JPS6127675B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heating surface light source device suitable for the construction of a semiconductor wafer irradiation heating furnace.

Among devices generally used for heat treatment, an irradiation heating furnace that irradiates a workpiece with radiation from a lamp has the following features.

(1) Since the heat capacity of the lamp itself is extremely small, the heating temperature can be rapidly increased and decreased.

(2) By controlling the power supplied to the lamp, the heating temperature can be easily controlled.

(3) Non-contact heating using radiation from a lamp, so there is no contamination of the object to be treated.

(4) The start-up time after startup is short and energy efficiency is high, so energy consumption is low.

(5) Compared to direct current furnaces, high frequency furnaces, etc., the equipment is smaller and the cost is lower.

The irradiation heating furnace is used for heat treatment and drying of steel materials, plastic molding, thermal property testing equipment, etc. Particularly recently, processes that require heating in semiconductor manufacturing, such as impurity diffusion processes, chemical vapor deposition processes, recovery processes for crystal defects in ion implantation layers, heat treatment processes for electrical activation, and The use of an irradiation heating furnace in place of the conventionally used electric furnace, high frequency furnace, etc. is being considered as a heating furnace when carrying out a heat treatment process for nitriding or oxidizing the surface layer of a silicon wafer. This is because the irradiation heating furnace does not contaminate the object to be processed or have a negative electrical effect, has low power consumption, and can evenly heat a large area of the object using conventional heating equipment. This is because it is not possible to cope with the recent increase in the area of semiconductor wafers.

As mentioned above, the irradiation heating furnace has various features,
Although widely used in industry, conventional irradiation heating furnaces have the disadvantage that they cannot uniformly irradiate and heat a large area of a workpiece to a high temperature because the temperature rises quickly. In other words, a lamp is a device that is equipped with an envelope made of quartz glass or the like and forms an ignition source or a linear beam of light, and cannot be used alone to form a two-dimensional area light source. Although it is possible to uniformly heat a region, it is not possible to uniformly heat a large area.

The present invention has been made based on the above circumstances, and an object of the present invention is to provide a heating surface light source device that can irradiate synchrotron radiation with uniform irradiation energy density onto a large flat area. shall be.

A feature of the present invention is that a plurality of lamps each having a filament provided with alternating non-light-emitting parts and light-emitting parts in a long rod-shaped tubular envelope made of glass are provided along the tube axis of the envelope. in close proximity to each other, their tube axes are parallel to each other, and the sealing portion of each lamp protrudes outward beyond the edge of the mirror with the surface of the glass forming the sealing portion exposed. They are arranged side by side on one plane.

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

FIG. 1 shows an example of a semiconductor wafer irradiation heating furnace constructed using a heating surface light source device according to an embodiment of the present invention. In this example, as also shown in FIG. Flat mirrors 2 and 3 are arranged to cover the upper and lower sides of the irradiation space 1, respectively. A plurality of semicircular concave grooves m are formed in line on the reflective surface of each of these main mirrors 2 and 3, and each of them is arranged in a lateral direction (in FIG. 1, it is a left-right direction, In Figure 2, it extends over its entire length in the direction perpendicular to the plane of the paper. A first air path member 4 and a second air path member 6 are connected to one side edge and the other side edge in the lateral direction of the main mirrors 2 and 3, respectively, and a blower 5 is connected to the first air path member 4. or connect the exhaust fan 7 to the second air path member 6. One lamp support 8 and the other lamp support 9 are provided near the outlet of the first air path member 4 and near the entrance of the second air path member 6, respectively,
These lamp supports 8 and 9 support both ends of a long rod-shaped halogen lamp 10 extending along the gutter-like groove m in the main mirrors 2 and 3, respectively, so that the lamp 10 is placed in the irradiation space 1. It is arranged so that it is located on one plane facing the Further, the lamp supports 8 and 9 are fixed by screws 24 to side mirrors 20 and 21 having mirror surfaces on their inner surfaces, which are arranged so as to cover both sides of the irradiation space 1. As shown in FIG. 3, the lamp 10 is sealed by a groove-shaped holding part 23 in cooperation with a lamp receiving groove 22 formed at a position corresponding to the groove m at each upper edge and lower edge. The lamp 10 is held in a tubular portion close to the sealing parts 12, 12, and as shown in FIG. With the surface of the glass forming the sealing part exposed, it is placed so that it protrudes outward beyond both end edges of the mirrors 2 and 3, that is, inside the first air path member 4 and the second air path member 6. For the external leads 14, 14 extending from the exposed sealing parts 12, 12, the walls of the first air path member 4 and the second air path member 6 are covered with an insulating material 25 such as Teflon. , 25 to connect current supply lines 26, 26 extending therethrough. A water cooling mechanism is formed in the main mirrors 2 and 3 and the side mirrors 20 and 21, specifically, a water conduit W passing through the material members of the main mirrors 2 and 3 and the side mirrors 20 and 21. , connect the cooling water supply mechanism to this.

Here, as shown in FIG. 4, the lamp 10 consists of a tube-shaped enclosure 11 made of quartz glass, and metal foil sealed within sealing parts 12, 12 at both ends of the enclosure 11. Conductive members 13, 13
And, from these conductive members 13, 13, the envelope 1 is
1, external leads 14, 14 extending outside the conductive members 13, 13, internal leads 15, 15 extending into the enclosure 11, respectively, and these internal leads 1.
The filament 16 is connected between 5 and 15 and arranged along the tube axis of the enclosure 11, and a filament supporter 17.
It has non-light-emitting parts N and light-emitting parts R alternately, and has end non-light-emitting parts N' and N' at both ends. To give a specific numerical example, the diameter d ₁ of the grooves m of the main mirrors 2 and 3 is 20 mm, and the distance between the centers of adjacent grooves m.
d ₂ is 21 mm, total length k ₁ of lamp 10 is 335 mm, envelope 1
The outer diameter D of the tubular part 1 is 10 mm, and the filament 16
The length k ₂ of each non-light emitting part N′, N′ at both ends of is 37 mm,
The length _k3 of the filament 16 excluding the non-light emitting parts N' and N' at both ends is 230 mm, and the rating of the lamp 10 is 230V-
3200W, lamps 10 facing each other through irradiation space 1
The distance L ₁ between them is 80 mm, and the side mirror 20
and 21, the mutual separation distance L ₂ is 230 mm,
For each groove m, the lamp 10 is arranged so that the tube axis is located at a position displaced by 1 to 2 mm toward the bottom from the center of the semicircle associated with the groove m.
The blower or exhaust device connected to the first air path member 4 or the second air path member 6 has a maximum air volume of 8 m ³ /min. Therefore, by lighting the lamp 10, the main mirrors 2 and 3 and the side mirror 20
The light from the lamp 10 is emitted into the irradiation space 1 with the addition of reflection by
The object to be processed is heated by being positioned in the irradiation space 1 by a transfer mechanism such as a belt conveyor so as to pass through the objects 30 and 31, for example.

According to the above configuration, since a large number of bar-shaped lamps 10 are arranged in parallel in a high density on one plane so that their tube axes are parallel to each other, it is difficult to
Although it forms a line light source, the irradiation space 1
For the object to be processed in the interior, the plurality of lamps 10 virtually form a surface light source along one plane, and the width S of the gap between adjacent lamps 10 is set equally or appropriately. By doing so, the illuminance distribution in the direction in which the lamps 10 are arranged side by side can be made uniform.On the other hand, each lamp 10 has a filament 16 having non-light emitting parts N and light emitting parts R alternately. Therefore, the illuminance distribution in the length direction of each lamp 10 can be made uniform, and as a result, a large area of the workpiece can be heated with highly uniform irradiation energy density. To be more specific, according to the lamp 10 of the specific example described above, the illuminance pattern at a level 45 mm away from the tube axis of the lamp 10 is as shown in FIG. Due to the partial light emitting parts R' and R', the illuminance at both ends is higher than that at the center, but by combining this lamp 10 with the groove m in the numerical example described above,
The illuminance pattern at the same level is completely flat and highly uniform, as shown in FIG. 6B. Therefore, in the irradiation space 1, irradiation is performed with a uniform irradiation energy density both in the direction in which the lamps 10 are arranged and in the length direction of the lamps 10, and it is possible to uniformly heat the entire surface of the object to be processed. can.

Each of the lamps 10 is sealed instead of the conventional method in which a cap-shaped base member, also called a base, is provided to cover both end sealing portions and the lamp is supported via this base member. The department is
Since the surface of the glass forming the sealing part is exposed and protrudes outward from the edges of the mirrors 2 and 3, the light emitted from the lamp 10 and reflected by the mirrors 2 and 3 is The reflected light is not irradiated onto the sealing part 12 of the lamp, and since the glass surface of the sealing part is exposed, heat dissipation from the sealing parts 12, 12 is extremely effective. The sealing parts 12, 12 are not overheated.
The conductive members 13, 13 sealed therein are prevented from being oxidized and disconnected, and cracks are prevented from occurring in the sealing portion, so that the service life of the lamp is not shortened. As a result, the lamps 10 can be arranged in a high density, uniform heating can be achieved as described above, and the surface light source device for heating is suitable for constructing a semiconductor wafer irradiation heating furnace, for example. becomes.

By the way, although this is not an embodiment of the present invention, in a configuration in which a blower 5 is provided in the first air path member 4 and an exhaust fan 7 is provided in the second air path member 6, each lamp 10 The air from the blower 5 flows along the length of the enclosure 11 from one end located near the outlet of the second air duct member 4, and the other end of the second air duct member 6, located near the entrance, passes through the seal. Due to the wind from the exhaust fan 7 flowing along the length direction of the body 11, the envelope 1
1, and at the same time the main mirrors 2 and 3 are also forcibly cooled over their entire length, so that the air volume of the blower 5 and the exhaust fan 7 are the same or similar to each other. By keeping it as
To always cool the envelope 11 and the main mirrors 2 and 3 in a good and stable manner without causing large fluctuations in the cooling state of the envelope 11 and the main mirrors 2 and 3, whether or not there is an object to be processed in the irradiation space 1. I can do it. Further, since the sealing parts 12 and 12 of the lamp 10 are located outside of the side mirrors 20 and 21, they are not exposed to direct light from other lamps, and the lamp 10 is not exposed to the filament 16. In the tube wall portion surrounding the end non-light emitting portions N′ and N′,
Since the lamp 10 is held by the side mirrors 20 and 21 having a water cooling mechanism and the lamp supports 8 and 9 that cooperate with the side mirrors 20 and 21, heat conduction from the center of the envelope 11 of the lamp 10 is prevented; The sealing parts 12, 12 of the lamp 10 are effectively cooled because the sealing parts 12, 12 are exposed and located inside the first air passage member 4 and the second air passage member 6.
The deterioration of is significantly suppressed. Therefore, even if the lamps 10 have a high output, or even if adjacent lamps are arranged in a high density with a small distance between them, the envelopes 11 and sealing portions 12 of the lamps 10,
12 are prevented from reaching excessively high temperatures, and the service life of the lamps 10 is not shortened.

Here, to give an example of a temperature increase test using the example device shown in FIG. 1, each lamp 10 is
When a thermocouple was glued to a 4-inch square silicon wafer with a thickness of 450 μm, the heating temperature change when 1600 W of power was supplied to the lamp 10 was measured. It reaches a high temperature of 1400℃ within 10 seconds after lighting, and when the rated power of 3200W is supplied, it reaches 1400℃ within 3 seconds after lighting, and in both cases the final In a short time, the entire surface layer of the silicon wafer melted. As described above, it is extremely important in the semiconductor manufacturing process to be able to obtain temperatures high enough to melt silicon wafers, and this allows for the production of large areas and short It becomes possible to achieve a temperature increase over time.

Although not an embodiment of the present invention, the lamp 10
The lamp supports 8 and 9 that support the lamp 10 can also be forcibly cooled by a water cooling mechanism that directly cools them, and can prevent adverse effects such as deformation due to heat from the lamp 10. . Supporting the lamp 10 in its tubular portion in this manner means that the supported tube wall portion becomes the coldest point inside the envelope, and in the case of a halogen lamp, the temperature of the coldest point maintains the halogen cycle. However, in high-output halogen lamps, the temperature at the coldest point will never drop below 120°C, so the halogen cycle will be inhibited. It never happens. In addition, in the heat treatment of semiconductors using an irradiation furnace,
If the lamp is provided with a cap, dust such as adhesive debris generated by the cap will have a serious adverse effect on the characteristics of the semiconductor, but since the sealing parts 12, 12 can be left bare, such dust can be avoided. No problems will arise.

The heating surface light source device of the present invention comprises a plurality of lamps each comprising a long glass rod-shaped tube-shaped enclosure and a filament having alternating non-light-emitting parts and light-emitting parts arranged along the tube axis of the enclosure. are placed close to the mirror so that their tube axes are parallel to each other, and the sealing part of each lamp is placed outward from the edge of the mirror with the surface of the glass forming the sealing part exposed. Since they are arranged side by side on one plane so that they protrude, they effectively form a surface light source and can irradiate a large area with synchrotron radiation with uniform illuminance energy density. The object to be treated can be heated in a short time with uniform irradiation energy density, and overheating of the lamp, especially its sealing part, is well prevented, so that the service life of the lamp is not shortened.

In this way, in the present invention, a partially emitting type linear light source forming lamp, which has been developed as a copying machine lamp and used only for copying machines, is used, and the sealing portions at both ends of the lamp are By adopting a structure in which the surface of the glass forming the part is exposed and protrudes outward from the edge of the mirror, the problem of overheating of the sealing part of the lamp is solved and the lamp can be made with high density. This heating surface light source device is particularly suitable for a semiconductor wafer irradiation heating furnace.

[Brief explanation of the drawing]

FIG. 1 is an explanatory sectional view showing an example of a semiconductor wafer irradiation heating furnace incorporating the heating surface light source device of the present invention, and FIG. 2 is an explanation of the lamp and mirror of FIG. 1 viewed from the side. 3 is an explanatory diagram of lamp support, FIG. 4 is an explanatory diagram of the lamp used in the present invention, and FIG. 5 is a characteristic of heating temperature changes in a specific heating surface light source device. Curve diagrams and FIGS. 6A and 6B are characteristic curve diagrams showing the illuminance pattern of the lamp shown in FIG. 4 alone and in combination with a mirror, respectively. 1...Irradiation space, 2, 3...Main mirror, 4...
First air path member, 5...Blower, 6...Second air path member, 7...Blower, 8, 9...Lamp support, 10...Halogen lamp, 12...Sealing Department,
16...Filament, 20, 21...Side mirror, 23...Press portion, m...Concave groove.

Claims (1)

[Claims] 1. A large number of lamps each comprising a long glass rod-shaped tubular enclosure and a filament having alternating non-light-emitting parts and light-emitting parts arranged along the tube axis of the enclosure are placed close to a mirror, The tube axes of the lamps are parallel to each other, and the sealing portion of each lamp is placed on one plane so that it protrudes outward beyond the edge of the mirror with the surface of the glass forming the sealing portion exposed. A heating surface light source device characterized in that the heating surface light source device is arranged in parallel.