JP3789366B2 - Heat treatment equipment - Google Patents

Description

【００５６】
図９において曲線７１２（条件１）と曲線７１３（条件２）とを対比すると、曲線７１２では補助リング３１において相対照度が外側に向かって低下するが、曲線７１３では相対照度が補助リング３１上にて上昇することが分かる。すなわち、下側リフレクタ１２２を設け、さらに、補助リング３１に複数のランプからの反射光を実質的に集光させることにより全ランプを定格電力にて点灯したときの補助リング３１の加熱能力が向上される。
【００５７】
また、表１により、理想的な相対照度分布に近づけるように小グループのランプに電力配分を行うとき、従来の熱処理装置（条件３）ではおよそ基板９に対向するランプ４１１〜４１３並びにランプ４２１〜４２３の定格比が０〜２５％になるが、本実施の形態に係る熱処理装置１（条件４）ではこれらのランプの定格比を５０〜１００％とすることができる。なお、条件３および４において補助リング３１におよそ対向するランプ４１４，４２４の定格比は１００％とされる。
【００５８】
図１０の曲線７２４（条件３）に示すように、従来の熱処理装置では相対照度分布を理想的な状態へと近づけると、基板９への照度が理想的な照度（曲線７２１）の４０％程度に低下してしまう。したがって、このような照射では基板９を適切に加熱することが不可能となってしまう。一方、曲線７２５（条件４）に示すように本実施の形態に係る熱処理装置１では基板９への照度分布が理想的な照度分布にほぼ一致する。その結果、歩留まりを低下させることなく基板９に対するＲＴＰを極めて理想的に実現することができる。
【００５９】
さらに、従来の熱処理装置における条件３のように複数のランプに与えられる電力の定格比が大きく異なると、ランプ間での応答速度や色温度に差が生じたり、ランプ寿命に差が生じてしまうという問題が生じる。したがって、本実施の形態に係る熱処理装置１では、これらの問題の発生も抑制することが実現される。
【００６０】
以上のように、熱処理装置１ではランプからの反射光を補助リング３１に集光させることにより補助リング３１を効率よく加熱することができ、基板９の温度均一性を向上することができる。また、下側リフレクタ１２２をさらに設けることにより、基板９上の相対照度分布および照度分布を適切なものとすることができ、かつ、各ランプ間の点灯状態の相違を抑えることが実現される。
【００６１】
以上、本発明の一の実施の形態について説明してきたが、本発明は上記実施の形態に限定されるものではなく様々な変形が可能である。
【００６２】
例えば、半導体基板以外の材料（ガラス基板等）に対する加熱に熱処理装置１が使用されてもよい。
【００６３】
上段ランプ群４１と下段ランプ群４２とのランプは直交するのではなく、所定の角度にて交差してもよい。補助リング３１も基板９の外周を取り巻くのであれば、複数の部材により構成されてよい。
【００６６】
上側リフレクタ１２１および下側リフレクタ１２２の凹面の断面形状は楕円（弧）以外の形状（例えば、放物線や円弧）とされてもよい。凹面の対称面が基板９側に傾斜されることにより、補助リング３１や基板９の外縁部に反射光をおよそ集光させることができ、基板９の温度均一性が向上される。さらに、より多数のランプからの光を集光させるために、基板９上のランプに対応する凹面の対称面を外側に傾斜させてもよい。
【００６７】
また、下側リフレクタ１２２は下段ランプ群４２の両端領域からの光を反射する２つの反射領域を有する１つの面（例えば、中心軸１ａから離れた位置でつながっている２つのリフレクタ）として設けられてもよい。
【００６８】
基板９は水平に支持される必要はなく、熱処理装置１全体が傾けられてもよい。全体構成の上下関係が反転され、基板９の下面側に両ランプ群４１，４２が配置されてもよい。さらに、基板９の上下の両主面に対向するように上段ランプ群４１および上側リフレクタ１２１の組み合わせが上下に設けられてもよい。
【００６９】
上段ランプ群４１や下段ランプ群４２の点灯制御はランプ毎に個別に行われてもよい。ランプ制御部６が、下段ランプ群４２の配列方向に関して両端側の領域のそれぞれに存在するランプ（両端側の全てのランプである必要はない。）に供給される電力を他の領域に存在するランプから独立して制御することにより、補助リング３１を効率よく加熱することができ、基板９の温度均一性の向上が実現される。
【００７１】
【発明の効果】
本発明によれば、加熱の際に基板の温度均一性を向上することができる。
【図面の簡単な説明】
【図１】従来の熱処理装置の縦断面図である。
【図２】従来の熱処理装置の縦断面図である。
【図３】熱処理装置の縦断面図である。
【図４】熱処理装置の縦断面図である。
【図５】ランプとランプ制御部とを示すブロック図である。
【図６】補助リングに反射光が集光される様子を示す縦断面図である。
【図７】補助リングに反射光が集光される様子を示す縦断面図である。
【図８】１つのランプからの反射光が基板および補助リングに照射される領域を例示する図である。
【図９】基板の中心からの距離と相対照度との関係を示す図である。
【図１０】基板の中心からの距離と照度との関係を示す図である。
【符号の説明】
１ 熱処理装置
９ 基板
３１ 補助リング
４１ 上段ランプ群
４２ 下段ランプ群
１２１ 上側リフレクタ
１２２ 下側リフレクタ
３３１，３３２ カップリング部材
３３３ モータ
４１４，４２４ ランプ
１２１１，１２２１ 凹面[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat treatment apparatus for performing a process involving heating on a substrate.
[0002]
[Prior art]
As the demand for microfabrication of devices such as semiconductors increases, a rapid heating process (hereinafter referred to as “RTP”) is important as one of the heating processes of a semiconductor substrate (hereinafter referred to as “substrate”). Playing a role. In RTP, an infrared lamp is mainly used as a heating source, and the substrate is heated to a predetermined temperature (for example, 1200 ° C.) in a second order while maintaining a predetermined gas atmosphere in the processing chamber for a certain time (for example, several tens of seconds). Only after that temperature is maintained, rapid cooling is achieved by turning off the lamp.
[0003]
With RTP, processing that was difficult to achieve with long-term heat treatment in a conventional electric furnace, such as prevention of re-diffusion of impurities due to heat in the junction layer of transistors built into the substrate, and thinning of insulating films such as oxide films, etc. Done.
[0004]
As a heat treatment apparatus for performing RTP, a type in which two stages of rod-shaped lamps arranged in parallel are provided. 1 and 2 are longitudinal sectional views of this type of heat treatment apparatus 8. In the heat treatment apparatus 8, rod-shaped upper lamp groups 81 facing the X direction are arranged in the Y direction, and rod-shaped lower lamp groups 82 facing the Y direction are arranged in the X direction.
[0005]
The substrate 9 is horizontally disposed so as to face both the lamp groups 81 and 82, and is supported by an auxiliary ring 83 that covers the periphery of the substrate 9. A window member 84 that separates the internal space 80 is disposed between the lamp groups 81 and 82 and the substrate 9, and the upper surface of the upper lamp group 81 reflects light from the upper lamp group 81. Thus, a reflector 80a for efficiently irradiating the substrate 9 is provided.
[0006]
[Problems to be solved by the invention]
The auxiliary ring 83 is provided in order to maintain the temperature uniformity of the surface of the substrate 9 by preventing heat radiation from the end surface of the substrate 9 by being heated integrally with the substrate 9. Here, when the heating of the auxiliary ring 83 is insufficient, the temperature of the peripheral portion of the substrate 9 also does not increase. Therefore, sufficient heating of the auxiliary ring 83 is important to achieve temperature uniformity of the substrate 9.
[0007]
By the way, in the heat treatment apparatus 8, as shown in FIG. 2, the reflected light from the upper lamp group 81 is guided almost uniformly onto the substrate 9 and the auxiliary ring 83 by a plurality of concave surfaces formed uniformly on the reflector 80a. In the case of such a reflector, there is a possibility that the temperature of the auxiliary ring 83 cannot be sufficiently increased.
[0008]
Further, no consideration is given to the light emitted upward from the lower lamp group 82, and the degree of contribution of the reflected light from the reflector 80a in the heating of the auxiliary ring 83 is adjusted only by the upper lamp group 81. It will be done. As described above, it can be said that the structure of the heat treatment apparatus 8 is not preferable for heating the auxiliary ring 83 sufficiently efficiently.
[0009]
This invention is made | formed in view of the said subject, and aims at improving the temperature uniformity of the board | substrate in the case of heating by heating an auxiliary | assistant ring efficiently.
[0010]
[Means for Solving the Problems]
  The invention described in claim 1CircularA heat treatment apparatus for performing a process involving heating by irradiating a substrate with light, a reflecting surface facing a main surface of the substrate to be processed, a lamp group arranged along the reflecting surface, and an outer periphery of the substrate An auxiliary ring extending outward from the outer periphery along the outer circumference,A rotating mechanism for rotating the substrate while facing the reflecting surface;WithEach lamp included in the lamp group is a rod-shaped lamp facing a predetermined direction,The reflecting surface reflects light from the lamps included in the lamp group and substantially focuses the light on the auxiliary ring.
[0011]
Invention of Claim 2 is the heat processing apparatus of Claim 1, Comprising: The said reflective surface reflects the light from the some lamp | ramp contained in the said lamp group, and is substantially on the said auxiliary | assistant ring. Collect light.
[0012]
  Invention of Claim 3 is the heat processing apparatus of Claim 1 or 2, Comprising:The reflection surface collects light from a plurality of lamps included in the lamp group in the same region..
[0013]
  The invention according to claim 4Any one of claims 1 to 3The heat treatment apparatus according to claim 1,The average irradiation energy with respect to the distance from the central axis of rotation by the rotation mechanism is maximized on the auxiliary ring.
[0014]
  The invention described in claim 5Irradiates the substrate with light and performs processing that involves heatingA heat treatment apparatus,A reflective surface facing the main surface of the substrate to be processed, and a rod-shaped lamp group arranged along the reflective surface so as to face a predetermined direction;Between the lamp group and the other lamp group, another rod-shaped lamp group arranged so as to face a direction different from the predetermined direction between the lamp group and the main surface, A pair of reflecting surfaces for reflecting light from the lamps existing in the regions on both ends in the arrangement direction of the other lamp group;An auxiliary ring extending outward from the outer periphery along the outer periphery of the substrate,The reflecting surface reflects light from the lamps existing in each of the regions on both end sides in the arrangement direction of the lamp group to substantially collect the light on the auxiliary ring, and the pair of reflecting surfaces includes: The light from the lamps existing in each of the regions on both end sides in the arrangement direction of the other lamp group is reflected and condensed on the auxiliary ring.
[0015]
  The invention described in claim 6Claim 5A heat treatment apparatus,A rotation mechanism is further provided for rotating the substrate while facing the reflective surface.
[0016]
  Invention of Claim 7 is the heat processing apparatus of Claim 6, Comprising:The average irradiation energy with respect to the distance from the central axis of rotation by the rotation mechanism is maximized on the auxiliary ring.
[0017]
  The invention according to claim 8 provides:Any one of claims 5 to 7The heat treatment apparatus according to claim 1,The reflection surface reflects light from a plurality of lamps included in the lamp group and substantially focuses the light on the auxiliary ring.
[0018]
  The invention according to claim 9 is:Any one of claims 5 to 8The heat treatment apparatus according to claim 1,The reflecting surface condenses light from a plurality of lamps included in the lamp group in the same region.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
3 and 4 are longitudinal sectional views showing the configuration of the heat treatment apparatus 1 according to one embodiment of the present invention. The cut surface in FIG. 3 and the cut surface in FIG. It intersects perpendicularly with the central axis 1a facing. In FIGS. 3 and 4, description of parallel oblique lines with respect to the cross section of the details is omitted.
[0022]
The heat treatment apparatus 1 includes a main body 11 that is an apparatus main body, a lid 12 that covers an upper portion of the main body 11, and a reflection plate 13 that is disposed on a central bottom surface of the main body 11, thereby forming an internal space. The The internal space is partitioned up and down by a chamber window 21 made of quartz, and the substrate 9 is disposed in the lower processing space 10. The chamber window 21 and the main body 11 are sealed with an O-ring (not shown). The inner surface of the main body 11 is a cylindrical surface.
[0023]
The substrate 9 is transported into the processing space 10 by an external transport mechanism and placed on the auxiliary ring 31. The auxiliary ring 31 has a ring shape (ring shape centered on the central axis 1 a) that extends from the outer periphery to the outer side along the outer periphery of the substrate 9, and supports the substrate 9 by abutting against the peripheral edge of the lower surface of the substrate 9. . The auxiliary ring 31 is formed of, for example, silicon carbide (SiC), and the auxiliary ring 31 is heated integrally with the substrate 9. Thereby, compared with the case where only the board | substrate 9 is heated, the heat radiation from the peripheral part of the board | substrate 9 is suppressed, and the uniformity of the temperature of the board | substrate 9 improves.
[0024]
The auxiliary ring 31 is supported by a cylindrical support ring 32 centered on the central axis 1 a, and a coupling member 331 is attached to the lower end of the support ring 32. A coupling member 332 that faces the coupling member 331 is provided below the main body 11, and the coupling member 331 and the coupling member 332 constitute a magnetic coupling mechanism. The coupling member 332 is rotated around the central axis 1a by a motor 333 shown in FIG. Thereby, the coupling member 331 inside the main body 11 is rotated by a magnetic action, and the substrate 9 and the auxiliary ring 31 are rotated around the central axis 1a.
[0025]
A plurality of gas introduction ports 111 and exhaust ports 112 are formed on the side wall of the main body 11, and the gas in the processing space 10 is (forced) exhausted from the exhaust ports 112, or the substrate 9 is connected via the gas introduction ports 111. Gas replacement in the processing space 10 is performed by introducing a gas (for example, nitrogen, oxygen) according to the type of processing performed on the processing space 10. A quartz shower plate 22 having a large number of holes is provided between the substrate 9 and the auxiliary ring 31 and the chamber window 21, and the gas introduced from the gas introduction port 111 passes through the shower plate 22. 9 is uniformly applied to the upper surface. The gas used for the treatment is guided to the exhaust port 112 from below the support ring 32.
[0026]
The lower surface of the lid portion 12 is a reflecting surface (hereinafter referred to as “upper reflector”) 121 that faces the main surface (ie, upper surface) of the substrate 9, and each of them along the upper reflector 121 is shown in FIGS. 3 and 4. A rod-shaped upper lamp group 41 is arranged so as to face the X direction inside. Of the light from the upper lamp group 41, the light emitted upward is reflected by the upper reflector 121 and applied to the substrate 9.
[0027]
The upper reflector 121 has a constant cross-sectional shape perpendicular to the X direction (longitudinal direction of the lamp), and the cross-sectional shape is a part of an ellipse where each lamp is located at the focal point. As a result, most of the reflected light from each lamp of the upper lamp group 41 is selectively irradiated to specific regions on the substrate 9 and the auxiliary ring 31.
[0028]
Below the upper lamp group 41 (that is, between the upper lamp group 41 and the main surface of the substrate 9), rod-shaped lower lamp groups 42 are arranged so as to face each other in the Y direction. That is, the upper lamp group 41 and the lower lamp group 42 are attached to the lid 12 so as to be orthogonal to each other.
[0029]
Each of the upper lamp group 41 and the lower lamp group 42 is divided into small groups according to the distance from the central axis 1a. 4, reference numerals 411, 412, 413, and 414 are attached to the lamps of the grouped upper lamp group 41 from the central axis 1a side, and in FIG. 3, the central axis 1a is added to the lamps of the grouped lower lamp group 42. Reference numerals 421, 422, 423, and 424 are attached from the side.
[0030]
FIG. 5 is a block diagram showing a connection relationship between the lamps divided into small groups and the lamp control unit 6 that supplies power to the lamps (even a plurality of lamps are shown as one block). . As shown in FIG. 5, each group is individually connected to the lamp controller 6 and supplied with power independently of each other. Thereby, the intensity distribution of the light irradiated on the upper surface of the substrate 9 is controlled.
[0031]
On the other hand, in the heat treatment apparatus 1, as shown in FIG. 3, between the upper lamp group 41 and the lower lamp group 42, from the lamps 424 existing in both end regions in the arrangement direction (X direction) of the lower lamp group 42. Two lower reflectors 122 are provided on the lid portion 12 to reflect the light. The lower reflector 122 has a constant cross-sectional shape perpendicular to the Y direction (longitudinal direction of the lamp), and the cross-sectional shape is a part of an ellipse where each lamp is located at the focal point. As a result, most of the reflected light from the lamps on both ends with respect to the arrangement direction of the lower lamp group 42 is selectively irradiated to a specific region on the auxiliary ring 31.
[0032]
By providing the lower reflector 122, the heating efficiency of the auxiliary ring is improved as compared with the conventional heat treatment apparatus 8 illustrated in FIGS. That is, in the conventional heat treatment apparatus 8, the upward light among the light from the lower lamp group 82 is scattered before reaching the reflector 80 a located above the upper lamp group 81. Since the longitudinal direction of the lamp is orthogonal to the direction in which each concave surface (see FIG. 2) of the reflector 80a extends, the reflected light is further scattered.
[0033]
On the other hand, in the heat treatment apparatus 1, the light emitted upward from the lamp located below the lower reflector 122 is immediately reflected and contributes to the heating of the auxiliary ring 31 as will be described later.
[0034]
As shown in FIG. 4, a plurality of radiation thermometers 51 to 54 are attached to the lower surface of the reflecting plate 13 from the central axis 1 a toward the outside. The radiation thermometers 51 to 53 measure the temperature of the substrate 9 by receiving infrared light from the substrate 9 through the window member 50. The radiation thermometer 54 measures the temperature of the auxiliary ring 31 by receiving infrared light from the auxiliary ring 31 through the window member 50. Since the substrate 9 and the auxiliary ring 31 rotate, the temperatures of the substrate 9 and the auxiliary ring 31 corresponding to the distance from the central axis 1a are measured by the plurality of radiation thermometers 51 to 54.
[0035]
When processing involving heating is performed on the substrate 9, for example, power supply to the lamps 411 and 421 is controlled according to the measurement result of the radiation thermometer 51, and similarly, the radiation thermometers 52, 53, and 54 are controlled. Power supply to the lamps 412 and 422, the lamps 413 and 423, and the lamps 414 and 424 is controlled according to the measurement result. At this time, the substrate 9 and the auxiliary ring 31 rotate while facing the upper reflector 121 and the lower reflector 122 by a rotation mechanism constituted by a motor 333 and a coupling mechanism. Thereby, the heating of the substrate 9 and the auxiliary ring 31 is controlled so that the temperature of the substrate 9 is as uniform as possible.
[0036]
Next, the shapes of the upper reflector 121 and the lower reflector 122 will be described.
[0037]
FIG. 6 is a diagram showing a state in which light is irradiated from the upper lamp group 41 to the substrate 9 and the auxiliary ring 31. The cross-sectional shape of the upper reflector 121 taken along the YZ plane is such that a portion of an ellipse having the focal point of the center of the lamp and the position to be irradiated is arranged. Therefore, the light from each lamp is collected in a line on the substrate 9 and the auxiliary ring 31.
[0038]
Reflected light from lamps other than the lamps 414 existing in the regions on both ends in the arrangement direction in the upper lamp group 41 is guided almost directly below and is condensed on the substrate 9. On the other hand, the concave surface 1211 formed for each of the lamps 414 is formed in the X direction along the lamp 414 and has a symmetry plane (a plane including the elliptical symmetry axis 414 a and parallel to the X direction) of the substrate 9. It is inclined toward the substrate 9 from the normal direction (Z direction) of the surface. The axis of symmetry 414a is inclined so as to be in contact with substantially the inner surface of the auxiliary ring 31 (the outer surface of the substrate 9), and the reflected light from the plurality of lamps 414 is collected in the same region.
[0039]
FIG. 7 is a diagram illustrating a state in which the auxiliary ring 31 is irradiated with the reflected light from the lamps 424 existing in the respective regions on both ends with respect to the arrangement direction in the lower lamp group 42. A concave surface 1221 is formed along the lamp 414 so that the cross section of the pair of lower reflectors 122 is part of an ellipse with respect to each of the lamps 424, and a symmetrical surface (including an elliptical symmetry axis 424a in the Y direction). The parallel plane is inclined toward the substrate 9 from the normal direction (Z direction) of the main surface of the substrate 9. The symmetry axis 424a is inclined so as to be in contact with substantially the inner surface of the auxiliary ring 31 (the outer surface of the substrate 9), and the reflected light from the plurality of lamps 424 is collected in the same region.
[0040]
The concave surfaces 1211 and 1221 do not need to intersect with the symmetry plane, and the depth of the concave surface can be suppressed by tightly coupling the plurality of concave surfaces while using the concave surfaces that do not intersect with the symmetry plane. For example, in the case where light from one high-power lamp is condensed on the auxiliary ring 31 by one concave surface instead of the three concave surfaces 1211, it is necessary to form a large (deep) concave surface, By condensing light from a plurality of lamps on a plurality of shallow concave surfaces combined, the upper reflector 121 can be easily processed. The same applies to the lower reflector 122.
[0041]
As described above, in the heat treatment apparatus 1, the reflected light from the upper reflector 121 and the lower reflector 122 is collected on the auxiliary ring 31, so that the auxiliary ring 31 can be efficiently heated and the temperature of the substrate 9 is uniform. Is improved. Further, the reflected light from the plurality of lamps 414 and 424 is collected on the auxiliary ring 31 (particularly, the reflected light from the plurality of lamps is collected on one irradiation region on the auxiliary ring 31). ) Even if the power of one lamp is small, the auxiliary ring 31 can be rapidly heated to a high temperature.
[0042]
Next, how the reflected light is applied to the auxiliary ring 31 will be further described. As described above, in the heat treatment apparatus 1, the lamp is rod-shaped and one concave surface of the reflector is formed along the lamp, and the reflected light corresponding to one lamp is irradiated to the line-shaped region. FIG. 8 is a diagram illustrating a region 91 (shown by a thick line) in which reflected light from the lamp 420 corresponding to either the lamp 414 or the lamp 424 is irradiated on the auxiliary ring 31. As shown in FIG. 8, the light emitted from the end side of the lamp 420 and reflected is guided to the outside of the auxiliary ring 31. And since the board | substrate 9 and the auxiliary | assistant ring 31 rotate, the reflected light from the lamp | ramp 420 will be irradiated to the arbitrary areas of the auxiliary | assistant ring 31. FIG.
[0043]
From the above, when considering the relationship between the distance from the central axis 1a and the average irradiation energy at this distance (that is, the value obtained by dividing the irradiation energy for the concentric region by the area), the average irradiation energy Becomes the maximum at a distance slightly longer than the distance 91L between the central axis 1a and the center of the region 91. Therefore, even if the inclination of the concave symmetrical surface is set so that the reflected light is slightly irradiated on the substrate 9, the light from the reflector is substantially irradiated on the auxiliary ring 31 while being condensed.
[0044]
That is, the concave surfaces corresponding to the lamp 414 and the lamp 424 are provided to irradiate the auxiliary ring 31 with the reflected light, but it is not necessary to be designed so that the reflected light is not completely irradiated onto the substrate 9.
[0045]
In the heat treatment apparatus 1, a plurality of lamps exist in each of both end regions with respect to the arrangement direction of the lamp group, and the same region is irradiated. Therefore, reflected light from many lamps is applied to the auxiliary ring 31. The light can be condensed and the auxiliary ring 31 can be heated very efficiently.
[0046]
In FIG. 9, there is no lower reflector 122, and there is a heat treatment apparatus (that is, a conventional heat treatment apparatus) that does not collect the reflected light from the (upper) reflector on the auxiliary ring, and a lower reflector 122, and FIG. 6 is a diagram showing a relationship between a distance (radius) from the center of the substrate and a relative illuminance on the substrate and the auxiliary ring at the distance in the heat treatment apparatus 1 that collects reflected light from the upper reflector 121 on the auxiliary ring 31. . FIG. 10 is a diagram showing the relationship between the distance from the center of the substrate and the illuminance on the substrate and the auxiliary ring at the distance in the conventional heat treatment apparatus and the heat treatment apparatus 1 shown in FIGS.
[0047]
A range 71 shown in FIGS. 9 and 10 is a range where the substrate 9 exists, and a range 72 is a range where the auxiliary ring 31 exists. The relative illuminance distribution is referred to as an index for realizing the temperature uniformity of the substrate 9 and improving the yield of the semiconductor chip, and the illuminance distribution is referred to as an index of the ability to raise the temperature of the substrate 9 of the heat treatment apparatus. The
[0048]
The graph curve shown in each figure is a result obtained by simulation under the assumption that the substrate and the auxiliary ring are rotated (that is, average relative illuminance and illuminance with respect to the distance from the center of the substrate), and is compared with 2 The two heat treatment apparatuses are the same except that the presence or absence of the lower reflector 122 and the shape of the reflector are different. Hereinafter, even when referring to a conventional heat treatment apparatus, description will be made using the reference numerals attached to FIGS. 3 and 4.
[0049]
As specific conditions in the simulation, the substrate 9 has a diameter of 300 mm, the auxiliary ring 31 has a donut shape and a width of 20 mm, and the lamp interval between the upper lamp group 41 and the lower lamp group 42 is 20 mm.
[0050]
The lamps 411 to 413 of the upper lamp group 41 and the lamps 421 to 423 of the lower lamp group 42 have an output of 4000 W and a light emission length of 320 mm. The lamps 414 and 424 that mainly heat the auxiliary ring 31 in the upper lamp group 41 and the lower lamp group 42 have an output of 4200 W and a light emission length of 200 mm. Since the light emission lengths of the outer lamps 414 and 424 are shorter than those of the other lamps, even when the substrate 9 to be heated is circular, light is efficiently emitted from a lamp group arranged in a lattice form in two upper and lower stages. .
[0051]
9 and 10, solid line curves indicated by reference numerals 711 and 721 indicate ideal relative illuminance distribution and illuminance distribution. Various irradiation conditions of light when ideal heating can be performed have been obtained in advance by experiments. Curves 711 and 721 are obtained by calculating the relative illuminance distribution and the illuminance distribution at this time by illuminance simulation by the Monte Carlo method. It is.
[0052]
The long dashed curves indicated by reference numerals 712 and 722 indicate the relative illuminance distribution and the illuminance distribution when all lamps are rated on (hereinafter referred to as “condition 1”) in a conventional heat treatment apparatus. A short dashed curve indicated by indicates a relative illuminance distribution and an illuminance distribution when all the lamps are rated on (hereinafter, referred to as “condition 2”) in the heat treatment apparatus 1 according to the present embodiment.
[0053]
Dotted lines indicated by reference numerals 714 and 724 indicate the relative illuminance distribution and the illuminance distribution when the lamp is turned on so as to approach an ideal relative illuminance distribution in a conventional heat treatment apparatus (hereinafter referred to as “condition 3”). The two-dot chain lines indicated by reference numerals 715 and 725 are relative when the lamp is turned on so as to approach an ideal relative illuminance distribution in the heat treatment apparatus 1 according to the present embodiment (hereinafter referred to as “condition 4”). Illuminance distribution and illuminance distribution are shown. In the curves 714 and 724, the peak is located outside the auxiliary ring 31.
[0054]
Table 1 shows the ratio (rated ratio) of the power supplied to the lamps 411 to 414 and the lamps 421 to 424 with respect to the rated power under the conditions 1 to 4.
[0055]
[Table 1]

[0056]
In FIG. 9, when the curve 712 (condition 1) is compared with the curve 713 (condition 2), the relative illuminance decreases in the auxiliary ring 31 outward in the curve 712, but the relative illuminance increases on the auxiliary ring 31 in the curve 713. Can be seen to rise. That is, the lower reflector 122 is provided, and further, the heating ability of the auxiliary ring 31 is improved when all the lamps are lit at the rated power by substantially collecting the reflected light from the plurality of lamps on the auxiliary ring 31. Is done.
[0057]
Further, according to Table 1, when power is distributed to a small group of lamps so as to approach an ideal relative illuminance distribution, in the conventional heat treatment apparatus (condition 3), the lamps 411 to 413 facing the substrate 9 and the lamps 421 to 421 are arranged. The rated ratio of 423 is 0 to 25%, but in the heat treatment apparatus 1 (condition 4) according to the present embodiment, the rated ratio of these lamps can be set to 50 to 100%. In the conditions 3 and 4, the rated ratio of the lamps 414 and 424 substantially facing the auxiliary ring 31 is 100%.
[0058]
As shown by a curve 724 (condition 3) in FIG. 10, when the relative illuminance distribution is brought close to an ideal state in the conventional heat treatment apparatus, the illuminance to the substrate 9 is about 40% of the ideal illuminance (curve 721). It will drop to. Accordingly, it becomes impossible to appropriately heat the substrate 9 by such irradiation. On the other hand, as shown by a curve 725 (condition 4), in the heat treatment apparatus 1 according to the present embodiment, the illuminance distribution on the substrate 9 substantially matches the ideal illuminance distribution. As a result, RTP for the substrate 9 can be realized extremely ideally without reducing the yield.
[0059]
Furthermore, if the rated ratio of the power applied to a plurality of lamps is greatly different as in Condition 3 in the conventional heat treatment apparatus, a difference in response speed and color temperature between lamps or a difference in lamp life will occur. The problem arises. Therefore, in the heat treatment apparatus 1 according to the present embodiment, it is possible to suppress the occurrence of these problems.
[0060]
As described above, in the heat treatment apparatus 1, the auxiliary ring 31 can be efficiently heated by collecting the reflected light from the lamp on the auxiliary ring 31, and the temperature uniformity of the substrate 9 can be improved. Further, by further providing the lower reflector 122, the relative illuminance distribution and the illuminance distribution on the substrate 9 can be made appropriate, and the difference in lighting state between the lamps can be suppressed.
[0061]
Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made.
[0062]
For example, the heat treatment apparatus 1 may be used for heating a material other than a semiconductor substrate (such as a glass substrate).
[0063]
The lamps of the upper lamp group 41 and the lower lamp group 42 are not orthogonal to each other but may intersect at a predetermined angle. The auxiliary ring 31 may also be composed of a plurality of members as long as it surrounds the outer periphery of the substrate 9.
[0066]
The cross-sectional shape of the concave surface of the upper reflector 121 and the lower reflector 122 may be a shape (for example, a parabola or an arc) other than an ellipse (arc). Since the concave symmetrical surface is inclined toward the substrate 9, the reflected light can be approximately condensed on the auxiliary ring 31 and the outer edge of the substrate 9, and the temperature uniformity of the substrate 9 is improved. Further, in order to collect light from a larger number of lamps, the concave symmetrical surface corresponding to the lamps on the substrate 9 may be inclined outward.
[0067]
The lower reflector 122 is provided as one surface having two reflection regions that reflect light from both end regions of the lower lamp group 42 (for example, two reflectors connected at positions away from the central axis 1a). May be.
[0068]
The substrate 9 does not need to be supported horizontally, and the entire heat treatment apparatus 1 may be tilted. The vertical relationship of the entire configuration may be reversed, and both lamp groups 41 and 42 may be disposed on the lower surface side of the substrate 9. Further, a combination of the upper lamp group 41 and the upper reflector 121 may be provided vertically so as to face both the upper and lower main surfaces of the substrate 9.
[0069]
The lighting control of the upper lamp group 41 and the lower lamp group 42 may be performed individually for each lamp. The lamp controller 6 supplies the power supplied to the lamps existing in each of the regions on both ends in the arrangement direction of the lower lamp group 42 (not necessarily all the lamps on both ends) in the other regions. By controlling independently from the lamp, the auxiliary ring 31 can be efficiently heated, and the temperature uniformity of the substrate 9 is improved.
[0071]
【The invention's effect】
According to the present invention, the temperature uniformity of the substrate can be improved during heating.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a conventional heat treatment apparatus.
FIG. 2 is a longitudinal sectional view of a conventional heat treatment apparatus.
FIG. 3 is a longitudinal sectional view of a heat treatment apparatus.
FIG. 4 is a longitudinal sectional view of a heat treatment apparatus.
FIG. 5 is a block diagram illustrating a lamp and a lamp control unit.
FIG. 6 is a longitudinal sectional view showing how reflected light is collected on an auxiliary ring.
FIG. 7 is a longitudinal sectional view showing how reflected light is collected on an auxiliary ring.
FIG. 8 is a diagram illustrating a region in which reflected light from one lamp is irradiated to a substrate and an auxiliary ring.
FIG. 9 is a diagram showing the relationship between the distance from the center of the substrate and the relative illuminance.
FIG. 10 is a diagram illustrating a relationship between a distance from the center of a substrate and illuminance.
[Explanation of symbols]
1 Heat treatment equipment
9 Board
31 Auxiliary ring
41 Upper lamp group
42 Lower lamp group
121 Upper reflector
122 Lower reflector
331,332 Coupling member
333 motor
414, 424 lamp
1211, 1221 Concave surface

Claims (9)

A heat treatment apparatus for performing a process involving heating by irradiating light to a circular substrate,
A reflective surface facing the main surface of the substrate to be processed;
A group of lamps arranged along the reflecting surface;
An auxiliary ring extending outward from the outer periphery along the outer periphery of the substrate;
A rotation mechanism for rotating the substrate while facing the reflecting surface;
With
Each lamp included in the lamp group is a rod-shaped lamp facing a predetermined direction,
The heat treatment apparatus, wherein the reflection surface reflects light from lamps included in the lamp group and substantially focuses the light on the auxiliary ring. The heat treatment apparatus according to claim 1,
The heat treatment apparatus, wherein the reflecting surface reflects light from a plurality of lamps included in the lamp group and substantially concentrates the light on the auxiliary ring. The heat treatment apparatus according to claim 1 or 2 ,
The heat treatment apparatus, wherein the reflection surface collects light from a plurality of lamps included in the lamp group in the same region. The heat treatment apparatus according to any one of claims 1 to 3,
  The heat treatment apparatus characterized in that an average irradiation energy with respect to a distance from a central axis of rotation by the rotation mechanism is maximized on the auxiliary ring. A heat treatment apparatus for performing a process involving heating by irradiating a substrate with light ,
A reflective surface facing the main surface of the substrate to be processed;
A rod-shaped lamp group arranged along the reflecting surface so as to face a predetermined direction;
Another rod-shaped lamp group arranged so as to face a direction different from the predetermined direction between the lamp group and the main surface;
A pair of reflecting surfaces for reflecting light from lamps existing in both end regions in the arrangement direction of the other lamp group between the lamp group and the other lamp group;
An auxiliary ring extending outward from the outer periphery along the outer periphery of the substrate;
With
The reflecting surface reflects light from the lamps existing in each of the regions on both end sides in the arrangement direction of the lamp group to substantially collect the light on the auxiliary ring, and the pair of reflecting surfaces includes: A heat treatment apparatus characterized in that light from lamps existing in each of both end regions in the arrangement direction of the other lamp group is reflected and substantially condensed on the auxiliary ring. The heat treatment apparatus according to claim 5,
  A heat treatment apparatus, further comprising: a rotation mechanism that rotates the substrate while facing the reflecting surface. The heat treatment apparatus according to claim 6,
  The heat treatment apparatus characterized in that an average irradiation energy with respect to a distance from a central axis of rotation by the rotation mechanism is maximized on the auxiliary ring. A heat treatment apparatus according to any one of claims 5 to 7,
  The heat treatment apparatus, wherein the reflecting surface reflects light from a plurality of lamps included in the lamp group and substantially concentrates the light on the auxiliary ring. A heat treatment apparatus according to any one of claims 5 to 8,
  The heat treatment apparatus, wherein the reflection surface collects light from a plurality of lamps included in the lamp group in the same region.

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