TWI502164B - A measuring device and a film forming device - Google Patents

Description

Measuring device and film forming device

The present invention relates to a measuring device for measuring a specific value related to a film thickness, and a film forming device equipped with the measuring device, and more particularly to a measuring device capable of using an optical property value or an optical film thickness value as a characteristic value, and the measuring device Film forming device of the device.

In the step of producing an optical film product such as a dielectric multilayer film filter, film formation conditions are often controlled while monitoring optical characteristics or optical film thickness of a film formed on a substrate. That is, a measuring device for measuring an optical characteristic value or an optical film thickness value of a film and a film forming device equipped with the measuring device are widely known.

Further, in the measuring device for measuring the optical characteristic value or the optical film thickness value of the film, there is a device capable of measuring a change in the optical characteristic value of the film during the film formation in the vacuum container in which the film forming process is performed, that is, A device for performing an in-situ assay. For example, when a notch filter is manufactured by a vapor deposition film forming apparatus, if the refractive index of the vapor deposition material is measured at the stage of film formation by in-situ measurement, the vapor deposition can be utilized with good efficiency. Material, so the yield will increase.

In the film forming apparatus described in Patent Document 1, as an example of a device capable of performing in-situ measurement, a measuring device that emits measurement light to a film during film formation and measures the attenuation of the measurement light as a spectroscopic spectrum is disclosed. Next, in the film forming apparatus described in Patent Document 1, when the spectral spectrum obtained by measuring the attenuation of the measurement light is changed from the target spectral spectrum, the film formation conditions can be immediately controlled.

[Advanced technical literature]

[Patent Document 1] Japanese Patent Laid-Open No. Hei 7-90593

Further, regarding the performance of the measuring device, it is of course required to realize a measurement at a higher speed and obtain a measurement result with higher precision. On the other hand, it is also desirable to simplify the construction of the measuring device. In particular, in the film forming apparatus described in Patent Document 1, when the spectroscope necessary for measuring the spectroscopic spectrum by using a polychromator or a multi-channel analyzer is used, the number of devices is relatively large, and the installation space or manufacturing cost becomes higher. Big.

Further, in performing the in-situ measurement, when the vapor deposition material is vapor-deposited on the substrate in the film formation process, and an electron beam or a plasma is used, stray light is generated from the electron beam or the plasma. The influence of such stray light cannot be ruled out in the conventional spectrophotometry, and it has been difficult to perform in-situ measurement in the film formation process using electron beam or plasma.

Therefore, an object of the present invention is to provide a measuring device capable of realizing a higher-speed measurement and obtaining a higher-accuracy measurement result as a measuring device for measuring at least one of an optical characteristic value and an optical film thickness value of a film.

Further, another object of the present invention is to simplify the configuration of the measuring apparatus for achieving the above object. Further, another object of the present invention is to provide a film forming apparatus capable of performing an in-situ measurement of an assay device by eliminating the influence of stray light from an electron beam or a plasma in a film forming step.

The above-mentioned problem can be solved by the measuring device of the present invention, that is, a measuring device that measures an optical characteristic value including an optical film thickness value for a film formed on a substrate to be measured, and is characterized in that an optical signal generating mechanism is provided And an illumination unit, a detection unit, a signal separation unit, and a calculation unit for simultaneously measuring a plurality of optical specific values; the optical signal generation unit having a plurality of light source units for generating monochromatic light using an optical filter, the plurality of light source units The monochromatic light generated by each of the light source units is changed to a different set frequency according to each light source unit Generating a plurality of optical signals; the illuminating means multiplexes the plurality of optical signals emitted from the optical signal generating means to generate a multiplexed signal, and irradiates the multiplexed signal to the substrate for measurement by an optical fiber; The detecting means outputs an electrical signal as a detection signal when the multiplexed signal of the substrate to be measured is reflected or transmitted through the substrate after being irradiated by the illuminating means by the optical fiber; the signal separating mechanism is The electrical signal output by the detecting means applies a filtering process of the band pass filter, and the component signals of each of the set frequencies corresponding to each of the plurality of optical signals are separated from the electrical signal and extracted; The mechanism calculates the optical characteristic value displayed by the component signal for each of the set frequencies based on the component signal of each of the set frequencies separated by the signal separating unit from the electrical signal.

Moreover, the above-described problem can be solved by another measuring device according to the present invention, that is, a measuring device that measures an optical characteristic value including an optical film thickness value for a film formed on a substrate to be measured, and is characterized in that it has light a signal generating means, an illuminating means, a detecting means, a signal separating means, and a calculating means for simultaneously measuring a plurality of optical specific values; wherein the optical signal generating means includes a plurality of light source units for generating monochromatic light using an optical filter, The monochromatic light generated by each of the plurality of light source units is modulated to generate a plurality of optical signals according to different set frequencies of each of the light source units; the illumination mechanism is the plurality of optical signals emitted from the optical signal generating mechanism Multipleizing the multiplexed signal to illuminate the multiplexed signal on the substrate to be measured by an optical fiber; the detecting means reflects or transmits the multiplexed signal on the substrate to be measured after being received by the illuminating means by the optical fiber. When the multiplexed signal of the substrate for measurement is used, the electrical signal is output as a detection signal; The separating mechanism separates the component signals of each of the set frequencies corresponding to each of the plurality of optical signals from the electrical signal output by the detecting mechanism; the calculating mechanism is based on the electrical signal from the electrical signal by the signal separating mechanism The component signal of each of the set frequencies separated by the signal is used to calculate the optical characteristic value displayed by the component signal for each of the set frequencies; the signal separating mechanism has detection a lock-in amplifier that emits a signal of a specific frequency and amplifies the signal, and the electrical signal output by the detecting mechanism is input to the lock-in amplifier, so that each of the plurality of optical signals is extracted from the electrical signal The aforementioned component signals of the aforementioned set frequencies are amplified.

As long as it is any of the above two measurement devices, high-speed and high-accuracy measurement can be realized by the frequency multiplexing technique. That is, as long as it is the measuring device of the present invention, a plurality of pieces of information can be obtained at one time, and more specifically, a measurement result corresponding to the number of the set frequency types can be obtained at one time. Therefore, as a result of obtaining a plurality of measurement results at a time by the measuring apparatus of the present invention, the measurement accuracy is further improved and the measurement speed is also faster than the conventional measurement method using only the optical signal set to a single frequency.

More specifically, in the measuring apparatus of the present invention, the optical signals of the respective channels corresponding to the set frequency are simultaneously irradiated. On the other hand, as the film thickness of the film to be measured changes, the light intensity after the transmission or reflection of the optical signals of the respective channels changes, but by specifying the change for each channel, it can be simultaneously obtained on each channel. The optical characteristic value of the above film. Thereby, optical characteristic values can be acquired with high precision and instantaneously in each channel, in other words, at each set frequency. Such an effect cannot be achieved by using a spectroscopic spectrometer in which a spectroscope is combined with a CMOS or CCD sensor. The reason for this is that although the spectroscopic spectrometer can obtain optical characteristic values at high speed, on the other hand, a large number of measurement errors occur due to inherent interference of circuits in CMOS or CCD sensors. Therefore, in the above two measurement apparatuses of the present invention, a plurality of optical characteristic values can be obtained at a high speed in the same manner as the spectroscopic spectrometer, and further measurement can be achieved with respect to the spectroscopic spectrometer.

Furthermore, since either of the above-described two measuring devices does not need to use the spectroscope when dividing the multiplexed signal, the configuration of the measuring device can be relatively simplified.

Further, the measuring device may further include a digital signal processing unit that applies amplification processing to each of the component signals of each of the set frequencies separated from the detection signal; and the calculation means is based on the amplification processing The component signal is used to calculate the optical characteristic value displayed by the component signal.

As long as it is the above configuration, since the component signal after the amplification processing is used as the signal for calculating the calculation of the mechanism, a more accurate calculation result can be obtained. In other words, as long as the above configuration is achieved, a more accurate result can be obtained as a measurement result of the measuring device.

Further, the above problem can be solved by a film forming apparatus including a vacuum container that houses a substrate, and a vapor deposition material in which vapor deposition material is vapor-deposited on the substrate using an electron beam or a plasma in the vacuum container. A plating apparatus according to any one of claims 1 to 3, wherein the substrate for measurement is accommodated in the vacuum container while the film is formed on the substrate in the vacuum container. In the vapor deposition mechanism, the vapor deposition material is deposited on the substrate to be measured, and the measurement device holds the substrate to be measured in the vacuum container while the film is formed on the substrate in the vacuum container. In the state of the film formed on the side of the substrate to be measured, a plurality of optical characteristic values including optical film thickness values are simultaneously measured.

In the above film forming apparatus, the component of the stray light emitted from the electron beam or the plasma among the electric signals output from the detecting means can be cut off by the function of the band pass filter or the lock-in amplifier. Thereby, in the film formation step, the in-situ measurement can be performed without being affected by the stray light of the electron beam or the plasma. As a result of obtaining such an effect, since the step of preparing a film product for monitoring in batch processing for measuring the optical characteristic value or the optical film thickness value can be omitted, the productivity of the optical film product is improved, and the use of the vapor deposition material is saved. the amount.

According to the measuring device of the first or second aspect of the patent application, since the measurement is performed at a high speed and with high precision by the frequency multiplexing technique, a plurality of optical characteristic values can be obtained at a high speed in the same manner as the spectroscopic spectrometer, and compared with Spectroscopic spectrometers enable higher precision measurements. Further, since the spectroscope is not used, the configuration of the measuring device can be relatively simplified.

In the case of the measuring device of claim 3, a more accurate result can be obtained as a measurement result of the measuring device.

In the case of the measuring device of the fourth aspect of the patent application, the in-situ measurement can be performed without being affected by the stray light emitted from the electron beam or the plasma in the film forming step.

1‧‧‧vacuum container

2‧‧‧Substrate holder

3‧‧‧坩埚

4‧‧‧Electronic gun

5‧‧‧ evaporation mechanism

10‧‧‧Optical signal generating agency

11a, 11b, 11c, 11d, 11e, 11f‧‧‧ LED units

20‧‧‧ Illumination agency

21‧‧‧Splitting mirror

22‧‧‧ Concentrating lens

30‧‧‧Test institutions

31‧‧‧Photosensor Amplifier

50‧‧‧Signal separation mechanism

51‧‧‧Preamplifier

52‧‧‧ Filter

53‧‧‧A/D converter

60‧‧‧Lock-in amplifier

61‧‧‧Preamplifier

62‧‧‧ Filter

63‧‧‧Synchronous detection circuit

64‧‧‧Low-pass filter

65‧‧‧ Waveform forming circuit

66‧‧‧ phase processing circuit

67‧‧‧Reference signal generating device

70‧‧‧Digital Signal Processor

80‧‧‧Computed institutions

90‧‧‧ Controller

100‧‧‧Vapor deposition unit

101‧‧‧Measurement device

EB‧‧‧electron beam

LF‧‧‧ fiber

S‧‧‧ actual substrate

Sm‧‧‧ monitoring substrate

Fig. 1 is a view showing a schematic configuration of a film forming apparatus of the embodiment.

Fig. 2 is a view showing the configuration of an optical signal generating mechanism and an illuminating mechanism of the present embodiment.

Fig. 3 is a conceptual diagram showing a measuring method of the embodiment.

Fig. 4 is a view showing the detecting mechanism and the signal separating mechanism of the first example of the embodiment.

Fig. 5 is a view showing the detecting mechanism and the signal separating mechanism of the second example of the embodiment.

Hereinafter, an embodiment of the present invention (hereinafter referred to as the present embodiment) will be described with reference to the drawings.

Fig. 1 is a view showing a schematic configuration of a film forming apparatus of the embodiment. Fig. 2 is a view showing the configuration of an optical signal generating mechanism and an illuminating mechanism of the present embodiment. Fig. 3 is a conceptual diagram showing a measuring method of the embodiment. Fig. 4 is a view showing the detecting mechanism and the signal separating mechanism of the first example of the embodiment. Fig. 5 is a view showing the detecting mechanism and the signal separating mechanism of the second example of the embodiment.

First, a schematic configuration of a film forming apparatus of this embodiment will be described with reference to Fig. 1 .

The film forming apparatus is a device in which a vapor deposition material is vapor-deposited on the surface of the substrate in the vacuum vessel 1 to form a thin film. Hereinafter, as an example of the film forming apparatus, a vapor deposition apparatus 100 formed by a vapor deposition material that is evaporated by irradiation with an electron beam EB will be described as an example. However, the film forming apparatus to which the present invention is applicable can be formed by a plasma CVD (chemical vapor deposition) method, that is, a method of depositing a vapor deposition material on a substrate by using plasma. A device, a sputtering method in which ions are collided with a target to form a film, or a device for forming a film by ion plating.

In the vapor deposition device 100 of the present embodiment, a substrate (hereinafter referred to as an actual substrate S) and a monitoring substrate Sm for measuring a film thickness are provided in the vacuum chamber 1, and one of the film forming steps can be formed. The film formation conditions were appropriately adjusted while measuring the film quality of the film formed on the side of the monitoring substrate Sm.

More specifically, in the present embodiment, in the film forming step of forming a thin film on the actual substrate S, a film is formed on the monitor substrate Sm under the same conditions as the actual substrate S. In other words, in the present embodiment, the film quality of the film formed on the side of the actual substrate S is equivalent to the film quality of the film formed on the side of the monitoring substrate Sm, and the film quality of the film on the side of the substrate Sm is monitored, thereby managing the actual substrate. The film quality of the film on the S side.

Here, the actual substrate S refers to a substrate that is actually used as an optical film product. On the other hand, the monitoring substrate Sm corresponds to the substrate to be measured, and is used for monitoring the film value as described above.

Further, the film quality is an index relating to the optical characteristics of the film, that is, the optical property value of the film, and the optical property value in the present embodiment includes the concept of the optical film thickness value. Further, the optical property value includes, in addition to the optical film thickness value, a reflectance or transmittance, a refractive index, and an absorptance of a film (more precisely, a vapor deposition material constituting the film).

The configuration of the vapor deposition device 100 is as shown in Fig. 1, and includes a vacuum vessel 1, a substrate holder 2, a vapor deposition mechanism 5, and a measurement device 101 as main components. The components of the vapor deposition device 100 are substantially the same as those of the device that is known as a film deposition device that is a vacuum deposition method, except for the measurement device 101.

Specifically, a dome-shaped substrate holder 2 is disposed on the upper portion of the inner space of the hollow vacuum container 1, and a plurality of actual substrates S are mounted on the inner surface of the substrate holder 2. Further, an opening is formed in a central portion of the substrate holder 2, and one monitoring substrate Sm is provided directly under the opening. Further, for the purpose of uniformizing the amount of film formation between the actual substrates S, the substrate holder 2 is rotated about the rotation axis in the vertical direction during execution of the film formation step.

A vapor deposition mechanism 5 is disposed in a lower portion of the inner space of the vacuum vessel 1. In the vapor deposition mechanism 5 of the present embodiment, the vapor deposition material is vapor-deposited on the actual substrate S by using the electron beam EB in the vacuum chamber 1 in the film formation process. More specifically, the vapor deposition mechanism 5 has a crucible 3 in which a vapor deposition material is housed. The electron gun 4 that irradiates the electron beam EB irradiates the vapor deposition material in the crucible 3 with the electron beam EB from the electron gun 4 to evaporate the vapor deposition material.

The film forming step of forming a thin film on the actual substrate S is performed by the vapor deposition device 100 having the above configuration. Further, as described above, during the formation of the film on the actual substrate S in the vacuum chamber 1, the monitoring substrate Sm is housed in the vacuum container 1, and the vapor deposition mechanism 5 also vapor-deposits the vapor deposition material on the monitoring substrate Sm. That is, in the present embodiment, in the film formation step, substantially the same film is formed on both the actual substrate S and the monitor substrate Sm.

Further, the machine that operates when the film forming conditions are adjusted in the vapor deposition device 100 is controlled by the controller 90. The controller 90 outputs a control signal to the control target machine. Next, the control target device receives the control signal output from the controller 90 and adjusts the film formation condition as a result of the operation of the signal.

Next, a measurement device 101 which is a feature of the present embodiment among the components of the vapor deposition device 100 will be described.

The measuring device 101 measures a value including at least one of an optical characteristic value and an optical film thickness value of a film formed on the monitoring substrate Sm. Hereinafter, a measurement device 101 that measures both the refractive index and the optical film thickness value as optical characteristic values will be described as a specific example. However, the present invention is not limited thereto, and may be a device that measures an optical characteristic value other than the refractive index, or a device that measures only one of an optical characteristic value and an optical film thickness value.

In order to measure the refractive index and the optical film thickness value, the measuring device 101 injects light into the thin film formed on the monitoring substrate Sm. This light corresponds to the measurement light, is reflected by the monitoring substrate Sm or passes through the monitoring substrate Sm, and the reflected light or transmitted light is received by the detecting mechanism 30 described later. Next, the measuring device 101 calculates a refractive index and an optical film thickness value of the film which is a value indicated by the detection signal, based on the detection signal outputted when the detecting means 30 receives the reflected light or the transmitted light.

More specifically, the measuring device 101 has an optical signal generating mechanism 10, an illuminating mechanism 20, a detecting mechanism 30, a signal separating mechanism 50, and a digital signal processor as shown in FIG. 70 (labeled as DSP in Figs. 1, 4, and 5) and calculation means 80 are main constituent elements. Hereinafter, each component of the measuring device 101 will be described.

The optical signal generating mechanism 10 has a light source, and the optical signal emitted from the light source is guided to the illumination mechanism 20 by optical components such as a condenser lens.

Next, the optical signal generating unit 10 of the present embodiment is composed of a plurality of light sources, and the light emitted from each of the light sources is adjusted to a predetermined frequency, and the modulated light is guided as an optical signal to the illumination unit 20. Here, the frequency of the optical signal generated by the optical signal generating unit 10, that is, the frequency after modulation, is set to be different for each light source. That is, the optical signal generating unit 10 of the present embodiment emits a plurality of optical signals that are modulated to different setting frequencies.

As shown in FIG. 2, the optical signal generating mechanism 10 includes a plurality of LED units as light source units mounted on the light projector. In particular, in the present embodiment, six LED units are provided. Further, the number of the LED units is not limited to the above number, and may be set to any number as long as there are at least two or more.

Hereinafter, each of the six LED units will be referred to as a first LED unit 11a, a second LED unit 11b, a third LED unit 11c, a fourth LED unit 11d, a fifth LED unit 11e, and a sixth LED unit 11f.

Each of the first LED unit 11a to the sixth LED unit 11f includes a white LED or a RGB-based monochrome LED, a constant current driver for supplying a constant current to the LED, a collimating lens adjusted to parallel light, an optical filter, and a condensing light. lens. Here, as the LED of the light source of each of the LED units 11a to 11f, an output wavelength characteristic having a peak value of output power occurring in a predetermined wavelength region is used. Moreover, for ease of illustration, such components are not shown.

According to the above configuration, each of the LED units 11a to 11f generates monochromatic light using an optical filter. Specifically, in each of the LED units 11a to 11f, between the LED and the condensing lens, the spectroscopic filter as the first optical filter is disposed such that the mirror surface is inclined by about 45 degrees with respect to the optical axis of the LED. Further, a band pass filter as a second optical filter is disposed between the LED and the spectroscopic filter, more specifically, on the downstream side of the collimator lens and on the upstream side of the spectroscopic filter. Waves. Here, it is preferable that the second optical filter has a spectral distribution of light output having a half-value width of 20 nm (preferably 15 nm) or less to the light emitted from the first optical filter on the downstream side. Thereby, the output light having a narrow wavelength band can be emitted by the condensing lens, which contributes to an improvement in measurement accuracy of the optical film thickness.

Furthermore, the transmission of the optical signals from the LED units 11a to 11f is a pulse driving method in which an optical signal is emitted at a frequency divided by a frequency of a correct crystal oscillator. Thereby, the optical signal emitted from each LED unit is modulated, and the frequency of the modulated optical signal (hereinafter also referred to as the modulated optical signal) is 1310 Hz in the first LED unit 11a and in the second LED unit 11b. 1092 Hz is 867 Hz in the third LED unit 11c, 678 Hz in the fourth LED unit 11d, 437 Hz in the fifth LED unit 11e, and 218 Hz in the sixth LED unit 11f.

Further, the modulation method of the optical signal is not limited to the above, and as long as the optical signal is modulated so as to become the above-mentioned frequency, a known modulation method, for example, a digital direct synthesis oscillator (Direct Digital Synthesizer) may be used. , DDS) to adjust.

Further, the frequency of each modulated optical signal is not limited to the above-described set value, and may be set to a value other than the above value as long as it is set to a value that can be measured very suitably.

The illumination unit 20 multiplexes the five types of modulated optical signals emitted from the optical signal generating unit 10 to generate a multiplexed signal. Next, the illumination unit 20 irradiates the multiplexed signal to the monitor substrate Sm via the optical fiber LF. That is, in the present embodiment, instead of modulating the five types of modulated signals individually on the monitoring substrate Sm, as shown in FIG. 3, five types of modulated signals (labeled as f1, f2, F3, f4, f5, f6) are multiplexed and irradiated as a signal to the monitoring substrate Sm. Therefore, the optical fiber LF constituting the transmission path does not need to be set for each modulated signal, as shown in FIG. 3, as long as only one optical fiber LF for transmitting the multiplexed signal is provided.

The illumination unit 20 having the above functions is mounted on the light projector together with the optical signal generation unit 10, that is, the six LED units 11a to 11f. Further, the irradiation unit 20 includes a plurality of spectroscopic mirrors 21 and a collecting lens 22 as main components.

The configuration of the irradiation unit 20 of the present embodiment will be described. Five spectroscopic mirrors 21 are provided. Each of the dichroic mirrors 21 is arranged to correspond to each of the second to sixth LED units 11b to 11f as shown in FIG. 2 . Further, although the number of the spectroscopic mirrors 21 is not limited to the above number (five), it is preferable to correspond to the number of LED units, and particularly preferably one less than the number of LEDs as in the present embodiment. number.

The five spectroscopic mirrors 21 are arranged in a line shape along the optical path that is incident on the collecting lens 22. Further, each of the spectroscopic mirrors 21 is disposed in a state of being inclined by 45 degrees with respect to the optical path of the modulated optical signal emitted from the corresponding LED unit. On the other hand, the first LED unit 11a is disposed in parallel with the above-described five spectroscopic mirrors 21, and more specifically, is disposed at a position on the upstream side of the spectroscopic mirror 21 located on the most upstream side of the optical path.

Here, each of the spectroscopic mirrors 21 has a property of passing only light of a predetermined wavelength (in other words, a predetermined frequency) and reflecting light of other wavelengths. In the present embodiment, a plurality of modulated optical signals can be synthesized by the spectral characteristics of the spectroscopic mirror 21 to generate a multiplexed signal.

Specifically, the transmission bands of the five spectroscopic mirrors 21 arranged in a straight line are sequentially set to 620 to 780 nm, 580 to 780 nm, 540 to 780 nm, 500 to 780 nm, and 440 to 780 nm from the upstream side.

After the light is emitted from the first LED unit 11a to the five spectroscopic mirrors 21 having the transmission band as described above, only the optical signal having a wavelength of 640 nm passes through the dichroic mirror 21. Further, after the optical signal is emitted from the second LED unit 11b, the spectroscopic mirror 21 corresponding to the second LED unit 11b reflects light that is not in the transmission band (580 to 780 nm). Then, only the optical signal having a wavelength of 600 nm in the reflected light passes through the remaining dichroic mirror 21.

By the above action, the modulated optical signals emitted from the respective first LED unit 11a and second LED unit 11b are combined by the spectroscopic mirror 21. By the same sequence, for the modulated optical signal from the third LED unit 11c, only the signal with a wavelength of 560 nm is pumped. For the modulated optical signal from the fourth LED unit 11d, only the signal of the wavelength 520 nm is extracted, and for the modulated optical signal from the fifth LED unit 11e, only the signal of the wavelength 480 nm is extracted, for the signal from the sixth LED. After the modulated optical signal of the unit 11f, only the signal with a wavelength of 440 nm is extracted.

Then, by synthesizing the transmitted light passing through the spectroscopic mirror 21 in the modulated optical signal, a multiplexed signal obtained by multiplexing the five types of modulated optical signals is generated. The multiplexed signal is irradiated to the monitor substrate Sm through the optical fiber after the condensing lens 23 is collected.

Further, in the present embodiment, the optical signal is multiplexed by the spectroscopic mirror 21, but the present invention is not limited thereto. That is, the method of multiplexing the optical signals may be a well-known method other than the method of using the spectroscopic mirror 21, for example, a method using an optical multiplexer or a dielectric multilayer film filter.

The detecting means 30 is a person who reflects the multiplexed signal of the monitoring substrate Sm on the monitoring substrate Sm after being irradiated by the irradiation means 20 by an optical fiber and outputs a detection signal. In particular, the detecting mechanism 30 of the present embodiment includes a photoelectric conversion element, and receives the multiplexed signal reflected by the monitoring substrate Sm after being irradiated by the irradiation unit 20, and outputs an electrical signal as a detection signal.

The signal separating unit 50 separates the component signals of each set frequency corresponding to each modulated optical signal from the electrical signal outputted by the detecting unit 30. Here, the component signal has the same number as the modulated optical signal, that is, five types, as shown in FIG. 3, corresponding to the frequency of the modulated optical signal.

For the sake of simpler explanation, the electrical signal detecting mechanism 30 receives the output of the multiplexed signal reflected by the monitoring substrate Sm, and the detecting mechanism 30 is configured to receive the reflected light of each of the modulated optical signals after being individually multiplexed. The electrical signal synthesizer output. Next, the signal separating unit 50 extracts and separates the component signals of the same frequency as the frequency of the modulated optical signals emitted from the LED units from the electrical signals output from the detecting unit 30. That is, the component signals separated by the signal separation mechanism 50 can be regarded as the modulation of the individual reception being multiplexed. The electrical signals output by the detecting mechanism 30 are detected when the respective optical signals are reflected.

In addition, in FIG. 3, the frequency of each modulated optical signal is marked as n1~n6, the component signals are marked as g1~g6, and the frequency corresponding to the component signal is marked in parentheses. For example, the component signal g1 corresponds to the frequency n1 of the modulated optical signal f1 emitted from the first LED unit 11a, and the component signal g3 corresponds to the frequency n3 of the modulated optical signal f3 emitted from the third LED unit 11c.

As described above, the measuring apparatus 101 of the present embodiment uses the frequency multi-segmentation technique to realize high-speed and high-accuracy measurement. In other words, in the present embodiment, the same number of electrical signals as the frequency of the modulated optical signal, that is, the set frequency, can be simultaneously acquired as a component signal. Therefore, it is possible to simultaneously obtain measurement results relating to the monitoring substrate Sm in the same number as the component signals, that is, the component signals (in other words, the number of the set frequency types). As a result, in the present embodiment, the measurement accuracy is improved more than the conventional measurement method, and the measurement speed is also faster.

Here, as described above, the above-described effects of the measuring apparatus 101 of the present embodiment cannot be achieved by a spectroscopic spectrometer in which a spectroscope is combined with a CMOS or CCD sensor. The reason for this is that when it is a spectroscopic spectrometer, a large amount of measurement error is generated due to inherent interference of the circuit in the CMOS or CCD sensor or plasma light or stray light generated in the vacuum vessel 1. On the other hand, the measuring apparatus 101 of the present embodiment can eliminate the above-mentioned error factor and achieve high-speed and high-accuracy measurement.

Further, the value displayed by each component signal is a refractive index and an optical film thickness value of the vapor deposition material constituting the film, and can be obtained at each set frequency. Further, the optical film thickness value of each set frequency in Fig. 3 is marked with symbols d1 to d6, and the refractive index of each set frequency is marked with symbols S1 to S6.

The configuration of the detecting mechanism 30 and the signal separating mechanism 50 of the present embodiment will be described in detail.

The detecting mechanism 30 of the present embodiment is constituted by the photo sensor amplifier 31 (labeled PSA in the figure) shown in Figs. The photo sensor amplifier 31 has a photodiode as a photoelectric conversion element for converting a photocurrent generated when the photodiode receives light into a voltage and outputting a voltage signal. That is, the detecting mechanism 30 of the present embodiment receives the multiplexed signal by the photodiode and performs I/V conversion, and outputs an electrical signal, more specifically, an output voltage signal as a detection signal.

An example of the configuration of the signal separation mechanism 50 of the present embodiment is shown in FIG. Specifically, in the signal separating unit 50 of the present embodiment, the pre-amplifier 51 amplifies the electric signal output from the detecting unit 30, and applies filtering processing to the amplified electric signal. By this step, the signal separation mechanism 50 extracts the component signals of each set frequency from the electrical signals. Here, the filter 52 used in the filtering process is an analog filter, and more specifically, a band pass filter that passes a complex channel. That is, in the present embodiment, the center frequency of each of the transmission bands of the band pass filter is set to be the same frequency as the set frequency, and more specifically, is set to 1310 Hz, 1092 Hz, 867 Hz, 678 Hz, 437 Hz, and 218 Hz.

As described above, in the present embodiment, a filter is used when separating the component signals of the respective set frequencies from the multiplexed signal, more specifically, the electrical signal. That is, in the present embodiment, since the spectroscope is not used when dividing the multiplexed signal, the device configuration can be relatively simplified.

Then, the component signals of each of the set frequencies separated are converted into digital signals by the A/D converter 53, and then delivered to the digital signal processor 70.

Further, in the present embodiment, only the band pass filter is used as the filter 52. However, the present invention is not limited thereto, and an analog filter other than the band pass filter, that is, a high pass filter or a low pass filter may be combined.

Further, in the present embodiment, an analog filter is used as the filter 52, but a FIR filter (finite impulse response filter) which is a digital filter can also be used. Just use the center frequency The rate is set to a digital filter having the same frequency as the set frequency, more specifically, 1310 Hz, 1092 Hz, 867 Hz, 678 Hz, 437 Hz, and 218 Hz, that is, the component of each set frequency can be separated from the electrical signal output from the detecting mechanism 30. Signal. Further, when the FIR filter is used as the digital filter, the number of taps is set to 175 to 512.

Further, the configuration of the signal separating means 50 of the present embodiment can be considered in addition to the above-described configuration, that is, other components can be considered in addition to the separation of the component signals by the filter 52. Specifically, the configuration shown in FIG. 5 can also be considered as the configuration of the signal separating mechanism 50. The signal separating mechanism 50, which is constructed as shown in Fig. 5, inputs the electric signal output from the detecting unit 30 as the lock-in amplifier 60 of the main amplifier. The lock-in amplifier 60 has a function of detecting and amplifying a signal of a specific frequency in the input signal.

In particular, the lock-in amplifier 60 of the present embodiment has the same number of channels as the set frequency type. Therefore, the signal separating mechanism 50 illustrated in FIG. 5 extracts the component signals of each set frequency from the electrical signal by amplifying the electrical signals output from the detecting mechanism 30 to the lock-in amplifier 60 and amplifying them.

The lock-in amplifier 60 is described in detail, and the electrical signal output from the detecting mechanism 30 is input to the lock-in amplifier 60 as described above. At the same time, the reference signal generating means 67 inputs a reference signal set to the same frequency as the set frequency to the lock-in amplifier 60. Further, as shown in FIG. 5, the lock-in amplifier 60 includes a preamplifier 61 that amplifies an input electrical signal, specifically, a voltage signal, and a filter 62 that removes a high frequency or foldback signal included in the electrical signal, and will refer to The signal is formed into a rectangular wave-shaped waveform shaping circuit 65, and a phase processing circuit 66 that adjusts the phase difference between the reference signal and the electrical signal. Further, as the filter 62 described above, for example, a band pass filter or an anti-aliasing filter can be used.

Further, the lock-in amplifier 60 includes a synchronous detection circuit 63 that performs frequency conversion of synchronous detection, and a low-pass filter 64 that removes an AC component from the output signal of the synchronous detection circuit 63 and extracts a DC component (labeled as LPF in FIG. 5). . With the above configuration, the lock-in amplifier 60 The component signals of each set frequency in the electrical signal can be extracted and amplified by the input electrical signal and reference signal. That is, the center frequency of the lock-in amplifier 60 is set to be the same frequency as the set frequency, and more specifically, set to 1310 Hz, 1092 Hz, 867 Hz, 678 Hz, 437 Hz, and 218 Hz.

As described above, even if the signal multiplexed by the lock-in amplifier 60, more specifically, the electrical signal is divided into component signals of each set frequency, it can be the same as the case where the band pass filter 52 is used. In the meantime, the splitter is not used when dividing the multiplexed signal, so that the device configuration can be relatively simplified.

Then, the component signals of each of the set frequencies separated are converted into digital signals by the A/D converter 53, and then delivered to the digital signal processor 70.

In addition, the lock-in amplifier 60 can utilize an analog-type lock-in amplifier, a digital lock-in amplifier, a digital lock-in amplifier formed by a digital signal processor or a computer.

The digital signal processor 70 is a digital signal processing, that is, an amplification process, in which an amplification signal is applied to each component signal of each set frequency separated by the signal separation unit 50. Next, the digital signal processor 70 delivers the amplified component signal to the calculation unit 80.

The calculation unit 80 calculates the value displayed by each component signal for each set frequency based on the component signal of each set frequency separated by the signal separation mechanism 50. In particular, the calculation unit 80 of the present embodiment calculates the value displayed by the component signal based on the component signal amplified by the signal processor 70. In this way, by using the component signal after the amplification processing as the signal for calculating the calculation by the calculation unit 80, a more accurate calculation result can be obtained. That is, in the present embodiment, a more accurate result can be obtained as the measurement result of the measuring device 101.

The calculation unit 80 is constituted by a computer, and performs a predetermined arithmetic processing on the digital signal, that is, the component signal, to analyze the component signal. By this analysis, the value indicated by the component signal, specifically, the refractive index of the thin film formed on the monitor substrate Sm (more precisely, the refractive index of the vapor deposition material constituting the thin film) and the optical film thickness value are obtained.

Further, in the present embodiment, the analysis is performed for each component signal, in other words, for each set frequency. Therefore, in the present embodiment, the refractive index and optical film thickness of the film are specified for each set frequency.

More specifically, the reflectance when the substrate is irradiated with an optical signal in the film formation varies depending on the optical film thickness. Further, it is known that the shape of the curve relating to the thickness of the optical film and the reflectance changes in accordance with the frequency (wavelength) of the irradiated optical signal. With this property, in the present embodiment, the optical film thickness can be calculated for each set frequency by using optical signals that are modulated to a plurality of frequencies different from each other.

Further, the calculation means 80 transmits the data indicating the refractive index and the optical film thickness value of the film as a result of the calculation to the controller 90. The controller 90 that receives such data can adjust the film formation conditions in accordance with the refractive index or optical film thickness value of the film specified from the data.

The vapor deposition device 100 equipped with the measurement device 101 configured as described above can monitor the film formed on the monitoring substrate Sm in the vacuum container 1 during the execution of the film step. In other words, by using the measuring device 101 of the present embodiment, during the formation of the thin film on the actual substrate S in the vacuum container 1, the monitoring substrate Sm can be formed in the monitoring substrate Sm while the monitoring substrate Sm is housed in the vacuum container 1. The in-situ measurement of the refractive index and optical film thickness of the film was carried out.

The reason why the in-situ measurement can be performed in the present embodiment is that when the vapor deposition material is vapor-deposited on the actual substrate S using the electron beam EB or the plasma, the influence of the stray light generated from the electron beam EB or the plasma is affected. It affects the measurement results related to the refractive index of the film or the optical film thickness value. On the other hand, in the present embodiment, the components corresponding to the stray light among the electric signals output from the detecting means 30 can be cut off by the functions of the filter 52 such as the band pass filter described above or the lock-in amplifier 60. Thereby, even in the film forming step, the in-situ measurement can be performed without being affected by the electron beam EB or the stray light of the plasma.

Next, in the present embodiment, since the in-situ measurement can be performed satisfactorily, it is not necessary to monitor the substrate Sm in the batch process in order to measure the refractive index or the optical film thickness value. The step of the film. As a result, the workability of the film forming treatment, that is, the productivity of the film product can be improved.

Moreover, since it is not necessary to separately perform the batch process for forming the film for measurement on the monitoring substrate Sm, the amount of consumption of the vapor deposition material can be suppressed.

Furthermore, since the refractive index or the optical film thickness value of the film can be obtained for each set frequency, it is also possible to specify the distribution of the refractive index or the film thickness in the film to be measured, as long as it can be correlated with such distribution. The information is reflected in the film formation conditions, that is, the film formation control of the film can be performed more surely.

Although the measuring device and the film forming apparatus of the present embodiment have been described above, the present embodiment is merely an example for facilitating the understanding of the present invention, and the above-described members, arrangements, and the like are not intended to limit the present invention, and various modifications may be made in accordance with the gist of the present invention. Changes, modifications, and equivalents thereof are included in the invention. For example, the dimensions, shapes, and materials of the respective devices constituting the measuring device are as described above, but are not intended to limit the present invention in order to exhibit an effect of the present invention.

1‧‧‧vacuum container

2‧‧‧Substrate holder

3‧‧‧坩埚

4‧‧‧Electronic gun

10‧‧‧Optical signal generating agency

20‧‧‧ Illumination agency

30‧‧‧Test institutions

50‧‧‧Signal separation mechanism

70‧‧‧Digital Signal Processor

80‧‧‧Computed institutions

90‧‧‧ Controller

100‧‧‧Vapor deposition unit

101‧‧‧Measurement device

EB‧‧‧electron beam

LF‧‧‧ fiber

S‧‧‧ actual substrate

Sm‧‧‧ monitoring substrate

Claims (4)

In a measuring apparatus, a vapor deposition material is deposited on a substrate to be measured by an electron beam or a plasma to form an optical film, and an optical property including an optical film thickness value is measured for the film formed on the substrate to be measured. The value is characterized by comprising: an optical signal generating means, an illuminating means, a detecting means, a signal separating means, and a calculating means; the optical signal generating means having a plurality of light source units for generating monochromatic light using an optical filter, the plurality of light source units The monochromatic light generated by each of the light source units is modulated to generate a plurality of optical signals according to different set frequencies of each light source unit; the illumination mechanism is to multiplex the plurality of optical signals emitted from the optical signal generating unit And generating a multiplexed signal, and irradiating the multiplexed signal to the substrate for measurement by an optical fiber; and the detecting means is configured to reflect or transmit the Measured substrate to the substrate to be measured after being received by the illuminating means by the optical fiber. When the multiplexed signal of the substrate is used, the electrical signal is output as the detection signal; the signal separation mechanism, Filtering the electrical signal outputted by the detecting means, and separating the component signals of each of the set frequencies corresponding to each of the plurality of optical signals from the electrical signal, and extracting the component signals; Calculating the optical characteristic value displayed by the component signal by the signal separation unit from the component signal of each of the set frequencies separated by the electrical signal; the number of types of the set frequency may be set to an arbitrary number of at least two The aforementioned filtering process uses a transmission band deviation corresponding to the aforementioned electron beam or the aforementioned plasma Performing a band pass filter that sets the frequency of the stray light and is set to the same center frequency as the set frequency; and applying the filtering process to the electrical signal, the signal separating mechanism sets each of the set frequencies The component signals are simultaneously extracted, and the calculation means performs a process of analyzing the component signals and calculating the optical specific values for each of the set frequencies, and simultaneously measuring the optical specific values of the same number as the number of the types. In a measuring apparatus, a vapor deposition material is deposited on a substrate to be measured by an electron beam or a plasma to form an optical film, and an optical property including an optical film thickness value is measured for the film formed on the substrate to be measured. The value is characterized by comprising: an optical signal generating means, an illuminating means, a detecting means, a signal separating means, and a calculating means; the optical signal generating means having a plurality of light source units for generating monochromatic light using an optical filter, the plurality of light source units The monochromatic light generated by each of the light source units is modulated to generate a plurality of optical signals according to different set frequencies of each light source unit; the illumination mechanism is to multiplex the plurality of optical signals emitted from the optical signal generating unit And generating a multiplexed signal, and irradiating the multiplexed signal to the substrate for measurement by an optical fiber; and the detecting means is configured to reflect or transmit the Measured substrate to the substrate to be measured after being received by the illuminating means by the optical fiber. When the multiplexed signal of the substrate is used, the electrical signal is output as the detection signal; the signal separation mechanism, Separating a component signal of each of the set frequencies corresponding to each of the plurality of optical signals from the electrical signal outputted by the detecting means; the calculating means is separated from the electrical signal by the signal separating mechanism each The component signal of the set frequency is used to calculate the optical characteristic value displayed by the component signal; the signal separating mechanism has a lock-in amplifier that detects and amplifies a signal of a specific frequency; the lock-in amplifier is a transmission band Deviating from a frequency corresponding to the frequency of the stray light emitted from the electron beam or the plasma, and setting the center frequency to be the same as the set frequency; the number of types of the set frequency may be set to an arbitrary number of at least 2 or more; Inputting the electrical signal to the lock-in amplifier, the signal separating means simultaneously extracting the component signals of each of the set frequencies, and the calculating means performs the analysis of the component signals for each of the set frequencies and calculates the optical specific value. The treatment is performed by simultaneously measuring the aforementioned optical specific values of the same number as the above-mentioned kinds. The measuring device according to claim 1 or 2, further comprising a digital signal processing unit that applies amplification processing to each of the component signals of each of the set frequencies separated from the detection signal; The optical characteristic value displayed by the component signal is calculated based on the component signal after the amplification process. A film forming apparatus comprising: a vacuum container for accommodating a substrate; and a vapor deposition mechanism for depositing a vapor deposition material on the substrate by using an electron beam or a plasma in the vacuum container, wherein the invention has the patent application scopes 1 to 3 The measuring device according to any one of the present invention, wherein the substrate to be measured is accommodated in the vacuum container while the thin film is formed in the vacuum container, and the vapor deposition means further vapor-deposits the vapor deposition material to be measured. Substrate In the above-described measuring apparatus, while the film is formed on the substrate in the vacuum container, the film to be formed on the side of the substrate to be measured is simultaneously measured and contained in a state in which the substrate to be measured is held in the vacuum container. A plurality of optical property values of the film thickness value.