JP2012222056A - Heat treatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To heat a work surface uniformly by simple control without using extra members, in a heat treatment apparatus in which a plurality of rod-like heater lamps are arranged in parallel, and a control unit performing the lighting control of the heater lamps is provided.SOLUTION: Heater lamps are divided into a central lamp group, and end lamp groups arranged on both sides thereof. A control unit controls lighting of the heater lamps constituting the central lamp group after lighting the heater lamps constituting the end lamp groups, so that the reaction time zones where the central region and the end region of a work are in a temperature region above the thermal reaction temperature substantially match.

Description

  The present invention relates to a heat treatment apparatus using a heater lamp, and more particularly to a heat treatment apparatus in which a plurality of heater lamps are arranged in parallel on a workpiece (semiconductor wafer).

Generally, a heat treatment apparatus using a heater lamp is required to uniformly and uniformly heat the surface of a semiconductor substrate, a glass substrate, or the like. For example, in ion implantation in which a silicon crystal is doped with a P-type or N-type impurity, there is a problem that the original crystal is broken at the time of implantation. To restore the broken crystal, high temperature annealing is called. There is a method. This is to return the disordered silicon atoms to their original state by heating, but if exposed to a high temperature for too long, the distribution implanted by ion implantation collapses and diffuses deeply from the surface. It is necessary to stop heating instantaneously after reaching.
In such a heat treatment apparatus using a heater lamp, conventionally, a plurality of rod-shaped heater lamps are arranged in parallel in close proximity to the workpiece. However, simply lighting the lamps side by side has a problem that the work peripheral area is inferior in heatability compared with the work central area, and temperature unevenness occurs on the work surface.

In order to solve such problems, conventionally, the power of the peripheral lamp that irradiates the periphery of the workpiece is made larger than the power of the center lamp that irradiates the center of the workpiece, and the periphery of the workpiece is strongly heated against the center of the workpiece. As a result, a method of uniformly heating the entire work surface has been used. As another method, for example, as shown in JP 2000-58470 A (Patent Document 1), a special heat retaining member such as a guard ring is provided around the work so that heat does not escape from the work. Thus, there has been a method for preventing the temperature from decreasing.
However, the former method has a problem in that delicate temperature control around the workpiece and the center of the workpiece is not easy, and the control mechanism and the control process are complicated. Further, the latter method has a problem that the cost of the apparatus and the size of the apparatus are increased, for example, an extra member is required.

JP 2000-58470 A

  The problem to be solved by the present invention is that a plurality of rod-shaped heater lamps are arranged in parallel, and in a heat treatment apparatus having a control unit for controlling lighting of the heater lamps, simple control without using extra members. It is to be able to heat the workpiece surface uniformly.

In order to solve the above problems, a heat treatment apparatus according to the present invention divides the plurality of heater lamps into a central lamp group and end lamp groups arranged on both sides thereof, and the control unit includes the end lamp group. The heater lamps constituting the central lamp group are controlled to be turned on after the heater lamps constituting the partial lamp group are turned on.
The heating time (T1) for the heating temperature (Tb) of the irradiation region corresponding to the end lamp group to reach the workpiece reaction temperature (Ts) is the heating temperature of the irradiation region of the workpiece corresponding to the central lamp group. (Ta) is larger than the temperature rise time (T2) for reaching the thermal reaction temperature (Ts), and the control unit corresponds to the irradiation region corresponding to the end lamp group and the central lamp group. The lighting start times of both lamp groups are controlled so that the reaction time zone in the temperature region equal to or higher than the thermal reaction temperature matches the irradiation region.
Further, the heating temperature (Tb) of the irradiation region corresponding to the end lamp group and the heating temperature (Ta) of the irradiation region of the workpiece corresponding to the central lamp group are set to the thermal reaction temperature (Ts) at the same timing. The lighting start time of both lamp groups is controlled so as to reach.
Further, the heating temperature (Tb) of the irradiation region corresponding to the end lamp group and the heating temperature (Ta) of the irradiation region corresponding to the central lamp group are a predetermined maximum temperature (Ts) or higher. Th) is controlled to arrive at the same timing.
Further, the heater lamps are arranged such that a first heater lamp group arranged in parallel and a second heater lamp group arranged in parallel in a direction orthogonal to the first heater lamp group are overlapped in a cross-beam shape. It is characterized by.

  According to the heat treatment apparatus of the present invention, first, the heater lamps that constitute the end lamp group are turned on first, and then the central lamp group is turned on, so that the heater lamp corresponding to the periphery of the workpiece having a slow temperature increase rate is obtained. Is turned on first, and the heater lamp corresponding to the center of the workpiece with a high heating rate is turned on later.Therefore, the reaction time zone in the temperature region above the predetermined thermal reaction temperature at which the heat treatment of the target workpiece starts is set. The entire surface of the workpiece can be matched, and the processing can be performed uniformly.

Top view of the heat treatment apparatus of the present invention Cross-sectional view of FIG. Control explanatory drawing of the 1st lighting pattern in the heat processing apparatus of this invention Control explanatory diagram of the second lighting pattern Illustrative control of conventional lighting pattern Explanatory drawing of the other Example of this invention

FIG. 1 is an overall top view of a heat treatment apparatus 1 according to the present invention, and a plurality of rod-shaped heater lamps 2 and 2 are arranged in parallel so as to face the workpiece W above the workpiece W. Each heater lamp 2 is a filament lamp having a filament 4 inside an arc tube 3 made of a light transmissive material such as quartz glass.
The arc tube 3 is filled with a halogen gas such as bromine and performs a so-called halogen cycle. As a numerical example of the heater lamp 2, the length is 300 mm, the outer diameter is 13 mm, and the rated power is 2000 W.
The plurality of heater lamps 2, 2 are arranged in a central lamp group A corresponding to the central portion of the workpiece W, and end lamp groups B corresponding to both end portions of the workpiece W, arranged on both sides of the central lamp group A. It is divided into.
In this embodiment, among the plurality of heater lamps 2, 2, five located at the center constitute a central lamp group A, and two located on both sides constitute an end lamp group B. However, the present invention is not limited to this, and depending on the size of the workpiece W and the number of heater lamps 2, the division is divided into appropriate numbers.

  As shown in FIG. 2, a reflector 5 is provided above the heater lamps 2, 2, and the heater lamps 2, 2 are controlled to be turned on by the control unit 6. A work W such as a semiconductor wafer placed on the stage 7 is disposed below the heater lamp 2 so as to face the temperature, and a temperature sensor is attached to the stage 7. Feedback.

The heaters 2 and 2 belonging to the lamp groups A and B are controlled to be lit as shown in FIGS. 3 shows the first lighting pattern of the present invention, FIG. 4 shows the second lighting pattern, the vertical axis of FIGS. 3 and 4 represents the surface temperature (° C.) of the workpiece W, and the horizontal axis is time. (Seconds).
FIG. 5 shows a conventional lighting pattern. First, the conventional lighting pattern will be described. All the lamps start to light up at the same time, and the temperature rises. However, in the end region of the workpiece, the temperature increase rate (Tb) is slower than the temperature increase rate (Ta) in the central region. There is a difference in the time (T1) and (T2) to reach the heat reaction temperature (Ts) at which the heat reacts.
Then, when the lamps are turned off at the same time after a lapse of a predetermined time, the temperature of the workpiece decreases, but the time to decrease to the thermal reaction temperature (Ts) can be greatly increased. As a result, the central region of the workpiece There is a large difference between the reaction time zones (Δta) and (Δtb) in which the end region is in the temperature region equal to or higher than the thermal reaction temperature (Ts).
The thermal reaction temperature and reaction time are determined by the material of the workpiece and the processing to be obtained. If the lighting pattern is set in accordance with the time (Δtb) on the end region side, the time (Δta) of the central region is set. Is too long, the above-mentioned problems occur in the reaction in the central region, and if the time is set in accordance with the reaction time (Δta) on the central region side, the reaction time (Δtb) in the end region is too short. As a result, the reaction is not sufficiently performed, and as a result, the reaction on the entire surface of the workpiece is uneven.

On the other hand, in the present invention, as shown in FIGS. 3 and 4, the lighting start time is adjusted so that the reaction time zone in which the workpiece center region and the end region are in the temperature region equal to or higher than the thermal reaction time is substantially the same. I try to let them.
In FIG. 3, lighting is controlled so that the time (t3) for the central region of the workpiece to reach the thermal reaction temperature (Ts) matches the time (t5) for the end region to reach. That is, first, the end lamp group B is turned on at time (t1), and then the central lamp group A is turned on after the lapse of time (Δt1).
As the lamp groups A and B are turned on, the center area and the end area of the workpiece are heated, but there is a difference in the heating rate (Ta) (Tb). The thermal reaction temperature (Ts) is reached at (t5). The lighting start times (t1) and (t2) are adjusted and controlled so that these times (t3) and (t5) coincide.

The center lamp group A and the end lamp group B are turned off after a predetermined time (several seconds) has elapsed.
During this time, the temperature of the center region and the end region of the work reaches a predetermined maximum temperature (Th), and then the lamp is turned off and descends, and the thermal reaction temperature at time (t4) and time (t6), respectively. (Ts).
Time zones (Δta) and (Δtb) in the temperature region above the thermal reaction temperature (Ts) are reaction times.

Further, FIG. 4 controls the temperature of the center region and the end region of the workpiece so as to simultaneously reach a predetermined maximum temperature (Th) equal to or higher than the thermal reaction temperature (Ts).
First, the end lamp group B is turned on at time (t1), and then the central lamp group A is turned on after a lapse of time (Δt1).
As the lamp groups A and B are turned on, the center region and the end region of the workpiece are heated, but there is a difference in the heating rate (Ta) (Tb). The thermal reaction temperature (Ts) is reached at time (t5). At this point, there is a slight difference in the arrival time of the two regions to the thermal reaction temperature (Ts), but both regions further increase in temperature and reach the maximum temperature (Th) at substantially the same timing. The lighting start times (t1) and (t2) are adjusted and controlled so that the maximum temperature arrival time (t7) matches.
At that time, the lamp is extinguished and the workpiece temperature decreases, and each temperature falls to the thermal reaction temperature (Ts), but the time zone (Δta), (Δtb) in the temperature region above this thermal reaction temperature (Ts). ) Is the reaction time.

In any of the above lighting patterns, the lighting start time of the central lamp group A and the end lamp group B is shifted, the end lamp group B corresponding to the end region of the work having a slow temperature rise rate is turned on first, Since the central lamp group corresponding to the central area of the workpiece is turned on after the time has elapsed, the time zone in which both areas are in the temperature range above the thermal reaction temperature can be made substantially coincident. The temperature uniformity on the surface can be significantly improved.
In addition, the notation that the thermal reaction time zones are matched does not mean that they are matched in a strict sense, and in the comparison with the conventional example, in order to prevent practical unevenness in the heat treatment on the entire surface of the workpiece. It is only necessary that the time zones in which the center region and the end region of the workpiece are in the temperature region equal to or higher than the thermal reaction temperature substantially coincide.

  As described above, in the heat treatment apparatus in which the same heater lamps are arranged in parallel, the present invention first turns on the end lamp group corresponding to the end region where the heating rate is slow in the workpiece, and then increases the heating rate. By turning on the central lamp group corresponding to the fast central region, the thermal reaction time zone in the temperature region above the thermal reaction temperature can be made almost the same in the entire surface region of the workpiece, Thermal reaction treatment is performed uniformly in the entire region.

FIG. 6 shows another embodiment of the present invention.
In this embodiment, as shown in FIG. 6A, the first heater lamp group X and the second heater lamp group Y are arranged above the workpiece W.
As shown in FIG. 6B, the first heater lamp group X includes a plurality of heater lamps 2 and 2 arranged in parallel above the workpiece W, and the heater lamps 2 of the second heater lamp group Y. 2 are arranged above the first heater lamp group X in parallel in a cross-beam shape so that the tube axis direction is orthogonal thereto.
The first heater lamp group X and the second heater lamp group Y are each divided into a central lamp group A and end lamp groups B on both sides thereof.
In the above-described configuration, the end lamp groups B and B of the first heater lamp group X and the second heater lamp group Y are first turned on by a control unit (not shown in FIG. 6), and then the center lamp is turned on after a predetermined time has elapsed. The lamp groups A and A are turned on.

  In the embodiment shown in FIGS. 1 and 2, the temperature uniformity in the tube axis direction of the heater lamp on the surface of the work W is achieved by making the length of the lamp 2 longer than the work W by a predetermined length. However, in another embodiment shown in FIG. 6, the temperature uniformity of the workpiece in the lamp tube axis direction in the first heater lamp group X is achieved by the second heater lamp group Y arranged orthogonal thereto. It is. Thereby, more accurate temperature uniformity can be obtained on the entire surface of the workpiece W, and more precise heat treatment can be achieved.

DESCRIPTION OF SYMBOLS 1 Heat processing apparatus 2 Heater lamp 3 Arc tube 4 Filament 5 Reflector 6 Control part 7 Stage A Center lamp group B End lamp group X 1st heater lamp group Y 2nd heater lamp group W Workpiece

Claims (5)

In the heat treatment apparatus provided with a control unit for controlling the lighting of the heater lamps while arranging a plurality of rod-shaped heater lamps in parallel,
The heater lamp is divided into a central lamp group and end lamp groups arranged on both sides thereof.
The said control part is a heat processing apparatus characterized by controlling to turn on the heater lamp which comprises the said center lamp group, after lighting the heater lamp which comprises the said edge part lamp group. The controller is
The heating time (T1) for the heating temperature (Tb) of the irradiation region of the workpiece corresponding to the end lamp group to reach the thermal reaction temperature (Ts) is:
The heating temperature (Ta) of the irradiation region of the workpiece corresponding to the central lamp group is in a relationship greater than the temperature raising time (T2) for reaching the thermal reaction temperature (Ts),
The lighting start time of both lamp groups is controlled so that the reaction time zone in the temperature region equal to or higher than the thermal reaction temperature of the irradiation region corresponding to the end lamp group and the irradiation region corresponding to the central lamp group coincide. The heat treatment apparatus according to claim 1, wherein the heat treatment apparatus is provided.   Control is performed so that the heating temperature (Tb) of the irradiation region corresponding to the end lamp group and the heating temperature (Ta) of the irradiation region corresponding to the central lamp group reach the thermal reaction temperature (Ts) at the same timing. The heat treatment apparatus according to claim 2, wherein the heat treatment apparatus is provided.   The heating temperature (Tb) of the irradiation region corresponding to the end lamp group and the heating temperature (Ta) of the irradiation region corresponding to the central lamp group are a predetermined maximum temperature (Th) equal to or higher than the thermal reaction temperature (Ts). The heat treatment apparatus according to claim 2, wherein the heat treatment apparatus is controlled to arrive at the same timing. In the heater lamp, a first heater lamp group arranged in parallel and a second heater lamp group arranged in parallel in a direction orthogonal to the first heater lamp group are arranged so as to overlap in a grid pattern. The heat treatment apparatus according to claim 1 or 2, characterized by the above.

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