JPH1167681A - Substrate processing unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently heat a substrate while suppressing heating of a quartz member, and to appropriately perform measurements of temperature, by providing lamps for heating the substrate by irradiating light having an effective wavelength band not exceeding a fundamental absorption edge wavelength, to a substrate. SOLUTION: A substrate processing unit 1 has a device for irradiating light from lamps 21 to heat a semiconductor substrate 9. Temperatures of the substrate 9 under heating is measured by a radiation thermometer 31. In this substrate processing unit 1, the substrate 9 is subjected to heat treatment in a quartz chamber 41 made of quartz. Sulfer is employed for the lamps 21, leading to high spectral radiation intensity of the light as within a wavelength of 0.4-0.7 μm. A wavelength band of high spectral radiation intensity is called an effective wavelength band. Si has a character of efficiently absorbing light whose wavelength is 1.1 μm or less. Since the effective wavelength band of the light emitted from the lamps 21 does not exceed the fundamental absorption edge wavelength of Si, the light emitted from the lamps 21 is efficiently absorbed by the substrate 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate processing apparatus for performing processing involving heating using a lamp on a substrate such as a semiconductor substrate for manufacturing a semiconductor device. CVD (Chemical Vapor De
(Position) etc., which relates to a substrate processing apparatus for rapidly raising and lowering the temperature of a substrate.

[0002]

2. Description of the Related Art In a substrate processing apparatus for performing a process involving heating using a lamp, a halogen lamp has conventionally been used as a heating source.
The emission spectral characteristic of this halogen lamp shows a characteristic substantially in accordance with Planck's equation regarding radiation (radiation). FIG. 9 shows the spectral irradiation characteristics according to the Plump equation. Note that the wavelength is λ,
If the temperature is T, the radiation intensity distribution L by Planck's equation
(Λ, T) is

[0003]

(Equation 1)

[0004] However,

[0005]

(Equation 2)

[0006]

On the other hand, when the object to be heated is Si (silicon), which is the material of the semiconductor substrate, the relationship between the wavelength of the received light and the transmittance is as shown in FIG. Although this transmittance varies depending on the temperature of Si, it is known that the transmittance has characteristics shown in FIG. 10 from room temperature to about 900K. That is, Si has a property of transmitting light having a wavelength of about 1.1 to 20 μm at a rate of slightly more than 50%.

A comparison between FIG. 9 and FIG. 10 shows that when a Si substrate, which is a semiconductor substrate, is heated using a halogen lamp, a large amount of light having a wavelength passing through the Si is irradiated, so that a high heating efficiency can be obtained. Can not. Specifically, the heating efficiency (the ratio of the energy absorbed by the Si substrate to the lamp spectral radiant intensity (energy calculated by the above formula 1)) is determined from the relationship between the spectral radiant intensity of the halogen lamp and the transmittance of Si. And as shown in FIG. 11,
The heating efficiency is about 0.5. In FIG. 11, since the energy absorbed by the substrate processing apparatus itself is not considered, the heating efficiency is actually lower.

When a halogen lamp is used as described above,
Since the heating efficiency of the semiconductor substrate is low, the substrate processing apparatus needs to be 150
It is estimated that power of about kW is required. However, it is practically impossible to supply such large electric power.

In such a substrate processing apparatus, usually,
In order to isolate the processing environment from the outside, light from a halogen lamp is applied to the semiconductor substrate through a quartz chamber or a quartz window material. As shown in FIG. 10, quartz has a property of absorbing light having a wavelength of about 5 μm or more. When light from a halogen lamp is irradiated through quartz, the energy of light having a wavelength component of 5 μm or more is obtained. Is absorbed by quartz.

However, since the light emitted from the halogen lamp contains a large amount of light having a wavelength of 5 μm or more, an inefficient phenomenon occurs in that much of the light energy is consumed for heating the quartz. Would.

Further, when the quartz member is heated to a high temperature as described above, there arises a problem that the radiation emitted from the quartz acts as noise in the temperature measurement of the semiconductor substrate.

Further, in the temperature measurement using a radiation thermometer, generally, radiation in a wavelength band of about 5 to 10 μm from a semiconductor substrate is used for measurement, and light from a halogen lamp is also a component of light in this wavelength band. Therefore, there is also a problem that the light of the halogen lamp acts as a noise component.

In view of the above, an object of the present invention is to provide a substrate processing apparatus capable of efficiently heating a substrate, suppressing heating of a quartz member, and performing appropriate temperature measurement. And

[0015]

According to a first aspect of the present invention, there is provided a substrate processing apparatus for performing processing involving heating of a substrate, wherein the substrate is irradiated with light having an effective wavelength band equal to or less than a fundamental absorption edge wavelength of the substrate. And a lamp for heating the substrate.

According to a second aspect of the present invention, in the substrate processing apparatus according to the first aspect, the substrate is a silicon substrate, and the lamp emits light having an effective wavelength band of about 1.1 μm or less.

According to a third aspect of the present invention, there is provided a substrate processing apparatus for performing a process involving heating of a substrate, comprising: a lamp for heating the substrate by irradiating the substrate with light; and a quartz member for separating the substrate from the lamp. And the light emitted from the lamp is light having an effective wavelength band included in a transmission wavelength region of the quartz member.

According to a fourth aspect of the present invention, there is provided a substrate processing apparatus for performing a process involving heating on a substrate, comprising: a temperature measuring means for measuring a temperature of the substrate in a non-contact manner by receiving light emitted from the substrate; A lamp for heating the substrate by irradiating the substrate with light having an effective wavelength band outside the measurement wavelength band of the temperature measuring means.

According to a fifth aspect of the present invention, in the substrate processing apparatus of the fourth aspect, the temperature measuring means is a radiation thermometer using a photocell.

[0020]

FIG. 1 is a longitudinal sectional view showing the structure of a substrate processing apparatus 1 according to a first embodiment of the present invention. The substrate processing apparatus 1 is a substrate processing apparatus that irradiates light from a lamp 21 to heat a semiconductor substrate 9 (hereinafter, simply referred to as a “substrate”).
1, the temperature is measured.

In the substrate processing apparatus 1, the substrate 9 is heated in a quartz chamber 41 made of quartz. In the quartz chamber 41, the substrate 9 is placed and supported on a soaking ring 51 made of SiC (silicon carbide) on a support 52 made of quartz. In addition, the heat equalizing ring 51 supports the substrate 9 with a claw portion, and
And plays a role in making the heat distribution of the substrate 9 uniform.

The support table 52 is connected to a lid 54 via an arm 53.
The substrate 9 is carried in and out of the quartz chamber 41 together with the support 52 by moving the lid 54 in the horizontal direction as indicated by an arrow 5M.

The quartz chamber 41 is supported via a flange 42. The quartz chamber 41 is further provided with a gas supply port 411 for supplying a processing gas.
Has an exhaust port 41 for exhausting gas inside the quartz chamber 41.
2 are provided.

Lamps 21 are provided above and below the quartz chamber 41, and when these lamps 21 are turned on, the lamps 21 are passed through the quartz chamber 41.
The substrate 9 is heated by irradiating light from the substrate 9. That is, the quartz chamber 41 plays a role of isolating the space where the substrate 9 exists from the space where the lamp 21 exists. Further, during heating, N ₂ gas is supplied from the gas supply port 411.
An atmosphere adjusting gas such as (nitrogen) and an inert gas, and a processing gas such as NH ₃ (ammonia), O ₂ (oxygen), and N ₂ O (dinitrogen monoxide) are supplied into the quartz chamber 41 and 9 is subjected to a process involving heating.

The lamp 21 and the quartz chamber 41 are covered by the lamp house 6, and a cooling water channel 61 is provided inside the lamp house 6. Thereby, the lamp 2
The lamp house 6 receiving the light from 1 is cooled to prevent the temperature of the lamp house 6 from rising. The inner wall of the lamp house 6 is mirror-finished so as to reflect the light from the lamp 21 so that the light from the lamp 21 can be efficiently radiated to the substrate 9 without being absorbed by the lamp house 6. Has become.

The lamp house 6 is provided with a radiation thermometer 31. The radiation thermometer 31 receives light emitted from the substrate 9 through the window member 32 and measures the temperature of the substrate 9 in a non-contact manner. It is supposed to.

FIG. 2 is a block diagram showing a control system relating to lighting control of the lamp 21 of the substrate processing apparatus 1 shown in FIG. 1, and shows an electrical connection relationship between the lamp 21 and the radiation thermometer 31.

The power from the power supply 8 is supplied to the lamp 21 via the power controller 22, and a signal from the radiation thermometer 31 is input to the power controller 22 via the temperature controller 33. ing.

The temperature controller 33 controls the distribution of power supplied from the power controller 22 to each lamp 21. This control includes PID feedback control for calculating a PID coefficient based on the temperature measured by the radiation thermometer 31. Has become. Thereby, the rise and fall of the temperature of the substrate 9 during the heat treatment are appropriately controlled.

The configuration of the substrate processing apparatus 1 has been described above. Next, the spectral characteristics of the lamp 21 used in the substrate processing apparatus 1 will be described, and the substrate processing apparatus 1 according to the present invention will be described.
We will clarify the characteristics of.

FIG. 3 is a diagram showing the spectral characteristics of the lamp 21 used in the substrate processing apparatus 1 in the form of a spectral curve. The horizontal axis shows the wavelength, and the vertical axis shows the relative radiation intensity with respect to the wavelength. This lamp 21 is a lamp using S (sulfur) and has a wavelength of about 0.4 to 0.7 μm as shown in FIG.
Has a high spectral radiation intensity. In the following description, a wavelength band having a high spectral radiant intensity (for example, a wavelength band having a spectral radiant intensity equal to or more than １ ／ of the highest spectral radiant intensity, is approximately 0.4 to 0.7 in the lamp 21).
The wavelength band is μm. ) Is called an “effective wavelength band”.

On the other hand, in the semiconductor substrate formed of Si, the absorptance (depending on the temperature) with respect to the wavelength of the irradiation light is as shown in FIG. It has the property of efficiently absorbing light having a wavelength of 0.1 μm or less. The wavelength at the position indicated by the symbol A is called the fundamental absorption edge wavelength of Si. 3 and 4, the effective wavelength band of the light emitted by the lamp 21 is Si.
It can be seen that the light of the lamp 21 is efficiently absorbed by the substrate 9 because the wavelength is equal to or less than the fundamental absorption edge wavelength. That is, the substrate 9 can be efficiently heated by using the lamp 21.

In the conventional method of heating a substrate using a halogen lamp, the halogen lamp emits light substantially in accordance with the spectral radiant intensity shown in FIG. 9 as described above, and is longer than the fundamental absorption edge wavelength of Si. The substrate 9 is irradiated with light of a large wavelength. Therefore, most of the light from the halogen lamp is transmitted without being absorbed by Si,
Most of the electric power applied to the halogen lamp is not used for heating the substrate 9 (see FIG. 11). Also, 90
At a relatively low temperature of about 0K, halogen lamps
Since most of the components have wavelengths longer than the fundamental absorption edge wavelength of i, it is difficult to control the temperature at a low temperature.

As described above, the lamp 2
The effective wavelength band of light from 1 is less than the fundamental absorption edge wavelength of the substrate 9 (about 1.1 μm for Si shown in FIG. 4 and about 2 μm for Ge (germanium) as shown in FIG. 10). Therefore, the light from the lamp 21 is absorbed by the substrate 9 more efficiently than the halogen lamp. That is, lamp 2
1 can be used for heating the substrate 9 with high efficiency. As a result, the power to be supplied to the substrate processing apparatus 1 can be kept low. In particular, it is possible to overcome the problem that the power supply to the substrate processing apparatus is increased due to the recent increase in the size of the substrate. Further, the temperature controllability at a relatively low temperature up to about 900K is also improved.

Next, the relationship between the spectral characteristics of the lamp 21 and quartz will be described.

As shown in FIG. 10, quartz has the property of transmitting light having a wavelength of about 5 μm or less. Therefore, 5
Lamp 21 having an effective wavelength band of light having a wavelength shorter than μm
Is irradiated on the substrate 9 without being absorbed by the quartz. Thereby, the lamp 21 is moved to the quartz chamber 41.
, And the substrate 9 can be efficiently heated.

On the other hand, in the case of a conventional halogen lamp, 5 μm
m, the light component having a wavelength longer than m is absorbed by the quartz chamber 41,
Is heated. As a result, the light from the halogen lamp cannot be effectively used for heating the substrate. In addition, since the radiated light is emitted from the quartz chamber 41 having a high temperature, the radiated light is taken into the radiation thermometer 31 as noise, which makes accurate temperature measurement difficult.

As described above, by using the lamp 21 having the spectral characteristics shown in FIG. 3 instead of the halogen lamp,
The substrate 9 can be efficiently heated without heating the quartz chamber 41. Further, it is possible to reduce the occurrence of noise in temperature measurement due to the high temperature of the quartz chamber 41.

Next, the relationship between the spectral characteristics of the lamp 21 and the radiation thermometer 31 will be described.

In the substrate processing apparatus 1 shown in FIG. 1, the lamp 21 is arranged between the radiation thermometer 31 and the substrate 9, and a part of the light of the lamp 21 emits the radiation temperature through the window material 32. The light enters the total 31. FIG. 5 shows the spectral characteristics of the light from the lamp 21 and the light emitted from Si at this time. Here, when a thermopile radiation thermometer using a thermocouple is used as the radiation thermometer 31, the wavelength band of radiation light from the substrate 9 conventionally used for measuring the temperature of the substrate 9 is about 5 to 10 μm. (An example of a conventional measurement method will be described later.) When a radiation thermometer using a photocell is used, a wavelength band of about 0.8 to 1 μm (shown by a symbol B2). is there. In the following description, these wavelength bands used for temperature measurement will be referred to as measurement wavelength bands. On the other hand, the effective wavelength band of the lamp 21 is 0.4 to 0.7 μm.
m, it does not act as a noise component on the radiation thermometer 31.

On the other hand, the spectral characteristics of the conventional halogen lamp almost follow the Planck's equation shown in Equation 1, and the radiated light from Si also almost follows the Planck's equation.
As shown in FIG.
The state includes the spectral curve of the emitted light from.
Therefore, when the light of the halogen lamp is incident on the radiation thermometer 31, it is impossible to measure the temperature of the substrate 9 properly.

As described above, since the effective wavelength band of the lamp 21 is outside the measurement wavelength band of the radiation thermometer, it does not affect the temperature measurement, and accurately measures the temperature of the substrate 9 during the heat treatment. be able to. This also realizes accurate control of heating of the substrate 9 by the configuration shown in FIG.

FIG. 7 is a longitudinal sectional view showing the structure of a substrate processing apparatus 1a according to a second embodiment of the present invention.

The substrate processing apparatus 1a is an apparatus for performing processing involving heating by irradiating the substrate 9 with light from a lamp 21 similarly to the substrate processing apparatus 1 shown in FIG. Only in that the light from the lamp 21 is emitted. In FIG. 7, the same components as those in FIG. 1 are denoted by the same reference numerals.

In the substrate processing apparatus 1a, a substrate 9 to be processed is mounted on a heat equalizing ring 51 on a support 52 and processed. However, the support table 52 is fixed to the chamber body 7 which forms a part of the outer shell of the substrate processing apparatus 1a. It is arranged on the ring 51.

The chamber body 7 has an opening at the top, and a quartz window 43 is arranged so as to close this opening.
That is, a chamber that is a space where the substrate 9 is processed by the chamber body 7 and the quartz window 43 is formed.

Further above the quartz window 43, the lamp 21 having the same spectral characteristics shown in FIG.
Are arranged, and the lamp house 6 is arranged so as to cover these lamps 21. That is, the substrate 9 is isolated from the lamp 21 by the quartz window 43. With such a configuration, the upper surface of the substrate 9 is irradiated with the light from the lamp 21 through the quartz window 43 to heat the substrate 9. It is to be noted that a required processing gas or the like is supplied into the chamber from the gas supply port 72 during the heat treatment of the substrate 9 as in the first embodiment.

The inner surface of the lamp house 6 is mirror-finished so that the light from the lamp 21 is not absorbed by the lamp house 6. Cooling channels 62, 7
1 is formed.

Also in this substrate processing apparatus 1a, a radiation thermometer 31 is arranged in the lamp house 6 and the chamber main body 7, and the temperature of the upper surface and the lower surface of the substrate 9 can be measured through the window material 32 in a non-contact manner. It has become. In the substrate processing apparatus 1a, since the substrate 9 is heated only from the upper surface, a plurality of radiation thermometers 31 can be arranged in the chamber body 7 (only two radiation thermometers are shown in FIG. 7). The temperature distribution can be measured.

FIG. 8 is a block diagram showing a control system relating to lighting control of the lamp 21 of the substrate processing apparatus 1a, and shows an electrical connection relationship between the lamp 21 and the radiation thermometer 31. In the substrate processing apparatus 1a, as in the first embodiment,
The temperature controller 33 receiving the signal from the radiation thermometer 31 sends a control signal to the power controller 22, and the power controller 22 supplies power from the power supply 8 to each lamp 21. As described above, the temperature distribution of the substrate 9 can be measured in the substrate processing apparatus 1a, so that the temperature distribution of the substrate 9 is also controlled based on the measurement result.

Since the substrate processing apparatus 1a uses the lamp 21 having the spectral characteristics shown in FIG. 3 as in the first embodiment, the substrate 9 is efficiently heated and the quartz window 43 is prevented from being heated to a high temperature. , And noise in temperature measurement can be reduced.

That is, the effective wavelength band of the lamp 21 is Si
, The light from the lamp 21 is efficiently absorbed by the substrate 9. As a result, the power used for heating the substrate 9 can be reduced.

Since the effective wavelength band of the lamp 21 is included in the transmission wavelength region of quartz (about 5 μm or less), the lamp 2
The light from 1 is not absorbed and the quartz window 43 does not become hot, so that it is possible to reduce waste of energy and generation of noise due to light emitted from the quartz window 43.

By the way, the substrate 9 is formed by using a halogen lamp.
When heating is performed from one side, a method of measuring the temperature from the other side of the substrate 9 through a window member 32 of CaF _{2 has} conventionally been used. Quartz is about 5 μm as shown in FIG.
Since light having a wavelength longer than 5 μm is not transmitted, the influence of light from the halogen lamp itself can be prevented by using light having a wavelength longer than 5 μm for temperature measurement. Also, Ca
F ₂ has the property of transmitting light up to a wavelength of about 10 μm. FIG. 6 schematically shows this relationship. From the above, the halogen lamp was isolated from the chamber by the quartz window 43, and C
In the window material 32 of aF ₂ it is possible to use the radiation thermometer 31 of the temperature measuring radiation from the substrate 9 in the wavelength band of about 5~10μm on which isolated from the chamber. Symbol B1 in FIG.
Is a wavelength band used for conventional temperature measurement.

When using radiation light in the measurement wavelength band of 5 to 10 μm, a thermopile radiation thermometer using a thermocouple is used as the radiation thermometer 31. However, the emissivity of this measurement wavelength band to be set before use is a parameter that greatly changes depending on the surface state of the substrate 9 and a change in the temperature of the substrate 9, and is accurate in a heating process involving a steep and large temperature change. It is difficult to perform temperature measurement.

On the other hand, when the lamp 21 having the spectral characteristics shown in FIG. 3 is used, the effective wavelength band of the lamp light is about 0.4 to
Since the measurement wavelength band used for measuring the temperature of the radiation thermometer using the photocell is about 0.8 to 1 μm, the effective wavelength band of the lamp light is outside the measurement wavelength band, This radiation thermometer can be used without any consideration that the light of the above type is incident on the radiation thermometer 31 (see reference numeral B2 in FIG. 5). This point is as described in the first embodiment.

When a radiation thermometer using this photocell is used, the measurement wavelength band is about 0.8 to 1 μm. In this wavelength band, the emissivity to be set hardly changes, and Si
The amount of light emitted from the light source is also sufficient. Therefore, accurate temperature measurement can be performed without complicated emissivity setting. As a result, even when a change in emissivity becomes a problem in a substrate processing apparatus using a halogen lamp, the substrate processing apparatus 1a according to the present invention can easily and accurately measure temperature by using a radiation thermometer using a photocell. It can be performed.

Although the embodiment according to the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible.

For example, in the above embodiment, the semiconductor substrate formed of Si has been mainly described.
The same applies to a semiconductor substrate formed of Ge.
As shown in FIG. 10, since the basic absorption edge wavelength of Ge is about 2 μm, the Ge substrate can be efficiently heated as long as the effective wavelength band of the lamp 21 is 2 μm or less.

Further, the spectral curve of the lamp 21 shown in FIG. 3 is an example of the spectral curve of a lamp that has been put into practical use. Efficient heating is possible as long as it is a band. In addition, as long as the effective wavelength band is included in the transmission wavelength region of the quartz, heating of the quartz can be prevented. As long as the effective wavelength band is outside the measurement wavelength band of the radiation thermometer, noise can be reduced.

[0061]

According to the first and second aspects of the present invention, since the effective wavelength band of the lamp is equal to or less than the fundamental absorption edge wavelength of the substrate, light from the lamp can be efficiently absorbed by the substrate. Heating efficiency can be increased. As a result, the power to be supplied to the substrate processing apparatus can be reduced.

According to the third aspect of the present invention, since the effective wavelength band of the lamp is included in the transmission wavelength region of the quartz member, the quartz member does not become hot while the substrate is subjected to a process involving heating. This enables efficient heating of the substrate. Further, when measuring the temperature of the substrate, it is possible to prevent generation of noise from the quartz member which has become high in temperature.

According to the fourth and fifth aspects of the present invention, since the effective wavelength band of the lamp is outside the measurement wavelength band, light from the lamp does not cause noise in the temperature measurement of the substrate.
Thereby, accurate temperature measurement of the substrate is realized.

Further, in the invention according to claim 5, since the temperature of the substrate is measured using a radiation thermometer using a photocell, accurate temperature measurement can be easily performed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a substrate processing apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a control system of the substrate processing apparatus shown in FIG.

FIG. 3 is a diagram showing spectral characteristics of a lamp used in the substrate processing apparatus shown in FIG.

FIG. 4 is a diagram showing a fundamental absorption edge wavelength of Si.

5 is a diagram showing a spectral curve of a lamp and Si used in the substrate processing apparatus shown in FIG.

FIG. 6 is a diagram showing a spectral curve of a halogen lamp and Si.

FIG. 7 is a longitudinal sectional view of a substrate processing apparatus according to a second embodiment of the present invention.

8 is a block diagram showing a control system of the substrate processing apparatus shown in FIG.

FIG. 9 is a diagram showing the spectral radiation intensity according to Planck's equation.

FIG. 10 is a diagram showing transmittance with respect to wavelengths of Si, Ge, quartz, and CaF ₂ .

FIG. 11 is a diagram showing the efficiency with which light from a halogen lamp is used for heating Si.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 1a Substrate processing apparatus 9 Substrate 21 Lamp 31 Radiation thermometer 41 Quartz chamber 43 Quartz window A Basic absorption edge wavelength B1, B2 Measurement wavelength band

Claims (5)

[Claims] 1. A substrate processing apparatus for performing a process involving heating on a substrate, comprising a lamp for heating the substrate by irradiating the substrate with light having an effective wavelength band equal to or less than a fundamental absorption edge wavelength of the substrate. A substrate processing apparatus characterized by the above-mentioned. 2. The substrate processing apparatus according to claim 1, wherein said substrate is a silicon substrate, and said lamp is about 1.1.
A substrate processing apparatus for irradiating light having an effective wavelength band of not more than μm. 3. A substrate processing apparatus for performing processing involving heating on a substrate, comprising: a lamp for heating the substrate by irradiating the substrate with light; and a quartz member for separating the substrate from the lamp.
The substrate processing apparatus, wherein the light emitted from the lamp is light having an effective wavelength band included in a transmission wavelength region of the quartz member. 4. A substrate processing apparatus for performing a process involving heating on a substrate, comprising: a temperature measuring means for measuring a temperature of the substrate in a non-contact manner by receiving radiation light from the substrate; A substrate processing apparatus, comprising: a lamp for heating a substrate by irradiating the substrate with light having an effective wavelength band outside the measurement wavelength band. 5. The substrate processing apparatus according to claim 4, wherein said temperature measuring means is a radiation thermometer using a photocell.