JP3277669B2 - Semiconductor manufacturing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus provided with a temperature measuring device utilizing a temperature measuring method using Raman scattered light.

[0002]

2. Description of the Related Art Various methods have been proposed for measuring the surface temperature of a wafer in a process chamber of a semiconductor manufacturing apparatus. As the method, there have been proposed a method of measuring the temperature of the wafer surface by attaching a thermocouple to the surface of the wafer, and a method of measuring the temperature of the wafer surface using a radiation thermometer. The former method utilizes a thermoelectromotive force between different metals. On the other hand, the latter measurement method measures the temperature of the wafer using thermal radiation emitted from the wafer.

[0003]

However, in the method of measuring temperature using a thermocouple, contamination is a problem because the thermocouple is brought into contact with the wafer. Also,
In order to measure the uniformity of the wafer temperature, it is necessary to attach thermocouples to the wafer by the number of measurement points. For this reason,
Temperature measurement is very troublesome. Also, if many thermocouples are attached, the heat capacity of the wafer changes and accurate temperature measurement cannot be performed.

In temperature measurement using a thermal radiation thermometer,
The emissivity of the wafer becomes an issue. Assuming that the value measured by the radiation thermometer is m, the true temperature is T, and the emissivity is ε, if k is a sensitivity of the radiation thermometer and f is a function representing radiation incident on the radiation thermometer, m = kf (T , Ε). As described above, since there are unknown numbers T and ε, it is necessary to determine ε first and substitute T into the original m = kf (T, ε) to determine T. Various methods for determining ε have been proposed, but none has been established. For this reason, since the relationship between the radiation amount and the surface temperature cannot be sufficiently grasped, the temperature of the wafer surface cannot be determined accurately.

An object of the present invention is to provide a semiconductor manufacturing apparatus provided with a temperature measuring device utilizing a temperature measuring method based on Raman scattered light which is excellent in non-contact and accurate measurement of the temperature of a wafer surface. .

[0006]

SUMMARY OF THE INVENTION The present invention is a semiconductor manufacturing apparatus provided with a temperature measuring device utilizing a temperature measuring method based on Raman scattered light which has been achieved to achieve the above object.

A semiconductor manufacturing apparatus according to the present invention has a chamber in which a stage on which a substrate is placed is provided. The stage has a plurality of lasers penetrating from the back side to the substrate mounting surface side. A laser light oscillator that oscillates laser light; and a laser light oscillated from the laser light oscillator passes through the laser light irradiation hole and irradiates the measured surface of the base. Laser light scanning means for adjusting the laser light to be transmitted, an optical fiber cable having a light receiving surface disposed on the emission direction side of the Raman scattered light emitted from the position of the substrate irradiated with the laser light, and transmitted by the optical fiber cable. A spectrometer for receiving the Raman scattered light, and obtaining the temperature of the surface to be measured of the base based on the intensity of the Raman scattered light measured by the spectrometer. Since those equipped with a temperature measuring device having a computing unit which is connected to the spectrometer.

In the temperature measurement using the Raman scattered light, the surface to be measured of the substrate is irradiated with a laser beam, and the intensity of the anti-Stokes light and the Stokes light of the Raman scattered light emitted at that time is measured. The temperature of the surface to be measured is determined based on the value. When a multilayer film is formed on the measurement surface of the base, the measurement surface of the base is irradiated with laser light,
At that time, the intensity of the anti-Stokes light and the Stokes light of the Raman scattered light emitted from each film is measured, and the temperature of the surface to be measured for each film is obtained based on the measurement value for each film.
When irradiating the measurement target surface of the substrate on which the multilayer film is formed with the laser light, the wavelength of the laser light is selected for each film type of the multilayer film and the laser light is applied.

When measuring the Raman scattered light by irradiating the surface to be measured with the laser beam, the irradiation position of the laser light with respect to the surface to be measured is moved and the anti-Raman scattering light at the moved irradiation position is moved. The intensity of the Stokes light and the Stokes light may be measured, and the temperature distribution of the surface to be measured may be obtained based on the measured value.

[0010]

In the above-mentioned semiconductor manufacturing apparatus, a plurality of laser light irradiation holes are provided on the stage, and a laser light oscillator or a laser light scanning means of the temperature measuring device is arranged so that the substrate is irradiated with the laser light through the holes. Is provided with a spectrometer that receives Raman scattered light through an optical fiber cable with a light-receiving surface in the emission direction of the Raman scattered light emitted from the stage. Measured without contact.

In the temperature measurement using the Raman scattered light, the temperature dependency of the Raman scattered light is used. Raman scattering is an inelastic scattering phenomenon of light due to elementary excitation in a solid such as lattice vibration (phonon). The Raman scattered light is observed when the energy shifts to the higher energy side (anti-Stokes light) or lower energy side (Stokes light) than the energy of the incident light, and the intensity increases as the temperature increases. Let the scattered light intensity of the anti-Stokes light be Ia
s and the scattered light intensity of the Stokes light is Is, then Is /
Ias is as shown in equation (1).

[0012]

(Equation 1) Here, ω _i is the frequency of incident light, ω ₀ is the frequency of phonons, h is Planck's constant, k _B is Boltzmann's constant, and T is temperature.

Accordingly, the temperature T can be obtained by measuring the scattered light intensity Ias of the anti-Stokes light and the scattered light intensity Is of the Stokes light. As described above, the intensity of the Raman scattered light emitted by irradiating the surface of the substrate with the laser light is measured, and the temperature of the substrate surface is determined based on the light intensity. . Therefore, contamination due to contact of the measuring device does not occur.

Further, when the surface of the substrate is formed of a multilayer film, the temperature is determined by measuring the Raman scattered light for each surface to be measured. Without measuring the temperature of each film surface of the multilayer film.

When irradiating a laser beam to the surface to be measured of the substrate on which the multilayer film is formed, the wavelength of the laser beam is selected and applied for each type of multilayer film, so that the laser beam extends to the inside of the multilayer film. Is incident. For this reason, Raman scattered light is generated on the surface of each film, so that the temperature of each film is measured.

When measuring the Raman scattered light by irradiating the surface to be measured with the laser light, the irradiation position of the laser light is moved and the intensity of the Raman scattered light at the irradiation position is measured. Is obtained.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the semiconductor manufacturing apparatus of the present invention will be described with reference to the schematic diagram of the semiconductor manufacturing apparatus shown in FIG.

As shown in FIG. 1, the semiconductor manufacturing apparatus 8 includes a chamber 6. The above chamber 6
Is provided with a stage 21. The stage 21 is provided with a plurality of laser beam irradiation holes 22 penetrating from the back surface side to the substrate mounting surface 21a side. The chamber 6 has a window 9 through which the laser beam L is incident.
For example, it is provided below the stage 21. Window 9 above
Is made of, for example, quartz glass and can transmit Raman scattered light R.

The laser beam L is transmitted through the window 9 and passes through the laser beam irradiating hole 22 onto the measured surface 81a of the substrate 81 placed on the stage 21. Is provided with a temperature measuring device 2.

The temperature measuring device 2 includes a laser light oscillator 11 for oscillating laser light, and a laser light L oscillated from the laser light oscillator 11 passing through a laser light irradiation hole 22 provided on a stage 21 and a base 81. And a laser beam scanning means 61 for adjusting the surface to be measured 81a to be irradiated. The laser light oscillator 11 has a power supply 15
Is connected.

The temperature measuring device 2 has a base 81
An optical fiber cable 32 having a light receiving surface 32a disposed on the emission direction side of the Raman scattered light R emitted from the position irradiated with the laser light L, and receives the Raman scattered light R transmitted by the optical fiber cable 32 Spectrometer 31
And an arithmetic unit 41 connected to the spectrometer 31 for obtaining the temperature of the measured surface 81a of the base 81 based on the intensity of the Raman scattered light measured by the spectrometer 31.

The laser light oscillator 11 only needs to emit Raman scattered light R when it irradiates the surface 81a to be measured of the instrument 81. For example, a semiconductor laser light oscillator, a gas laser light oscillator, a solid laser light An oscillator, an excimer laser light oscillator, a die laser light oscillator, a liquid laser light oscillator, or the like can be used.

Further, in the case where the laser light oscillator 11 comprises a wavelength-variable laser light oscillator, for example, a die laser light oscillator, when the laser light L is applied to the surface of the substrate 81, the laser light L is formed on the surface. It is possible to select the laser beam L having a wavelength that emits the Raman scattered light R most strongly according to the type of the film (not shown). Therefore, highly sensitive temperature measurement becomes possible.

Further, when the laser light oscillator 11 is constituted by a semiconductor laser light oscillator, the laser light oscillator 1
1 can be miniaturized.

The laser beam scanning means 61 comprises a reflecting mirror 62 rotatable, for example, in the direction of the arrow, and a driving unit 63 for rotating the reflecting mirror 62. This drive unit 6
Although not shown, the mirror 3 may rotate the reflecting mirror 62 three-dimensionally.

The optical fiber cable 32 is composed of a plurality of cables as shown in the figure, and the light receiving surface 32a of each optical fiber cable 32 is located in the chamber 6 and emitted through each laser beam irradiation hole 22. It is arranged to face the Raman scattered light R to be emitted. Although not shown, the light receiving surface 32a of the optical fiber cable 32 transmits Raman scattered light R that passes through the window 9 through the laser beam irradiation hole 22 and is emitted to the outside of the chamber 6. They may be arranged to face each other. Also,
The number of the optical fiber cables 32 arranged so as to be opposed to the Raman scattered light R emitted through each of the laser light irradiation holes 22 may be singular or plural.

As described above, in the temperature measuring device 2, the Raman scattered light R is received by the optical fiber cable 32, so that the Raman scattered light R can be received near the irradiation position of the laser light L. Therefore, a sufficient amount of Raman scattered light R is incident on the spectrometer 31. Further, by connecting the plurality of optical fiber cables 32, it is possible to receive the Raman scattered light R in the vicinity of a plurality of laser beam irradiation positions.

It is preferable to use, for example, a multi-channel type spectrometer as the spectrometer 31. This multi-channel spectrometer has, for example, a solid-state imaging device and a spectral dispersion system such as a diffraction grating. The spectrometer 31 is connected to a calculation unit 41 that calculates the surface temperature of the base 81 based on the intensity of the Raman scattered light R measured by the spectrometer 31.

In the above multi-channel spectrometer,
Raman scattered light is received with high sensitivity. Further, in the multi-channel spectrometer, the Raman scattered light R emitted from the surface of the substrate irradiated with the laser light L is measured in real time by a photodiode array. Ends in a short time. Therefore, the temperature measurement accuracy is improved.

As described above, the semiconductor manufacturing apparatus 8 is configured.

In the semiconductor manufacturing apparatus 8, the stage 21
A plurality of laser light irradiation holes 22 are provided in
Since the laser light oscillator 11 and the laser light scanning means 61 of the temperature measuring device 2 are arranged in a state in which the measured surface 81b on the back surface side of the base 81 is irradiated with the laser light L through the base 2, the temperature of the base 81 Is measured in a non-contact manner from the stage 21 side. Therefore, when etching or sputtering is performed by disposing an electrode (not shown) or a target (not shown) above the base 81, the temperature of the base 81 during the process is measured.

That is, the laser light L oscillated from the laser light oscillator 11 is applied to each laser light irradiation hole 22 by the laser light scanning means 61 provided on the optical path.
Irradiated on the surface to be measured 81a. At that time, the Raman scattered light R is emitted from the irradiation surface of the laser light L. The emitted Raman scattered light R is received by the light receiving surface 32a of the optical fiber cable 32, and the received Raman scattered light R is transmitted to the spectrometer 31 through the optical fiber cable 32,
The light intensity is measured by the spectrometer 31. Then, the signal S of the measured light intensity is transmitted to the arithmetic unit 41. In the arithmetic unit 41, based on the transmitted light intensity signal S,
The temperature of the base 81 is obtained from the relationship shown in the above equation (1).

Here, an example of a temperature measuring method using Raman scattered light will be described with reference to a flowchart of the temperature measuring method shown in FIG. 2 and an intensity distribution diagram of the Raman scattered light shown in FIG. In FIG.
The vertical axis indicates light intensity, and the horizontal axis indicates energy.

As shown in FIG. 2, in a first procedure S1 "irradiation of laser light", the surface to be measured of the base is irradiated with laser light.
As long as the laser light emits Raman scattered light when irradiated on the surface to be measured, for example, a semiconductor laser light,
Gas laser light, solid laser light, excimer laser light, die laser light or liquid laser light may be used.

Next, a second procedure S2 "measurement of Raman scattered light" is performed. In the second procedure S2, the intensity distribution Ras (peak intensity Ias) of the anti-Stokes light of the Raman scattered light emitted from the measured surface of the base when the laser light is irradiated
And the intensity distribution Rs (intensity peak Is) of the Stokes light are measured.

FIG. 3 shows the intensity distribution of the Raman scattered light at this time.
It will be explained by. As shown in FIG. 3, an intensity distribution Ras (peak intensity Ias) of the anti-Stokes light and an intensity distribution Rs (intensity peak Is) of the Stokes light are obtained on both sides of the intensity distribution Iin of the incident laser light (Rayleigh light). For example, the substrate is made of silicon, in the laser light, wavelength 780 nm, output is used as the 2W, when performing temperature measurement, + 521 cm wave number ^-1 anti-Stokes light and -521Cm ^-1 And Stokes light having a wave number of

Then, a third procedure S3 "calculation of temperature" shown in FIG. 2 is performed. In the third procedure S3, based on the measured anti-Stokes light and Stokes light intensity Ias, Is, the measured value of the substrate irradiated with the laser light is obtained from the equation (2) showing the relationship that Is / Ias depends on the temperature. Find the surface temperature.

[0038]

(Equation 2) Here, ω _i is the frequency of incident light, ω ₀ is the frequency of phonons, h is Planck's constant, k _B is Boltzmann's constant, and T is temperature.

By narrowing the beam diameter of the laser beam to a small value, it becomes possible to measure the temperature in a minute range (a state close to a point) on the surface of the substrate.

The temperature measurement method using Raman scattered light utilizes that Is / Ias of Raman scattered light has temperature dependency. Raman scattering is a lattice vibration (phonon)
Is an inelastic scattering phenomenon of light due to elementary excitation in a solid, and the scattered light is observed when the energy of the incident light shifts to a higher energy side (anti-Stokes light) and a lower energy side (Stokes light). And, as the temperature increases, their strength increases. Therefore, the temperature T can be easily calculated and obtained from the relationship shown in the equation (1). Since the temperature of the surface to be measured of the substrate is obtained in a non-contact manner, no contamination occurs on the surface of the substrate.

The method for measuring the temperature when a multilayer film is formed on the temperature measuring surface side of the substrate by using the semiconductor manufacturing apparatus described with reference to FIG. 1 will be described below with reference to the multilayer film temperature measuring method shown in FIG. This will be described with reference to the explanatory diagram and the intensity distribution diagram of the Raman scattered light in FIG. In FIG. 5, the vertical axis indicates light intensity, and the horizontal axis indicates energy.

As shown in FIG. 4, the multilayer film 91 formed on the surface of the base 81 is made up of, for example, a first film 92 and a second film 92.
Of the film 93.

In this case, the surface to be measured is irradiated with the laser beam L in the first step S1 in the same manner as described with reference to FIG. When irradiating the laser beam L, the first film 92
The wavelength may be changed between the case where the temperature is measured and the case where the temperature of the second film 93 is measured. For example, the first film 92
When the temperature of the second film 93 is measured, the wavelength at which a large amount of Raman scattered light is generated is selected, and when the temperature of the second film 93 is measured, the Raman scattered light is Is selected, the wavelength at which the most occurs.

Next, in a second procedure S2, the first and the first data at that time are obtained.
Raman scattered light R ₉₂ , emitted from the second films 92, 93,
The intensity of _R93 is measured. As shown in FIG. 5, the intensity distribution of the Raman scattered light at this time is such that the intensity distribution Ras ₂ of the anti-Stokes light emitted from the first film 92 is on both sides of the intensity distribution Iin of the incident laser light (Rayleigh light). (Peak intensity Ias ₂ ), the intensity distribution of Stokes light Rs ₂ (peak intensity Is ₂ ), the intensity distribution of anti-Stokes light emitted from the second film 93 Ras ₃ (peak intensity Ias ₃ ), and the intensity of Stokes light A distribution Rs ₃ (peak intensity Is ₃ ) is obtained.

Then, in a third step S3, the first and second films 9 are formed.
The intensity of anti-Stokes light of 2 and 93 Ias _1, Ias ₂ and the first, the intensity of the Stokes light of the second film 92 and 93 I
On the basis of s ₁ and Is ₂ , in the same manner as described with reference to FIG. 1 above, Is ₁ / Ias ₁ , Is ₂ / Ias ₂
The temperatures of the surfaces to be measured 92a and 93a for each of the second films 92 and 93 are obtained.

In the above description, the method of measuring the temperature of a film having a two-layer structure has been described. However, the temperature can be measured in the same manner as described above for a single-layer film or a multilayer film having three or more layers.

In the temperature measuring method, the temperature is determined by measuring the Raman scattered light for each of the first and second films 92 and 93 on the surface of the substrate. The temperature of each film surface of the film is measured. In addition, since the wavelength of the laser light is selected and irradiated for each type of multilayer film, laser light of a wavelength that emits sufficient Raman scattered light from the film whose temperature is to be measured enters the multilayer film. It becomes possible to do.

[0048]

As described above, according to the semiconductor manufacturing apparatus of the present invention, since the temperature measuring device using Raman scattered light is provided, the surface temperature of the substrate during the process can be measured in a short time without contact. can do. Further, according to a semiconductor manufacturing apparatus in which a plurality of laser light irradiation holes are provided on a stage, and a laser light oscillator or a laser light scanning means of a temperature measuring device is arranged in a state where the laser holes are irradiated on the substrate through the laser light irradiation holes, The temperature of the substrate can be measured from the stage side in a non-contact manner. Therefore, the present invention can be applied to an etching apparatus or a film forming apparatus in which an electrode or a target is arranged above a base.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a semiconductor manufacturing apparatus.

FIG. 2 is a flowchart of a temperature measuring method according to an embodiment.

FIG. 3 is an intensity distribution diagram of Raman scattered light.

FIG. 4 is an explanatory diagram of a method for measuring a temperature of a multilayer film.

FIG. 5 is an intensity distribution diagram of Raman scattered light.

[Explanation of symbols]

2 ... Temperature measuring device, 6 ... Chamber, 8 ... Semiconductor manufacturing device, 11 ... Laser light oscillator, 21 ... Stage, 31 ...
Spectrometer, 32: optical fiber cable, 41: computing unit, 61: laser beam scanning means, L: laser beam,
R: Raman scattered light

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01K 11/12 G01K 11/20 H01L 21/20 H01L 21/66 H01S 3/08

Claims (1)

(57) [Claims] 1. A semiconductor manufacturing apparatus having a chamber in which a stage on which a substrate is placed is provided, wherein the stage is provided with a plurality of laser beam irradiation holes penetrating from the back surface side to the substrate placement surface side. A laser light oscillator that oscillates laser light, and a laser that adjusts the laser light oscillated from the laser light oscillator so as to pass through the laser light irradiation hole and irradiate the surface to be measured of the base. Optical scanning means, an optical fiber cable having a light receiving surface disposed on the emission direction side of the Raman scattered light emitted from the position of the substrate irradiated with the laser light, and receiving the Raman scattered light transmitted by the optical fiber cable Measuring the temperature of the measured surface of the substrate based on the intensity of the Raman scattered light measured by the spectrometer. A semiconductor manufacturing apparatus comprising a temperature measuring device having a connected arithmetic unit.