JPS63260127A - Light irradiation apparatus - Google Patents

Abstract

PURPOSE:To simplify the control of the light emitting amount of each light source and to facilitate the control for uniform lighting, by providing control means, which can control the light emitting amounts of annular light sources comprising a plurality of the light sources, which are connected in series all together. CONSTITUTION:The innermost first annular light sources 1a and 1b of semicircular light sources 1a-3a are connected in series. These light sources and second annular light sources 2a and 2b are connected in parallel, respectively. The light emitting amounts of the light sources are controlled all together by a first power control means 7. Semicircular light sources 10a, 10b, 20a, 20b, 30a and 30b are connected by the silimar way, and the light emitting amounts are controlled all together by the first power control means 7. Outermost third annular light sources 3a, 3b, 30a and 30b are connected in parallel, respectively, and the light emitting amounts are controlled all together by a second power control means 8. Even if light emitting power per unit length of each light source when the same voltage is applied is different, the control can be performed by one power control part, by connecting a plurality of the light sources, which form the desired annular light sources, in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a light irradiation device such as a lamp annealing device used in a semiconductor wafer processing process.

[Conventional technology]

As this type of light irradiation device, in addition to the above-mentioned lamp annealing device, auxiliary heating devices for sputtering devices, epitaxial devices, and ashing devices are known. In either device, it is necessary to control the heating temperature and to equalize the temperature distribution of the semiconductor wafer (hereinafter simply referred to as wafer) in order to ensure uniformity of reaction within the wafer substrate. Particularly in lamp annealing equipment, heat escapes around the wafer, resulting in uneven temperature distribution, resulting in slip lines and variations in semiconductor characteristics depending on the position on the wafer surface. In order to solve this problem, by using multiple annular light sources arranged concentrically instead of a bar-shaped light source, a substantially rotationally symmetrical light source that matches the approximately circular wafer shape is constructed. A light irradiation device capable of uniformly irradiating light was previously proposed in Japanese Patent Application No. 61-211208 by the same applicant as the present application.

[Problem that the invention seeks to solve]

The multiple concentric annular light sources disclosed in the above-mentioned earlier application make it possible to uniformly irradiate the entire wafer surface, but this assumes that each annular light source emits the same amount of light per unit length. . In practice, the length of the light emitting part of each annular light source is different, so in order to equalize the amount of light emitted per unit length, it is necessary to control the supplied power according to the length of the light source and the resistance value. A complex control system configuration is required. If each annular light source is configured with a single light source, the spacing between the electrodes will increase due to manufacturing constraints, resulting in a large number of non-light emitting parts, making uniform illumination difficult. It is conceivable to configure it by combining arc-shaped lamps. However, even in this case, it is difficult to match the ratings of all the light sources that make up each annular light source, and as the number of light sources increases, the configuration for controlling the light amount of each lamp becomes complicated, and the control for uniform illumination becomes difficult. The problem is that it becomes difficult.

If the lengths of the light sources are not that different, by changing the wire resistance, you can make the applied voltage the same to make each semicircular lamp emit the same amount of light per unit length, and multiple light sources can be connected in parallel and batched. Controlled and uniform irradiation is possible. However,
If the lengths of the light sources are greatly different, the applied voltage cannot be made the same to make the amount of light emitted per unit length the same.0For example,
The rated voltage is 100V on the inner circumference, 200V on the middle circumference, and 200V on the outer circumference.

There is a method of using a transformer or a separate power control section, but the number of parts increases.

Therefore, an object of the present invention is to easily control the amount of light emitted by each light source when each of a plurality of annular light sources arranged concentrically is configured by a combination of a plurality of light sources, and to achieve uniform illumination. An object of the present invention is to provide a light irradiation device that is easy to control.

[Means for solving problems]

The present invention provides a light irradiation device having a plurality of annular light sources arranged concentrically, in which each of the plurality of annular light sources is configured by a combination of a plurality of light sources, and a predetermined one of the concentric annular light sources A fI that can control the amount of light emitted by connecting a plurality of light sources forming a ring light source in series, and collectively control the amount of light emitted by the ring light source made up of the plurality of light sources connected in series.
It is equipped with IITIJ means.

The annular light source configured by this series connection is used as an inner annular light source, and has a configuration in which the amount of light emitted per unit length can be controlled independently of the amount of light emitted per unit length of other annular light sources. This is desirable.

[Effect]

According to the present invention as described above, by connecting in series a plurality of light sources forming a predetermined annular light source among a plurality of concentrically arranged annular light sources, the combined load and other annular light sources are configured. Since the voltage applied to the load of the light source can be the same, at least two annular light sources can be collectively controlled by the same control means. Therefore, it is possible to simplify the configuration of the control device, and it is also easy to equalize the amount of light emitted per unit length, making it possible to efficiently perform uniform irradiation.

〔Example〕

The present invention will be explained below based on Examples.

Embodiments of the present invention are described in the earlier publication [(Patent Application No. 61-211
As disclosed in No. 208), the light irradiation device is based on a light irradiation device that irradiates an irradiated object using a plurality of annular light sources arranged concentrically instead of the conventional rod-shaped light source.

FIG. 1 is a cross-sectional view showing the schematic configuration of such a light irradiation device, and FIG. 2 is a plan view showing the configuration of concentrically arranged annular light sources in this device. A wafer 5, which is an object to be irradiated and supported by a wafer 6, is placed in a chamber 4 made of quartz or the like and through which heating irradiation light is transmitted. Above the chamber 4 are semicircular light sources 1allb12a12b13a forming three annular light sources arranged concentrically on a plane parallel to the wafer 5 as shown in FIG.
13b, and below the chamber 4 there are semicircular light sources 10 forming three annular light sources similarly arranged concentrically.
a, 10b, 20a, 20b, 30a, and 30b are arranged. Three annular light sources are arranged concentrically above and below the wafer, with the first annular light source being the innermost one being the two semicircular light sources 1a and 1b (10a, 10b).
), the middle second annular light source is composed of two semicircular light sources 2a, 2b (20a, 20b), and the outermost third annular light source is composed of two semicircular light sources 3a, 3b (3
0a, 30b).

These semicircular light sources are halogen lamps, and the electric bridge is provided in an extension part that extends perpendicularly to the semicircular light emitting part, and the spacing between the electrodes is small to reduce the non-light emitting part. It is configured to be.

FIG. 3 is a circuit diagram showing a configuration for controlling the amount of light emitted from each concentric light source in the above embodiment. Six semicircular light sources 1a, 1b, 2a, 2b arranged above the chamber 4,
Among 3a and 3b, two semicircular light sources 1a and lb forming the innermost first annular light source are connected in series, and these two semicircular light sources 1a and lb are connected in series.
Two semicircular light sources 2a and 2b forming one series-connected semicircular light source and a second annular light source are connected in parallel, respectively, and the amount of light emitted is collectively controlled by the first power control means 7.

Further, six semicircular light sources 10a, 10b, 20a, 20b, 30a, 30b are arranged below the chamber 4.
Similarly, two semicircular light sources 10a and 10b forming the innermost first annular light source are connected in series, and two semicircular light sources 20a and 10b forming the second annular light source are connected in series.
, 20b are connected in parallel, and the first power control means 7
It is collectively controlled by. Further, a semicircular light source 3a forms the outermost third annular light source.

3b, 30a, and 30b are each connected in parallel to the second
The amount of light emitted is collectively controlled by the power control means 8.

Here, the rated voltage of each semicircular light source 1a, lb, loa, and 10b constituting the innermost first annular light source is 1o.
ov, whereas the rated voltage of each semicircular light source forming the second annular light source and the third annular light source is 200V,
Since two of the innermost annular light sources are connected in series, the combined rated voltage is 200V, making it possible to control the same rated voltage as the semicircular light source that makes up the second annular light source. There is. Therefore, as described above, the first power control means 7 controls the semicircular light sources 1a and 1b, which constitute the first annular light source and the second annular light source, respectively, having different rated voltages.
, 2a, 2b (10a.

10b, 20a, 20b) can be controlled all at once.

The first power control means 7 and the second power control means 8 are each controlled by the main control means 9. The main control means 9 controls the entire surface of the wafer based on temperature distribution information on the wafer surface detected by a temperature measuring optical system (not shown) configured by aligning the optical axis with the concentric center of annular light sources arranged concentrically. The first and second power control means 7.8 are controlled to adjust the amount of light emitted from the first and second annular light sources and the amount of light emitted from the third annular light source so that the temperature distribution becomes a desired temperature distribution. The first and second power control means 7.8 adjust the amount of light emitted by adjusting the power supplied from the AC power supply 100 to the power required for each light source using a phase controller using Cyrisk. The main control means 9 emits a signal that defines the control amount of the phase control based on the sirisk in each power control means.

In such a light irradiation device, a temperature or power profile is inputted from the outside to the main control means 9, and the device is controlled to realize the profile. The reason for the configuration in which only the semicircular light source that forms the outer annular light source is controlled separately is to prevent uneven temperature distribution due to heat escape around the wafer. This is to independently perform control such as increasing the light emission power. In advance, specifications are set so that the amount of light emitted per unit length of the outer semicircular light sources 3a, 3b, 30a, and 30b is larger than that of the other inner semicircular light sources when the voltage is the same, and all semicircular light sources It is also possible to control them all at once by one power control means.

FIG. 4 is a plan view showing the configuration of a striped light source in a second embodiment of the present invention. In this embodiment as well, there are six semicircular light sources 11a, 11b, 21a, 21b, 3 on the top surface of the wafer.
Three annular light sources composed of 1a and 31b are arranged,
Six semicircular light sources 12a and 12b are also provided on the lower surface of the wafer.

Three annular light sources composed of 22a, 22b, 32a, and 32b are arranged. As shown in the figure, this embodiment is designed so that the electrode portions of the semicircular light sources forming each annular light source and the non-light emitting portions between the electrode portions and the opposing intervals are not located on the same radial direction between adjacent annular light sources. It was placed in

That is, the semicircular light source 1 constituting the innermost first annular light source
1a, Ilb (12a, 12b) and the radial direction of the non-light emitting part as the interval between them constitutes a second annular light source. Semicircular light sources 21a, 21b (22a).

The light emitting portion 22b) is located at an angle of 45° away from the concentric center N in the radial direction. Further, semicircular light sources 31a and 31b forming the outermost third annular light source
The radial direction in which the non-light-emitting portion in (32a, 32b) is also approximately 45 mm from the position of the non-light-emitting portion in the second annular light source.
They are placed offset by °. In this way, by distributing the non-emitting parts throughout the concentrically arranged annular light sources so that the radial directions of the non-emitting parts of adjacent annular light sources do not match, uniform irradiation can be achieved over the entire wafer surface. becomes possible. Regarding the concentric annular light sources arranged vertically facing the wafer, the upper and lower annular light sources are arranged so that the non-light emitting parts of the annular light sources above and below the wafer do not align in the same radial direction. It is desirable that they be arranged relatively rotated by a predetermined angle.

In the second embodiment as well, as shown in the circuit diagram of FIG. 5, the two semicircular light sources 11a, llb and 12a, 12b constituting the innermost first annular light source are connected in series. has been done. and semicircular light sources 21a, 21b, and 22a forming a second annular light source.

22b are connected in parallel, and the inner light source control means 7
Collectively controlled by 0. And the rated voltage is 100
V innermost semicircular light sources 11a, llb and 12a
, 12b are connected in series, so the combined voltage is equal to the voltage of each semicircular light source 21a, 12b forming the second annular light source.
Same as rated voltage of 21b, 22a, 22b < 200
(2) It is possible to control the semicircular light source forming the innermost first annular light source and the semicircular light source forming the second annular light source with the same rated voltage to provide uniform illumination.

In addition, in this second embodiment, four semicircular light sources 31a, 31b and 32a, 32b forming an outer third annular light source disposed on the upper surface and lower surface of the wafer, respectively, are shown in FIG. With respect to the direction from the concentric center N of the orientation flant part (hereinafter simply referred to as orientation flat) 5a of the wafer 5 shown by the broken line in , the direction in which the non-light emitting part including each electrode part is located is 90''. The semicircular light source 31a located on the upper surface of the orientation flat side of the wafer 5 and the semicircular light source 32a located on the lower surface of the orientation flat side of the wafer 5 are connected in parallel to form the first external light source control means. 8
1, and the orientation flat of the wafer 5 on the other hand.
The semicircular light sources 31b and 32b located above and below on the opposite side are also connected in parallel and collectively controlled by the second external light source control means 82.

In this way, by controlling the outermost annular light source independently of the semicircular light source that makes up the inner annular light source, it is possible to correct the uneven temperature distribution caused by heat escape around the wafer, and also to control the temperature distribution on the orientation flat side. By configuring the semicircular light source and the opposite side to be separated, it is also possible to correct non-uniformity in temperature distribution due to asymmetry in the shape of the orientation flat.

The configuration of the outermost annular light source is not limited to the configuration shown in FIG. 4, and other configurations are also possible.

For example, as shown in the plan view of FIG. 6, an arcuate light source 33b is placed in a portion corresponding to the angular range from the concentric center of the orientation flat 5a of the wafer, and one third annular light source is placed in the remaining angular range. An arcuate light source 33a is arranged, and these two arcuate light sources form a third annular light source. In addition, here, two semicircular light sources 13a and 13b (14a,
14b), two semicircular light sources 23a, 23b (
24a, 24b) in the radial direction of the non-light emitting part is about 90
° They are placed out of alignment.

Therefore, the non-light-emitting portions of any adjacent annular light sources are not located on the same radius (this is advantageous for uniform illumination).

FIG. 7 shows another configuration of the outermost third annular light source, in which, compared to the configuration shown in FIG. 6, a linear light source 35b ( 3
6b) are arranged above and below with the wafer in between, and arcuate light sources 35a (36a) are arranged above and below in areas other than the orientation flat 5a, and the other configurations are the same as in the case of FIG. Finally, in the configuration shown in FIG. 8, in the radial region corresponding to the orientation flat 5a of the wafer 5, the middle part is a straight line and only the ends are formed in an arc shape so as to have a phase shape with the outer shape of the wafer. Light sources 37b (38b) are placed above and below the wafer, and arcuate light sources 37 are arranged in other radial areas.
a (38a) is arranged. Each inner light source has the same structure as described above, so the same figure numbers as in FIGS. 6 and 7 are given. In either configuration, by connecting the innermost semicircular light source in series, as shown in FIG. 5, for example, it is possible to integrally control the semicircular light source with the other light sources to provide uniform illumination.

Note that lamp annealing equipment normally performs rapid heating and cooling, so as in each of the above embodiments, heating is performed simultaneously from both the top and bottom of the wafer so that the heat distribution in the thickness direction of the wafer is symmetrical. Although the wafer is prevented from warping, it is also possible to heat the wafer by irradiating light from only one side of the wafer. It goes without saying that in this case as well, by connecting the inner semicircular light source in series, it becomes possible to control it integrally with the other light sources.

In addition, although the configuration described above is such that one annular light source is mainly formed from two semicircular light sources, the present invention is not limited to this, and it is also possible to form one annular light source using a plurality of arcuate lamps. Even in such a case, if the arcuate light sources forming the inner annular light source with a shorter circumference are connected in series and then connected in parallel with the outer annular light source for collective control, the control means It is possible to have a simple configuration.

Furthermore, in the above embodiment, it is preferable to arrange a reflection mirror on the side opposite to the wafer of each light source to increase the illumination efficiency. In this case, in order to correct the non-uniformity of the temperature distribution at the orientation flat, It is desirable to correct the amount of light irradiation by changing the shape of the reflecting mirror for the outer annular light source for illuminating the orientation flat, thereby making it possible to prevent slip lines at the orientation flat.

〔Effect of the invention〕

As described above, according to the present invention, in a light irradiation device having a plurality of annular light sources arranged concentrically, in configuring each annular light source with a plurality of light sources, the unit length of each light source when the same voltage is applied is Even if the light emitting power per unit is different, by connecting a plurality of light sources forming a desired annular light source in series, it is possible to control the power with one power controller, for example, a phase controller using a thyristor. It becomes possible to configure the structure easily and inexpensively.

The light irradiation device according to the present invention can be applied not only to lamp annealing devices but also to auxiliary heating devices for other semiconductor processes, such as sputtering devices, epitaxial devices, and ashing devices.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a schematic configuration of a light irradiation device according to the present invention, FIG. 2 is a plan view showing a configuration of annular light sources arranged concentrically in the first embodiment, and FIG. 3 is a diagram showing the first embodiment. FIG. 4 is a plan view showing the configuration of concentrically arranged annular light sources in the second embodiment of the present invention, and FIG. Second
FIGS. 6, 7, and 8 are circuit diagrams showing the configuration of a control means for controlling the light amount of each light source in the embodiment. FIG. 3 is a plan view showing the configuration of a light source for correcting non-uniformity of temperature distribution in a flat portion. [Explanation of symbols of main parts] 5...Wafer N...Concentric center of annular light source la, lb, 2a, 2b, 3a, 3b, 1
0a+ 10b+ 20a, 20b, 30a, 3
0b; 11a, llb, 21a, 21b+
31a+ 31b, 12a, 12b, 22a,
22b + 32a + 32b; 13a, 13b,
23a, 23b, 33a, 33b, 14a,
14b, 24a, 24b, 34a, 34b...
・A light source that forms an annular light source (semicircular light source)? , 8.
70.81.82...Applicant for control means Nippon Kogaku Kogyo Co., Ltd. Agent Patent attorney Takashi Watanabe Male flute 3 diagram flute 5 diagram

Claims (1)

[Claims] 1) In a light irradiation device having a plurality of concentrically arranged annular light sources, each of the plurality of annular light sources is configured by a combination of a plurality of light sources, and one of the concentric annular light sources is A plurality of light sources are connected in series to form a predetermined annular light source,
A light irradiation device comprising a control means capable of collectively controlling the amount of light emitted from the predetermined annular light source made up of the plurality of light sources connected in series. 2) Claim 1, wherein the predetermined annular light source made up of the plurality of light sources connected in series is an inner annular light source among the plurality of annular light sources arranged concentrically.
The light irradiation device described in section. 3) The light irradiation device according to claim 1 or 2, wherein the annular light sources arranged concentrically are constituted by a combination of arc-shaped light sources. 4) A patent claim characterized in that the control means has a control means for independently controlling the amount of light emitted by a plurality of light sources constituting an outer annular light source among the annular light sources arranged concentrically. The light irradiation device according to the ranges 1 to 2.