JP2007280670A - Plasma treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma treatment apparatus which completely detects an abnormal discharge caused during the discharge of plasma used for film deposition and surface treatment. <P>SOLUTION: Plasma light (STEP 1) is received by a spectroscope (STEP 2), various processes (STEP 4, STEP 5) are applied to a plurality of outputs of the spectroscope receiving lights having various wave lengths, thereby detecting an abnormal discharge (STEP 7). When it is decided that the abnormal discharge needs to stop film deposition, the process proceeds to the plasma stop (STEP 10) and later step. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention provides various functional thin films such as electrode films, dielectric protective films, semiconductor films, transparent conductive films, electrochromic films, fluorescent films, superconductive films, dielectric films, solar cell films, antireflection films, Abrasion film, optical interference film, reflection film, antistatic film, conductive film, antifouling film, hard coat film, undercoat film, barrier film, electromagnetic wave shielding film, infrared shielding film, ultraviolet absorption film, lubricating film, shape memory The present invention relates to film formation, magnetic recording film, light-emitting element film, biocompatible film, corrosion-resistant film, catalyst film, gas sensor film, plasma film processing apparatus for performing surface treatment.

  In the plasma processing, abnormal discharge may occur, and this abnormal discharge causes problems such as defective product such as film formation and destruction of the processing apparatus.

  For this reason, a technique for detecting abnormal discharge has been developed, and Patent Document 1 proposes detecting abnormal discharge in real time by detecting a spike-like decrease in ultraviolet light observed during abnormal discharge. Yes.

Moreover, although it is not detection of abnormal discharge, it is proposed in patent document 2 to manage a plasma processing process by detecting plasma light with a spectrometer.
Japanese Patent Laying-Open No. 2005-340632 JP 2005-340547 A

  In Patent Document 1, an abnormality is detected by detecting a spike-like decrease in ultraviolet light that occurs during abnormal discharge. However, when abnormal discharge occurs, in most cases, abnormalities such as arc discharge are detected. Light emission due to discharge occurs.

  Therefore, if the decrease in the ultraviolet light is detected as in the cited document 1, there is a problem that the abnormality is overlooked without being detected as a decrease in the detected light amount due to the light emission at the time of abnormal discharge. In particular, since light emission due to abnormal discharge is light emission for a very short time, there are many cases where the light is buried in plasma light and cannot be detected.

  An object of the present invention is to solve the problems in the prior art relating to the detection of abnormal discharge occurring during such plasma processing.

The object is achieved by the following invention.
1.
A spectroscope that receives plasma light generated when irradiating plasma on a workpiece and a processing unit that performs different processing on a plurality of outputs that receive light of different wavelengths from the output of the spectroscope. A plasma processing apparatus.
2.
2. The plasma processing apparatus according to claim 1, wherein the processing means includes an averaging processing means for averaging the output of the spectroscope by the plasma light generated in a normal state at a predetermined period.
3.
3. The plasma processing apparatus according to 1 or 2, wherein the processing unit includes a peak detection unit that detects a peak of the output of the spectrometer due to light generated by abnormal discharge.
4).
3. The plasma processing apparatus according to claim 2, further comprising a determination unit that determines whether or not the output of the averaging processing unit is normal.

  According to the present invention, the detection output of plasma light emission and the detection output of light emission due to abnormal discharge are separately detected and processed, so that plasma generated constantly even in the case of a minor abnormality that causes defects in the formed film. It is detected separately from the light, and it becomes possible to detect the abnormality without omission.

  The present invention will be described below with reference to illustrated embodiments, but the present invention is not limited to these embodiments.

  FIG. 1 is a diagram showing a configuration of a plasma processing apparatus according to an embodiment of the present invention.

  The illustrated plasma processing apparatus is an example of an atmospheric pressure plasma processing apparatus.

  A processing gas is introduced from a gas supply source (not shown), a high-frequency voltage is applied between the electrodes 1 and 2, and plasma is generated in a space A between the electrodes 1 and 2. The electrode 2 is a drum-shaped electrode, and the processing film S is transported by the electrode 2 and is plasma-treated in the space A to form a film on the processing film.

  Light such as plasma light generated in the space A is transmitted to a spectroscope 4 by being transmitted by a light receiving unit including a condensing lens 3A, an optical fiber 3B, and a condensing lens 3C.

  The spectroscope 4 has a diffraction grating 4A and a CCD array 4B. By reading the light split by the diffraction grating 4A with the CCD array 4B, light of different wavelengths is incident on pixels at different positions in the CCD array 4B. Light that is wavelength-resolved to nm is detected. The spectroscope 4 detects light in a wavelength range of 200 to 800 nm or more.

  Reference numeral 5 denotes a display device, which displays a change in light output with time detected by the spectroscope 4 for each wavelength.

  Note that the plasma processing apparatus is not limited to the atmospheric pressure plasma, and the present embodiment is applied to various plasma processing apparatuses such as plasma CVD that forms a film by generating a plasma while evaporating a processing substance in a vacuum chamber. Can be used.

  Although the wavelength of normal plasma light varies depending on the content of processing, plasma light having a constant wavelength distribution is constantly generated for each processing. On the other hand, at the time of abnormality, light having a wavelength different from that at normal time is generated in a pulse shape. If the light generated in the space A is detected without being separated, the abnormal light may not be detected separately from the normal light, but the light intensity is normal by detecting the wavelength separated by the spectroscope 4. Even abnormal light weaker than plasma light can be detected. Therefore, in addition to the arc discharge that destroys the device, abnormal discharge that can cause defects in the formed film can be detected without leakage.

  In addition, a detection accuracy can be improved by arrange | positioning the light-receiving part comprised by 3 A of condensing lenses in the several position which can observe the space A, for example, the several position of the width direction of the process film S. FIG.

  FIG. 2 is a block diagram of a processing unit that processes the output of the spectrometer 4.

  The output of the CCD array 4B that receives the plasma light having the wavelength λ1 generated in the normal state is processed by the averaging circuit 6, and the moving average value is calculated.

  The output of the CCD array 4B that receives the light of wavelength λ2 generated during abnormal discharge is processed by the peak detection circuit 7 to detect the peak of the output.

  In this way, different processing is performed by the averaging circuit 6 and the peak detection circuit 7 on the light detection output of the wavelength λ1 and the light detection output of the wavelength λ2.

  The control unit 8 serving as a determination unit inputs the outputs of the averaging circuit 6 and the peak detection circuit 7 to stop the device and control the display device 5 and the recording unit 9 when an abnormality occurs.

  The display device 5 and the recording unit 9 display and record the abnormality occurrence time together with the abnormal discharge display / recording. The control unit 8 calculates the abnormality occurrence position on the processing film S from the abnormality occurrence time. Display and record.

  FIG. 3 is a diagram showing a film forming process using the present invention.

  In STEP 1, plasma discharge is performed to form a film, and plasma emission occurs in the space A.

  In STEP2, the output of the spectroscope 4 is read at 100 msec intervals.

  In STEP 3, the moving average process is performed on the output when the normal light having the wavelength λ 1 is detected at an interval of 10 sec.

  In STEP 4, output peak detection is performed by detecting abnormal light of wavelength λ 2.

  In STEP 5, it is determined whether or not the averaged output is within a normal range. In STEP5, it is determined whether or not the average value of the output of receiving the light of wavelength λ1 is equal to or higher than a certain level. If it is above a certain level, it is judged as normal, and if it is below a certain level, it is judged as abnormal.

  In STEP 6, it is determined whether or not the peak of abnormal light is above a certain level. When it is above a certain level, arc discharge has occurred. The determination result of STEP 6, that is, the information taken into STEP 7 includes information on the intensity of abnormal light having the wavelength λ 2 as well as information on the presence of arc discharge.

  In STEP 7, comprehensive judgment based on the judgment results in STEP 5 and 6 is performed.

  That is, the following situation determination is performed, and processing corresponding to each case is executed.

  For normal judgment in STEP5, the process proceeds to STEP8 to continue film formation.

  In STEP 7, in addition to the case where abnormality is determined in STEP 5, when it is determined that there is an arc discharge in STEP 6, the process proceeds to STEP 9 to continue film formation.

  STEP 9 is a process in the case where an abnormality that does not result in stopping the film formation occurs. In STEP 9, the abnormality occurrence time and the abnormality occurrence position on the processing film are recorded while the film formation is continued.

  This record is used for product inspection in the inspection process after film formation.

  If it is determined in STEP 7 that the arc discharge has a level that requires the film formation to be stopped, the plasma discharge is stopped in STEP 10, and the process conditions are reset in STEP 11. Film formation by is resumed.

It is a figure which shows the structure of the plasma processing apparatus which concerns on embodiment of this invention. It is a block diagram of the process part which processes the output of a spectrometer. It is a flowchart which shows the film forming process using embodiment of this invention.

Explanation of symbols

1, 2 Electrodes 3A, 3C Condensing lens 4 Spectroscope 4A Diffraction grating 4B CCD
5 Display Device 6 Averaging Circuit 7 Peak Detection Circuit 8 Control Unit 9 Recording Device

Claims (4)

A spectroscope that receives plasma light generated when irradiating plasma on a workpiece and a processing unit that performs different processing on a plurality of outputs that receive light of different wavelengths from the output of the spectroscope. A plasma processing apparatus. The plasma processing apparatus according to claim 1, wherein the processing unit includes an averaging processing unit that averages an output of the spectroscope by the plasma light generated in a normal state at a predetermined period. The plasma processing apparatus according to claim 1, wherein the processing unit includes a peak detection unit that detects a peak of the output of the spectrometer due to light generated by abnormal discharge. The plasma processing apparatus according to claim 2, further comprising a determination unit that determines whether or not the output of the averaging processing unit is normal.

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