JPH11224879A - Semiconductor manufacturing equipment - Google Patents

Abstract

(57) Abstract: An ultrathin oxide film formed by a rapid increase in temperature by suppressing the heating of a seal component mounted in a quartz chamber without reducing the mechanical strength of the quartz chamber while having a simple configuration. Is realized. An absorber for transmitted light is mounted on a surface of a chamber. The transmitted light 111 is transmitted to the chamber 10
When the emission angle from one surface is less than the critical angle, the light is totally reflected on the surface. At this time, an electromagnetic wave called an evanescent wave generated by the incident light is generated in the vicinity of the surface of the chamber 101, and the intensity of the evanescent wave attenuates exponentially according to the distance from the surface, but generally within a distance of about the wavelength of the light. It is thought to have occurred. By arranging the absorber 112 that absorbs the evanescent wave 303 in this region, the energy of the transmitted light 111 is absorbed, and the heating of the O-ring 107, which is a sealing part of the reflected light, can be suppressed.

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, and more particularly to a semiconductor manufacturing apparatus for processing an object such as a silicon wafer by heating or the like.

[0002]

2. Description of the Related Art For example, in a heat treatment apparatus of a semiconductor manufacturing apparatus, a silicon wafer housed in a quartz chamber is heated by radiant heat radiated from a lamp or a heater from the outside of the chamber, and an oxygen gas or the like flows into the chamber. In some cases, an oxide film layer is formed on the wafer surface.

In recent miniaturization of semiconductor devices and devices having a new structure such as a flash memory, the thickness of the oxide film needs to be formed to be very thin, about several nm. To this end, the heat treatment time must be as short as possible, but the heating temperature is about 900
Since the temperature is very high, that is, from C to 1000 C or more, the time to reach the heating temperature must be as short as possible. This is because the formation of an oxide film proceeds even during heating and raising the temperature, which makes it difficult to form a uniform and thin film.

In order to apply heat to the wafer in as short a time as possible, the wafer is directly heated by irradiating the wafer with radiation emitted from, for example, a halogen lamp or a heater from outside the quartz chamber. Is commonly done. As for the radiant light, infrared light having a wavelength of about 2 to 3 μm is the strongest, and light of this wavelength is not absorbed by quartz which is a material of the chamber. The wafer is heated.

[0005]

However, not all of the radiated light reaches the wafer, and some of the radiated light repeats internal reflection in the quartz material and reaches a position distant from the heater. There is. Just the quartz chamber plays the role of an optical fiber.

There is a problem that the light transmitted through the inside of the material of the quartz chamber heats and degrades the components mounted on the surface of the quartz chamber.

For example, in order to seal a quartz chamber in a vacuum, a flange is provided at a joint portion with another chamber. Here, an O 2 made of a polymer compound such as fluororubber is used. A ring is used as a gasket.

When such a material is heated to about 300 ° C. or more, the material deteriorates, loses its elasticity, and deteriorates, and cannot serve as a gasket. A soft and elastic material such as a polymer compound must be used to seal easily breakable materials such as quartz.In addition, considering corrosion resistance to gases used in the process, fluorine High molecular compounds such as rubber must be used.

Therefore, even if the wafer is heated in a short time to form an ultra-thin oxide film by rapid temperature rise, a powerful heater cannot be used due to the above-described restrictions, and the ultra-thin oxide film cannot be used. Had its limits. The performance of a flash memory or the like is greatly affected by the thinning of the oxide film and the uniformity of the film quality. However, the above-mentioned problems cause a problem and limit the device performance.

[0010] Further, a mechanism for cooling the flange portion with water and a countermeasure such as the necessity of newly providing a water leak detector are required, which is a problem in reducing the cost of the manufacturing apparatus.

[0011] In order to reduce the transmitted light inside the quartz chamber, there has been proposed a method of making a part of the quartz chamber opaque. For example, JP-A-2-268420
As described in the publication, a part of the furnace tube, which is a quartz chamber, is formed of opaque quartz, thereby blocking transmitted light traveling toward the O-ring through the part.

A similar system is adopted in Japanese Patent Application Laid-Open No. 64-44017. JP-A-64-4
In Japanese Patent No. 4016, a shield plate for transmitted light is embedded in a material of a quartz tube. Also, in Japanese Patent Application Laid-Open No. 3-67499, in order to prevent the light emitted from the plasma generated inside the quartz tube from propagating inside the quartz tube and heating the O-ring, the quartz tube is also heated. A part is formed of an opaque substance.

However, when a part of the quartz chamber or tube is made of opaque quartz, there is a problem that the mechanical strength of the quartz chamber or the tube itself is weakened.

For example, the viscosity of quartz glass at 1200 ° C. is 4.0 × 10 11 Pa · s for transparent quartz, and 7.4 × 10 10 Pa · s for opaque quartz at 1200 ° C.
There is only s. The compressive strength of a 24 mm diameter rod-shaped sample at room temperature is 1130 MPa for transparent quartz, whereas it is only 268 MPa for opaque quartz.

Further, the bending strength of the torsion at room temperature is 46.5 MPa for transparent quartz, but only 15.8 MPa for opaque quartz. The temperature at which bending occurs due to a decrease in viscosity during long-time heating is 1100 ° C. for transparent quartz, and 1050 ° C. for opaque quartz.

As described above, the mechanical strengths of the two materials are significantly different. In order to form one chamber, two materials must be joined by welding, and there are problems such as cracks occurring at the time of heating and heating and accumulation of internal stress.

Therefore, it is difficult to form a furnace body for performing rapid heating and heating from different materials from the viewpoint of strength reliability. Also, making the whole chamber of opaque quartz is
It goes without saying that the light cannot reach the wafer in the chamber and cannot be used.

An object of the present invention is to reduce the mechanical strength of a quartz chamber while maintaining a simple structure,
Suppresses the heating of the sealing components mounted in the quartz chamber,
An object of the present invention is to realize a semiconductor device capable of forming an extremely thin oxide film by rapid temperature rise.

[0019]

Means for Solving the Problems (1) In order to achieve the above object, the present invention is configured as follows. That is,
In a semiconductor manufacturing apparatus including at least a heat treatment container and a heating light source disposed outside or inside the heat treatment container, an absorbing member having a characteristic of absorbing light of a specific wavelength is provided on a surface of the heat treatment container. Place.

(2) Preferably, in the above (1),
The absorbing member is disposed on the surface of the heat treatment container with an interval equal to or less than the specific wavelength, and at least a part of light or an electromagnetic wave radiated from the heating light source forms a heat treatment container. When transmitting or propagating inside, the electromagnetic energy formed by the evanescent effect in the vicinity of the surface of the heat treatment container is absorbed by the absorbing member, so that at least a part of the light or electromagnetic wave transmitted or propagated. Decay.

(3) Preferably, in the above (1) or (2), the heat treatment container is connected to another treatment container separate from the heat treatment container via a seal member. The material of the absorbing member is the same as the material of the sealing member.

(4) Preferably, the above (1),
In (2) or (3), the absorbing member is formed of a material having elasticity.

(5) Preferably, in the above (4), the absorbing member is annular, and the annular absorbing member is arranged on an outer peripheral surface of the heat treatment container.

(6) Preferably, in (1) to (5), the light absorbed by the absorbing member is:
Includes 5 μm wavelength.

(7) Preferably, in (1) to (5), the light absorbed by the absorbing member includes a wavelength at which the spectral radiant flux from the heating light source is maximized.

(8) Preferably, in the above (1) to (7), the material of the heat treatment container is quartz.

(9) Preferably, in the above (1) to (8), the heating light source is a lamp or a heater for heating an object to be processed inside the processing container.

(10) Preferably, in the above (1) to (8), the heating light source is generated inside the processing container to heat an object to be processed inside the processing container. It is a light emitting material such as plasma.

An absorber having the property of absorbing transmitted light is mounted on a portion of the surface of a conventional heat treatment container comprising a transparent quartz chamber where transmitted light causes internal reflection. When the transmitted light causes internal reflection, the absorber absorbs electromagnetic waves called evanescent waves leaking to the surface of the quartz chamber, thereby attenuating the internally reflected light energy and propagating to reach other members such as a seal member. Light is reduced to prevent heat deterioration of the seal member and the like.

[0030]

FIG. 1 is a schematic sectional view of a semiconductor manufacturing apparatus according to a first embodiment of the present invention, in which the present invention is applied to a quartz furnace for wafer heating processing. In FIG. 1, a chamber (heat treatment container) 101
Is made of, for example, quartz and has a substantially rectangular cross section. Further, in order to rapidly heat the wafer 102, a heater (heating light source) 103 must be brought as close as possible to the wafer 102.
Is narrow and the inner surface of the chamber 101 is narrow, and the cross section of the chamber 101 is an elongated rectangle.

Since the inside of the chamber 101 must be depressurized or flow a special gas before or during the processing, the chamber 101 can be evacuated, so that the furnace body is not damaged by external pressure. As described above, the reinforcing member called the rib 104 is welded to the outer surface of the furnace body. Rib 10
4 is also made of a plate material to reduce the manufacturing cost. In addition, since the required strength cannot be obtained unless the height of the rib 104 is sufficiently high, generally, the width of the rib is smaller than the dimension of the width of the rib.
The height dimension is larger.

The wafer 102 processed in the chamber 101 is transferred to a connection chamber 105 separate from the heating furnace without being exposed to the atmosphere or the like, so that an O-ring (seal member) mounted on the flange 106 is used. 107 and the connection chamber 10 while maintaining the airtightness.
5 are connected.

Since quartz is a material that is easily broken, an O-ring 107 made of a soft material is pressed against the flange 106 to maintain airtightness. Therefore, as the material of the O-ring 107, fluorine rubber having high corrosion resistance to gas used in the process is generally used.

Radiation light 108 emitted from heater 103
Is emitted in the direction of the wafer 102 so that the heater cover 110 does not leak to the outside, and the wafer 102 is heated. At this time, part of the radiation 108
01 propagates through the quartz material as the transmitted light 111 while repeating internal reflection.
7 is deteriorated by heating.

Therefore, in the first embodiment of the present invention, the portion A (the heater 103 of the quartz chamber 101) in FIG.
And the part B (the part between the flange 106 and the portion facing the flange 106) and the part B (the end of the chamber 101 on the connection chamber 105 side and the end of the connection chamber 105 on the chamber 101 side) through the inside of the quartz chamber 101. O-ring 1
07 is heated by the absorber 112
Absorbs and attenuates.

Before describing the absorption of heat rays in detail, the internal propagation of radiation 108 emitted from heater 103 will be described. The light that has entered the interior from a surface made of quartz material travels straight and then hits another surface and is emitted to the outside as it is, or returned to the inside without being able to escape to the outside by internal reflection. In quartz, light having an incident angle of about 44 ° or more with respect to the surface is internally reflected.

In the case of a plate-like shape as in the quartz chamber 101 in FIG. 1, the light once internally reflected has an incident angle of about 44 ° or more on other surfaces. The internal reflection continues throughout the inside, and reaches the distant portion where the O-ring 107 is mounted. Here, the incident angle is an angle formed by a normal to a surface on which light is incident and incident light.

The intensity of the radiated light 108 emitted from the heater 103 varies depending on the wavelength λ of the light. It is known that the intensity of radiated light for each wavelength λ can be approximated within a practically acceptable error range by Planck's law of radiation. Assuming that the energy density radiated in the minute wavelength region dλ is Edλ, the following equation (1) holds. E = 8πhc / [λ ⁵ {exp (hc / kλT) −1}] (1) where h is Planck's constant, c is the speed of light, k is Boltzmann's constant, and T is the temperature of the heater. E is called the spectral radiant flux divergence, but it does not matter if it is interpreted as the intensity of the radiated light.

Radiation light 1 obtained for each temperature of heater 103
The intensity E of 08 is shown in FIG. In FIG. 2, the light having the highest intensity E of the radiated light is light having a wavelength of about 2 to 2.5 μm. If light around this wavelength can be prevented from reaching the O-ring 107, the heating of the O-ring 107 can be prevented most effectively.

Hereinafter, a specific structure of the quartz chamber 101 will be described. FIG. 3 is an enlarged view of a portion A in FIG. 1 and is an explanatory diagram of reduction of transmitted light by the absorber 112. In FIG. 3, transmitted light 1
Eleven absorbers 112 are mounted. Transmitted light 111
As described above, when the incident angle 301 to the surface of the chamber 101 is equal to or smaller than the critical angle, the light is totally reflected by the surface to generate a reflected light 302.
1, an evanescent wave 30 generated by the incident light
An electromagnetic wave called No. 3 is generated.

Although the intensity of the evanescent wave 303 attenuates exponentially with the distance from the surface, it can be considered that the intensity is generated within a distance approximately equal to the wavelength of light. In this region, the absorber 11 that absorbs the evanescent wave 303
By arranging 2, the energy of the transmitted light 111 is absorbed by the absorber 112, and as a result, the reflected light 302 can be attenuated.

The material of the absorber 112 is an O-ring 107
Fluoro rubber of the same material as that described above can be used. This is because light having a wavelength that heats the O-ring 107 can be effectively removed by the absorber of the same material. Chamber 1
Considering the wavelength of the transmitted light 111, the gap between 01 and the absorber 112 needs to be about several μm or less, so the absorber 112 needs to be closely attached to the chamber 101.

Therefore, for example, a sheet of fluorine rubber having a thickness of about 3 mm is tightly wound around the outer periphery of the quartz chamber 101, and is brought into close contact with the surface of the chamber 101 by the elasticity (elasticity) of the fluorine rubber itself. Good. When a gap d of several μm or less is secured without being closely attached to the chamber 101, a thin sheet may be interposed as the spacer 304.

Since the absorber 112 is heated by the absorption of the evanescent wave 303, it is necessary to release the heat. Therefore, a heat radiating member 305 may be attached to the surface of the absorber 112 so as to actively radiate heat to the atmosphere. When the absorber 112 is made of fluororubber, the surface of the fluororubber may be processed into irregularities to increase the area in contact with the atmosphere, thereby providing the same function as the heat dissipating member 305. The surface of the heat radiating member 305 may be air-cooled or water-cooled.

The absorber 112 does not need to be solid,
A grease-like paste can be applied to the surface of the quartz chamber 101 in advance. Of course, the quartz chamber 10
The paste applied to 1 should absorb the evanescent wave 303. Further, the thickness of the paste needs to be equal to or larger than the wavelength of the transmitted light 111.

When the absorber 112 is made of fluorine rubber, it has a high elasticity. Therefore, if the absorber is formed in a ring shape (annular shape), it can be easily mounted on the outer peripheral surface of the chamber 101.

The portion to which the absorber 112 is attached is selected from the portion not irradiated with the radiation 108 from the heater 103. For example, in FIG. 1, the space between the ribs 104 and the side surface, the back surface of the flange 106, and the like.

The absorber 112 does not always need to be provided outside the quartz chamber 101. For example, as shown in FIG. 4 which is an enlarged view of a portion B in FIG.
06 than the O-ring 107 attached to the
A sheet of an absorber made of the same material as the O-ring together with the O-ring 107 in the flange 106
May be sandwiched.

The sheet 112 of the absorber is made of O-ring 1
If the material is the same as 07, the material is hardly affected by corrosive gas or the like flowing into the chamber 101, so there is no need to worry about gas contamination by the absorber 112.

Further, in order to maintain the airtightness with the O-ring 107, the flange
Therefore, the absorber 112 is strongly pressed against the flange 106 at the same time.

In this way, the light propagating toward the O-ring 107 travels toward the O-ring 107 while repeating internal reflection inside the flange 106. However, they are effectively absorbed by the sheet of the absorber 112 in front. Removed. Although there is a possibility that the absorber 112 may be degraded by heating, it does not require a vacuum sealing function such as the O-ring 107 and has only a function as a heat absorbing member.

As described above, according to the first embodiment of the present invention, the light 1
Since the absorbing member 112 having a simple configuration is mounted on the surface between the portion where the 08 is irradiated and the portion where the O-ring 107 is mounted, the light 108
However, before reaching the O-ring 107, it is attenuated by the absorbing member 112, so that heating of the O-ring 107 can be suppressed.

Therefore, while having a simple structure, the mechanical strength of the quartz chamber 101 is not reduced and
The sealing component mounted on the quartz chamber 101, ie, O
It is possible to realize a semiconductor device capable of forming an ultrathin oxide film by rapid heating while suppressing the heating of the ring 107.

Incidentally, there is a semiconductor manufacturing apparatus in which the chamber 101 is made of a metal such as stainless steel, and the wafer 102 is placed in a space formed by the metal and a quartz plate and subjected to heat treatment.

FIG. 5 is a view showing a second embodiment of the present invention, in which a semiconductor device in which a chamber 101 is made of metal is a schematic sectional view of a heating furnace with a lid. In the semiconductor manufacturing apparatus shown in FIG. 5, a wafer to be processed 102 is housed in a chamber 101 made of, for example, stainless steel, and a lid 501 made of, for example, a quartz plate is provided on an upper portion thereof.
There is.

A part of the radiation 108 from the heater 103 is blocked by the heater cover 110 so as not to hit the O-ring 107. Here, the space between the chamber 101 and the lid 501 is sealed with an O-ring 107, and the radiation 108
And heat.

A part of the radiated light 108 propagates through the inside of the lid 501 as transmitted light 111, and there is a possibility that the O-ring 107 is heated and deteriorated. Chamber 101 and O-ring 10
The O-ring 107 is cooled by cooling the portion in contact with
Although it is possible to prevent the heating of the semiconductor device, such a configuration increases the manufacturing cost and the like and increases the price of the semiconductor manufacturing apparatus.

Therefore, in the second embodiment of the present invention, the inside of the O-ring 107, that is, the O-ring 107 is prevented from being heated by the transmitted light 111 in the lid 501.
On the heater 103 side, the absorber 112 is mounted on the lid 501. In this case, the transmitted light 111 is absorbed by the absorber 1 due to the evanescent effect as described with reference to FIG.
And the transmitted light 11 reaching the O-ring 107
1 can be attenuated. As described above, in the second embodiment of the present invention, the same effect as in the first embodiment can be obtained.

Although the above-described example is an example of an apparatus using a quartz chamber, even if the chamber is made of another material,
If an absorber having a property of absorbing light having a wavelength transmitted through the inside of the chamber is used, it is possible to attenuate the transmitted light inside the chamber.

Further, in the above-described example, all the radiation light is emitted from the heater, but a lamp may be used. Further, for example, when processing is performed while generating plasma in a chamber, light generated from plasma may propagate inside the chamber in the same manner as radiated light from a heater, and may deteriorate the O-ring and the like by heating. .

In such a case, similarly to the above-described example,
By mounting an absorber on the surface of the chamber, the light propagating inside the chamber is attenuated, the heating of the seal components mounted in the chamber is suppressed, and a semiconductor device capable of forming an ultrathin oxide film by rapid temperature rise is realized. can do.

The light absorbed by the absorbing member 112 is
It includes the wavelength at which the divergence of the spectral radiant flux from the heating light source 103 is maximized.

[0063]

Since the present invention is configured as described above, it has the following effects. Despite a simple configuration, a semiconductor device capable of forming an ultrathin oxide film by rapidly increasing the temperature by suppressing the heating of a seal component mounted in the quartz chamber without lowering the mechanical strength of the quartz chamber is realized. be able to.

As a result, the device can be miniaturized, and a higher-performance semiconductor device can be produced.

Further, in the semiconductor manufacturing apparatus, it is possible to simplify a cooling mechanism such as an O-ring and the like, and to reduce the price of the apparatus.

[Brief description of the drawings]

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

FIG. 2 is a graph showing radiation light intensity E obtained for each heater temperature.

FIG. 3 is an enlarged view of a portion A in FIG. 1 and is an explanatory diagram of reduction of transmitted light by an absorber.

FIG. 4 is an enlarged view of a portion B in FIG. 1;

FIG. 5 is a schematic sectional view of a semiconductor manufacturing apparatus according to a second embodiment of the present invention.

[Explanation of symbols]

 101 Chamber 102 Wafer 103 Heater 104 Rib 105 Connection Chamber 106 Flange 107 O-Ring 108 Radiation Light 110 Heater Cover 111 Transmitted Light 112 Absorber 301 Incident Angle 302 Reflected Light 303 Evanescent Wave 304 Spacer 305 Heat Dissipating Member 501 Cover

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Nobuo Tsumaki 502 Kandachicho, Tsuchiura-shi, Ibaraki Machinery Research Laboratory, Hitachi, Ltd. (72) Inventor Toshimitsu Miyata 3-14-20 Higashinakano, Nakano-ku, Tokyo (P 'S Higashinakano Building) Kokusai Electric Corporation

Claims (10)

[Claims] 1. A semiconductor manufacturing apparatus comprising at least a heat treatment container and a heating light source disposed outside or inside the heat treatment container, wherein light having a specific wavelength is absorbed on a surface of the heat treatment container. A semiconductor manufacturing apparatus comprising an absorbing member having characteristics. 2. The semiconductor manufacturing apparatus according to claim 1,
The absorbing member is disposed on the surface of the heat treatment container with an interval equal to or less than the specific wavelength, and at least a part of light or an electromagnetic wave radiated from the heating light source forms a heat treatment container. When transmitting or propagating inside, the electromagnetic energy formed by the evanescent effect in the vicinity of the surface of the heat treatment container is absorbed by the absorbing member, so that at least a part of the light or electromagnetic wave transmitted or propagated. A semiconductor manufacturing apparatus characterized by attenuating. 3. The semiconductor manufacturing apparatus according to claim 1, wherein the heat treatment container is connected to another treatment container separate from the heat treatment container via a seal member.
A semiconductor manufacturing apparatus, wherein a material of the absorbing member is equivalent to a material of the sealing member. 4. The semiconductor manufacturing apparatus according to claim 1, wherein the absorbing member is formed of a material having elasticity. 5. The semiconductor manufacturing apparatus according to claim 4, wherein
The semiconductor manufacturing apparatus, wherein the absorbing member is annular, and the annular absorbing member is disposed on an outer peripheral surface of the heat treatment container. 6. The semiconductor manufacturing apparatus according to claim 1, wherein the light absorbed by said absorbing member has a wavelength of 2.5 μm. . 7. The semiconductor manufacturing apparatus according to claim 1, wherein the light absorbed by the absorbing member has a wavelength at which the spectral radiation flux from the heating light source is maximized. A semiconductor manufacturing apparatus characterized by including: 8. The semiconductor manufacturing apparatus according to claim 1, wherein a material of said heat treatment container is quartz. 9. A semiconductor manufacturing apparatus according to claim 1, wherein said heating light source is a lamp or a heater for heating an object to be processed inside a processing container. Semiconductor manufacturing equipment. 10. The semiconductor manufacturing apparatus according to claim 1, wherein said heating light source is generated inside said processing container to heat an object to be processed inside said processing container. A semiconductor manufacturing apparatus characterized in that it is a light emitting material such as plasma.