JP2000266529A - Film thickness measuring method, film thickness measuring device and film forming device - Google Patents

Abstract

[PROBLEMS] To easily and accurately measure the thickness of an ultra-thin silicon oxide film or the like in a film thickness measuring device used in a silicon semiconductor process. SOLUTION: A monochrome X-ray generator 20, a substrate 3 held in a vacuum and having a film 15 formed on its surface, and excited by monochrome X-rays of the monochrome X-ray generator 20 connected to the substrate 3 and the ground. An ammeter 4 for measuring the amount of electrons was provided. When the substrate 3 is irradiated with the monochromatic X-rays, the photoelectrons are excited to the vacuum level from the atoms on the substrate 3 and emitted, and the substrate surface is electrically positively charged. To a steady state. The amount of sample current measured in this steady state can be accurately measured to a small value and is proportional to the amount of photoelectrons radiated in vacuum, and the photoelectrons have a correlation with the atomic density of the film 15 near the substrate surface and its composition. Therefore, the film thickness on the substrate 3 can be accurately measured by measuring the amount of sample current.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring a film thickness of a sample, and more particularly to a film thickness measuring method for determining a film thickness by measuring the amount of electron emission from a surface by X-ray excitation photoelectrons with an ammeter. And a film thickness measuring device and a film forming device.

[0002]

2. Description of the Related Art In recent years, in the field of semiconductors, there has been a demand for a film thickness measuring method for accurately measuring various kinds of deposits, surface protective films, and several atomic layers of a silicon oxide film. Conventionally, as a technique in such a field, there is a literature described as follows.
Journal of Japan Society of Applied Physics 57 (12) 1988 Shuichi Kawabata, "Problems in Ellipsometry and Measurement of Ultrathin Films" 28-36.
For example, as a nondestructive measuring method, there is an ellipsometry method (Japanese Patent Laid-Open No. 6-341813). This is a method of measuring a change in the polarization state when light is reflected on the sample surface, and measuring the film thickness by fixing the refractive index of the optical constant of the sample surface. In the ellipsometry method, the surface film can be detected with high sensitivity, but the thinner the film thickness, the denser the equi-refractive index curve, and the more difficult it is to accurately determine the optical constant and measure the film thickness. come. Further, the film thickness is calculated by fitting the film thickness of each layer by using the fact that the elliptical polarization state of the reflected light differs depending on the substance, using a spectroscopic ellipsometry method. In addition, FT-
Using the RAS method of IR (Japanese Patent Laid-Open No. 5-63053), 12
There is a method of observing an absorption peak at 50 cm ^-1 and calculating the thickness of the silicon oxide film from the peak height. Further, there is a method of obtaining the film thickness of the surface layer from the ratio of the intensity of the surface layer to the intensity of the substrate layer by X-ray photoelectron spectroscopy (JP-A-9-14947). In addition, as a destructive measurement method, there is direct observation using a cross-sectional electron micrograph (cross-sectional TEM).

An example of the conventional film thickness measurement described above will be described below with reference to the drawings.

Conventionally, a film thickness measuring method is disclosed in Japanese Patent Application Laid-Open No. 9-14946.
What is described in the issue is known.

FIG. 7 is a schematic view of a conventional film thickness measuring method utilizing X-ray diffraction. In FIG. 7, 5 is a substrate, 6 is a surface film, 7 is an X-ray irradiator, 8 is an X-ray intensity detector, and 9 is a diffracted X-ray. The X-ray irradiator 7 is arranged above the substrate 5, and the X-ray intensity detector 8 has an angle at which only the diffracted X-rays 9 from the substrate 5 generated by diffracting the X-rays irradiated on the film 6 are detected. Fixed. The operation of the X-ray film thickness measuring device configured as described above will be described below.

First, when measuring the film thickness of the film 6 formed on the substrate 5, the intensity of the diffracted X-ray 9 generated by diffracting the X-ray irradiated from the X-ray irradiator 7 on the film 6 is measured. The X-ray intensity detector 8 to be measured is fixed at a position where only the diffracted X-ray 9 from the substrate 5 is detected, and the incident angle of the irradiated X-ray is set to 0.
The intensity of the diffracted X-rays 9 from the substrate 5 corresponding to the incident angle of the X-rays is measured by the X-ray intensity detector 8 and the X-ray intensity from the substrate 5 corresponding to the incident angle of the X-rays. Line 9
Of the intensity of the diffracted X-rays 9 is converted into an incident depth, and the value of the incident angle of the X-ray which causes the rising point to change from the zero value of the measured intensity of the diffracted X-ray 9 to the increasing tendency is converted into the incident depth. Find the thickness.

[0007]

However, the above configuration has the following problems.

(A) Ellipsometry method: For a film thickness of 2 nm or less, the film thickness is detected to be relatively large, but the deviation from the physical film thickness becomes large. Also, the calculation for detecting the film thickness is very complicated.

(B) RAS of FT-IR in infrared absorption method
Method: Equipment for optical refraction of incident infrared light, and equipment for optical refraction of reflected and transmitted light are required. Becomes difficult. In addition, a large measurement area is required.

(C) X-ray photoelectron spectroscopy: A large electrostatic hemisphere type spectroscope is required, and it is necessary to calculate the peak distribution of the energy distribution spectrum of photoelectrons and to calculate them from these values.

(D) Direct observation by cross-sectional electron micrograph (cross-sectional TEM): Sample preparation requires time and skill. For example, a milling operation is required to produce a cross-sectional TEM sample, which requires several hours, and it is difficult to produce a large number of samples at one time. Further, it is impossible to use it during film formation or during a process for destructive measurement.

(E) Film thickness measuring method using X-ray diffraction: Although the film thickness is effective at a film thickness of about a micrometer, a film thickness of several nm cannot be measured accurately.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method and apparatus for measuring the thickness of a very thin oxide film having a thickness of 2 nm or less in a simple and accurate manner. It is to provide a device.

[0014]

According to a first aspect of the present invention, there is provided a method for measuring a film thickness, wherein a substrate is connected to a ground and held in a vacuum, and a monochromatic X-ray is applied to the substrate. Is characterized in that the film thickness on the substrate is measured by the current value supplied from the ground when the light is irradiated.

According to the film thickness measuring method having the above-described structure, when monochrome X-rays are irradiated on a substrate, photoelectrons are excited from atoms on the substrate to a vacuum level and emitted, and the substrate surface is electrically positively charged. As a result, electrons flow from the ground to the substrate surface, and a steady state is established. The amount of sample current measured in this steady state can be accurately measured to a very small value (pA) and is proportional to the amount of photoelectrons radiated in vacuum, and the photoelectrons are equal to the atomic density of the film near the substrate surface. There is a correlation in its composition. Therefore, by measuring the amount of sample current, the film thickness on the substrate proportional to this amount of current can be accurately measured.

According to a second aspect of the present invention, in the film thickness measuring method, the substrate is held in a vacuum with the substrate connected to the ground, and a sample current supplied from the ground when the substrate is irradiated with monochromatic X-rays is measured. The film thickness is determined by a film thickness dependence curve of a sample current calculated from the atomic density of the film on the substrate and the sensitivity coefficient to X-ray irradiation.

As described above, while the substrate is connected to the ground and held in a vacuum, the sample current supplied from the ground when the substrate is irradiated with monochrome X-rays is measured, and the atomic density of the substrate and the film on the substrate is measured. The film thickness is determined by the film thickness dependence curve of the sample current calculated by the sensitivity coefficient to X-ray irradiation. The film thickness can be determined without increasing the thickness or correcting the film thickness during etching without a correction curve.

According to a third aspect of the present invention, there is provided a film thickness measuring apparatus comprising: a monochrome X-ray generator; a substrate having a film formed on a surface thereof which is held in vacuum; and a monochrome X-ray generator connected to the substrate and ground. And an ammeter for measuring the amount of electrons excited by the line.

As described above, the monochrome X-ray generator, the substrate which is held in a vacuum and has a film formed on its surface, and the amount of electrons which are connected to the substrate and the ground and which are excited by the monochrome X-rays of the monochrome X-ray generator. When a monochrome X-ray is irradiated on the substrate, photoelectrons are excited from atoms on the substrate to a vacuum level and emitted, and the substrate surface is electrically positively charged. Since the ammeter is connected between the substrate and the ground, electrons flow from the ground to the surface of the substrate, and are electrically neutralized to be in a steady state. In this steady state, the amount of the sample current from the ground is measured, and the current value can be accurately measured to a very small value (pA). Therefore, the film on the substrate proportional to this current amount is also accurately measured. it can. Therefore, the thickness of the ultrathin film can be measured very simply and accurately.

According to a fourth aspect of the present invention, there is provided a film thickness measuring apparatus according to the third aspect.
, A mechanism for moving the substrate in the plane direction is provided. As described above, since the mechanism for moving the substrate in the surface direction is provided, the current distribution in the substrate surface indicates the in-plane film thickness distribution, and the film thickness can be measured at all positions.

According to a fifth aspect of the present invention, there is provided a film thickness measuring apparatus comprising: a conventional X-ray source; a substrate which is held in a vacuum and has a film formed on a surface; an electrode located between the conventional X-ray source and the substrate; An ammeter connected to the ground for measuring the amount of electrons excited by the conventional X-ray source, wherein electrons emitted from the conventional X-ray source are cut off by applying a voltage to the electrodes.

Thus, a conventional X-ray source,
A substrate having a film formed on the surface held in a vacuum, an electrode located between the conventional X-ray source and the substrate, and an ammeter connected to the substrate and the ground for measuring the amount of electrons excited by the conventional X-ray source; When conventional X-rays are applied to a substrate, photoelectrons are excited from atoms on the substrate to a vacuum level and emitted, and the substrate surface is electrically positively charged. At this time, a voltage is applied to an electrode located between the conventional X-ray source and the substrate to generate an electric field, thereby blocking electrons emitted from the conventional X-ray source, thereby improving X-ray intensity. And
Since the ammeter is connected between the substrate and the ground, electrons flow from the ground to the surface of the substrate, and are electrically neutralized to be in a steady state. The amount of sample current from the ground in this steady state was measured, and the current value was a very small value (pA).
Since the measurement can be performed accurately, the film on the substrate that is proportional to the amount of current can also be accurately measured. Further, since the electrons emitted from the conventional X-ray source are cut off, the sample current can be increased by improving the X-ray intensity, and the film thickness can be measured more accurately.

According to a sixth aspect of the present invention, there is provided a film forming apparatus comprising: a monochrome X-ray generator; a substrate held in a vacuum; and a current connected to the substrate and the ground for measuring the amount of electrons excited by the monochrome X-ray generator. A substrate, an exposure nozzle for introducing a gas into the substrate to form a film on the substrate surface, and a substrate heating device for controlling the temperature of the substrate.

As described above, the monochrome X-ray generator, the substrate held in vacuum, the ammeter connected to the substrate and the ground for measuring the amount of electrons excited by the monochrome X-ray generator, An exposure nozzle for introducing a gas to form a film on the surface of the substrate and a substrate heating device for controlling the temperature of the substrate are provided. A membrane is formed.

According to a seventh aspect of the present invention, there is provided the film forming apparatus according to the sixth aspect, further comprising a mechanism for moving the substrate in a plane direction thereof. As described above, since the mechanism for moving the substrate in the surface direction is provided, the current distribution in the substrate surface indicates the in-plane film thickness distribution, and the film thickness can be measured at all positions. Therefore, it is possible to measure not only a representative point but also the in-plane film thickness distribution during film formation.

[0026] In the film forming apparatus according to the present invention, a conventional X-ray source, a substrate held in a vacuum, an electrode located between the conventional X-ray source and the substrate, and a conventional X-ray connected to the substrate and ground. An ammeter that measures the amount of electrons excited by the source, an exposure nozzle that introduces gas to the substrate to form a film on the substrate surface, and a substrate heating device that controls the temperature of the substrate, and applies a voltage to the electrodes By doing so, electrons emitted from the conventional X-ray source are blocked.

Thus, a conventional X-ray source,
A substrate held in a vacuum, an electrode located between the conventional X-ray source and the substrate, an ammeter connected to the substrate and ground for measuring the amount of electrons excited by the conventional X-ray source, and a gas applied to the substrate. An exposure nozzle for introducing and forming a film on the surface of the substrate, and a substrate heating device for controlling the temperature of the substrate are provided, and when a voltage is applied to the electrodes, electrons emitted from the conventional X-ray source are cut off. As in 5, the sample current can be increased by improving the X-ray intensity, and the film can be formed while measuring the film thickness accurately.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a conceptual diagram of a film thickness measuring apparatus according to a first embodiment of the present invention. In FIG. 1, an Al target 1 and a quartz crystal 2 together constitute a monochrome X-ray generator 20, and an ammeter 4 is connected between a silicon substrate 3 on which a silicon oxide film 15 is mounted and a ground. Is electrically connected to the ground. The Al target 1, the quartz crystal 2, and the silicon substrate 3 are held in a vacuum. The ammeter 4 measures the amount of electrons excited by the monochrome X-rays of the monochrome X-ray generator 20.

The operation of the film thickness measuring apparatus configured as described above will be described below. Thermions accelerated by the high electric field of 14 kV hit the Al target 1, generate X-rays (Kα rays), are diffracted by the quartz crystal 2 under Bragg reflection conditions, and monochromatic X-rays are condensed on the silicon substrate 3. 3 is irradiated. Photoelectrons are excited to a vacuum level and emitted from silicon atoms and oxygen atoms on the silicon substrate 3 on which the silicon oxide film 15 is mounted, and the substrate surface is electrically positively charged. The silicon substrate 3 is sufficiently electrically connected to the ground, and electrons flow from the ground to the surface of the substrate, and are electrically neutralized, so that the silicon substrate 3 enters a steady state. The silicon oxide film thickness to be measured is very thin (2 nm or less) and is neutralized by supplying electrons from the substrate. The amount of sample current from the ground in this steady state is measured. This amount of current is proportional to the amount of photoelectrons excited by monochrome X-rays and emitted in a vacuum, and the photoelectrons are correlated with the atomic density near the substrate surface and its composition. Since the current value can be accurately measured to a very small value (pA), the oxide film thickness proportional to the current amount can also be accurately measured.

FIG. 2A is a diagram showing the correlation between the thickness of the silicon oxide film and the amount of sample current in the film thickness measuring apparatus according to the first embodiment, and FIG. 2B is an explanatory diagram for measuring the amount of sample current.
As shown in FIG. 2, a very good linear characteristic is shown in a region of 2 nm or less, and by measuring the sample current amount,
Our experiments have shown for the first time that the oxide film thickness can be accurately calculated from 2 nm to 0 nm. In this way, the sample current characteristics with respect to the oxide film thickness were measured,
Rather than determining the linear correlation characteristic, the unknown film thickness can be determined by comparing the unknown film thickness with the linear correlation characteristic.

As described above, according to this embodiment, A
1. A monochrome X-ray generator 20 including a target 1 and a quartz crystal 2, a silicon substrate 3 on which a silicon oxide film 15 is mounted, and an ammeter 4 between the substrate and the ground are provided. The oxide film thickness can be accurately measured.

A second embodiment of the present invention will be described with reference to FIG.

FIG. 3 is a conceptual diagram of a film forming apparatus showing a second embodiment of the present invention. As shown in FIG. 3, this film forming apparatus has an exposure nozzle 10 and an infrared heating device 11 installed on a silicon substrate 3 in the equipment of the film thickness measuring apparatus of the first embodiment. The exposure nozzle 10 introduces a gas into the silicon substrate 3 to form a silicon oxide film 15 on the substrate surface.
Generate The infrared heating device 11 can control the temperature of the silicon substrate 3.

The operation of the film forming apparatus configured as described above will be described below. By irradiating the silicon substrate 3 with infrared rays from the infrared heating device 11 while performing exposure at a desired oxygen partial pressure from the oxygen exposure nozzle 10, oxidation is performed on the cleaned silicon surface while controlling the temperature from room temperature to 1100 ° C. A film 15 is generated. At the same time, by irradiating the silicon substrate 3 with monochrome X-rays and measuring the amount of sample current at that time, the film can be formed while accurately measuring the thickness of the ultra-thin film during the film formation.

The present invention can be applied to an etching method for etching a silicon oxide film by introducing an F-based gas from an exposure nozzle 10 to a sample on which an oxide film has been formed in advance. In this case, the film thickness can be controlled while accurately measuring the remaining oxide film thickness at the time of etching.

As described above, the equipment of the film thickness measuring device of the first embodiment includes the exposure nozzle 10 and the infrared heating device 11.
By disposing the film on a silicon substrate, film formation and etching can be performed while accurately controlling the film thickness.

A third embodiment of the present invention will be described with reference to FIG.

FIG. 4 is a conceptual diagram of a film thickness measuring device and a film forming device showing a third embodiment of the present invention. As shown in FIG. 4, the film thickness measuring device and the film forming device further include an XY moving mechanism 12 connected to the silicon substrate 3 in addition to the second embodiment. With this, the electric conduction to the ground can be sufficiently taken.

The operation of the film thickness measuring device and the film forming device configured as described above will be described below. During the film formation described in the second embodiment, the XY moving mechanism 12 is used to move a different substrate position to the focal point of monochrome X-rays,
The accompanying sample current is measured. The in-plane current distribution indicates the in-plane film thickness distribution, and the film thickness can be measured at all positions in principle.

As described above, by providing the XY moving mechanism 12 for moving the substrate in the plane direction, it is possible to measure not only a representative point but also the in-plane film thickness distribution during film formation. Further, when configured as a film thickness measuring device, the exposure nozzle 10 and the infrared heating device 11 may not be provided.

Next, a fourth embodiment of the present invention will be described.

The apparatus configuration used for this film thickness measuring method is the same as that of the second embodiment. The operation will be described below. Before the substrate is introduced into the measuring apparatus, the film thickness is measured by another measuring method, for example, a measuring method of the oxide film thickness based on the distance between Si atoms by cross-sectional TEM. The substrate is connected to the ground and held in a vacuum, and after the device is inserted, the sample current supplied from the ground when the substrate is irradiated with monochrome X-rays is measured by the method described in the first embodiment. The sample current value is theoretically calculated from the atomic density of the substrate, the atomic density of the film, the ratio of each constituent element, and the sensitivity coefficient to X-ray irradiation. Based on this, a film thickness dependence curve (theoretical curve) of the sample current is prepared. Further, by applying the theoretical curve to the film thickness measured in advance, the film thickness can be determined without increasing the film thickness in the film forming apparatus or the film thickness during etching without a correction curve.

The derivation of the theoretical curve is shown below. The amount of photoelectrons Im from the substrate is given by: Im = αmNmλm exp [− (d / λo / sin θ)] (1) Αm is the photoelectron generation coefficient of the substrate, Nm is the atomic density of the substrate, λm is the inelastic scattering length of the substrate, d is the film thickness, λo is the inelastic scattering length of the film, and θ is the escape angle. It is. The photoelectron quantity Io from the film is expressed by the following equation: Io = αo Noλo [1-exp [-(d / λo / sinθ)]] Αo is the photoelectron generation coefficient of the film,
No is the atomic density of the film. Then, the photoelectron quantity I from the substrate and the film, that is, the sample current is expressed by the following equation: I = Im + Io. As an example, No = 2, Nm = 1 (others are
The tendency of the sample current under the condition of αm = αo = 1, λm = λo, θ = 90 °) can be calculated and becomes as shown in FIG.

As described above, by providing a film thickness measurement and a theoretical curve in advance, the oxide film thickness can be easily calculated directly from the sample current during film formation without a correction curve obtained from many measurements.

A fifth embodiment of the present invention will be described with reference to FIG.

FIG. 6 is a conceptual diagram of a film thickness measuring device and a film forming device according to a fifth embodiment of the present invention. As shown in FIG. 6, the film thickness measuring apparatus and the film forming apparatus are provided with a conventional X-ray source 21 instead of the monochromatic X-ray source as compared with FIG.
Is an electrode. The electrode 14 is located between the Al target 13 and the silicon substrate 3. In this embodiment, the electrode 14
X-ray source 2 by applying a voltage to
Blocks electrons emitted from 1. Except for this, the same members as those in FIG. 4 are denoted by the same reference numerals.

The operation of the film thickness measuring and film forming measuring apparatus configured as described above will be described below. Conventional X-rays are generated from the Al target 13 as an X-ray generator, and are not converted to monochrome. At this time,
The X-ray intensity increases as compared with the case of monochrome conversion. The conventional X-ray generator 21 emits electrons other than X-rays. A negative electric field generated by a voltage applied to the electrode 14 causes the electrons, which are related to the background size and noise, which are not related to the thickness of the object to be measured, to completely reach the substrate.

As described above, by providing the electrode 14 between the Al target 13 and the substrate 3 and applying a voltage to the electrode 14, the sample current can be increased by improving the X-ray intensity, and the film thickness can be further increased. Can be measured accurately. Further, when configured as a film thickness measuring device, the exposure nozzle 10 and the infrared heating device 11 may not be provided.

In the first to fifth embodiments, the sample has been described as an example in which the sample is constituted by a silicon substrate on which a silicon oxide film is mounted. However, the present invention can be similarly applied to a film and a substrate of another element.

[0051]

According to the film thickness measuring method of the present invention, when the substrate is connected to the ground and held in a vacuum, and the substrate is irradiated with monochrome X-rays, the current supplied from the ground is applied. Since the film thickness on the substrate is measured based on the value, the extremely thin film can be measured very simply and accurately. That is, when monochrome X-rays are irradiated on the substrate, photoelectrons are excited to a vacuum level from atoms on the substrate and emitted, and the substrate surface is electrically positively charged, so that electrons flow from the ground to the substrate surface. , Comes to a steady state. The amount of sample current measured in this steady state is very small (p
The measurement can be performed accurately up to A) and is proportional to the amount of photoelectrons emitted in a vacuum. The photoelectrons are correlated with the atomic density of the film near the substrate surface and its composition. Therefore, by measuring the amount of sample current, the film thickness on the substrate proportional to this amount of current can be accurately measured.

According to the film thickness measuring method of the second aspect of the present invention, the substrate is held in a vacuum with the substrate connected to the ground, and the sample current supplied from the ground when the substrate is irradiated with monochromatic X-rays is measured. The film thickness is determined from the film thickness dependence curve of the sample current, which is calculated based on the atomic density of the substrate and the film on the substrate and the sensitivity coefficient to X-ray irradiation. By applying the curve, it is possible to determine the film thickness without increasing the film thickness during film formation and without correcting the film thickness during etching.

According to the film thickness measuring apparatus of the third aspect of the present invention, a monochrome X-ray generator, a substrate which is held in a vacuum and has a film formed on its surface, and a monochrome X-ray which is connected to the substrate and the ground. 2. An ammeter for measuring the amount of electrons excited by monochrome X-rays of the generator.
The thickness of the ultra-thin film can be measured accurately and very simply.

According to a fourth aspect of the present invention, since a mechanism for moving the substrate in the plane direction is provided in the third aspect, the current distribution in the substrate surface indicates the in-plane film thickness distribution, and the film thickness measurement is performed at all positions. Becomes possible.

According to the film thickness measuring apparatus of the present invention, a conventional X-ray source, a substrate which is held in a vacuum and has a film formed on its surface, and a conventional X-ray source which is connected to the substrate and the ground. Since an ammeter is provided for measuring the amount of electrons excited by the method, the film thickness on the substrate in proportion to this amount of current can be accurately measured by measuring the amount of sample current as in the first aspect. In this case, by applying a voltage to the electrodes to generate an electric field, electrons emitted from the conventional X-ray source are blocked, so that the sample current can be increased by improving the X-ray intensity, and the film thickness can be more accurately adjusted. Can be measured.

According to the film forming apparatus of the present invention, the monochrome X-ray generator, the substrate held in vacuum, and the electrons connected to the substrate and the ground and excited by the monochrome X-ray generator are provided. Since it has an ammeter that measures the amount, an exposure nozzle that introduces gas to the substrate and generates a film on the substrate surface, and a substrate heating device that controls the temperature of the substrate,
A film can be formed while accurately measuring the film thickness on the substrate surface as in the third aspect.

According to the seventh aspect, since a mechanism for moving the substrate in the plane direction is provided in the sixth aspect, the current distribution in the substrate surface indicates the in-plane film thickness distribution, and the film thickness measurement is performed at all positions. Becomes possible. Therefore, it is possible to measure not only a representative point but also the in-plane film thickness distribution during film formation.

According to the film forming apparatus of the present invention, the conventional X-ray source, the substrate held in vacuum, the electrode located between the conventional X-ray source and the substrate, the substrate and the ground are connected to each other. An ammeter connected to measure the amount of electrons excited by a conventional X-ray source, an exposure nozzle for introducing a gas to the substrate and forming a film on the substrate surface,
A substrate heating device for controlling the temperature of the substrate is provided, and by applying a voltage to the electrodes, the electrons emitted from the conventional X-ray source are blocked, so that the X-ray intensity is improved as in claim 5. The sample current can be increased, and the film can be formed while accurately measuring the film thickness.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a film thickness measuring device according to a first embodiment of the present invention.

FIG. 2A is a diagram showing a correlation between a silicon oxide film thickness and a sample current amount in the film thickness measuring apparatus according to the first embodiment, and FIG.
FIG. 4 is an explanatory diagram for measuring a sample current amount.

FIG. 3 is a conceptual diagram of a film forming apparatus showing a second embodiment of the present invention.

FIG. 4 is a conceptual diagram of a film thickness measuring device and a film forming device showing a third embodiment of the present invention.

FIG. 5 is a theoretical curve showing a relationship between a sample current calculation value and a film thickness in a fourth embodiment of the present invention.

FIG. 6 is a conceptual diagram of a film thickness measuring apparatus and a film forming apparatus showing a fifth embodiment of the present invention.

FIG. 7 is a conceptual diagram of a conventional film thickness measuring device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Al target 2 Quartz crystal 3 Silicon substrate 4 Ammeter 5 Substrate 6 Coating 7 X-ray irradiation device 8 X-ray intensity detector 9 Diffracted X-ray 10 Exposure nozzle 11 Infrared heating device 12 XY moving mechanism 13 Al target 14 Electrode 15 Silicon oxide Membrane 20 Monochrome X-ray source 21 Conventional X-ray source

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F067 AA27 BB17 FF06 HH04 JJ05 KK09 LL00 PP12 4M106 AA13 BA20 CA48 DH03 DH16 DH19 DH34 DH60 DJ04

Claims (8)

[Claims] 1. The method according to claim 1, wherein the substrate is held in a vacuum with the substrate connected to a ground, and a film thickness on the substrate is measured by a current value supplied from the ground when the substrate is irradiated with monochrome X-rays. Thickness measurement method. 2. A substrate is connected to a ground and held in a vacuum, and a sample current supplied from the ground when the substrate is irradiated with monochromatic X-rays is measured to determine the atomic density of the substrate and the film on the substrate. A film thickness measuring method, wherein the film thickness is determined by a film thickness dependency curve of the sample current calculated by a sensitivity coefficient to X-ray irradiation. 3. A monochrome X-ray generator, a substrate having a film formed on its surface held in a vacuum, and an amount of electrons connected to the substrate and ground and excited by monochrome X-rays of the monochrome X-ray generator. A film thickness measuring device provided with an ammeter for measuring. 4. The film thickness measuring apparatus according to claim 3, further comprising a mechanism for moving the substrate in the plane direction. 5. A conventional X-ray source, a substrate which is held in a vacuum and has a film formed on a surface thereof, an electrode located between the conventional X-ray source and the substrate, and wherein the conventional X-ray source is connected to the substrate and ground. An ammeter for measuring an amount of electrons excited by an X-ray source, and applying a voltage to the electrode to block electrons emitted from the conventional X-ray source. 6. A monochrome X-ray generator, a substrate held in a vacuum, an ammeter connected to the substrate and ground for measuring an amount of electrons excited by the monochrome X-ray generator, A film forming apparatus comprising: an exposure nozzle for introducing a gas to form a film on the substrate surface; and a substrate heating device for controlling the temperature of the substrate. 7. The film forming apparatus according to claim 6, further comprising a mechanism for moving the substrate in the plane direction. 8. A conventional X-ray source, a substrate held in a vacuum, an electrode located between the conventional X-ray source and the substrate, and connected to the substrate and ground and excited by the conventional X-ray source. An ammeter for measuring the amount of electrons generated, an exposure nozzle for introducing a gas to the substrate to form a film on the surface of the substrate, and a substrate heating device for controlling the temperature of the substrate, and applying a voltage to the electrode. A film forming apparatus for cutting off electrons emitted from the conventional X-ray source.