wafer is required, so that the throughput is increased. The cost of the dummy wafer can be reduced. In addition, the product manufactured by the process of the present embodiment can manufacture a high-quality product that does not contain fine particles exceeding a specified value, and thus a highly reliable product.
In the above embodiment, the application example to the etching processing apparatus has been described. However, as described above, the scope of application of the present invention is not limited to this. Application to an apparatus or a film forming apparatus enables real-time monitoring of fine particles in the ashing apparatus and the film forming apparatus, thereby reducing defects caused by the ashing process and the film forming process during the photolithography process. Therefore, it is possible to prevent the occurrence of defective products and improve the yield.
[0135]
In an etching processing apparatus that does not include a fine particle monitoring apparatus (plasma suspended fine particle measuring apparatus 1100), the processing chamber is not necessarily cleaned in an appropriate time. Therefore, cleaning is performed at a time when it is not necessary to clean, and throughput is reduced, or conversely, processing is continued even when the time to be cleaned has passed, resulting in a large amount of defective products and reduced yield. Sometimes. There is also a method of performing a prior work with a dummy wafer for checking fine particles in the processing chamber and determining the cleaning time from the result. In this case, extra work is performed during a series of steps, resulting in a decrease in throughput and a cost for dummy wafers. However, with the increase in wafer diameter, the cost of dummy wafers is inevitably increased, and the reduction of prior work by dummy wafers for checking fine particles in the processing chamber is also a big problem.
[0136]
On the other hand, according to the present embodiment, since the object to be processed can be processed while monitoring the contamination status in the processing chamber in real time, the cleaning time is optimized, and no prior work with a dummy wafer is required, so that the throughput is increased. The cost of the dummy wafer can be reduced. In addition, the product manufactured by the process of the present embodiment can manufacture a high-quality product that does not contain fine particles exceeding a specified value, and thus a highly reliable product.
In the above embodiment, the application example to the etching processing apparatus has been described. However, as described above, the scope of application of the present invention is not limited to this. Application to an apparatus or a film forming apparatus enables real-time monitoring of fine particles in the ashing apparatus and the film forming apparatus, thereby reducing defects caused by the ashing process and the film forming process during the photolithography process. Therefore, it is possible to prevent the occurrence of defective products and improve the yield.
[0137]
According to the present invention, since the backscattered light detection is performed, the irradiation / detection optical system can be constituted by a single unit, and mounting and adjustment are simple, and a small fine particle detection apparatus can be realized.
[0138]
In addition, backscattered light detection does not detect reflected light from the surface of the observation window, which can cause significant noise, and scattered light from the inner wall of the processing chamber. Furthermore, it is weak due to plasma emission noise, which is a problem in detecting fine particles in plasma. Detects backscattered light signals from fine particles separately, improving detection sensitivity and enabling detection of fine particles on the order of submicron, which is expected to be difficult to detect with conventional methods. A device can be realized.
[0139]
In addition, the illumination light can be scanned, and the irradiation / detection optical system can be slid vertically, so that different plasma regions can be observed, and fine particle detection is performed on the entire surface of the wafer, and the number of fine particles. Thus, it is possible to know the size and distribution, and the operator can realize a fine particle detection apparatus capable of confirming the information on the display in real time.
[0140]
Furthermore, according to the present invention, since the contamination status in the processing chamber can be determined in real time based on the information on the number, size, and distribution of the generated fine particles, the cleaning time is optimally determined and high. Semiconductor devices can be produced with high throughput and high yield.
[0141]
In addition, since the processing can proceed while constantly monitoring the number of fine particles in the processing chamber, it can be applied to the production of a high-quality and highly reliable circuit board that does not contain fine particles exceeding the reference value.
[0142]
Next, an eighth embodiment of the present invention will be described with reference to FIGS.
First, before describing the eighth embodiment of the present invention, a method for manufacturing a semiconductor integrated circuit using a conventional technique will be described with reference to FIG. 32, for example, contact hole etching of 256 Mbit DRAM, 0.18 μm process and the like. A general process flow will be described by taking an oxide film etching process typified by a trench or via hole etching of a Cu dual damascene process employed in a high-speed CMOS LSI or the like as an example. In the process flow described below, in order to etch a non-processed film formed of a different material on the wafer surface, which can be performed using a parallel plate type oxide film etching apparatus UNITY-IEM manufactured by Tokyo Electron Co., Ltd. An etching process is used as an example in which two different processing processes are carried out in succession in a single process.
[0143]
First, in STEP 1, in order to perform a desired etching process, process parameters determined from calculation or experimental verification in advance corresponding to various process flows and taking into consideration the material of the non-processed film, the etching depth, and the like. From the stored list of process recipes, an appropriate process recipe is set by the operator.
[0144]
Next, in STEP 2, the temperature of the lower electrode on which the wafer is mounted is set. When the wafer is loaded in STEP3, in SETP4, as a process gas from the shower plate of the upper electrode, for example, C ₄ F ₈ And Ar and O ₂ Is supplied. In SETP5, after the gas is supplied in STEP4, when the pressure in the processing chamber reaches a stable state, for example, 4 [Pa], RF power is applied to generate plasma. In SETP6, the etching process is started by the plasma, and after a predetermined time, for example, 60 [s], is set in STEP7, for example, the etching process is completed in STEP8.
[0145]
Immediately after the completion of the etching process in STEP 8, the RF power is stopped in STEP 9, and then the purge gas is supplied in STEP 10 to remove the remaining process gas. At this time, some of the suspended fine particles are removed out of the processing chamber together with the purge gas. Thus, the first etching process is completed.
[0146]
Subsequently, a second etching process is performed. In STEP 11, as a process gas, for example, CF ₄ Is supplied. In SETP12, after the gas is supplied in STEP9, when the processing chamber pressure reaches a stable state, for example, 7 [Pa], RF power is applied to generate plasma. At SETP13, the etching process is started by the plasma, and after a predetermined time, for example, 30 [s], is set at STEP14, for example, 30 [s], the etching process is terminated at STEP15. Immediately after the end of the etching process in STEP 15, the RF power is stopped in STEP 16, and then purge gas is supplied in STEP 17 to remove the remaining process gas. At this time, some of the suspended fine particles are removed out of the processing chamber together with the purge gas. Thus, the second etching process is completed, and the wafer is unloaded.
[0147]
In the process flow, the gas flow rate, the RF power, etc. are constantly monitored by the mass flow controller 10001 and the RF power controller 10002 attached to the etching apparatus, and when the monitoring result deviates from the set value, The supply of process gas and the application of RF power are stopped, and the etching process is stopped.
[0148]
On the other hand, FIG. 31 shows an improved process flow of the prior art shown in FIG. In the new process flow described below, the same elements having the same configuration and performance as those of the prior art process flow are given the same numbers. The difference from the prior art shown in FIG. 32 is that a plasma suspended fine particle measuring apparatus shown in the first to seventh embodiments of the present application is newly provided. That is, from the time immediately before the process gas is supplied in STEP 1 to the step until the STEP 18 wafer is unloaded, and even when the plasma etching apparatus is in a standby state, the suspended fine particles in the process chamber are always present. Monitoring. The in-plasma suspended fine particle analyzer shown in the first to sixth embodiments of the present application is not a fine particle detection method that is effective only when plasma emission is present. It goes without saying that fine particles can be detected even in the case of not doing so.
[0149]
The suspended fine particle measuring apparatus in plasma is configured such that the mass flow controller 10001 and the RF power controller 10002 associated with the plasma etching apparatus can be controlled through a computer. That is, process control such as change of gas flow rate or change of gas type such as start and stop of RF power application, start and stop of gas supply, and the like is possible. In the computer, at least one fine particle information among the number of fine particles generated, the fine particle diameter, and the fine particle distribution from the plasma suspended fine particle measurement device is captured at each step and recorded in the database 610. Compared with fine particle management information that has been calculated or experimentally verified in advance, process control is performed based on the comparison result. In particular, in the Cu dual damascene process, the aperture ratio may reach 50%, and the allowable range due to the fine particles (foreign matter) adhering to the wafer is narrowed. Therefore, not only the fine particles generated during the process are detected. Based on the fine particle detection result, it is expected that it is essential to control the process.
[0150]
The characteristics (example of process control) of the method for manufacturing a semiconductor integrated circuit by providing the function of measuring suspended fine particles in plasma will be described below.
[0151]
The STEP 10 is a purge gas supply step, in which fine particles floating with the purge gas are exhausted are removed outside the processing chamber. That is, the number of fine particles in the processing chamber decreases with time. Here, the number of fine particles excluded by the purge gas, in other words, the number of fine particles floating in the processing chamber naturally varies depending on the contamination state in the processing chamber. In the present example having a function of measuring fine particles suspended in plasma, it was confirmed that fine particles floating in the processing chamber were sufficiently removed by exhausting the purge gas, and then proceeded to the next STEP11. . In the prior art, the purge gas is supplied for a preset time and proceeds to the next STEP 8. Therefore, before the fine particles are sufficiently eliminated, the process gas is supplied in STEP 11, and the fine particles are supplied into the processing chamber. There is a possibility that the second etching process may be performed in a state where there are many. On the other hand, according to the present embodiment, the etching process can be started from an initial state where the number of fine particles in the processing chamber is small.
[0152]
In STEP 3, when the wafer transfer port of the processing chamber is opened to load the wafer, a part of the deposited film formed at the wafer transfer port is peeled off due to factors such as friction. It is conceivable that the purge gas flow is disturbed in the space newly formed between the system and a part of the deposited film floats in the processing chamber. Therefore, if fine particles are detected when the transfer port is opened, the wafer is not immediately transferred into the processing chamber. For example, the wafer is kept on the transfer arm and the number of fine particles in the processing chamber is sufficient. After the decrease, the wafer was loaded and the etching processing after STEP 4 was performed.
[0153]
In the above two examples, the process flow at the time of switching each step is controlled based on the measurement result of suspended particles in plasma. However, the suspended particle measuring apparatus in the present invention is a floating particle generated in a processing chamber. It has a feature that fine particles can be detected in real time during plasma processing. Therefore, in STEP 6 to STEP 9 and STEP 12 to STEP 16, the fine particle management shown in the seventh embodiment can be performed based on the fine particle monitoring result during the etching process.
[0154]
Also, in any step, if a large amount of fine particles are detected and no measures are taken to prevent adhesion of fine particles to the wafer, the processing is immediately stopped and the etching apparatus The operator was informed to perform maintenance.
[0155]
Moreover, the process control which can be implemented is not limited to what was demonstrated above. That is, the relationship between the process of generating fine particles and the process captured by the computer is stored, and a new process control means can be appropriately added using the stored result as a database. Furthermore, not only the process control but also the setting value of the process condition can be changed when it is determined that the setting contents of the process recipe selected in STEP 1 should be changed prior to the wafer processing. . That is, according to the present embodiment, better process conditions can be found as processing is repeated.
[0156]
In an etching processing apparatus that does not include a fine particle monitoring apparatus (floating fine particle measurement apparatus 1100 in plasma), each processing step of the process flow cannot be started at an appropriate timing. The wafer has not been processed. The processing may be started in a state where fine particles are generated in the processing chamber, or the processing may be continued to produce a large number of defective products and reduce the yield.
[0157]
In addition, there is a means of performing a preliminary work with a dummy wafer for checking fine particles in the processing chamber, and knowing the state of fine particle generation in the processing chamber from the result, but in this case, it is not always necessary at the time of the preliminary work with the dummy wafer and the start of the product However, the state in the processing chamber is not always the same, and the process conditions cannot be directly controlled.
[0158]
On the other hand, according to the present embodiment, the contamination status in the processing chamber is monitored in real time for each processing step of the process flow based on the information on the number of generated fine particles, the size, and the distribution. Since the target object can be processed while changing the process conditions to the optimum values according to the contamination status in the processing chamber, and the timing for starting each processing step can be set, the process flow can be optimized. Since no prior work with a dummy wafer is required, the throughput is improved and the cost of the dummy wafer can be reduced. In addition, the product manufactured by the process of the present embodiment can manufacture a high-quality product that does not contain fine particles exceeding a specified value, and thus a highly reliable product.
In the above embodiment, the application example to the etching processing apparatus has been described. However, as described above, the scope of application of the present invention is not limited to this. Application to an apparatus or a film forming apparatus enables real-time monitoring of fine particles in the ashing apparatus and the film forming apparatus, thereby reducing defects caused by the ashing process and the film forming process during the photolithography process. Therefore, it is possible to prevent the occurrence of defective products and improve the yield.
[0159]
【The invention's effect】
As described above, according to the present invention, since the backscattered light detection is performed, the irradiation / detection optical system can be configured as a single unit, and mounting and adjustment are simple, and a small fine particle detection device can be realized.
[0160]
In addition, backscattered light detection does not detect reflected light from the surface of the observation window, which can cause significant noise, and scattered light from the inner wall of the processing chamber. Furthermore, it is weak due to plasma emission noise, which is a problem in detecting fine particles in plasma. Since the signal of the backscattered light from the fine particles is separated and detected, the detection sensitivity is improved, and it is possible to detect fine particles on the order of submicron, which is expected to be difficult to detect by the conventional method.
[0161]
In addition, the illumination light can be scanned, and the irradiation / detection optical system can be slid vertically, so that different plasma regions can be observed, and fine particle detection is performed on the entire surface of the wafer, and the number of fine particles. The size and distribution can be known, and the operator can confirm the information on the display in real time.
[0162]
Furthermore, according to the present invention, the contamination status in the processing chamber can be determined in real time based on the information on the number of generated fine particles, the size, and the distribution, so that the cleaning time is optimized and the throughput is improved. In addition to improvement, it is possible to prevent the occurrence of defective defects and improve the yield. In addition, since the processing can proceed while constantly monitoring the number of fine particles in the processing chamber, the circuit board manufactured in this way is a high-quality and highly reliable product that does not contain fine particles exceeding the reference value.
[0163]
Further, according to the present invention, it is not necessary to judge the contamination status of the processing chamber using the dummy wafer or the contamination status judgment by sampling inspection, so that the cost of the dummy wafer can be reduced and the throughput can be improved.
[0164]
Furthermore, according to the present invention, it is possible to detect the number and generation position of fine particles on the entire wafer surface by multi-stage detection with a long focal beam and off-axis, and the state of generation of floating fine particles in plasma compared to the conventional method. Detailed judgment can be made.
[0165]
In addition, it can be used in combination with a method that separates and detects backscattered light from weak fine particles in two regions of wavelength and frequency from plasma emission. Compared to the conventional method, it is possible to detect the number of fine particles and the generation position on the entire surface of the wafer, and the detailed determination of the state of occurrence of floating fine particles in the plasma can be performed stably. .
[0166]
Furthermore, by adding a gain adjustment function to the output section of each channel for multi-stage detection with shifted axes, it becomes possible to correct variations in detection sensitivity due to the difference in illumination beam irradiation energy, so that floating fine particles are uniformly distributed over the entire wafer surface. Can be detected stably with high detection sensitivity.
[0167]
These effects enable real-time monitoring of the contamination status in the etching chamber, reduce the generation of defective wafers due to attached fine particles (foreign matter), and enable the production of high-quality semiconductor elements, and the apparatus The effect of being able to accurately grasp the cleaning time is born.
[0168]
In addition, since the frequency of the prior work check operation for fine particles using a dummy wafer can be reduced, the effects of cost reduction and productivity improvement are produced. In addition, the production line can be automated.
[Brief description of the drawings]
FIG. 1 is a schematic front view showing a configuration of an etching processing apparatus having a suspended fine particle measuring apparatus in plasma according to a first embodiment of the present invention.
FIG. 2 is an explanatory diagram showing an observation window and a laser beam incident angle in the first embodiment of the present invention.
FIG. 3 is an explanatory view showing a state of imaging fine particle scattered light by a CCD camera in the first embodiment of the present invention.
FIG. 4 is an explanatory diagram showing a state of receiving fine particle scattered light by a bundle fiber in the first embodiment of the present invention.
FIG. 5 is an explanatory diagram showing a state of wavelength / frequency separation from plasma emission of fine particle scattered light in the first embodiment of the present invention.
FIG. 6 is an explanatory diagram showing a slide function of the illumination / detection optical system of the apparatus for measuring suspended fine particles in plasma according to the first embodiment of the present invention.
FIG. 7 is an explanatory diagram illustrating a detection signal, a signal after threshold processing, and a display example on a display according to the first embodiment of the present invention.
FIG. 8 is an explanatory diagram showing a display example of a detection signal, a fine particle size and the number of fine particles generated, and a two-dimensional distribution of fine particles in the first embodiment of the present invention.
FIG. 9 is an explanatory view showing a configuration of an etching processing apparatus having a suspended fine particle measuring apparatus in plasma according to a second embodiment of the present invention.
FIG. 10 is an explanatory diagram of an optical system for detecting fine particle scattered light in a second embodiment of the present invention.
FIG. 11 is an explanatory view showing a configuration of an etching processing apparatus having a suspended fine particle measuring apparatus in plasma according to a third embodiment of the present invention.
FIG. 12 is an explanatory diagram of an optical system for detecting fine particle scattered light in a third embodiment of the present invention.
FIG. 13 is an explanatory view showing a configuration of an etching processing apparatus having a suspended fine particle measuring apparatus in plasma according to a fourth embodiment of the present invention.
FIG. 14 is an explanatory diagram of an optical system for detecting fine particle scattered light in a fourth embodiment of the present invention.
FIG. 15 is a diagram showing an etching apparatus and a plasma suspended fine particle measuring apparatus in a fifth embodiment of the present invention.
FIG. 16 is a diagram showing the reception of scattered light by the off-axis detection optical system and the multistage bundle fiber in the fifth embodiment of the present invention.
FIG. 17 is a diagram illustrating reception of scattered light by an imaging optical system and a bundle fiber.
FIG. 18 is a diagram showing a beam spot size of a focused beam by a spherical lens over the wafer.
FIG. 19 is a diagram showing temporal changes in detected light intensity at nine points on a wafer in a fifth embodiment of the present invention.
FIG. 20 is a diagram showing temporal changes in fine particle signal intensity at nine points on a wafer in a fifth embodiment of the present invention.
FIG. 21 is a diagram showing the generation distribution and size of fine particles on the entire wafer surface in the fifth embodiment of the present invention.
FIG. 22 is a diagram showing a modified example of the reception of scattered light by the off-axis detection optical system and the multistage bundle fiber in the fifth embodiment of the present invention.
FIG. 23 is a diagram illustrating scattered light reception by a detection optical system and a multi-stage bundle fiber with the illumination optical system and the detection optical system separated from each other in the fifth embodiment of the present invention.
FIG. 24 is a diagram showing an etching apparatus and a plasma suspended fine particle measuring apparatus in a sixth embodiment of the present invention.
FIG. 25 is a schematic view of a manufacturing process of a semiconductor integrated circuit device in which an etching processing apparatus with a suspended fine particle measurement apparatus in plasma according to a seventh embodiment of the present invention is introduced along the flow of processing. It is explanatory drawing shown in.
FIG. 26 is an explanatory view schematically showing a process of forming a contact hole according to a seventh embodiment of the present invention, using a cross-sectional structure, along the flow of processing.
FIG. 27 is an explanatory view schematically showing an example of a defect caused by attached foreign matter in a contact hole etching process according to a seventh embodiment of the present invention.
FIG. 28 is an explanatory view showing a parallel plate type plasma etching apparatus.
FIG. 29 is a schematic front view showing the configuration of an etching processing apparatus having a suspended fine particle measuring apparatus in plasma according to the fifth embodiment of the present invention.
FIG. 30 is a diagram showing a modified example of the reception of scattered light by the off-axis detection optical system and the three-channel one-dimensional sensor in the fifth embodiment of the present invention.
FIG. 31 is a diagram showing an example of a process flow of oxide film etching according to the eighth embodiment of the present invention.
FIG. 32 is a diagram showing an example of an oxide film etching process flow using an etching apparatus having a suspended fine particle measurement apparatus in plasma according to the eighth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Etching apparatus 10 ... Observation window 21 ... Laser light source
22 ... A / O modulator 23 ... oscillator 24 ... polarizing beam splitter
33 ... Optical fiber 34 ... Spectroscope 35 ... Photoelectric conversion element
40 ... interference filter 41 ... CCD camera 42 ... beam splitter
50 ... Amplifier 51 ... Lock-in amplifier 61 ... Computer
601 ... Film to be processed 602 ... Resist 603 ... Mask pattern
604 ... resist pattern 605 ... resist removal section
606 ... Contact hole 2000 ... Laser irradiation optical system
3000 ... scattered light detection optical system 6000 ... signal processing system

Claims (14)

Generating plasma in the processing chamber to generate a thin film on the object to be processed in the processing chamber or processing the thin film generated on the object to be processed;
While processing the object to be processed by generating plasma in the processing chamber, a step of scanning and irradiating the processing chamber with a laser beam having a desired wavelength intensity-modulated at a desired frequency through an observation window When,
A bundle fiber in which the light receiving end face is formed in a multistage shape in the optical axis direction different from the optical axis of the laser light irradiated with the backscattered light scattered by the fine particles floating in the processing chamber by the irradiation and passed through the observation window. the method comprising the steps of: receiving in,
Detecting the frequency component from the received light signal obtained by receiving the light;
Obtaining information on the position and size of fine particles present in the region irradiated with the laser beam in the processing chamber using the detected signal;
And a step of mapping and outputting information on the position and size of the obtained fine particles. Wherein among the light receiving signal captured, obtained by receiving light with received by the wavelength separating the light of the wavelength components of the backscattered light is scattered passed through said observation window by the fine particles in the processing chamber The method further includes detecting a frequency component and determining at least one of a position and a size of the fine particle using a detection signal obtained by the detection and an image obtained by the imaging. A method for manufacturing a circuit board according to claim 1.   2. The method of manufacturing a circuit board according to claim 1, wherein the desired frequency is a frequency different from a frequency of an excitation source used for the thin film generation or processing and an integer multiple thereof. Applying a resist on the substrate;
Exposing a resist coated on the substrate;
Developing the exposed resist;
Forming a pattern on the substrate by etching process using a plasma etching apparatus a substrate by developing the resist,
Ashing the substrate on which the pattern is formed,
In the etching step,
A substrate developing the resist by generating plasma in the plasma etching apparatus when an etching treatment, the interior of the plasma etching apparatus that is generating the plasma of the laser beam through the window portion of the plasma etching apparatus Irradiates the light receiving end face in an optical axis direction different from the optical axis of the laser that irradiates the scattered light back-scattered by fine particles floating inside the plasma etching processing apparatus through the window portion. Detecting with a bundle fiber formed in a multi-stage shape, and creating mapping data of information on the position and size of fine particles existing in the region irradiated with the laser beam inside the plasma etching processing apparatus A method of manufacturing a circuit board. The laser beam producing method of the circuit board according to claim 4, characterized in that the intensity-modulated laser beam at a desired frequency to be irradiated by scanning the inside of the plasma etching apparatus. Forming a thin film on a substrate;
Applying a resist on the substrate on which the thin film is formed;
Transferring the pattern formed on the mask to the resist by exposing the resist applied on the substrate using an exposure apparatus; and
Developing the exposed resist using a developing device;
Forming a hole pattern in a thin film formed on the substrate by etching the substrate on which the resist has been developed using a plasma etching processing apparatus;
Ashing the substrate on which the hole pattern is formed,
In the step of performing the etching process, when the substrate on which the resist is developed by generating plasma in the plasma etching processing apparatus is etched, a laser beam is passed through the window of the plasma etching processing apparatus. The laser which scans and irradiates the inside, and irradiates the scattered light from the fine particles floating inside the plasma etching processing apparatus through the window part, separated from the reflected light from the wall surface of the plasma etching processing apparatus The position and size of fine particles present in the region irradiated with the laser beam inside the plasma etching processing apparatus are detected by a bundle fiber in which the light receiving end face is formed in a multistage shape in the optical axis direction different from the optical axis of the beam. circuit group, characterized in that to create the mapping data information about of The method of production. 7. The method of manufacturing a circuit board according to claim 6 , wherein the laser beam scanned and irradiated inside the plasma etching processing apparatus is a laser beam whose intensity is modulated at a desired frequency. The information on the distribution of the optical axis direction and the scanning direction of the laser beam of fine particles present in the region irradiated with the laser beam inside the plasma etching apparatus is obtained from the detected scattered light. Item 7. A method for manufacturing a circuit board according to Item 6 . 7. The circuit board manufacturing method according to claim 6, wherein the fine particle mapping data is displayed on a monitor screen. 7. The circuit board manufacturing method according to claim 6 , wherein information relating to a contamination state inside the plasma etching apparatus is output based on the created mapping data . A step of loading a substrate on which a resist pattern is formed on the surface inside the plasma etching apparatus,
Evacuating the inside of the plasma etching processing apparatus carrying the substrate into a vacuum and controlling the flow rate of a processing gas to introduce and set a desired pressure;
A step of applying high frequency power to generate plasma inside the plasma etching apparatus to an electrode of the plasma etching apparatus,
Etching the substrate having a resist pattern formed on the surface with the generated plasma; and
The plasma by irradiating scans the inside to the laser beam of the plasma etching apparatus via the window portion of the plasma etching apparatus in the middle of the substrate are etched float inside the plasma etching apparatus The plasma etching processing apparatus is configured to detect with a bundle fiber in which a light receiving end face is formed in a multistage shape in an optical axis direction different from an optical axis of the laser beam that irradiates backscattered light from fine particles to be emitted through the window portion. Creating mapping data of information on the position and size of fine particles present in the region irradiated with the laser beam inside
Method of manufacturing a circuit board, characterized in that it comprises a step of unloading the substrate after evacuating the processing gas from the interior of the plasma etching apparatus to stop the introduction of the process gas from the plasma etching apparatus. 12. The method of manufacturing a circuit board according to claim 11 , wherein the laser beam scanned and irradiated inside the plasma etching processing apparatus is a laser beam whose intensity is modulated at a desired frequency. 12. The circuit board manufacturing method according to claim 11, wherein the created mapping data is displayed on a monitor screen. 12. The method for manufacturing a circuit board according to claim 11 , wherein information relating to a contamination state inside the plasma etching apparatus is output based on the created mapping data .

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