JP2003322617A - Thin film measurement apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin film measurement apparatus for measuring an arbitrary location of a thin film and not limiting a measured location. <P>SOLUTION: The thin film measurement apparatus for measuring the thin film has a semiconductor laser for radiating a laser light with a predetermined wavelength to the measured thin film, a drive signal creation means for creating a drive signal for driving the semiconductor laser, a control means for controlling the drive signal creation means so as to create the drive signal, a photo diode for receiving a thin film interference reflection signal from the thin film when the semiconductor laser radiates the laser light to the measured thin film and a process means for obtaining an interference reflectance based on the thin film interference reflection signal received by the photo diode. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film measuring device, and more specifically, to various kinds of semiconductors, metals, etc. formed by crystal growth on substrates made of various materials such as silicon and sapphire. The present invention relates to a thin film measuring device suitable for measuring a thin film made of the above material.

[0002]

2. Description of the Related Art Conventionally, as a method for measuring a thin film, a method for measuring the temperature of the thin film and a method for measuring the interference reflectance of the thin film are known.

As a method of measuring the temperature of the thin film, a method of measuring the temperature of the thin film using a thermocouple or a pyrometer is known.

A method of measuring the temperature of a thin film using a thermocouple is a known method in which the thermocouple is brought into contact with the thin film to measure the temperature. However, the measurement point where the thermocouple and the thin film come into contact with each other is arbitrarily determined. Since it is difficult to change it, there is a problem that the measurement location of the thin film is limited.

On the other hand, in the method of measuring the temperature of a thin film using a pyrometer, the thermal radiation signal, which is the thermal radiation from the thin film, is sensed by the pyrometer and the sensed thermal radiation signal is processed to determine the thermal radiation temperature. This is a known method of acquiring, that is, a so-called thermal radiation temperature measuring method. As a conventional thin film measuring device by a thermal radiation temperature measuring method using such a pyrometer, a thin film measuring device using a pyrometer using an optical system and a thin film measuring device using a pyrometer using an optical fiber are known. ing.

FIG. 1 shows a thin film measuring apparatus using a pyrometer using an optical system as a conventional thin film measuring apparatus by a thermal radiation temperature measuring method using a pyrometer.

A thin film measuring apparatus 200 using a pyrometer utilizing this optical system is a thin film measuring device 200 made of various materials such as semiconductors and metals formed on a substrate 100 made of various materials such as silicon and sapphire. It measures temperature.

The thin film measuring apparatus 200 includes an optical system 202 including a lens and a pyrometer sensing unit 204.
, Temperature display unit 206, pyrometer sensing unit 204
And a signal cable 208 that connects the temperature display unit 206 with the temperature display unit 206.

On the other hand, FIG. 2 shows a thin film measuring apparatus using a pyrometer using an optical fiber as a conventional thin film measuring apparatus by a thermal radiation temperature measuring method using a pyrometer.

A thin film measuring apparatus 300 using a pyrometer utilizing this optical fiber is used to measure the temperature of a thin film 102 made of various materials such as semiconductors and metals formed on a substrate 100 made of various materials such as silicon and sapphire. Is measured.

The thin film measuring apparatus 300 has an optical system 302 including a lens, a pyrometer sensing / display unit 304, and an optical fiber 306 connecting the optical system 302 and the pyrometer sensing / display unit 304. Is configured.

The thin film measuring apparatus 200 (300) described above is based on the thermal radiation temperature measuring method, and the pyrometer sensing unit 204 (pyrometer sensing / display unit 30) is used.
In 4), a process of detecting a heat radiation signal which is heat radiation light from the thin film 102 and converting the sensed heat radiation signal into temperature information is performed, and the temperature information is displayed in the temperature display unit 206.
It is displayed as a temperature in the (pyrometer sensing / display unit 304).

Here, in order to convert the thermal radiation signal into temperature information, for example, the following method can be adopted.

That is, as shown in FIG. 3 (a), 600 ° C. which can be obtained from Plank's formula
The temperature information is obtained based on the wavelength of the sensed thermal radiation signal using the graph showing the blackbody radiation energy at 1200 ° C. (the vertical axis in the graph shown in FIG. 3A is an arbitrary unit. .). Note that FIG. 3B is an enlarged view in the short wavelength region of FIG.

When attention is paid to a thermal radiation signal having a wavelength of 600 nm, it can be seen that the radiation power of the blackbody radiation energy remarkably increases at 1000 ° C. or higher. Therefore, the pyrometer sensing unit 204 (pyrometer sensing / display unit 3) capable of sensing the thermal radiation light in the 1 μm band.
It can be understood that the temperature of around 1000 ° C. can be measured by using 04). The actual surface of the thin film is not a black body, but it can be corrected by multiplying it by a calibration constant.

By the way, in a thin film measuring apparatus using a pyrometer using an optical system having the structure shown in FIG. 1, the entire structure of the device becomes large and it is difficult to downsize the entire device. There was a problem.

On the other hand, the thin film measuring device using a pyrometer using an optical fiber as shown in FIG. 2 has a problem that the price is high.

Further, the method of measuring the interference reflectance of the thin film is to irradiate the thin film with light, receive the thin film interference reflected light as the interference reflected light, analyze the received thin film interference reflected light, and This is a known method for obtaining the interference reflectance, which is a so-called thin film interference reflectance measuring method.

As a conventional thin film measuring apparatus using such a thin film interference reflectance measuring method, for example, a thin film measuring apparatus having a structure shown in FIG. 4 is known.

The thin film measuring apparatus 400 by this thin film interference reflectance measuring method measures a thin film 102 made of various materials such as semiconductors and metals formed on a substrate 100 made of various materials such as silicon and sapphire. Is.
The thin film formed on the substrate may be a single layer or a plurality of layers.

The thin film measuring apparatus 400 measures the white light source 402 that emits white light, the first optical fiber 404 that guides the white light of the white light source 402, and the white light that is guided by the first optical fiber 404. An optical system 406 including a lens for collecting and irradiating a thin film 102 formed on a certain substrate 100 and a lens for receiving reflected light from the thin film 102, and the optical system 406 received the light. A second optical fiber 408 that guides the reflected light from the thin film 102, a spectroscope 410 that disperses the white light guided by the second optical fiber 408, and a white light source 40.
2 and the operation of the spectroscope 410 and the spectroscope 4
And a personal computer 412 that processes an output signal from the device 10 using a predetermined software program based on the thin film interference reflectance measurement method.

In the above structure, the white light of the white light source 402 is guided to the optical system 406 by the first optical fiber 404, and the thin film 102 is irradiated from the optical system 406.

On the other hand, the thin film interference reflection signal, which is the reflected light from the thin film 102, is received by the optical system 406, and the optical system 40
The thin film interference reflection signal which is the reflected light received by the
It is guided to the spectroscope 410 by the optical fiber 408.

In the spectroscope 410, the thin-film interference reflection signal, which is the reflected light guided by the second optical fiber 408, is dispersed and an output signal indicating the spectral result is output to the personal computer 412.

The personal computer 412 executes data processing on the output signal from the spectroscope 410 based on the thin film interference reflectance measurement method, acquires and outputs the interference reflectance of the thin film 102.

Here, FIG. 5 is a graph showing an example of the result of measuring the change over time in the interference reflectance of the thin film 102 using the thin film measuring apparatus 400 based on the above-mentioned conventional thin film interference reflectance measuring method (the vertical axis indicates the interference). The reflectance (R) is shown, and the horizontal axis shows the thin film growth time (time (s).) The thin film 102 used for this measurement was a low-temperature deposited gallium nitride film formed on a sapphire substrate. This is a high-temperature-deposited gallium nitride thin film formed on the sapphire substrate by subsequent annealing. The measurement wavelength of the interference reflectance of the thin film 102 was 600 nm.

In the graph shown in FIG. 5, the sapphire substrate was heat-treated at 1190 ° C. in a hydrogen atmosphere in the time zone (1). The thin film interference reflection signal received by the thin film measuring apparatus 400 by the conventional thin film interference reflectance measurement method includes a component (heat radiation component) due to a heat radiation signal which is heat radiation light from the thin film 102. The trapezoidal change in the interference reflectance during the time period of (1) is 1190
The thin film measuring device 400 measures the heat radiation component due to the heat radiation signal, which is the heat radiation light from the thin film 102 generated by a high temperature such as ° C.
Is due to the detection of. Since the subsequent formation of the low temperature deposited gallium nitride is performed at a low temperature such as 550 ° C., the signal detected by the thin film measuring device drops.

Next, in the time period of (2), the low-temperature deposited gallium nitride is formed at a low temperature of 550 ° C.
The interference reflectance increases due to the formation of the low-temperature deposited gallium nitride in the time period of (2).

After forming the low temperature deposited gallium nitride, an annealing treatment is performed in the time zone (3).
The interference reflectance is reduced by this annealing treatment.

Subsequent to the time period (3), the high temperature deposited gallium nitride is formed at a high temperature of 1100 ° C. in the time period (4). In the time zone of (4), a short time after the formation of the high-temperature deposited gallium nitride is started, the interference reflectance exhibits a sinusoidal vibration. The cycle of this oscillation provides the speed of thin film growth.

However, the interference reflectance showing a sinusoidal vibration obtained by the thin film measuring apparatus according to the above-mentioned conventional thin film interference reflectance measuring method includes a thermal radiation component due to thin film formation at a high temperature of 1100 ° C. However, there is a problem that the measured interference reflectance is affected by the thermal radiation component.

Further, in the above-mentioned conventional thin film measuring apparatus, it is necessary to provide an optical system at the ends of the first optical fiber and the second optical fiber, and the spectroscope for wavelength selection is provided. There has been a problem that the size of the whole is increased and the manufacturing cost is increased.

[0033]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned various problems of the prior art, and an object thereof is to measure an arbitrary place of a thin film. The present invention intends to provide a thin film measuring apparatus that enables the above-mentioned thing and that the measuring place is not limited.

Another object of the present invention is to provide a thin film measuring apparatus which has a reduced overall size and improved portability.

Another object of the present invention is to provide a thin film measuring apparatus capable of multi-channeling.

Another object of the present invention is to provide a thin film measuring device which is designed to reduce costs.

It is also an object of the present invention to remove the thermal radiation signal from the thin film interference reflection signal so that the measured interference reflectance is not affected by the thermal radiation component. The present invention is intended to provide a thin film measuring device capable of performing the above.

Another object of the present invention is to separate the thermal radiation signal from the thin film interference reflection signal so that the temperature information and the interference reflectance information can be acquired at the same measurement point at the same time. An object of the present invention is to provide a thin film measuring device.

[0039]

In order to achieve the above object, the invention according to claim 1 of the present invention is a thin film measuring apparatus for measuring a thin film, wherein the thin film to be measured has a laser of a predetermined wavelength. A semiconductor laser that emits light, a drive signal generation unit that generates a drive signal that drives the semiconductor laser, a control unit that controls the generation of the drive signal by the drive signal generation unit, and a thin film to be measured by the semiconductor laser. A photodiode that receives a thin film interference reflection signal from the thin film when irradiating the thin film with a laser beam, and a processing unit that acquires an interference reflectance based on the thin film interference reflection signal received by the photodiode. I had it.

According to a second aspect of the present invention, when the photodiode does not irradiate the thin film to be measured by the semiconductor laser with laser light, the photodiode emits a heat radiation signal from the thin film. Light is received, and the processing means acquires the temperature information based on the thermal radiation signal received by the photodiode.

Here, like the invention according to claim 3 of the present invention, a plurality of operation modes for the drive signal generation means to generate the drive signals are set, and the control means has a plurality of operation modes. The drive signal generation means may be controlled so as to generate the drive signal in any one of the operation modes.

According to a fourth aspect of the present invention, in a plurality of operation modes, the drive signal generating means drives the first mode in which the drive signal generating means generates a constant drive signal, and the drive signal generating means drives. A second mode for generating a square-wave drive signal that repeats an ON section in which a signal is generated and an OFF section in which a drive signal is not generated, and a drive signal generation unit generates a drive signal modulated by a modulation signal. The third mode and the fourth mode in which the drive signal generation unit generates the drive signal modulated so as to include the off section in which the drive signal is not generated by the modulation signal may be included.

According to a fifth aspect of the present invention, operation mode selecting means for selecting one of a plurality of operation modes is provided.
The control means may control the drive signal generation means in the operation mode selected by the operation mode selection means.

Further, as in the sixth aspect of the present invention, each of the semiconductor laser and the photodiode may be provided in plural.

Further, as in the invention according to claim 7 of the present invention, the plurality of semiconductor lasers and the photodiodes may be arranged in a single thin film.

Further, as in the invention described in claim 8 of the present invention, the plurality of semiconductor lasers and the photodiodes may be arranged corresponding to each of the plurality of thin films.

[0047]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an example of an embodiment of a thin film measuring apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 6 is a conceptual structural explanatory view of an example of the embodiment of the thin film measuring apparatus according to the present invention.

The thin film measuring apparatus 10 is constructed by including a light emitting / receiving module 16 having a semiconductor laser 12 and a photodiode 14. Here, the semiconductor laser 12 functions as a light emitting element that irradiates the thin film 102 to be measured formed on the substrate 100 with laser light of a predetermined wavelength. Further, the photodiode 14 receives a thin film interference reflection signal that is reflected light from the thin film 102 when the semiconductor laser 12 is driven to irradiate the thin film 102 with laser light, and the driving of the semiconductor laser 12 is stopped. The thin film 102 functions as a light receiving element that receives a thermal radiation signal that is thermal radiation light from the thin film 102 when the thin film 102 is not irradiated with laser light.

Further, the thin film measuring apparatus 10 receives light by the power source 18 as a drive signal generating means for generating and supplying a current as a drive signal for driving the semiconductor laser 12 of the light emitting / receiving module 16 and the photodiode 14. An amplification amplifier 20 as a received light signal amplification circuit for amplifying a thin film interference reflection signal and a heat radiation signal from the thin film 102, a control means for controlling the generation of a current as a drive signal by the power source 18 as a drive signal generation means, and an amplification amplifier 20. The thin-film interference reflection signal received by the photodiode 14 amplified by is processed by using a software program based on the thin-film interference reflectance measurement method, and the thermal radiation signal received by the photodiode 14 amplified by the amplification amplifier 20 is processed. A software program based on thermal radiation temperature measurement method A personal computer 22 as a processing means for processing have, personal computer 2
A digital / analog converter 24 for converting a digital control signal from 2 into an analog control signal and outputting the analog control signal to the power supply 18;
Thin film interference reflection signal (analog signal) and thermal radiation signal (analog signal) that are output signals from the amplification amplifier 20.
Is converted into a digital signal and output.

Here, when the digital / analog converter 24 and the analog / digital converter 26 having a structure capable of multi-channel processing are used, multi-channel measurement is performed by using a plurality of semiconductor lasers 12 and photodiodes 14, respectively. You will be able to do it. It should be noted that detailed configurations and operational effects when such multi-channelization is performed will be described later.

Further, regarding the semiconductor laser 12, the thin film 1 depending on the material of the thin film 102 to be measured.
The semiconductor laser 12 capable of irradiating the laser beam of 02 with an effective wavelength may be appropriately selected. For example, when the thin film 102 to be measured is a III-V group nitride semiconductor, the semiconductor laser 12 may be a red semiconductor laser that emits red light in the wavelength band of 600 nm.

To convert the thermal radiation signal into temperature information, the graphs shown in FIGS. 3 (a) and 3 (b) are used, but as described above, the wavelength 60
Focusing on the 0 nm thermal radiation signal, the radiation power was remarkably increased at 1000 ° C. or higher. Therefore, by using a photodiode capable of receiving a thermal radiation signal in the wavelength band of 1 μm as the photodiode 14, it is possible to measure the temperature around 1000 ° C. Although the actual surface of the thin film 102 is not a black body, it can be corrected by multiplying it by a calibration constant.

With the above structure, this thin film measuring apparatus 1
In order to measure the thin film 102 by 0, the light emitting / receiving module 16 in which the semiconductor laser 12 and the photodiode 14 are incorporated is installed above the measurement target portion of the thin film 102 to be measured.

Here, in the thin film measuring apparatus 10, a plurality of operation modes for the power supply 18 to generate a current as a drive signal are set. Personal computer 22
Is configured to generate a current as a drive signal in any one of a plurality of operation modes selected as a drive signal.
And controls the thin film interference reflection signal and the heat radiation signal received by the photodiode 14 according to the selected operation mode.

The operating mode in which the personal computer 22 controls the power source 18 may be set in advance, or the user interface of the personal computer 22 may be selected from a plurality of operating modes. An operation element or the like as an operation mode selection unit for selecting any one of the operation modes is provided, and the personal computer 22 controls the power supply 18 in the operation mode selected by the operation mode selection unit. Good.

Next, the operation mode set in the thin film measuring apparatus 10 will be described with reference to FIG. 7. In the thin film measuring apparatus 10, the "DC mode" is used.
(See FIG. 7A), “Chopper mode” (FIG. 7)
(B)), "modulation mode" (see Fig. 7 (c)), and "composite mode" (see Fig. 7 (d)) are set.

That is, according to the thin film measuring apparatus 10, as will be described later, it is possible to perform chopper driving and modulation driving which cannot be performed by the conventional thin film measuring apparatus method in which white light from a white light source is dispersed and used. The operation in a plurality of operation modes can be realized. By utilizing the various operation modes described below, the photodiode 14
It is possible to separate the thin film interference reflection signal and the heat radiation signal and receive them, or it is possible to remove the heat radiation signal from the thin film interference reflection signal that is received by the photodiode 14, and to convert the heat radiation signal into the temperature information. It will also be possible to process as.

(1) DC mode (see FIG. 7A) The DC mode is an operation mode in which the current as a drive signal for driving the semiconductor laser 12 is constant. In the DC mode, the personal computer 22 controls the power supply 18 so that the current as a drive signal for driving the semiconductor laser 12 is constant. Therefore, in the DC mode, the semiconductor laser 12 maintains the ON state in which it continuously irradiates the laser light with a constant output value.

This DC mode is similar to the operation mode in the conventional thin film measuring apparatus as shown in FIG.
The interference reflection signal received by the photodiode 14 includes a heat radiation signal, and the same result as that obtained by the conventional thin film measuring apparatus as shown in FIG. 3 (see FIG. 4) is obtained.

In the DC mode, the personal computer 22 as the processing means has the photodiode 14
The thin film 10 based on the thin film interference reflection signal received by the
The interference reflectance of 2 is calculated.

(2) Chopper Mode (See FIG. 7B) The chopper mode is an operation mode in which the on / off of the electric current as the drive signal for driving the semiconductor laser 12 is repeated. In the chopper mode, the personal computer 22 uses the power supply 1 so that the ON section in which the current as the drive signal for driving the semiconductor laser 12 is generated and the OFF section in which the current is not generated are repeated to form a square wave.
Control eight. Therefore, in chopper mode,
The semiconductor laser 12 repeats an ON state in which it emits a laser beam at a constant output value and an OFF state in which it stops emitting a laser beam.

According to this chopper mode, the thin-film interference reflection signal received by the photodiode 14 while the current for driving the semiconductor laser 12 is in the ON section includes the thermal radiation signal, but the semiconductor laser 12 is When the driving current is off, the photodiode 14 can receive the heat radiation signal from the thin film 102. Therefore, based on the difference between the thin film interference reflection signal received by the photodiode 14 in the ON section and the thermal radiation signal received by the photodiode 14 in the OFF section, the influence of the thermal radiation component is determined. The removed interference reflectance can be acquired. It is possible to remove the thermal radiation component from the thin film interference reflection signal only by using the mechanical chopper in the conventional thin film measuring device as shown in FIG. 3, but the thermal radiation component itself is extracted and processed as temperature information. It is not possible.

In the chopper mode, the personal computer 22 as the processing means receives the thin film interference reflection signal received by the photodiode 14 in the ON section and the photodiode 14 in the OFF section. The interference reflectance of the thin film 102 is calculated based on the difference from the thermal radiation signal, and the temperature information of the thin film 102 is calculated based on the thermal radiation signal received by the photodiode 14.

In other words, in the chopper mode of the thin film measuring apparatus 10, it becomes possible to measure the temperature based on the heat radiation signal of the thin film 102 when the semiconductor laser 12 is extinguished. That is, it becomes possible to measure the local surface temperature of the thin film 102. Further, the thermal radiation signal can be removed from the thin film interference reflection signal to obtain the interference reflectance with the influence of the thermal radiation signal eliminated.

That is, in the chopper mode, it is possible to simultaneously obtain the change in the interference reflectance from one local point of the thin film 102 and the temperature information. Making it possible to acquire multiple points of such local information by making the system multichannel described later is very effective also in the pursuit of changes over time in the crystal growth apparatus.

(3) Modulation Mode (Refer to FIG. 7C) In the modulation mode, the current as the drive signal for driving the semiconductor laser 12 is not included in the off section by the modulation signal (the modulation waveform is arbitrary). Is an operation mode in which the drive signal is modulated (∂I). In the modulation mode, the personal computer 22 controls the power supply 18 so that the modulation signal gives a modulation (∂I) to the current as the drive signal for driving the semiconductor laser 12. Therefore, in the modulation mode, the output value of the semiconductor laser 12 is modulated (∂I). That is, according to the thin film measuring apparatus 10, since the semiconductor laser 12 is used as the light emitting element, it is possible to modulate the laser light applied to the thin film 102 as an input optical signal. The modulated signal may be generated by the personal computer 22.

In this modulation mode, modulation (∂I) is applied to the current as the drive signal for driving the semiconductor laser 12, and the thin film interference reflection signal (∂L (t)) is handled as the differential signal. The personal computer 22 as the processing means is a differential amount of the change in the interference reflectivity, ∂L.
(T) / ∂I is acquired and L is calculated by numerical integration work.
After obtaining (t), the thermal radiation signal which is a direct current component is removed from the thin film interference reflection signal.

In other words, in the modulation mode of the thin film measuring apparatus 10, the thermal radiation signal can be removed from the thin film interference reflection signal, and the interference reflectance without the influence of the thermal radiation signal can be obtained.

(4) Composite mode (see FIG. 7D) The composite mode is an operation mode in which the above-mentioned chopper mode and modulation mode are combined, and the semiconductor laser 1
By modulating a current as a drive signal for driving 2 including an off section in which no current is generated by a modulation signal (modulation waveform is arbitrary), modulation (∂I) including an off section is given to the drive signal. It is an operation mode. In the composite mode, the personal computer 22 controls the power supply 18 so that the modulation signal gives a current (driving signal) for driving the semiconductor laser 12 that includes a turn-off section to the modulation (∂I). Therefore, in the composite mode, the output value of the semiconductor laser 12 is modulated (∂I) so as to include the off section. That is, according to the thin film measuring apparatus 10, the semiconductor laser 1 is used as the light emitting element.
Since 2 is used, it is possible to modulate the laser light applied to the thin film 102, which is an input optical signal, so as to include the off section. The modulated signal may be generated by the personal computer 22.

In this composite mode, when the current for driving the semiconductor laser 12 is in the off section, the current for driving the semiconductor laser 12 in the chopper mode is in the same state as in the off section, and the photodiode 14 causes A thermal radiation signal from the thin film 102 can be received. Therefore, it is possible to acquire the temperature information of the thin film 102 based on the thermal radiation signal received by the photodiode 14 when the current driving the semiconductor laser 12 is in the off section.

In the composite mode, when the current for driving the semiconductor laser 12 is in the ON section, the same state as in the modulation mode described above is obtained, and the heat radiation signal is removed from the thin film interference reflection signal to obtain the heat radiation signal. It is possible to obtain the interference reflectance excluding the influence of.

Therefore, in the composite mode, the thin film 1
It is possible to simultaneously obtain the change in the interference reflectance from one local point 02 and the temperature information. Making it possible to acquire multiple points of such local information by making the system multichannel described later is very effective also in the pursuit of changes over time in the crystal growth apparatus.

Next, the above-mentioned multi-channel configuration will be described. Since the light emitting / receiving module 16 in the thin film measuring apparatus 10 is small, it is possible to arrange a plurality of light emitting / receiving modules 16 in an array. . Since the signal acquisition on the personal computer 22 side can easily support multiple channels, the interference reflectance distribution and temperature distribution of the entire thin film 102 can be acquired very easily. Further, at that time, the measurement time and the measurement location of the interference reflectance and the temperature can be matched.

Since the light emitting / receiving module 16 has a very simple structure, even if a plurality of the light emitting / receiving modules 16 are arranged for the purpose of increasing the number of channels, the price increase can be significantly suppressed.

In FIG. 8, as an example of the multi-channel thin film measuring apparatus 10, in a single film forming apparatus, a plurality of light emitting / receiving modules 16 are arranged in series instead of a single light emitting / receiving module 16. The conceptual explanatory drawing of the thin film measuring device 10 which provided the light emitting / receiving module head block array 30 arrange | positioned is shown.

That is, as shown in FIG. 8, in order to measure a substantially circular thin film 102 formed by a uniform flow of a source gas on a rotating substrate 100 with a single film forming apparatus, a thin film measuring apparatus is used. Instead of a single light emitting / receiving module 16, a module having a light emitting / receiving module head block array 30 in which a plurality of light emitting / receiving modules 16 are arranged in the radial direction of the thin film 102 may be used as the module 10.

By doing so, the distribution information on the interference reflectance and the temperature information in the thin film 102 can be easily and easily acquired.

On the other hand, FIG. 9 shows another example of the multi-channel thin film measuring apparatus 10 in a multi-film forming apparatus.
Instead of a single light emitting / receiving module 16, multiple light emitting /
A conceptual explanatory view of a thin film measuring apparatus 10 provided with a light emitting / receiving module head block plate 40 in which the light receiving modules 16 are radially arranged in satellites is shown.

That is, as shown in FIG. 9, a thin film 102 formed by a uniform source gas flow is formed on a plurality of substrates 100 radially arranged on a rotating turntable by a multi-layer film forming apparatus. For measurement, a single light emitting / receiving module 1 is used as the thin film measuring device 10.
Instead of 6, a light emitting / receiving module head block plate 40 in which a plurality of light emitting / receiving modules 16 are radially arranged in satellites may be used. In addition,
The thin film 102 formed on each substrate arranged on the turntable and each light emitting / receiving module 16 of the light emitting / receiving module head block plate 40 are aligned and arranged, and the light emitting / receiving module head block plate is arranged. 40 and the turntable are synchronously rotated.

By doing so, the interference reflectance and the temperature information of each thin film 102 formed on each substrate arranged on the turntable can be easily and easily acquired, and each portion of the multi-film deposition apparatus can be obtained. It is possible to build a system that constantly monitors the film formation site information.

According to the thin film measuring device 10 described above, the semiconductor laser 12 and the photodiode 14 can be easily arranged at arbitrary positions, so that it becomes possible to measure an arbitrary position on the thin film 102. The measurement location of the thin film 102 is not limited.

Further, according to the thin film measuring apparatus 10, since the optical system, the optical fiber and the spectroscope are not used, it is possible to reduce the size of the entire apparatus and to reduce the manufacturing cost. it can.

Further, according to the thin film measuring apparatus 10, the semiconductor laser 12 irradiates the thin film 102 by on / off controlling or modulating the current which is the drive signal generated by the power source 18 by the microcomputer 22. By controlling or modulating the intensity of laser light, it becomes possible to separate the thermal radiation component from the measured interference reflectance, and the measured interference reflectance is affected by the thermal radiation component. It is possible to eliminate the risk of receiving it, and it is possible to simultaneously obtain the interference reflectance and temperature information of the same measurement point on the thin film,
It is possible to acquire the reflectance change and temperature information from one local point in the thin film.

Further, in the thin film measuring apparatus 10, it is possible to perform simultaneous multi-point observation with a large-sized apparatus as the size and the number of channels are increased. At that time, the thin film measuring apparatus 10 is very advantageous because it is inexpensive.

The above-described embodiment can be modified as described in (1) to (3) below.

(1) In the above embodiment, the semiconductor laser 12 as a light emitting element and the photodiode 14 as a light receiving element are integrated as the light emitting / receiving module 16, but the invention is not limited to this. Of course, the semiconductor laser 12 as a light emitting element and the photodiode 14 as a light emitting element may be separately configured.

(2) In the above embodiment, the semiconductor laser 12 as a light emitting element and the photodiode 14 as a light receiving element are integrated as the light emitting / receiving module 16, but the invention is not limited to this. Of course, the power source 18 as a semiconductor laser drive power source
And the amplification amplifier 26 as a light reception signal amplification circuit,
It may be integrated into the light receiving module 16.

(3) The above-described embodiments and the modifications described in (1) and (2) above may be combined appropriately.

[0090]

Since the present invention is configured as described above, it is possible to measure an arbitrary place on the thin film, and therefore, there is an excellent effect that the measuring place is not limited. .

Further, since the present invention is configured as described above, it has an excellent effect that the overall structure of the device can be downsized and the portability can be improved.

Further, since the present invention is configured as described above, it has an excellent effect that it becomes possible to have multiple channels.

Further, since the present invention is configured as described above, it has an excellent effect that the cost can be reduced.

Further, since the present invention is constructed as described above, it has an excellent effect that the interference reflectance obtained by the measurement is not affected by the thermal radiation component.

Further, since the present invention is configured as described above, the thermal radiation signal is separated from the thin film interference reflection signal, and the temperature information and the interference reflectance information are acquired at the same measurement point at the same time. It has an excellent effect that it becomes possible to do.

[Brief description of drawings]

FIG. 1 is a conceptual configuration explanatory diagram showing a thin film measuring apparatus using a pyrometer using an optical system as a conventional thin film measuring apparatus by a thermal radiation temperature measuring method using a pyrometer.

FIG. 2 is a conceptual configuration explanatory diagram showing a thin film measuring apparatus using a pyrometer using an optical fiber as a conventional thin film measuring apparatus by a thermal radiation temperature measuring method using a pyrometer.

FIG. 3 (a) is a graph showing the blackbody radiant energy at 600 ° C. to 1200 ° C. that can be obtained from Plank's formula (the vertical axis is an arbitrary unit); It is an enlarged view in the short wavelength region of (a).

FIG. 4 is a conceptual configuration explanatory view showing a conventional thin film measuring apparatus by a thin film interference reflectance measuring method.

5 is a graph showing an example of the result of measuring the change over time in the interference reflectance of a thin film using the conventional thin film measuring apparatus based on the thin film interference reflectance measuring method shown in FIG. The vertical axis of the graph represents the interference reflectance (R), and the horizontal axis of the graph represents the growth time (time (s)) of the thin film.

FIG. 6 is a conceptual configuration explanatory view showing an example of an embodiment of a thin film measuring apparatus according to the present invention.

FIG. 7 is an explanatory view of an operation mode of the thin film measuring apparatus according to the present invention, (a) shows a DC mode, (b) shows a chopper mode, (c) shows a modulation mode, and (d) shows a composite mode. Indicates the mode.

FIG. 8 shows an example of the multi-channel thin film measuring apparatus according to the present invention shown in FIG. 7, in which a plurality of light emitting / receiving modules are arranged in series instead of a single light emitting / receiving module in a single film forming apparatus. It is a conceptual explanatory drawing of the thin film measuring device which provided the light emitting / light receiving module head block array arrange | positioned.

9 is another example of the multi-channel thin film measuring apparatus according to the present invention shown in FIG. 7, in which a plurality of light emitting / receiving modules are radially arranged instead of a single light emitting / receiving module in a multi-layer film forming apparatus. It is a conceptual explanatory drawing of the thin film measuring device which provided the light emitting / light receiving module head block plate arrange | positioned at satellite.

[Explanation of symbols]

10 Thin Film Measuring Device According to the Present Invention 12 Semiconductor Laser 14 Photodiode 16 Light Emitting / Receiving Module 18 Power Supply 20 Amplifying Amplifier 22 Personal Computer 24 Digital / Analog Converter 26 Analog / Digital Converter 30 Light Emitting / Receiving Module Head Block Array 40 Light Emitting / Receiving Module head block plate 100 Substrate 102 Thin film 200 Conventional thin film measuring device using a pyrometer that uses an optical system 202 Optical system 204 Pyrometer sensing unit 206 Temperature display unit 208 Signal cable 300 Conventionally using a pyrometer that uses an optical fiber Thin film measuring device 302 Optical system 304 Pyrometer sensing / display unit 306 Optical fiber 400 Conventional thin film measuring device by thin film interference reflectance measurement method 402 White light source 404 First optical fiber Iber 406 Optical system 408 Second optical fiber 410 Spectrometer 412 Personal computer

Continued front page    (72) Inventor Katsunori Aoyagi             2-1, Hirosawa, Wako-shi, Saitama RIKEN             Within (72) Inventor Shoji Ta             1-13-10 Hatogaoka, Hatoyama-cho, Hiki-gun, Saitama Prefecture F term (reference) 2G059 AA02 BB10 DD12 EE02 EE09                       FF01 FF11 GG01 GG03 GG07                       HH02 KK01 KK03 MM09                 2G066 AC16 AC20 BA12 BA34 CA11                       CA16                 4M106 AA01 AA10 BA05 CA22 CA31                       DH02 DH12 DH32 DJ11                 5F045 AB14 AF09 DP15 GB05 GB10

Claims (8)

[Claims] 1. A thin film measuring apparatus for measuring a thin film, comprising: a semiconductor laser for irradiating a thin film to be measured with laser light of a predetermined wavelength; and a drive signal generating means for generating a drive signal for driving the semiconductor laser, Control means for controlling the generation of the drive signal by the drive signal generation means, and a photodiode for receiving a thin film interference reflection signal from the thin film when the thin film to be measured is irradiated with laser light by the semiconductor laser. A processing unit for obtaining an interference reflectance based on a thin film interference reflection signal received by the photodiode. 2. The thin film measuring device according to claim 1, wherein the photodiode is configured such that when the thin film to be measured is not irradiated with laser light by the semiconductor laser,
A thin film measuring device which receives a thermal radiation signal from the thin film, and wherein the processing means acquires temperature information based on the thermal radiation signal received by the photodiode. 3. The thin film measurement apparatus according to claim 1, wherein a plurality of operation modes for the drive signal generation means to generate a drive signal are set, and the control means. Is a thin film measurement apparatus for controlling the drive signal generating means so as to generate a drive signal in any one of the plurality of operation modes. 4. The thin film measuring apparatus according to claim 3, wherein in the plurality of operation modes, the drive signal generating unit generates a constant drive signal.
And a second mode in which the drive signal generating unit generates a square-wave drive signal that repeats an ON period in which the drive signal is generated and an OFF period in which the drive signal is not generated, and the drive signal generating unit. A third mode in which a drive signal modulated by a modulation signal is generated, and a fourth mode in which the drive signal generation means generates a drive signal modulated so as to include an off section in which the drive signal is not generated by the modulation signal. Thin film measuring device with a mode. 5. The thin film measurement apparatus according to claim 3, further comprising an operation mode selection unit that selects an operation mode from among a plurality of operation modes. The means controls the drive signal generating means in the operation mode selected by the operation mode selecting means. 6. The thin film measuring device according to claim 1, claim 2, claim 3, claim 4, or claim 5, wherein a plurality of semiconductor lasers and a plurality of photodiodes are provided, respectively. A thin film measuring device. 7. The thin film measuring apparatus according to claim 6, wherein the plurality of semiconductor lasers and the photodiodes are arranged on a single thin film. 8. The thin film measuring apparatus according to claim 6, wherein the plurality of semiconductor lasers and the photodiodes are arranged corresponding to each of the plurality of thin films.