JPH07151606A - Instrument for measuring temperature of substrate - Google Patents

Abstract

PURPOSE:To provide a measuring instrument which can accurately measure the temperature of a substrate heated by the irradiation with light with high response and has excellent durability at high temperatures and a long service life. CONSTITUTION:The front end section of a light guiding member 12 is inserted into a heat mediating member 14 which is formed of a light shielding material having fixed emissivity and has a closed front end section and the energy radiated from the heat mediating member 14 which is heated to the same temperature as that of a substrate 24 by thermal conduction from the substrate 24 is detected by transfer the energy to a radiation thermometer through the light guiding member 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat treatment apparatus, for example, a lamp annealing apparatus, which is provided in a heating furnace when various heat treatments are applied to various substrates such as semiconductor wafers and liquid crystal display (LCD) glass substrates. The present invention relates to a temperature measuring device that measures the temperature of a substrate that is being heat-treated.

[0002]

2. Description of the Related Art When a semiconductor device is manufactured by subjecting a substrate to various heat treatments in a heating furnace by a heat treatment apparatus,
Accurate measurement of the surface temperature of the substrate during heat treatment is extremely important due to the complexity of the manufacturing process.

In order to measure the surface temperature of the substrate, a method of directly detecting the temperature of the substrate by means of detecting means such as a thermocouple and measuring the temperature, and heat radiated from the surface of the substrate housed in the heating furnace. There is a method of measuring the temperature of the substrate in a non-contact manner by detecting the energy with a radiation thermometer arranged outside the heating furnace. Among these, as a device for carrying out a method for contact-type temperature measurement of the temperature of a substrate housed in a heating furnace and heated by light irradiation, Japanese Patent Laid-Open No. 148545/1992 discloses a detecting means such as a thermocouple. There is disclosed a temperature measuring device in which is covered and covered with a covering member, a part of the covering member is formed into a flat surface, and a part of the substrate is supported by the flat surface of the covering member. When this temperature measuring device is used, the temperature of the substrate is measured by a contact method, so that the temperature of the substrate can be accurately measured, and the detecting means is covered with the covering member, and the detecting means is Since it is in contact with the substrate through the member and is also isolated from the heating atmosphere in the heating furnace by the covering member, it is not necessary to contaminate the substrate surface with metal components such as thermocouples, so a dummy wafer etc. must be prepared separately. There is no need to go out.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
The temperature measuring device disclosed in Japanese Patent Publication No. 5 has many excellent points as described above. However, since the detection means, for example, the thermocouple, is placed in the heating furnace and heated to the same temperature as the substrate, there are problems such as secular change and disconnection at high temperatures exceeding 1,100 ° C.
Further, since the covering member covering the thermocouple is in surface contact with the surface of the substrate, the temperature quickly becomes the same as the temperature of the substrate due to heat conduction, but further the heat conduction from the covering member to the thermocouple occurs. Since it takes extra time to detect the temperature as much as it has to be heated, the responsiveness of the temperature measuring device deteriorates. Therefore, when it is intended to be used in a device for rapidly heating and heat-treating a substrate such as a light irradiation heating type heat treatment device, the temperature control lacks reliability.
There is a problem such as. Further, there is heat conduction to the thermocouple from a portion other than the detection point of the covering member, so that the temperature at the detection point of the covering member cannot be accurately measured, resulting in a temperature measurement error. There is also.

The present invention has been made in view of the above circumstances, and it is possible to measure the temperature of a substrate heated by light irradiation more accurately and with good responsiveness.
Moreover, it is a technical subject to provide a temperature measuring device which has excellent durability at high temperatures and has a long device life.

[0006]

According to the present invention, the temperature of the substrate heated by light irradiation is measured by a contact method, and the detecting means in that case is constructed as follows. That is, at least the tip end portion of the linear optical waveguide member is inserted into the heat transfer medium member which is formed of a light shielding material having a constant emissivity and is closed, and the front end light receiving surface of the light guide member is the inner surface of the heat transfer medium member. The detection means is constituted by facing or abutting the optical waveguide member and optically connecting the end portion of the optical waveguide member to the radiation thermometer directly or through a light guide path such as an optical fiber. Here, the light-shielding material forming the heat-transmitting member does not necessarily have to have a perfect light-shielding property, and when the temperature of the substrate is measured by this detecting means, a disturbance that hinders accurate temperature measurement. It suffices that the light can be prevented from entering the tip light receiving surface of the optical waveguide member in the heat transfer member within an allowable level. The emissivity of an object changes with temperature, and the "constant emissivity" in the above means that the emissivity at each temperature is constant, and the emissivity value itself is known. The emissivity at each temperature is guaranteed to be constant, and the value of the radiant energy detected by the radiation thermometer and the temperature of the heat transfer medium member at that time are constantly associated with each other. You can go. The outer surface of the heat transfer member of the detection means is brought into surface contact with part of the substrate. In this case, by supporting a part of the substrate by the heat transfer member, the outer surface of the heat transfer member can be brought into surface contact with the substrate. In this detection means, a radiation thermometer is used to measure the temperature. However, in this detection means, the temperature of the substrate is measured by directly contacting the heat transfer medium forming a part thereof with the surface of the substrate. I try to measure
Further, since it has a feature as a contact type temperature measuring detection unit, in this specification, it is referred to as a contact type temperature measuring unit.

[0007]

In the temperature measuring device having the above-mentioned structure, since the outer surface of the heat transfer member forming a part of the detecting means is in surface contact with the substrate, the heat transfer from the substrate is efficiently performed and Closely follows the temperature of the substrate and is close to the substrate with extremely high accuracy. Then, the energy radiated from the heat transfer medium whose temperature is almost the same as that of the substrate passes through the light guide member whose tip light receiving surface is inserted into the heat transfer member and faces or abuts against the inner surface of the heat transfer member. That the temperature of the heat transfer member, and thus the surface temperature of the substrate, is measured by sensing with a radiation thermometer, which is optically connected to the end of the wave member or directly through a light guide. Become. Thus, it is the temperature of the heat transfer member that is directly detected, but since the heat transfer member and the substrate are close to each other with extremely high accuracy as described above, the temperature of the substrate can be accurately measured. Will be. In this detecting means, the heat mediating member into which the tip portion of the optical waveguide member is inserted is formed of a light-shielding material and has a closed shape, so that the light source for light irradiation, the substrate surface, or the heating furnace Ambient light emitted from the wall surface or the like is prevented from entering the light receiving surface at the tip of the optical waveguide member, and it is ensured that only the radiant energy from the heat transfer member is detected to accurately measure the temperature.

Further, the heat transfer medium forming a part of the detecting means has a constant emissivity in the above-mentioned sense, and the energy radiated from such heat transfer medium is detected by the radiation thermometer. As a result, the temperature of the substrate is measured, so the non-contact temperature measuring method in which the energy radiated from the surface of the substrate is directly detected by the radiation thermometer to measure the surface temperature of the substrate. There is no problem like in. That is, in substrates having various film structures and impurity concentrations, the emissivity differs for each substrate, and in order to perform accurate temperature measurement, it is necessary to obtain the emissivity for each different type of substrate in advance. Yes, the work is very troublesome. Further, the emissivity of the substrate changes even during the heat treatment of the substrate when the film undergoes a composition change, a particle size change, or the like, and an accurate temperature is almost never measured. It is impossible. In contrast,
In the device according to the present invention, the energy radiated from the surface of the substrate is not measured, but the energy radiated from the heat transfer medium having a constant emissivity at substantially the same temperature as the substrate is measured by a radiation thermometer. Since the temperature of the substrate is indirectly measured by detecting with, the substrate temperature is always accurately measured regardless of the type of the substrate, the surface state of the substrate, or the state of the film formed thereon. It becomes possible to measure the surface temperature of.

Further, in the temperature measuring device according to the present invention, a detecting means such as a thermocouple is not used, and the optical waveguide member is disposed inside the heating furnace, and the light guided to the outside of the heating furnace through the optical waveguide member. Since it is detected by a radiation thermometer, there is no problem in durability at high temperature and the service life is long.
Further, since the radiant energy guided by the optical means from the heat transfer medium is detected to measure the temperature, the responsiveness is good, and further, the heat transfer at the portion facing or abutting the light receiving surface at the tip of the optical waveguide member. Since the temperature is measured by detecting the radiant energy from the inner surface of the member, it is possible to perform accurate temperature measurement without the risk of temperature measurement error as in the device using the thermocouple.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

First, a schematic structure of a light irradiation type heat treatment apparatus in which the temperature measuring apparatus according to the present invention is used will be described with reference to FIG. FIG. 5 is a side sectional view of an essential part showing an example of the configuration of the light irradiation type heat treatment apparatus and showing a part thereof in a vertical section. In the figure, reference numeral 40 denotes a heating furnace having an opening 42 for inserting and removing a substrate, and the heating furnace 40 is made of quartz glass having infrared transparency. Further, a cylindrical front chamber 44 is provided so as to be connected to the opening 42 of the heating furnace 40. The front end opening surface of the front chamber 44 is configured to be closed by a lid 46,
A resin packing 48 is provided on the contact surface between the front end surface of 44 and the lid 46.
Is attached, and the inside of the heating furnace 40 can be kept airtight when the heating furnace 40 is sealed by the lid 46.
Further, in the vertical direction of the heating furnace 40, a plurality of light irradiation light sources 50 such as a halogen lamp and a sequinon arc lamp are arranged in line so as to face the upper wall surface and the lower wall surface of the heating furnace 40, respectively. Further, a reflecting plate 52 is arranged behind each light source 50.

A quartz susceptor (substrate support) 66 is fixedly provided on the inner surface side of the lid body 46, and a semiconductor wafer (hereinafter referred to as a substrate) 24 is placed on a support portion 68 of the susceptor 66. Supported. The outer surface side of the lid 46 is fixed to the support block 62, and the lid 46 is opened and closed by linearly moving the support block 62 in the direction of the arrow by a drive mechanism (not shown), and the heating furnace 40 is opened through the opening 42. The substrate 24 is loaded into the heating furnace 40, and the substrate 24 is unloaded from the heating furnace 40. Substrate 24 loaded into heating furnace 40
Are mounted and supported at three positions, that is, two projecting supporting portions 70 provided on the annular supporting portion 68 of the susceptor 66 and the tip of the detecting portion 10 of the temperature measuring device. Like the susceptor 66, the detection unit 10 is fixed to the inner surface side of the lid body 46.

Hereinafter, the detection unit of the temperature measuring device according to the present invention
10 will be described in detail.

FIG. 1 shows a first embodiment of the present invention and is a partially enlarged vertical sectional view showing a tip portion of a detecting portion 10 of a temperature measuring device. The detection unit 10 is formed by inserting a linear optical waveguide member 12 into a slender tubular heat transfer member 14 having a closed end.

The optical waveguide member 12 has an outer diameter of 0.4, for example.
It is formed of a quartz rod or a sapphire rod having a size of about mm. The tip of the optical waveguide member 12 is a light receiving surface, and the tip light receiving surface 16 faces the inner surface of the tube of the heat transfer member 14 with a gap of 0.1 mm. A gap of 0.1 mm is also formed between the outer peripheral surface of the tip of the optical waveguide member 12 and the inner surface of the tube of the heat transfer medium member 14. Here, the tip light receiving surface 16 of the optical waveguide member 12 and the tube inner surface of the heat transfer medium member 14 are
Further, the outer peripheral surface of the tip end portion of the optical waveguide member 12 and the inner surface of the tube of the heat transfer medium member 14 may be opposed to each other with a gap or may be brought into contact with each other without a gap. On the other hand, the optical waveguide member 12 penetrates the lid body 46, and the end portion thereof is guided by a light guide path, for example, an optical fiber 74, and a radiation thermometer 76.
Is optically connected to.

The heat transfer member 14 is formed into a tubular shape having an outer diameter of 0.9 mm and an inner diameter of 0.6 mm, and a length of about 200 mm.
However, it is processed and formed on a flat surface of a small area orthogonal to the axis of the optical waveguide member 12, and a flat surface 27 is also formed on the upper surface of the tip portion that is continuous with the end surface 26 of the tip portion. The tube wall of the heat transfer medium member 14 has an enlarged sectional view of the portion A in FIG.
T between the high-purity SiC (silicon carbide) layers 18 and 20 formed by the CVD method (chemical vapor deposition method), respectively.
It has a three-layer structure in which an iN (titanium nitride) film 22 is formed. Further, the heat transfer member 14 has a thin tube wall having a thickness of, for example, about 0.2 mm, and has a very small heat capacity as compared with the substrate. The high-purity SiC layers 18 and 20 formed by the CVD method have high heat resistance and high thermal conductivity. On the other hand, since they do not contain impurities that may be a source of contamination on the surface of the substrate, Not polluting. Further, the TiN film 22 has a light-shielding property.
The iN film 22 causes disturbance light radiated from the light source for light irradiation of the heat treatment apparatus, the surface of the substrate, or the inner wall surface of the heating furnace to enter the light receiving surface of the tip of the optical waveguide member 12 enclosed in the tubular heat transfer member 14. Is prevented from doing.

The radiation thermometer 76 optically connected to the end portion of the optical waveguide member 12 via the optical fiber 74 has a spectral sensitivity in a part of the wavelength range of 0.5 μm to 2 μm, for example. For example, one using a detection element of Si (silica) or Ge (germanium) is used.

In the temperature measuring device constructed as described above, when the substrate 24 is heated and its surface temperature rises in the process of heat-treating the substrate 24 by the light irradiation type heat treatment device, the heat mediating member 14 is generated by heat conduction. Is also heated and the temperature rises. At this time, the heat transfer medium 14 is transferred to the substrate 24 as described above.
The heat transfer efficiency is extremely high because the heat capacity is extremely small as compared with the above, and the flat surface 27 is in surface contact with the lower surface of the substrate 24. Therefore, the heat transfer member 14 quickly reaches the same temperature as the temperature of the substrate 24. In particular, the end surface 26 that is adjacent to and continues to the flat surface 27 is always at the same temperature as the temperature of the substrate 24 without any time difference. Then, the radiant energy corresponding to the temperature is radiated from the end surface 26 of the heat transfer medium member 14 heated to the same temperature as the substrate 24, and the radiant energy enters the optical waveguide member 12 from the tip light receiving surface 16 thereof. The radiant energy incident on the optical waveguide member 12 is detected by a radiation thermometer 76 optically connected to the end portion of the optical waveguide member 12 via an optical fiber, and the heat transfer member 14 is detected from the detected radiant energy.
Temperature is calculated. In this way, the temperature of the substrate 24, which is the same temperature as the heat transfer member 14, is obtained. A heating control circuit 78 controls the electric power supplied to the light source 50 based on the temperature detected by the radiation thermometer 76.

In the above embodiment, a gap is provided between the tip light receiving surface 16 of the optical waveguide member 12, the tube inner surface of the heat transfer medium member 14, and the outer surface of the tip end of the optical waveguide member 12 and the tube inner side surface of the heat transfer member 14. Since it is formed, it has the following effects. That is, since the gap is formed between the optical waveguide member 12 and the heat transfer medium member 14, the light guide member 12 having a larger heat capacity than the heat transfer medium member 14.
There is almost no heat conduction from the substrate 24 to the substrate via the heat transfer member 14. Therefore, heat is not taken from the vicinity of the contact portion of the substrate 24 with the heat transfer member 14, and the substrate 24 to be heated is heated.
The temperature can be measured without disturbing the in-plane temperature distribution of.

The temperature measuring device according to the present invention is configured as described above, but the scope of the present invention is not limited by the above description and the contents of the drawings, and various modifications are made without departing from the scope of the invention. Examples may be included. For example, as shown in FIGS. 3 and 4 (enlarged cross-sectional view of portion B in FIG. 3), the detection unit 10 is erected upward on the lower inner surface of the heating furnace 40, and a substrate support member (not shown) is provided. 2) may be provided upright, and the substrate 24 may be supported at three points, that is, the end face 26 of the detection unit 10 and the substrate supporting members. Further, the detection unit 10 does not necessarily support the substrate 24, as long as the heat medium member 14 is in thermal close contact with the substrate 24, the tip light receiving surface 16 of the optical waveguide member 12 is. It is desirable that the facing or abutting portion or its vicinity is in surface contact with the substrate 24. Further, the radiation thermometer may be directly connected to the end portion of the optical waveguide member 12 without using the optical fiber 74. Furthermore, the shape of the heat transfer member of the detection unit is
It does not have to be tubular, and may be tubular or hollow flat plate. Also, regarding the shape material of the heat transfer medium member, C
An appropriate material other than high-purity SiC and TiN by the VD method may be used. Further, although TiN is used as the light-shielding material in the above-mentioned embodiment, it is a material that does not have a high light-shielding property as TiN. However, any one can be used as long as it can suppress the influence of ambient light, which hinders accurate temperature measurement, to an allowable level or less.

[0021]

Since the present invention is constructed and operates as described above, if the temperature measuring device according to the present invention is used, the temperature of the substrate heated by the light irradiation is measured by the conventional contact type temperature measuring device. The temperature of the substrate can be measured more accurately and the reliability of temperature control can be improved. Moreover, since the temperature measuring device according to the present invention does not use a thermocouple or the like, the temperature measuring device has excellent durability at high temperatures and has a long device life. As described above, the present invention can provide a temperature measurement device having excellent performance for temperature control in a device for rapidly heating and heat-treating a substrate such as a light irradiation heating type heat treatment device.

[Brief description of drawings]

FIG. 1 is a partially enlarged vertical sectional view showing a tip portion of a detection unit of a substrate temperature measuring device according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a portion A of FIG.

3 is a partially enlarged vertical cross-sectional view showing a state in which the detection unit shown in FIG. 1 is brought into surface contact with a substrate.

FIG. 4 is an enlarged cross-sectional view of portion B of FIG.

FIG. 5 is a side sectional view of a main part of a light irradiation type heat treatment apparatus in which the temperature measuring apparatus according to the present invention is used.

[Explanation of symbols]

 10 Detection unit of temperature measuring device 12 Optical waveguide member 14 Heat transfer medium member 16 Light receiving surface of tip of light guide member 24 Substrate 26 End face of heat transfer medium member

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical indication location H01L 21/66 T 7630-4M // H01L 21/22 501 N 9278-4M (72) Inventor Nishii Kiyofumi 322 Hazushi Furukawa-cho, Fushimi-ku, Kyoto City Dainichi Honshu Screen Manufacturing Co., Ltd.Rakusai Factory (72) Masaki Nishida 322 Hazushi-Furukawa-cho Fushimi-ku, Kyoto City Dainichi Screen Manufacturing Co., Ltd. Rakusai Factory

Claims (2)

[Claims] 1. A substrate temperature measuring device for measuring the temperature of a substrate, which is housed in a heating furnace and heated by irradiation of light from a heating means, with a detection means for contact-type temperature measurement,
At least the tip portion of the linear optical waveguide member is inserted into a heat transfer medium member formed of a light-shielding material having a constant emissivity and closed, so that the light receiving surface of the front end of the optical wave guide member is thermally transferred. While being opposed to or in contact with the inner surface of the member, the end portion of the optical waveguide member is configured to be optically connected to the radiation thermometer directly or via a light guide path, and the outer surface of the heat transfer medium member is formed of the substrate. An apparatus for measuring a temperature of a substrate, which is in partial surface contact. 2. The temperature measuring device for a substrate according to claim 1, wherein at least a part of the substrate is supported by the heat transfer member.