JP2000068222A - Substrate heat treatment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate heat treatment device for operating uniform processing in a face a substrate to be processed. SOLUTION: The filament densities of lamps 20a, 20b, 20c, and 20d are set so that filament densities Fa, Fb, Fc, and Fd can fulfill the relation Fa>Fb>Fc>Fd. An equal power is supplied to the all the lamps 20a, 20b, 20c, and 20d. The filament densities Fa-Fd fulfill the relation so that stronger light intensity can be obtained at the peripheral side of the substrate W, even if the supplied power is equal. Thus, the temperature of the substrate w can be held uniform in a face to be processed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a semiconductor wafer,
The present invention relates to a substrate heat treatment apparatus that performs a process involving heating by a plurality of lamps on a substrate such as a glass substrate for a photomask, a glass substrate for a liquid crystal display, and a substrate for an optical disk (hereinafter, simply referred to as a “substrate”).

[0002]

2. Description of the Related Art Conventionally, in a substrate heat treatment apparatus for performing processing by supplying a gas while heating a substrate with a lamp, for example, using a straight pipe, the length, filament density, color temperature (filament thickness), etc. A plurality of lamps having exactly the same specifications are arranged, and the processing is performed while irradiating light to heat the substrate.

[0003]

FIG. 6 is a diagram showing a change in temperature between the peripheral portion and the central portion of the substrate during the heat treatment by the conventional apparatus. However, in the measurement of FIG. 6, the power supplied to each lamp is the same at the same time. As can be seen from FIG. 6, when the substrate temperature is maintained at the target temperature of 800 ° C. (when the temperature is maintained), the temperature at the peripheral edge of the substrate is lower than that at the center. Therefore, the in-plane unevenness of the processing quality of the substrate is apt to occur.

An object of the present invention is to overcome the above-mentioned problems in the prior art, and an object of the present invention is to provide a substrate heat treatment apparatus capable of performing uniform processing on a surface to be processed of a substrate.

[0005]

To achieve the above object, an apparatus according to a first aspect of the present invention is a substrate heat treatment apparatus for performing processing involving heating of a substrate with light from a plurality of lamps. Further, a plurality of lamps having non-uniform specifications are spatially distributed along the surface to be heated of the substrate.

According to a second aspect of the present invention, there is provided the substrate heat treatment apparatus according to the first aspect, wherein the plurality of lamps are a plurality of incandescent lamps, and the non-uniformity of the specification is:
It is characterized in that it includes non-uniformity in filament density of a plurality of incandescent lamps.

According to a third aspect of the present invention, there is provided the substrate heat treatment apparatus according to the second aspect, wherein the non-uniformity of the filament density is such that the filament density is closer to the periphery of the substrate. It is characterized by a high degree of non-uniformity.

According to a fourth aspect of the present invention, in the substrate heat treatment apparatus of the second or third aspect, each of the plurality of incandescent lamps is a halogen lamp. .

According to a fifth aspect of the present invention, there is provided the substrate heat treatment apparatus according to any one of the first to fourth aspects, wherein the plurality of lamps are a plurality of straight tubes,
The non-uniformity of the specifications includes a non-uniformity in length of the plurality of straight pipes.

Further, according to a sixth aspect of the present invention, there is provided the apparatus for heat treating a substrate according to any one of the first to fifth aspects, wherein the substrate has a substantially circular shape in plan view. The lamp is housed substantially horizontally in the body, and the plurality of lamps are arranged so as to face the substrate in the furnace body.

The "specifications" of the lamp in the present invention refer to structural factors specific to the lamp that define light emission characteristics, such as intensity distribution and spatial distribution of light emission from the lamp.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

<1. Overall configuration and schematic processing> FIG.
FIG. 2 is a partial longitudinal sectional view showing the substrate heat treatment apparatus according to the embodiment of the present invention. The furnace body 55 is a casing having a mirror-like inner surface and serving as a reflector. Inside the furnace body 55, a chamber (processing chamber) 10 and a plurality of lamps 20a to 20d which will be described later in detail are respectively provided above and below the chamber. Is provided. A furnace port block 50 is provided on the front side (the right side in FIG. 1) of the chamber 10.

A susceptor 35, which is a means for supporting the substrate, is fixed to the movable flange 30. Also, the susceptor 35
Has three support pins 36 (only two are shown in the side view of FIG. 1), and the support pins 36 support the substrate W to be processed in a substantially horizontal posture.

The movable flange 30 is configured to be movable in a horizontal direction (X-axis direction in FIG. 1). Since the susceptor 35 fixed to the moving flange 30 supports the substrate W, the substrate W also moves in the positive and negative directions of the X axis as the moving flange 30 moves. That is, the susceptor 35 fixed to the movable flange 30 enters and exits the chamber 10 while supporting the substrate W.

When the movable flange 30 moves toward the chamber 10 and comes into contact with the furnace port block 50, the furnace port is closed and the substrate W is stored and held substantially horizontally at a predetermined position in the chamber 10. Then, in this state, the lamp 20a
The heat treatment of the substrate W is performed by performing light irradiation from ２０20d.

On the other hand, when the moving flange 30 moves to the opposite side to the chamber 10, the furnace port is opened, and the moving flange 30 further moves to move the substrate W into the chamber 10.
And it is drawn out of the furnace opening block 50. In this state, the transfer of the substrate W (replacement of the unprocessed substrate W and the processed substrate W) is performed between the substrate transfer robot (not shown) and the susceptor 35 outside the apparatus.

During the heat treatment of the substrate W, the surrounding atmosphere is filled with a processing gas such as nitrogen dioxide, ammonia or the like in order to perform processing such as film formation on the heated substrate W. Gas flow in chamber 1
A gas introduction port 60 and a gas exhaust port 70 are provided to be formed in 0. The gas inlet 60 is provided through the furnace body 55 and the end of the chamber 10 and communicates with gas supply means outside the apparatus. Further, the gas exhaust port 70 is provided so as to penetrate the furnace port block 50 and communicates with an exhaust unit outside the apparatus. The processing gas introduced from the gas inlet 60 is supplied to the chamber 10
The gas flows through the inside and is exhausted from the gas exhaust port 70 to form a gas flow in the chamber 10.

Further, this apparatus is equipped with a lamp 2 outside the furnace body 55.
0a to 20d, each of which has a lamp control unit 80 electrically connected thereto.
The power supplied to each of the 20d is controlled.

In the substrate heat treatment apparatus having the above-described schematic configuration, when performing the heat treatment, first, the moving flange 30 moves in the positive direction of the X-axis, and is moved from the substrate transfer robot outside the chamber 10 and the furnace port block 50. The unprocessed substrate W is transferred to the susceptor 35. Then, the moving flange 30 moves in the negative direction of the X-axis, and the substrate W is stored and held at a predetermined position in the chamber 10 (the state shown by the solid line in FIG. 1). In this state, a processing gas is introduced into the chamber 10, and the lamps 20 a to 20 d are turned on in a state where a gas flow is formed in the chamber 10, so that the substrate W is subjected to processing involving heating.

When the above processing is completed, the moving flange 3
0 moves in the positive direction of the X-axis in FIG.
And it is taken out of the furnace opening block 50. Then, the substrate transfer robot takes out the processed substrate W from the susceptor 35, whereby a series of processes is completed. And
The above processing is repeated for a plurality of substrates W.

<2. Features> Next, features of the present invention will be described. FIG. 2 is a cross-sectional view showing a planar configuration of the substrate heat treatment apparatus in this embodiment. In the present invention, the specifications such as the type, shape, filament density, and color temperature of the plurality of lamps are different from each other. Above all,
In the apparatus of this embodiment, the lamp lengths and the filament densities of the lamps 20a to 20d are different from each other. Hereinafter, these will be described.

First, as a premise, in this apparatus, since the shape of the substrate W to be handled is substantially circular, the furnace body 55 has a cylindrical shape, and therefore, the furnace body 55 has a substantially circular shape in plan view. Has become. Therefore, the lamp 20
a to 20d are straight tube incandescent lamps having different lengths, more specifically, halogen lamps.
0b, 20c, and 20d are lengths La and L, respectively.
Assuming that b, Lc, and Ld, the relationship of La <Lb <Lc <Ld is satisfied. Thereby, the lamps 20a-2
Each of Od has a length that can be accommodated in the furnace body 55. In this way, by making the lengths of the plurality of straight tube lamps different from each other as described above, the furnace body 55
It can be arranged according to the shape of.

Each of the lamps 20a, 20b, 20c,
20d has different filament densities from each other and is non-uniform in a horizontal plane (in plan view).
That is, the filament density (the number of turns per unit length of the filament) of each of the lamps 20a, 20b, 20c, and 20d is determined by the filament density Fa, Fb, and F, respectively.
Assuming that c and Fd, the relationship of Fa>Fb>Fc> Fd is satisfied. In this embodiment, equal (uniform) power is supplied to all the lamps 20a to 20d as described later. However, since the lamps 20a to 20d satisfy the above-described relationship of the filament densities Fa to Fd, the power to be supplied can be increased toward the periphery of the substrate W.
As a result, the temperature of the substrate W can be kept uniform within the surface to be processed without fine control of the supplied power.

Further, since there is no need to provide a difference in the power supplied to the lamps 20a to 20d in the surface to be processed, it is not necessary to use a lamp having a larger rated value than necessary to obtain a predetermined output.

FIG. 3 is a graph showing a change over time in the power supplied to the lamp and the substrate temperature in the apparatus of this embodiment. As described above, in this embodiment, the lamp 20a
The power is controlled as shown in the lower part of FIG. That is, in this embodiment, when the temperature is raised, the supply power is immediately set to near 100% of the rated value to rapidly raise the temperature of the substrate W, and when the temperature of the substrate is maintained after reaching the target temperature, the supply to the lamp is continued. The power is set to about 50% of the rated value.

Here, the apparatus of this embodiment will be compared with a conventional apparatus. In the case of the conventional apparatus in which the specifications of the lamps are equal to each other as described above, the power supplied to the lamp facing the vicinity of the periphery of the substrate is strongly increased when performing the heat treatment against the temperature decrease of the periphery of the substrate as described above. It may be possible to prevent this by weakly controlling the power supplied to the lamp facing the center.

In FIG. 6, when the temperature is raised, the substrate W
The temperature at the peripheral portion is higher than the temperature at the central portion, and when the temperature is maintained, the temperature at the central portion is higher than the temperature at the peripheral portion (hereinafter referred to as “reversal phenomenon”). It is considered that it is difficult to eliminate the phenomenon by controlling the lamp in the conventional apparatus as described above. The reason will be described below.

FIG. 4 is a graph showing a change in the wavelength distribution of transmittance at each temperature of silicon (Si) mainly used for a substrate, especially a semiconductor wafer. As shown in FIG. 4, for silicon, 1
At a wavelength of about μm, the transmittance sharply decreases and approaches “0”. Here, since the reflectance is almost constant irrespective of the wavelength, the absorption rate of silicon light rapidly decreases at 1 μm according to the law of conservation, and the absorption rate decreases considerably at longer wavelengths.

FIG. 5 is a graph showing the emission wavelength distribution depending on the power supplied to the halogen lamp. As shown in the figure, the halogen lamp has a different wavelength distribution depending on the supplied power. In particular, the wavelengths at the peak positions P1 to P5 are deviated in the range of 1 μm to 2.5 μm according to the supplied power. That is, when the supply power is reduced, the emission wavelength shifts to the longer wavelength side.

By the way, when a process involving heating of a substrate is performed by the above-described conventional apparatus under the above-described control, the power supplied to the lamp is substantially 100% at the peripheral portion of the substrate in consideration of the temperature rise of the substrate. % (Rated value).
As shown in FIG. 5, when 100% power is supplied, the peak position P
One wavelength is about 1 μm. Further, since the supply power of the lamp at the center at the time of temperature rise is lower than 100%, the emission wavelength at that time is light having a peak position longer than 1 μm.
At this time, assuming that the temperature of the substrate W is between room temperature and 500 ° C.,
As can be seen from FIG. 4, the absorptivity of light having a wavelength of about 1 μm at the peripheral portion of the silicon substrate is high, and the absorptivity of light having a wavelength longer than 1 μm at the central portion is low. Therefore, it is considered that the temperature at the peripheral portion of the substrate tends to increase when the temperature is increased.

Conversely, when the temperature is maintained, when the power supplied to the lamp facing the peripheral portion of the substrate is about 60%, the wavelength at the peak position P3 is about 1.2 μm from FIG. Is considered to be about 1000 ° C., there is almost no distribution in the absorptance according to the wavelength from FIG.
Because the absorptivity is uniform, the peripheral area of the substrate has a larger surface area than the central area, so that the heat dissipation at the peripheral area of the substrate is greater than the difference in power supplied by control, and the temperature at the peripheral area is lower than the central area. It seems to be. This is a result suggesting that a phenomenon similar to the reversal phenomenon in the conventional device occurs. As described above, in the conventional apparatus, when the power supplied to the lamp facing the central portion of the substrate and the lamp facing the peripheral portion are made different from each other to suppress the temperature drop at the peripheral portion of the substrate, the above-described reverse rotation occurs. The phenomenon is easy to occur.

On the other hand, in the apparatus of this embodiment,
As described above, in the lamps 20a to 20d, the filament density is higher at the peripheral portion, but the lamps 20a to 20d
Since d has a uniform power supply, their emission wavelengths are uniform. Thereby, the light absorptivity of the substrate becomes uniform in the surface to be processed. Therefore, the occurrence of the above-described reversal phenomenon can be suppressed.

As described above, according to this embodiment, since each of the lamps 20a to 20d is an incandescent lamp, the filament density is closer to the periphery of the substrate W, so that the temperature distribution of the substrate W By providing a filament density distribution that complements the temperature distribution on the surface to be processed, uniform processing can be performed within the surface of the substrate to be processed. Further, by making the filament density distribution as described above, uniform processing can be performed in the surface to be processed without adjusting the supply power of each lamp, so that the emission wavelength does not change, and therefore, the light emission is not changed. Since the absorptance does not change, non-uniformity of the temperature in the surface to be processed can be efficiently compensated, and uniform processing can be easily realized.

The lamps 20a to 20d are straight tubes, and the lamp lengths La, Lb, Lc and Ld are La <Lb.
Since <Lc <Ld is satisfied, there is little waste with respect to the shape of the circular substrate W, and the efficiency is good.

Further, since the furnace body 55 is substantially circular in a plan view, when a circular substrate W is accommodated, the size of the apparatus and the area occupied by the apparatus can be reduced as compared with a square furnace body. Equipment manufacturing costs can also be reduced.

<3. Modifications> Although an example of the substrate heat treatment apparatus has been described in the above embodiment, the present invention is not limited to this.

For example, in the above embodiment, the lamp 20
Although the filament densities and lengths of a to 20d are different from each other, other specifications such as different color temperatures of light emitted from the lamps may be used.

In the above embodiment, the furnace body 55 has a cylindrical shape. However, the furnace body may be a cube, a rectangular parallelepiped, a pentagonal prism,
It may be a polygonal prism such as a prism.

Further, although the lamps 20a to 20d are intuitive, the mini lamps may be distributed in the plane so that their filament densities are different from each other, such as different specifications.

[0041]

As described above, according to the first to sixth aspects of the present invention, a plurality of lamps having non-uniform specifications are spatially distributed. By distributing the specifications of the lamp so as to be uniform, uniform processing can be performed in the surface to be processed.

According to the second aspect of the present invention, since the plurality of lamps are a plurality of incandescent lamps, the non-uniformity of the specification includes the non-uniformity of the filament density of the plurality of incandescent lamps. By making the temperature distribution have a filament density distribution that complements the temperature distribution on the surface to be processed, uniform processing can be performed on the surface to be processed of the substrate. Further, by setting the filament density distribution as described above, uniform processing can be performed on the surface to be processed without adjusting the supply power of each lamp. Since the absorptance does not change, non-uniformity of the temperature in the surface to be processed can be efficiently compensated, and uniform processing can be easily realized.

According to the third aspect of the present invention,
Since the filament density is higher at the peripheral portion of the substrate, when the temperature at the peripheral portion of the substrate is apt to decrease, the temperature can be compensated to perform uniform processing on the surface to be processed.

According to the fifth aspect of the present invention,
Since the plurality of lamps are a plurality of straight tubes and the non-uniformity of the specification includes the non-uniformity of the length of the lamp, the lamp can be reduced in waste according to the shape of the substrate.

In particular, according to the invention of claim 6,
When the substrate is accommodated substantially horizontally in a substantially circular furnace body in a plan view, a plurality of lamps are arranged so as to face the substrate in the furnace body. The apparatus size and the area occupied by the apparatus can be reduced as compared with the furnace body, and the apparatus manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a partial vertical sectional view showing a substrate heat treatment apparatus according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a planar configuration of the substrate heat treatment apparatus according to the embodiment.

FIG. 3 is a graph showing the change over time in lamp supply power and substrate temperature in the apparatus of the embodiment.

FIG. 4 is a graph showing a change in a wavelength distribution of transmittance at each temperature of silicon.

FIG. 5 is a graph showing an emission wavelength distribution according to power supplied to a halogen lamp.

FIG. 6 is a diagram showing a temperature change between a peripheral portion and a central portion of a substrate during a heat treatment by a conventional apparatus.

[Explanation of symbols]

 20a-20d Lamp 55 Furnace La-Ld Length Fa-Fd Filament density W Substrate

Claims (6)

[Claims] 1. A substrate heat treatment apparatus for performing a process involving heating of a plurality of lamps on a substrate, the plurality of lamps having non-uniform specifications being spatially distributed along a surface to be heated of the substrate. A substrate heat treatment apparatus. 2. The substrate heat treatment apparatus according to claim 1, wherein the plurality of lamps are a plurality of incandescent lamps, and the non-uniformity of the specification is a non-uniformity of a filament density of the plurality of incandescent lamps. A substrate heat treatment apparatus, comprising: 3. The substrate heat treatment apparatus according to claim 2, wherein the non-uniformity of the filament density is a non-uniformity such that the filament density is closer to the periphery of the substrate. Substrate heat treatment apparatus. 4. The substrate heat treatment apparatus according to claim 2, wherein each of the plurality of incandescent lamps is a halogen lamp. 5. The substrate heat treatment apparatus according to claim 1, wherein the plurality of lamps are a plurality of straight tubes, and the specification non-uniformity is the plurality of straight tubes. A substrate heat treatment apparatus characterized by including non-uniformity in length. 6. The substrate heat treatment apparatus according to claim 1, wherein the substrate is stored substantially horizontally in a furnace having a substantially circular shape in plan view. The heat treatment apparatus for a substrate, wherein the plurality of lamps are arranged so as to face the substrate in the furnace body.