JPH0778830A - Semiconductor manufacturing equipment - Google Patents

Abstract

PURPOSE:To control uniformly and accurately the temperature of a semiconductor substrate. CONSTITUTION:An outer heat rays absorbing plate 4 has optical property which absorbs at least heat rays components of absorption wavelength band which a reaction vessel 2 has, out of heat rays for heating being outputted from a heat rays source 3, and transmits the other heat rays components. An inner heat rays absorbing plate 9 has optical property which absorbs radiation heat rays radiated from a semiconductor substrate 6 in a heated state, converts the absorbed rays into secondary heat rays, and again outputs them. Suitable combinations of the plates 4 and the plates 9 are arranged in the spaces inside and outside a reaction vessel. It is desirable for the inner heat rays absorbing plate to have optical property which practically transmits effective wavelength components in the heat rays for heating, or optical property which absorbs heat rays for heating and converts the rays into secondary heat rays.

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, in particular, an annealing apparatus using a heat source such as an infrared lamp, a halogen lamp, a ceramic heater, a chemical vapor deposition (CVD) apparatus, an impurity diffusion apparatus and other semiconductor manufacturing apparatuses. It is a thing.

[0002]

2. Description of the Related Art In order to improve the performance of a semiconductor device and reduce its variation, it is necessary to uniformly and accurately control the temperature of a semiconductor substrate during the manufacturing process of the semiconductor device. Measures have been proposed.

For example, a semiconductor manufacturing apparatus disclosed in Japanese Patent Laid-Open No. 4-355911 heats a semiconductor substrate by irradiating a heating heat ray through a first transmission window provided in a part of a reaction container, and The substrate temperature is measured through a second transmission window provided in another part of the reaction container.
According to this apparatus, the first transmission window is made of a material having an optical property of absorbing the detection heat ray component in the specific wavelength range, and the first transmission window is made of a material having an optical property of transmitting the detection heat ray component. By configuring the second transmission window, the substrate temperature can be measured (controlled) by selectively detecting the detection heat ray component contained in the radiant heat ray radiated from the heated semiconductor substrate. .

Since this conventional apparatus does not have means for keeping the temperature of the semiconductor substrate in a heated state, it is necessary to additionally irradiate the heating wire for heating by an amount corresponding to the amount of heat radiated from the semiconductor substrate. In addition, the reaction container and the heat ray transmission window absorb the heat rays for heating and the radiation rays emitted from the semiconductor substrate, causing an abnormally high temperature, and the detection wavelength component in the heat rays re-radiated from these members causes noise interference. Therefore, there is a problem in that the substrate temperature cannot be accurately measured.

On the other hand, the semiconductor manufacturing apparatus described in Japanese Patent Application Laid-Open No. 5-5183 aims at making the heating heating wire uniform by disposing a diffusion plate for the heating heating wire inside the reaction vessel. Even if the heat rays for use can be made uniform, it does not even out the radiant heat rays radiated from each part of the semiconductor substrate in a heated state, so that variations in the substrate temperature distribution are completely eliminated. There is a problem in that it cannot be prevented. Further, as in the case of the conventional device, since it does not have a means for keeping the temperature of the semiconductor substrate in a heated state, it is necessary to irradiate the heating wire with an extra amount corresponding to the amount of heat radiated from the semiconductor substrate. There is.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art and to provide an improved hot wire heating type semiconductor manufacturing apparatus capable of uniformly and accurately controlling the temperature of a semiconductor substrate. To provide.

[0007]

The above object is to provide a heat ray absorbing plate for absorbing a heat ray component in a specific wavelength range in either a heating heat ray passing space outside the reaction vessel or a reaction vessel inner space near the semiconductor substrate. Alternatively, it can be solved by disposing them on both sides. It is desirable to dispose the heat ray absorption plate both outside and inside the reaction vessel, but it is possible to expect some effect by disposing it either inside or outside the reaction vessel. Is.

The heat ray absorbing plate (hereinafter referred to as "external heat ray absorbing plate") disposed in the outer space of the reaction vessel is a heat ray component of at least the absorption wavelength band of the reaction vessel among the heat rays for heating emitted from the heat ray source. It is desirable to have an optical property of absorbing quartz and transmitting other heat ray components. Such optical property is such that when a reaction vessel made of quartz glass is used, quartz glass, high silica glass It can be realized by configuring the external heat ray absorbing plate with any one of borosilicate glass and borosilicate glass.

The external heat ray absorbing plate functions also as a member for diffusing and transmitting the heat ray for heating emitted from the heat ray source, and has a large number of vent holes for letting a cooling gas flow. It is desirable to have one. By adopting such a structure, the irradiation amount of the heating heat ray to the semiconductor substrate can be made uniform, and the abnormal heating of the external heat ray absorbing plate can be prevented in advance by using the appropriate cooling means in combination. Because you can.

On the other hand, the heat ray absorbing plate (hereinafter referred to as "internal heat ray absorbing plate") arranged in the inner space of the reaction vessel is designed to substantially transmit the effective wavelength component in the heating heat ray irradiated from the heat ray source. In addition to such optical properties, it is desirable to have such optical properties that it absorbs radiant heat rays radiated from a semiconductor substrate in a heated state, converts them into secondary heat rays, and radiates them again. Such optical properties can be realized by configuring the internal heat ray absorbing plate with any one of quartz glass, high silica glass and borosilicate glass.

The internal heat ray absorbing plate absorbs the heat ray for heating emitted from the heat ray source and the radiant heat ray radiated from the semiconductor substrate in the heated state instead of the above-mentioned optical property, and converts it into a secondary heat ray. It may have an optical property of re-radiating. Such an optical property is that the internal heat ray absorbing plate is made of any one of carbon, silicon, silicon carbide, silicon nitride, and a material in which a quartz glass coating or a ceramic coating is applied to the surface of metal or metal oxide. Can be realized by

[0012]

[Function] A reaction vessel made of quartz glass is used, and any one of quartz glass, high silica glass and borosilicate glass is used.
When an external heat ray absorbing plate made of seed is used, the heat ray absorbing wavelength band of the reaction vessel and the external heat ray absorbing plate are both 3 μm.
Since the heating heat ray emitted from the heat ray source is about 3 m, the heat ray component of about 3 μm is absorbed by the external heat ray absorbing plate and then passes through the reaction container to reach the semiconductor substrate. For this reason, the reaction container does not excessively absorb heat energy and become abnormally high in temperature, and it is possible to effectively prevent the emission of undesired secondary heat rays that hinder the accurate measurement of the substrate temperature.

Even if the heat ray component of about 3 μm contained in the heat ray for heating is absorbed by the external heat ray absorbing plate,
Since the heating heat ray after passing through the absorption plate contains a heat ray component of about 1 μm, which is effective for heating the semiconductor substrate, it does not hinder the heating of the substrate.
The external heat ray absorbing plate is ideally arranged so as to occupy the entire cross section of the heating heat ray passage space between the heat ray source and the reaction vessel, but normally 80% of the entire cross section of the space is provided. As long as it occupies, the performance can be fully exhibited.

On the other hand, when the internal heat ray absorbing plate is made of any one of quartz glass, high silica glass and borosilicate glass, it absorbs radiant heat rays (usually around 3 μm) radiated from the heated semiconductor substrate. Then becomes high temperature,
The semiconductor substrate is kept warm by re-radiating a secondary heat ray of about 4 μm. As a result, the distribution of the substrate temperature becomes uniform, and it becomes possible to obtain a desired substrate temperature with a relatively weak heating wire.

When the internal heat ray absorbing plate is made of any one of carbon, silicon, silicon carbide, silicon nitride, and a material in which the surface of the metal or metal oxide is coated with quartz glass or ceramics, Since the heating heat ray does not penetrate, the semiconductor substrate cannot be directly heated by the heat ray, but the internal heat ray absorbing plate absorbs the heat energy of the heating heat ray and becomes a high temperature and re-radiates the secondary heat ray of about 4 μm. It is sufficiently possible to heat the semiconductor substrate using the secondary heating wire. The heat retaining effect of the semiconductor substrate is the same in this case as well.

In both cases of the heat ray transmitting type and the heat ray blocking type, the internal heat ray absorbing plate can be arranged and used in the internal space of the reaction vessel through which the heating heat ray emitted from the heat ray source passes. However, according to the results of the trial production experiments by the present inventors,
When a heat ray source is arranged in the reaction vessel outside space on one surface side of the semiconductor substrate, and an internal heat ray absorbing plate is arranged in the reaction vessel inside space on the other surface side of the substrate (the opposite side to the heat ray source), It was possible to obtain a more satisfactory heat retention effect.

[0017]

【Example】

<Embodiment 1> FIG. 1 shows an embodiment of a semiconductor manufacturing apparatus according to the present invention. The apparatus main body 1 has a hollow structure as shown in the figure, and a quartz glass reaction container 2 is provided at the center thereof.
Is provided. In the upper space and the lower space of the reaction container 2, a plurality of heat ray irradiation lamps 3 (for example, halogen lamps) are arranged in parallel so as to vertically intersect. Although not shown in detail, a gutter-shaped aluminum alloy concave reflecting mirror with a gold coating is provided on the ceiling and floor inside the apparatus body 1, and the heating heat rays emitted from the heat ray irradiation lamp 3 are provided. Are efficiently focused toward the reaction container 2.

The external heat ray absorbing plates 4 are arranged in the upper and lower spaces (heat ray passing space) between the heat ray irradiation lamp 3 and the reaction vessel 2, respectively. In the case of the present embodiment, the external heat ray absorbing plate 4 is made of quartz glass having a ground glass surface for heat ray diffusion formed on the surface thereof, and a nitrogen gas for cooling is flowed over the entire surface thereof. A large number of vent holes 5 were formed. The semiconductor substrate 6, which is a workpiece, was loaded on the heat ray transmission type substrate support 7 installed at the bottom of the reaction vessel 2 with the guard ring 8 attached. The internal heat ray absorbing plate 9 was made of quartz glass like the external heat ray absorbing plate 4, and was placed inside the reaction vessel 2 near the lower side of the semiconductor substrate 6. The internal heat ray absorbing plates 9 can be arranged in a sandwich shape on both sides of the substrate 6 as required.

The reaction gas and the purge gas are introduced into the reaction vessel 2 from a gas introduction system (not shown) on the left side of the drawing, and after passing through the same vessel, a gas exhaust system (not shown) on the right side of the drawing.
Was evacuated using. Further, although not shown, a water passage is provided inside the wall of the apparatus main body 1, and during use of the apparatus,
The apparatus body 1 was cooled by passing cooling water through the water passage. The temperature of the substrate 6 was measured through the observation window 11 by disposing the radiation thermometer 10 below the device body 1. The measurement data was transferred to the power control device 12, and the power supplied to the heat ray irradiation lamp 3 was controlled based on the data.

In addition, during use of the apparatus, a cooling nitrogen gas is blown into the gap between the apparatus main body 1 and the reaction vessel 2, and the gas is fed to the reaction vessel 2, the external heat ray absorbing plate 4 (vent hole 5),
The heat ray irradiation lamp 3 was circulated in this order. External heat ray absorbing plate 4
Is effective in suppressing undesired radiation of secondary heat rays, and the cooling of the reaction vessel 2 is effective in reducing metal contamination which is an obstacle to heating heat ray irradiation. The external heat ray absorbing plate 4 can be cooled by attaching a water pipe made of glass to the absorbing plate. When the heating temperature of the semiconductor substrate 6 is about 500 ° C., the external heat ray absorbing plate 4 can be made of borosilicate glass.

With such a manufacturing apparatus, an unprocessed silicon substrate was loaded into the reaction vessel 2 and annealed at a temperature of 1000.degree. First, when the annealing treatment was performed with both the external heat ray absorbing plate 4 and the internal heat ray absorbing plate 9 removed, the variation (reproducibility) of the substrate temperature for each annealing treatment was about 5 ° C. Next, when the same annealing treatment was performed with only the external heat ray absorbing plate 4 or only the internal heat ray absorbing plate 9 attached, in the former case, the variation in substrate temperature can be improved to around 1 ° C. In the latter case, the variation in substrate temperature could be improved to around 3 ° C. Finally, when the same annealing process was performed with both the internal heat ray absorbing plate 4 and the internal heat ray absorbing plate 9 attached, the variation in the substrate temperature could be reliably reduced to 1 ° C. or less. In addition, when the same annealing treatment was performed using a silicon substrate having a polysilicon film formed on its surface and a silicon substrate having its surface doped with ions, the external heat ray absorbing plate 4 and / or the internal heat ray absorbing plate 9 was used. It was confirmed that the difference in the variation in the substrate temperature between the case of using the above and the case of not using these members was further increased.

In this experiment, the internal heat ray absorbing plate 9 made of quartz glass having an optical property of substantially transmitting the effective wavelength component in the heating heat ray irradiated from the heat ray source was used. Can be made of a material that does not transmit the heating rays, for example, silicon. However, in this case, as shown in FIG. 1, it is necessary to provide a through hole 13 for temperature detection in the internal heat ray absorbing plate 9. The presence of the through holes 13 does not substantially affect the function of the internal heat ray absorbing plate 9 as long as the diameter thereof is appropriate.

The frosted glass surface (diffusing surface) formed on the external heat ray absorbing plate 4 functions to make the heating heat rays uniform. According to the experimental results of the present inventors, the irradiation uniformity of the heating heat ray on the substrate 6 [(maximum illuminance-minimum illuminance) / average illuminance × 100%] is about 5% when the diffusion surface is not provided.
However, it was possible to improve it to about 3% by providing a diffusion surface. The same effect can be obtained by forming an appropriate diffusion surface on the outer surface or the inner surface of the reaction container, but it is not preferable because it lowers the pressure resistance of the reaction container and makes cleaning operation difficult. .

The semiconductor manufacturing apparatus shown in FIG. 1 can also be used as a CVD apparatus. The present inventors
By removing the internal heat ray absorption plate 9 and using only the external heat ray absorption plate 4 installed in the reaction vessel 2 by introducing a carrier gas containing a reaction gas such as monosilane gas or disilane gas, An experiment for forming a polysilicon film was conducted. However, JP-A-3-40
According to the method described in Japanese Laid-Open Patent Publication No. 423, pure carrier gas was flowed through the observation window 11 to prevent the reaction container 2 from becoming cloudy.

As a result of the experiment, it was possible to obtain a good variation of about 3 ° C. with respect to the target value of the substrate temperature of 650 ° C. When a similar experiment was conducted using an apparatus in which the external heat ray absorbing plate 4 was also removed, the variation in substrate temperature decreased to about 10 ° C. A similar experiment was conducted using an impurity doping gas such as a phosphorus compound, but the results were the same.

<Embodiment 2> FIG. 2 shows another embodiment of the present invention in which a silicon oxide film is formed on a silicon substrate. In this example, the low-pressure mercury lamp 20 (ultraviolet lamp) was arranged in the upper space of the reaction vessel 2, and the halogen lamp 3 (heat ray irradiation lamp) was arranged in the lower space of the reaction vessel 2. The other structure is substantially the same as that of the first embodiment, and the same or similar members as in the first embodiment are denoted by the same reference numerals as those in FIG. In this case, the internal heat ray absorbing plate 9 was removed and used.

A reaction gas composed of monosilane gas and laughing gas is introduced into the reaction vessel 2, and the silicon substrate 4 maintained at a temperature of 150 ° C. is irradiated with ultraviolet rays having a wavelength of 185 nm to form a silicon oxide film on the silicon substrate 6. Was formed. The substrate temperature variation (reproducibility) was extremely good, and a silicon oxide film having a desired high quality could be formed. In this embodiment, the halogen lamp is used as the heat ray irradiation lamp 3 for heating the silicon substrate, but it is also possible to use an infrared lamp or a ceramic heater.

[0028]

In the semiconductor manufacturing apparatus according to the present invention, the heat ray component in the wavelength band absorbed by the reaction vessel is removed (absorbed) by using the external heat ray absorbing plate. It has become possible to accurately measure and control the temperature of the semiconductor substrate while preventing the occurrence of heat generation. Moreover, since the semiconductor substrate can be kept warm by using the internal heat ray absorbing plate, it is possible to efficiently make the temperature of the semiconductor substrate uniform with relatively little electric power.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of a semiconductor manufacturing apparatus of the present invention.

FIG. 2 is a sectional view showing a second embodiment of the semiconductor manufacturing apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Device main body, 2 ... Reaction container, 3 ... Heat ray irradiation lamp, 4 ... External heat ray absorbing plate, 5 ... Vent hole, 6 ... Semiconductor substrate, 7 ... Substrate support base, 8 ... Guard ring, 9 ... Internal heat ray absorbing plate , 10 ... Radiation thermometer, 11 ... Observation window, 12 ... Power control device, 13 ... Through hole, 20 ... UV lamp.

Continuation of front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display location H01L 21/26 21/31 (72) Inventor Sukeyoshi Tsunekawa 888 Fujihashi, Ome-shi, Tokyo Hitachi, Ltd. Living Equipment Co., Ltd. Within the business unit (72) Inventor Tsuyoshi Kimura 888 Fujihashi, Ome-shi, Tokyo Inside the Living Equipment Division, Hitachi, Ltd. (72) Inventor Mitsuo Tokuda 888 Fujihashi, Ome-shi, Tokyo Within the Living Equipment Division, Hitachi, Ltd. (72) Invention Kotaro Koizumi 888 Fujibashi, Ome-shi, Tokyo Hitachi, Ltd. Living Equipment Division

Claims (11)

[Claims] 1. A heat ray transmissive reaction container for accommodating a semiconductor substrate which is a workpiece, and a heat ray source for irradiating at least one surface of the semiconductor substrate with heating heat rays from the outside of the reaction container. In the provided semiconductor manufacturing apparatus, a heat ray absorbing plate for absorbing heat ray components in a specific wavelength range is provided in either or both of the heating ray passage space outside the reaction vessel and the reaction vessel inner space near the semiconductor substrate. A semiconductor manufacturing apparatus characterized by the above. 2. The heat ray absorbing plate disposed in the outer space of the reaction vessel absorbs at least a heat ray component in an absorption wavelength band of the reaction vessel among heating heat rays emitted from a heat ray source,
The semiconductor manufacturing apparatus according to claim 1, which has an optical property of transmitting other heat ray components. 3. The semiconductor manufacturing according to claim 2, wherein the external heat ray absorbing plate also functions as a member for diffusing and transmitting the heat ray for heating emitted from the heat ray source. apparatus. 4. The semiconductor manufacturing apparatus according to claim 2, wherein the external heat ray absorbing plate has a large number of ventilation holes for flowing a cooling gas. 5. The reaction vessel is made of quartz glass, and the external heat ray absorbing plate is made of any one of quartz glass, high silica glass and borosilicate glass. The semiconductor manufacturing apparatus according to claim 4. 6. The heat ray absorbing plate disposed in the internal space of the reaction vessel has an optical property of substantially transmitting the effective wavelength component in the heat ray for heating irradiated from the heat ray source, and also has a heating state. Absorbs radiant heat rays emitted from a semiconductor substrate,
The semiconductor manufacturing apparatus according to claim 1, which has an optical property of being converted into a secondary heat ray and re-radiated. 7. The semiconductor manufacturing apparatus according to claim 6, wherein the internal heat ray absorbing plate is made of any one of quartz glass, high silica glass and borosilicate glass. 8. A heat ray absorbing plate disposed in the internal space of the reaction vessel absorbs the heat ray for heating applied from the heat ray source and the radiant heat ray emitted from the semiconductor substrate in the heated state, and converts it into a secondary heat ray. The semiconductor manufacturing apparatus according to claim 7, wherein the semiconductor manufacturing apparatus has an optical property of being re-radiated. 9. The internal heat ray absorbing plate is made of any one of carbon, silicon, silicon carbide, silicon nitride and a material in which a quartz glass coating or a ceramic coating is applied to the surface of metal or metal oxide. The semiconductor manufacturing apparatus according to claim 8, wherein. 10. The heat ray source is arranged in the reaction vessel outside space on at least one surface side of the semiconductor substrate, and the internal heat ray absorbing plate is provided in the reaction vessel inside space through which heating heat rays emitted from the heat ray source pass. The semiconductor manufacturing apparatus according to claim 5, wherein the semiconductor manufacturing apparatus is provided. 11. The heat ray source is arranged in a reaction container outside space on one surface side of a semiconductor substrate, and the internal heat ray absorbing plate is arranged in a reaction container inside space on the other surface side of a semiconductor substrate. The semiconductor manufacturing apparatus according to claim 5, wherein: