Light heating device and heating treatment method

Abstract

The present application provides a kind of light heating device and heating treatment method capable of heating substrate in shorter time.A kind of light heating device, for heating substrate, with: chamber, accommodate substrate;A pair of light-transmitting window, in the manner of opposing each other, set to the wall surface of chamber, to the chamber take in light for heating;Supporting member, in the chamber, in the manner of each main surface of substrate and each of a pair of light-transmitting window opposing, support substrate between a pair of light-transmitting window;Multiple LED elements, emit light towards the substrate supported by supporting member;Flashlight, emit light towards the substrate supported by supporting member;And first lighting control unit, after making LED element light up, after passing through specified time, carry out the control of making flashlight light up.

Description

TECHNICAL FIELD

[0001] The present application relates to a light heating apparatus and a heating treatment method. BACKGROUND

[0002] In a semiconductor manufacturing process, a method of introducing impurities into a Si crystal by ion implantation, which is called an ion implantation method, is generally used. In this method, in order to recover crystal defects generated at the time of ion implantation, a process of heating a semiconductor substrate to 1000°C or higher is performed.

[0003] Further, in recent years, a heating apparatus that can uniformly perform a heating treatment in a short time while forming an impurity diffusion layer thin and also requires miniaturization and high integration has been sought. Therefore, in a heating treatment of a semiconductor substrate of a miniaturized process, a light heating apparatus using a flash lamp described in Patent Literature 1, for example, is adopted.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent Application Laid-Open No. 2006-324389

[0007] When a semiconductor substrate is instantaneously subjected to temperature rising and falling between room temperature and 1000°C or higher, expansion and contraction due to a sharp temperature change occur, and warping and cracking can occur. Therefore, the light heating apparatus described in Patent Literature 1 adopts a structure in which, in order to reduce a temperature difference in temperature rising and falling due to heating by a flash lamp and thereby suppress warping and cracking of a semiconductor substrate, a halogen lamp is used to preheat a semiconductor substrate to a temperature at which a problem of thermal diffusion of impurities does not occur in the entire semiconductor substrate. Herein, in the present specification, a case where a semiconductor substrate is preheated to a prescribed temperature using another light source before a heating treatment using a flash lamp is referred to as "preheating". The preheating is performed in order to reduce a temperature gradient in the thickness direction of a semiconductor substrate in addition to the above reason.

[0008] Here, the present inventors and others have made intensive studies on further improvement and modification of the conventional light heating apparatus, and have found that the conventional light heating apparatus has the following problems. Hereinafter, detailed description will be made with reference to the drawings.

[0009] Figure 13 is a view schematically showing a structure of a conventional light heating apparatus 100 provided with a flash lamp 102 and a halogen lamp 103. As shown in Figure 13 the conventional light heating apparatus 100 is provided with a chamber 101, a flash lamp 102, and a halogen lamp 103.

[0010] Further, the chamber 101 is provided with a light-transmitting window 104 for taking in light emitted from the flash lamp 102 and the halogen lamp 103 to the inside, and a support table 105 for supporting the semiconductor substrate W1 that is a heating target in the chamber 101. Note that, in a case where the chamber 101 is set to be in a vacuum, the light-transmitting window 104 is hermetically sealed by an O-ring or the like, but in Figure 13 , the illustration of such a structure is omitted.

[0011] The halogen lamp 103 is lit before the heating based on the flash lamp 102 is performed, and performs preheating via the support table 105 and the heat transfer portion 106 until the semiconductor substrate W1 housed in the chamber 101 is stabilized at a prescribed temperature.

[0012] Here, how the temperature of the main surface W1a of the semiconductor substrate W1 changes and stabilizes in the preheating based on the halogen lamp 103 is described. Figure 14 is a graph showing an example of the change in the temperature of the main surface W1a of the semiconductor substrate W1 with time in a case where the conventional halogen lamp 103 is used as a preheating source. As shown in Figure 14 , the semiconductor substrate W1 performs preheating in a manner that the temperature of the main surface W1a is stabilized at a target temperature (600°C in the example) by adjusting the electric power supplied to the halogen lamp 103. Figure 14

[0013] The halogen lamp 103 has slow followability of the change in the light output with respect to the input electric power. That is, the halogen lamp 103 temporarily and continuously emits light of a high intensity even after the supply of the electric power is stopped. Therefore, as shown in Figure 14 , so-called overshoot occurs in which the temperature of the semiconductor substrate W1 rises higher than the target temperature.

[0014] Due to the occurrence of this overshoot, as shown in Figure 14 , the preheating based on the halogen lamp 103 gradually performs control to converge the temperature of the main surface W1a of the semiconductor substrate W1 toward the target temperature while passing the target temperature multiple times (fluctuating around 600°C in Figure 13 .

[0015] A case where the heating processing based on the flash lamp 102 is performed in a state where the temperature based on the preheating is not stabilized is described. In the state where the temperature is not stabilized, if the heating processing of the semiconductor substrate based on the flash lamp 102 is performed, the heat history (also referred to as "thermal budget") of the history of the temperature change received by the semiconductor substrate deviates.

[0016] ​The thermal history influences the diffusion of heat generated in the semiconductor substrate, and particularly in a fine process, contributes to the formation of an impurity diffusion layer. That is, if the deviation of the thermal history is large, the impurity diffusion layer is formed unevenly, and the characteristics of the elements formed on the substrate differ greatly on each semiconductor substrate. Therefore, in a case where the heating process based on the flash lamp 102 is performed in a state where the temperature based on the preheating is unstable, the results differ on each semiconductor substrate.

[0017] Therefore, in a case where the preheating is performed by the halogen lamp 103, the heating process by the flash lamp 102 needs to be performed when the temperature of the main surface Wla of the semiconductor substrate Wl is stabilized at the target temperature.

[0018] In addition, the above overshoot can also be suppressed by reducing the power supply to the halogen lamp 103 or the like before the target temperature is reached. Furthermore, by using a high-performance power controller to control the input power of the halogen lamp 103, it is also possible to accelerate the followability of the change in light output with respect to the input power of the halogen lamp 103.

[0019] Figure 15 is a graph showing an example of the change in the temperature of the main surface Wla of the semiconductor substrate Wl with time in a case where the input power of the halogen lamp 103 is controlled using a high-performance power controller. As shown in Figure 15 , an overshoot occurs even in a case where the above control is performed, and therefore a time T2 is required from the start of lighting until the temperature is stabilized. For comparison, Figure 15 , the graph shown in Figure 14 is also shown by a broken line.

[0020] However, in recent semiconductor manufacturing, several hundred thousand to several million semiconductor substrates are manufactured per year at one manufacturing site, and manufacturing devices and processing devices are expected that take even one second less in the time taken for processing each one. SUMMARY

[0021] The present application was made in view of the above problems, and an object thereof is to provide an optical heating device and a heating process method capable of performing a heating process of a semiconductor substrate in a shorter time.

[0022] Means for solving the problems

[0023] The optical heating device of the present application is an optical heating device for heating a substrate, characterized by comprising: a chamber that houses the substrate; a support member that supports the substrate in the chamber; a plurality of LED elements that emit light toward the substrate supported by the support member; a flash lamp that emits light toward the substrate supported by the support member; and a first lighting control section that performs control to light the flash lamp after a lapse of a prescribed time after lighting the LED elements.

[0024] The LED element has a rapid follow-up of the change in light output relative to input electric power in the light emission principle. That is, the LED element can immediately reduce the brightness or stop the emission of light when performing control to reduce or stop the supply of electric current. Therefore, by performing preheating of the substrate with the LED element and performing control to reduce or stop the light output from the LED element after a predetermined time required to reach the target temperature, it is possible to suppress the temperature from rising above the target temperature. Furthermore, immediately after reaching the target temperature, it is possible to perform the heat treatment with the flash lamp.

[0025] That is, by being configured as described above, it is possible to perform the heat treatment of the substrate without waiting for the stabilization of the temperature during preheating, and it is possible to complete the heat treatment in a shorter time than in the past.

[0026] In the light heating device described above, the chamber can have a light-transmitting window for taking in light for heating to the inside, the support member can support the substrate with the main surfaces of the substrate facing the light-transmitting window, and the plurality of LED elements and the flash lamp can be arranged to emit light toward the main surfaces of the substrate supported by the support member from the outside of the chamber via the light-transmitting window.

[0027] By being configured as described above, even in a state in which the chamber is filled with vacuum or processing gas, since the LED element and the flash lamp are arranged on the outside of the chamber, it is possible to prevent breakage of the light source during operation and the like. In addition, since the number of components arranged in the chamber is small, the source of dust, particles, and the like that contaminate the substrate as the object of heating is reduced, and it is possible to achieve a cleaner heat treatment.

[0028] The light heating device according to the technical solution 1, wherein the plurality of LED elements emit light toward one main surface of the substrate supported by the support member, and the flash lamp emits light toward the other main surface of the substrate supported by the support member.

[0029] Furthermore, in the light heating device described above, the chamber can have a pair of light-transmitting windows for taking in light for heating to the inside, the support member can support the substrate with the main surfaces of the substrate facing the pair of light-transmitting windows, respectively, and the plurality of LED elements and the flash lamp can be arranged to emit light toward the main surfaces of the substrate supported by the support member from the outside of the chamber via the light-transmitting windows.

[0030] By being configured as described above, flash light based on the flash lamp is irradiated to one main surface of the substrate housed in the chamber, and light emitted from the LED element is irradiated to the other main surface. Thereby, it is possible to suppress high-intensity light emitted from the flash lamp from being directly irradiated to the LED element.

[0031] Further, in the description of the structure having the light-transmitting window, as described above, even in a state where the chamber is filled with vacuum or a processing gas, since the LED element and the flash lamp are disposed outside the chamber, it is possible to prevent breakage of the light source and the like during operation. In addition, since the number of components disposed in the chamber is reduced, the generation source of dust, fine particles, and the like that contaminate the substrate as a heating target is reduced, and it is possible to achieve a cleaner heating process.

[0032] Also, the light heating device described above can include a radiation thermometer that measures the temperature of the main surface of the substrate, and the first lighting control section can perform control to light up the flash lamp after a prescribed time elapses from when the LED element is lighted up, and the temperature of the main surface of the substrate measured by the radiation thermometer reaches a prescribed temperature.

[0033] With the above structure, the heating process based on the flash lamp can be performed when the temperature of the main surface of the substrate reliably reaches a target temperature.

[0034] Also, the light heating device described above can include a second lighting control section that controls the current supplied to the LED element based on the temperature measured by the radiation thermometer, and the second lighting control section can perform control to supply the same current to each of the LED elements to start lighting up the LED elements, and after the LED elements are lighted up, in the temperature distribution of the main surface of the substrate measured by the radiation thermometer, decrease the current supplied to the LED element that irradiates the region that indicates the highest temperature, or increase the current supplied to the LED element that irradiates the region that indicates the lowest temperature.

[0035] For example, in a case where the substrate is heated by preheating, the temperature of the outer peripheral portion is likely to decrease compared to the temperature of the central portion. Therefore, in preheating using a plurality of LED elements, in a case where the same current is supplied to all of the LED elements, a temperature distribution is likely to be uneven on the entire substrate. In this way, in the heating process using the flash lamp, unevenness in the process is likely to occur, and warping, cracking, or the like of the substrate is likely to occur, or large unevenness in the characteristics of elements formed on the same substrate is likely to occur.

[0036] Therefore, as described above, the second lighting control section can control the current for each of the regions of the partitioned LED elements (about several hundred) to preheat the substrate in such a manner that the difference between the portion having the highest temperature and the portion having the lowest temperature in the temperature distribution during preheating is small, and it is possible to suppress unevenness in the process, warping, cracking, and the like of the substrate.

[0037] The substrate of the light heating device described above can be a semiconductor substrate or a glass substrate.

[0038] In addition, in the light heating device described above, the main light emission wavelength of the light emitted from the plurality of LED elements can be included in the range of 300 nm to 1050 nm.

[0039] The "main light emission wavelength" in the present specification refers to the wavelength of the highest intensity of the light emitted.

[0040] In particular, a semiconductor substrate composed of silicon (Si) has the following characteristics: the absorption rate is high and the transmittance is low for light in the wavelength band from ultraviolet light to visible light, but if the wavelength is longer than 1100 nm, the absorption rate sharply decreases and the transmittance becomes high. As shown in FIG. 1, if light having a wavelength of 1100 nm or more is irradiated to a semiconductor substrate, about 50% of the light transmits through the semiconductor substrate. Figure 5

[0041] In the case of a semiconductor substrate composed of silicon, if light having a wavelength of 1100 nm or more is irradiated to the surface opposite to the main surface that is the processing target, a part of the light transmits through the semiconductor substrate to reach the main surface that is the processing target. In this way, a wiring or the like formed on the main surface that is the processing target absorbs the light, and the temperature distribution becomes uneven, which can cause warping or cracking in the semiconductor substrate. Therefore, the main light emission wavelength of the light emitted from the LED elements is preferably 50% or more in absorption rate, 20% or less in transmittance, and 1050 nm or less in wavelength.

[0042] In addition, a semiconductor substrate composed of silicon decreases to about 10% or so at the lowest absorption rate with respect to light having a wavelength of less than 300 nm. Therefore, in order to ensure an absorption rate of at least 25% or more, the main light emission wavelength of the light emitted from the LED elements is preferably 300 nm or more.

[0043] By being configured as described above, the light emitted from the LED elements transmits through the semiconductor substrate and hardly reaches the main surface that is the processing target. Therefore, the main surface that is the processing target is uniformly heated by the light emitted from the flash lamp, and the entire semiconductor substrate is uniformly heated and processed.

[0044] In addition, as shown in FIG. 2, which is referred to in the description of the "Embodiments", the spectrum of the LED elements is narrow compared to that of the halogen lamp, and therefore it is possible to configure a light source that emits light showing a high intensity only in the wavelength range that is preferable as light for preheating the semiconductor substrate. Figure 4

[0045] ​​The heating treatment method of the present application is a heating treatment method of a substrate, characterized by comprising: a process (A) of housing the substrate in a chamber; a process (B) of lighting up a plurality of LED elements that emit light toward the substrate housed in the chamber; and a process (C) of lighting up a flash lamp that emits light toward the substrate housed in the chamber after the process (B) after a prescribed time elapses.

[0046] In addition, in the above heating treatment method, the process (C) can be a process of lighting up the flash lamp after the prescribed time elapses from the start of the process (B) until the temperature of the main surface of the substrate detected by a radiation thermometer reaches a prescribed temperature.

[0047] As described above, in the case of preheating by the light emitted from the LED elements, the heating treatment can be performed by lighting up the flash lamp after the target temperature is reached. That is, by employing the above method, the heating treatment of the substrate can be performed without a waiting time for stabilization of the temperature at the time of preheating, and the heating treatment can be completed in a shorter time than in the past.

[0048] In addition, in the above heating treatment method, each process can be a process in which a person operates a switch or a button by manual work.

[0049] Effects of the Invention

[0050] According to the present application, a light heating device and a heating treatment method that can perform the heating treatment of a substrate in a shorter time can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0051] Figure 1 is a side sectional view schematically showing the structure of an embodiment of a light heating device.

[0052] Figure 2 is a view of the light heating device when viewed from the +Z side in a state in which a reflector is removed. Figure 1

[0053] Figure 3 is a view of an LED substrate on which LED elements are arranged when viewed from the +Z side.

[0054] Figure 4 is a graph showing the spectrum of the light emitted from a flash lamp and LED elements.

[0055] Figure 5 is a graph showing the spectrum of the absorption and transmission of light by a semiconductor substrate composed of silicon.

[0056] Figure 6 is a flowchart showing the order of the heating treatment processes of the light heating device.

[0057] ​Figure 7 is a graph showing temperature changes of a main surface of a semiconductor substrate in a heating process by a light heating device.

[0058] Figure 8A is an example showing that a region of a semiconductor substrate is associated with an LED element, Figure 1 is an enlarged view of a periphery of an LED substrate of the light heating device of

[0059] Figure 8B is a view showing an example in which an LED substrate is divided into several regions.

[0060] Figure 9 is a cross-sectional view schematically showing a structure of an embodiment of a light heating device.

[0061] Figure 10 is a view of the light heating device when viewed from the -Z side. Figure 9

[0062] Figure 11 is a side cross-sectional view schematically showing a structure of another embodiment of a light heating device.

[0063] Figure 12 is a side cross-sectional view schematically showing a structure of another embodiment of a light heating device.

[0064] Figure 13 is a view schematically showing a structure of a conventional light heating device provided with a flash lamp and a halogen lamp.

[0065] Figure 14 is a graph showing an example of temperature changes of a main surface of a semiconductor substrate with time in a case where a conventional halogen lamp is used as a preheating source.

[0066] Figure 15 is a graph showing an example of temperature changes of a main surface of a semiconductor substrate with time when a high-performance power controller is used to control input power of a halogen lamp.

[0067] Symbol explanation

[0068] 1: light heating device

[0069] 10: chamber

[0070] 10a: observation window

[0071] 11: flash lamp

[0072] 12: LED element

[0073] 12a: LED substrate

[0074] 13: control section

[0075] ​13a: First lighting control unit

[0076] 13b: Second lighting control unit

[0077] 13c: Timer

[0078] 14: Radiation thermometer

[0079] 15: Light-transmitting window

[0080] 16: Support components

[0081] 17: Reflector

[0082] 100: Photothermal heating device

[0083] 101: Chamber

[0084] 102: Flash

[0085] 103: Halogen lamp

[0086] 104: Light-transmitting window

[0087] 105: Support platform

[0088] 106: Heat Transfer Section

[0089] W1: Semiconductor substrate

[0090] W1a, W1b: Main face Detailed Implementation

[0091] The photothermal device and heating method of the present invention will now be described with reference to the accompanying drawings. It should be noted that the following drawings concerning the photothermal device are schematic illustrations, and the dimensions and numbers shown in the drawings may not correspond to the actual dimensions and numbers.

[0092] [First Implementation Method]

[0093] Figure 1 This is a side sectional view schematically showing the structure of one embodiment of the light heating device 1. Figure 2 This is observed from the +Z side with the reflector 17 (described later) removed. Figure 1 The diagram shows the light heating device 1. Figure 1 As shown, the light heating device 1 of the first embodiment includes a chamber 10 for housing a semiconductor substrate W1, a plurality of flash lamps 11, a plurality of LED elements 12, a control unit 13, and a radiation thermometer 14.

[0094] In the following explanation, such as Figure 1 and Figure 2As shown, the direction in which multiple flash units 11 are arranged is designated as the X direction, the direction in which the flash units 11 extend is designated as the Y direction, and the direction orthogonal to the X and Y directions is designated as the Z direction. Furthermore, when representing directions, if positive or negative orientations are distinguished, such as "+Z direction" or "-Z direction", positive or negative signs are used to indicate them. If positive or negative orientations are not distinguished when representing directions, they are simply recorded as "Z direction".

[0095] like Figure 1 As shown, the chamber 10 has a support member 16 on its inner side for supporting the semiconductor substrate W1. The support member 16 supports the semiconductor substrate W1 such that its main surfaces (W1a, W1b) are arranged on the XY plane. Furthermore, the support member 16 only needs its main surfaces (W1a, W1b) to support the semiconductor substrate W1 on the XY plane; for example, the support member 16 may have multiple pin-shaped protrusions, which are used to point-support the semiconductor substrate W1. Here, the main surface W1a is the surface where circuit elements, wiring, etc., are formed and illuminated by light emitted from the flash lamp 11, while the main surface W1b is the surface illuminated by light emitted from the LED element 12 for preheating.

[0096] Additionally, the chamber 10 includes a pair of light-transmitting windows 15 arranged opposite each other in the Z direction. The pair of light-transmitting windows 15 are respectively configured to draw light emitted from the flash lamp 11 and light emitted from the LED element 12 into the chamber 10. Figure 1 and Figure 2 As shown, the chamber 10 is rectangular, but it can also be in shapes other than rectangular, such as a cylindrical shape that appears circular when viewed from the Z direction.

[0097] like Figure 1 As shown, a pair of light-transmitting windows 15 are respectively configured to face each of the main surfaces (W1a, W1b) of the semiconductor substrate W1 supported by the support member 16. That is, light emitted from the flash lamp 11 illuminates the main surface W1a of the semiconductor substrate W1 through the light-transmitting window 15 on the +Z side, and light emitted from the LED element 12 illuminates the main surface W1b of the semiconductor substrate W1 through the light-transmitting window 15 on the -Z side.

[0098] Furthermore, the light heating device 1 includes a radiation thermometer 14, and an observation window 10a for observing the temperature of the main surface W1a of the semiconductor substrate W1 is provided on the wall of the chamber 10 on the -X side. By providing the observation window 10a, such as... Figure 1 As indicated by the dashed arrow, the radiation thermometer 14 observes the temperature of the main surface W1a of the semiconductor substrate W1 through the observation window 10a.

[0099] The flash lamp 11 emits a flash toward the main surface Wla of the semiconductor substrate Wl when the light-on control is performed by the control section 13. The flash emitted from the flash lamp 11 is irradiated to the main surface Wla of the semiconductor substrate Wl via the light-transmitting window 15 on the +Z side of the chamber 10, and thus the semiconductor substrate Wl is instantaneously heated to 1000°C or higher.

[0100] The reflector 17 that reflects the light traveling toward the side opposite to the chamber 10 (+Z side) toward the chamber 10 side (-Z side) is provided on the +Z side of the flash lamp 11. Thus, the light emitted from the flash lamp 11 is not wasted and is irradiated to the main surface Wla of the semiconductor substrate Wl.

[0101] Further, in the first embodiment, a plurality of flash lamps 11 are provided, but as long as the intensity of the emitted light is sufficiently high, it can be constituted by only one, or the reflector 17 can not be provided.

[0102] Figure 3 is a view when the LED substrate 12a on which the LED elements 12 are provided is viewed from the +Z side. As shown in Figure 3 , the LED substrate 12a is configured such that the plurality of LED elements 12 placed thereon are arranged on the XY plane, and the light emitted from the LED elements 12 is directed toward the -Z side light-transmitting window 15.

[0103] As shown in Figure 1 and Figure 3 , the light heating device 1 of the first embodiment is configured to have a plurality of LED elements 12 on the same plane on one LED substrate 12a, but the LED substrate 12a can be configured to have a curved surface, and the LED elements 12 can be provided on the curved surface. Alternatively, a plurality of LED substrates 12a can be provided.

[0104] Here, the spectrum of the flash lamp 11 and the light emitted from the LED elements 12 is described. Figure 4 is a graph showing the spectrum of the light emitted from the flash lamp 11 and the LED elements 12, Figure 5 is a graph showing the spectrum of the absorption and transmission of light by the semiconductor substrate Wl made of silicon. Figure 4 The graph shown in Figure 5 is a graph showing the absorption and transmission of light by a silicon substrate on which no elements and wiring are formed. Further, Figure 4 For comparison with the existing structure, the spectrum of the halogen lamp 103 is also shown by a dotted line.

[0105] As shown in Figure 4As shown, in the first embodiment, the light emitted from the LED element 12 represents a light emission spectrum with a main emission wavelength of 400 nm and a band width of 100 nm or less with a relative intensity of 50% or more relative to the peak light intensity. The light emitted from the flash lamp 11 represents a broad light emission spectrum with a band width of 1000 nm or more.

[0106] like Figure 5 As shown, the silicon-based semiconductor substrate W1 has an absorption rate exceeding its transmittance for light in the wavelength range below 1100 nm, and a transmittance exceeding its absorption rate for light in the wavelength range above 1100 nm. Therefore, in order to efficiently heat the semiconductor substrate W1, the primary emission wavelength of the LED element 12 used in the preheating is preferably 1050 nm or less, with an absorption rate of 50% or more, a transmittance of 20% or less, in the silicon-based semiconductor substrate W1.

[0107] Furthermore, the silicon-based semiconductor substrate W1 exhibits significantly reduced absorption for light wavelengths below 300 nm. Therefore, the primary emission wavelength of the LED element 12 is preferably 300 nm or higher.

[0108] like Figure 4 As shown, the light emitted from the halogen lamp 103, like that from the flash lamp 11, has a broad emission spectrum with a wavelength of 1000 nm or more. Therefore, in conventional preheating based on the halogen lamp 103, light with a wavelength of 1100 nm or more passing through the semiconductor substrate W1 illuminates the main surface W1b of the semiconductor substrate W1 at a higher intensity.

[0109] The control unit 13 includes a first lighting control unit 13a for controlling the lighting of the flash lamp 11, a second lighting control unit 13b for controlling the lighting of the LED element 12, and a timer 13c for measuring the elapsed time since the LED element 12 was first lit. The first lighting control unit 13a controls the flash lamp 11 to light up when the timer 13c detects that a predetermined time has elapsed since the LED element 12 was lit. Preferred control methods for the second lighting control unit 13b will be described later. Alternatively, the timer 13c can be installed separately from the light heating device 1.

[0110] Hereinafter, each step of the heat treatment of the semiconductor substrate W1 performed by the light heating device 1 of the first embodiment will be described. Figure 6 This is a flowchart showing the sequence of the heating process in the light heating device 1. Figure 7 This is a graph showing the temperature change of the main surface W1a of the semiconductor substrate W1 during the heating process of the light-heating device 1. Additionally, Figure 7 It is shown in dashed lines for comparison with previous structures. Figure 13 andFigure 14 The graph shown represents the temperature change of the main surface W1a of the semiconductor substrate W1 during the heating process of a conventional light heating device 100.

[0111] like Figure 6 As shown, firstly, a semiconductor substrate W1 is housed within the chamber 10 (step S1). This step S1 corresponds to process (A).

[0112] After step S1 is executed, the second lighting control unit 13b controls the LED element 12 to start supplying current to the LED element 12, thereby lighting up the LED element 12 and starting preheating (step S2). This step S2 corresponds to process (B).

[0113] After step S2 is executed, timer 13c begins to measure the elapsed time, such as... Figure 7 As shown, the time T1 from standby until the semiconductor substrate W1 reaches the target temperature (step S3) is the time. This time T1 is appropriately determined based on the size, thickness, etc. of the semiconductor substrate W1. Figure 7 The setting shown is just one example, but it can be set to be shorter than the stabilization wait time T2 when using a high-performance power controller to control the input power of the halogen lamp.

[0114] When the timer 13c detects that a predetermined time has elapsed, the first lighting control unit 13a controls the flash lamp 11 to light up (step S4). This step S4 corresponds to process (C). At this time, in order to suppress the temperature rise of the LED element 12, the second lighting control unit 13b can also control the current supplied to the LED element 12 to reduce it.

[0115] After step S4 is executed, the second lighting control unit 13b stops the current supply in order to turn off the LED element 12 (step S5).

[0116] Furthermore, the LED element 12 is a light source used for preheating the semiconductor substrate W1, and it does not necessarily need to be lit when the flash lamp 11 is lit. That is, in this embodiment, step S5 is performed after step S4, but step S5 can also be performed simultaneously with the lighting control of the flash lamp 11 in step S4, or before step S4.

[0117] After performing step S5, when the temperature of the semiconductor substrate W1 drops to the temperature at which it is removed from the chamber 10, the semiconductor substrate W1 is removed (step S6).

[0118] At this point, whether the temperature inside chamber 10 has dropped to a level suitable for removing the semiconductor substrate W1 can be determined by radiation thermometer 14, or by timer 13c determining whether a predetermined time has elapsed. The temperature at which the semiconductor substrate W1 is removed from chamber 10 is arbitrarily set according to the device structure, etc. Figure 7 The temperature at which the sample was taken is indicated by a double-dotted line, but this setting is only one example.

[0119] By setting it to the above structure, such as Figure 7 As shown, light irradiation based on flash lamp 11 can be performed without the need for a temperature stabilization waiting time during preheating, which can shorten the heating process time by several seconds to tens of seconds compared to the past.

[0120] Furthermore, the LED element 12 is controlled to be lit by the control unit 13, thereby reducing temperature unevenness during preheating. Therefore, uneven temperature distribution on the semiconductor substrate W1 can be suppressed, and uneven heat treatment, warping, and cracking can be prevented.

[0121] Furthermore, in the first embodiment, since the main emission wavelength of the LED element 12 is 400 nm, for the reasons described above, the light emitted from the LED element 12 hardly reaches the main surface W1a of the semiconductor substrate W1. Therefore, it is possible to suppress uneven temperature distribution based on light absorption of circuit elements or wiring.

[0122] Furthermore, in step S2, the second lighting control unit 13b can also perform the following control: by reducing or increasing the power supplied to a specific LED element 12 among the plurality of LED elements 12, the brightness of each element is different.

[0123] Specifically, the second illumination control unit 13b performs the following control: after the LED element 12 is illuminated by supplying the same current, based on the temperature distribution of the main surface W1a of the semiconductor substrate W1 measured by the radiation thermometer 14, it reduces the current supplied to the LED element 12 that illuminates the area indicating the highest temperature. Alternatively, the second illumination control unit 13b can also perform the following control: it increases the current supplied to the LED element 12 that illuminates the area indicating the lowest temperature.

[0124] Figure 8A This is an example of how regions (W1p, W1q) of the semiconductor substrate W1 are associated with the LED element 12. Figure 1 An enlarged view of the area surrounding the LED substrate 12a of the light heating device 1. (See image below.) Figure 8AAs shown, the above control establishes a connection between each region (W1p, W1q) of the main surface W1a of the semiconductor substrate W1 and the LED elements (12p, 12q) that irradiate light onto each region (W1p, W1q) of the main surface W1a. The second lighting control unit 13b controls the current supplied to each LED element (12p, 12q) based on the temperature of each region (W1p, W1q). For ease of explanation, Figure 8A Only the X direction is shown in the diagram, but each region in the XY plane of the semiconductor substrate W1 is associated with any one of the LED elements 12 disposed on the LED substrate 12a.

[0125] Figure 8B This diagram illustrates an example of dividing the LED substrate 12a into several regions (Z1, Z2, Z3). As a reference... Figure 8A The description describes different control methods, for example, such as... Figure 8B As shown, there is a method where the LED substrate 12a is divided into several regions (Z1, Z2, Z3), and the second illumination control unit 13b controls the current supplied to the LED element 12 group for each region (Z1, Z2, Z3). In this method, the second illumination control unit 13b controls the current supplied to the LED element 12 group that irradiates light towards the region with the highest temperature, based on the temperature distribution of the main surface W1a of the semiconductor substrate W1 measured by the radiation thermometer 14.

[0126] In this control method, if each LED element 12 is observed individually, the second lighting control unit 13b performs the following control: based on the temperature distribution of the main surface W1a of the semiconductor substrate W1 measured by the radiation thermometer 14, it reduces the current supplied to the LED element 12 illuminating the area indicating the highest temperature. Alternatively, in this control method, the second lighting control unit 13b can also perform the following control: based on the temperature distribution of the main surface W1a of the semiconductor substrate W1 measured by the radiation thermometer 14, it increases the current supplied to the group of LED elements 12 illuminating the area indicating the lowest temperature.

[0127] The light heating device 1 is configured as a second lighting control unit 13b to control the lighting of the LED element 12, and may not include a radiation thermometer 14. Additionally, as... Figure 1 As shown, the light heating device 1 of the first embodiment is configured such that a radiation thermometer 14 is disposed outside the chamber 10, and the temperature of the main surface W1a of the semiconductor substrate W1 is measured through the observation window 10a. However, the radiation thermometer 14 may also be disposed inside the chamber 10.

[0128] In the above description, the heating treatment of the semiconductor substrate W1 composed of silicon was described, but the light heating device 1 can be used for heating other than the semiconductor substrate W1 composed of silicon, and heating of a substrate material other than a semiconductor substrate. As an example, it can be used in the heating treatment of a glass substrate in the manufacturing process of a display.

[0129] In addition, as described above, the width of the wavelength band in which the relative intensity of the LED element 12 mounted on the light heating device 1 is 50% or more with respect to the peak of the light intensity is 100 nm or less, and thus it is preferable to appropriately set the main emission wavelength of the emitted light in accordance with the absorption spectrum of the heating target from the viewpoint of heating efficiency or the like.

[0130] [Second Embodiment]

[0131] The structure of the second embodiment of the light heating device 1 of the present application will be described focusing on the points different from the first embodiment.

[0132] Figure 9 is a side sectional view schematically showing the structure of one embodiment of the light heating device 1. Figure 10 is a schematic view when the light heating device 1 is viewed from the -Z side. Figure 9 As shown in Figure 10 , the second embodiment of the light heating device 1 is formed in a circular ring shape when viewed in the Z direction.

[0133] The light heating device 1 of the second embodiment has the control section 13 as in the first embodiment, but in order to avoid complicated illustration, the control section 13 is not shown in Figure 9 .

[0134] In addition, the plane of the LED substrate 12a on which the LED element 12 is placed is inclined with respect to the XY plane, and the light emitted from the LED element 12 is irradiated to the main surface W1b of the semiconductor substrate W1 from a direction non-parallel to the Z direction.

[0135] By being configured as described above, the light heating device 1 can observe the inside of the chamber 10 from the light-transmitting window 15 on the -Z side through the inside of the LED substrate 12a, and can confirm the inside of the chamber 10, whether or not the semiconductor substrate W1 housed in the chamber 10 is deviated from the support member 16, and the like. In addition, as shown in Figure 9 and Figure 10 , by providing the radiation thermometer 14 on the -Z side of the chamber 10, the temperature of the main surface W1b of the semiconductor substrate W1 can be measured.

[0136] By being able to observe the temperature of the main surface W1b irradiated with the light emitted from the LED element 12, the second lighting control section 13b is able to control the current supplied to the LED element 12 based on the temperature distribution of each main surface (W1a, W1b) so that the temperature unevenness of the entire semiconductor substrate W1 becomes smaller.

[0137] [Other Embodiments]

[0138] Hereinafter, other embodiments will be described.

[0139] <1> In the above-described embodiments, the configuration in which the flash lamp 11 and the LED element 12 are arranged on opposite sides as viewed from the semiconductor substrate W1 has been described, but in the light heating apparatus 1, the flash lamp 11 and the LED element 12 can also be arranged on the same side as viewed from the semiconductor substrate W1. In addition, in the above-described embodiments, the flash lamp 11 and the LED element 12 are arranged outside the chamber 10, and emit light toward the semiconductor substrate W1 via the light-transmitting window 15 of the chamber 10, but the light heating apparatus 1 can also be configured such that the flash lamp 11 and the LED element 12 are arranged inside the chamber 10, and the chamber 10 does not have the light-transmitting window 15.

[0140] Figure 11 and Figure 12 is a side sectional view schematically showing another embodiment of the light heating apparatus 1. As shown in Figure 11 , the flash lamp 11 and the LED element 12 can also be arranged on the same side as viewed from the semiconductor substrate W1 in the light heating apparatus 1. Also, as shown in Figure 12 , the light heating apparatus 1 can also be configured such that the flash lamp 11 and the LED element 12 are arranged inside the chamber 10, and the chamber 10 does not have the light-transmitting window 15.

[0141] <2> In the above-described embodiments, the case where the timer 13c measures the elapsed time from the execution of step S2, and step S4 is executed after the elapsed time reaches a prescribed time T1 has been described. However, instead of this control content, the first lighting control section 13a can perform control to cause the flash lamp 11 to be lit when the temperature of the main surface W1a of the semiconductor substrate W1 measured by the radiation thermometer 14 is detected to have risen to a prescribed temperature after the execution of step S2. In this case, the time required from the execution of step S2 until the temperature of the main surface W1a of the semiconductor substrate W1 reaches the prescribed temperature corresponds to the "prescribed time". In addition, the "prescribed temperature" referred to here can be the target temperature of the semiconductor substrate W1.

[0142] <3> The light heating apparatus 1 can also be provided with an optical system such as a lens, a prism, a diffusion plate, an integrating optical system, or the like in order to cause the light emitted from the LED element 12 to be uniformly irradiated to the entire main surface W1b of the semiconductor substrate W1.

[0143] <4> The structure of the light heating device 1 described above is only an example, and the present application is not limited to the structures illustrated.

Claims

1. A photoheating device for heating a substrate, characterized in that, have: A chamber that houses the substrate; A support component supports the substrate within the cavity; Multiple LED elements emit light toward the substrate supported by the support member; A flashlight emits light toward the substrate supported by the support member; The first lighting control unit controls the flashlight to light up after the LED element has been lit up for a predetermined time. as well as The second lighting control unit reduces the power supplied to the LED element before or simultaneously with the first lighting control unit controlling the flash to light up.

2. The photoheating device according to claim 1, characterized in that, The chamber has a light-transmitting window on its wall for drawing in light for heating. The support member supports the substrate with the main surface of the substrate facing the light-transmitting window. The plurality of LED elements and the flash lamp are arranged such that light is emitted from the outside of the chamber via the light-transmitting window toward the main surface of the substrate supported by the support member.

3. The photoheating device according to claim 1, characterized in that, The plurality of LED elements emit light toward one main surface of the substrate supported by the support member. The flashlight emits light toward the other main surface of the substrate supported by the support member.

4. The photoheating device according to claim 3, characterized in that, The chamber has a pair of opposing light-transmitting windows for drawing in light for heating. The supporting member supports the substrate with each main surface of the substrate facing the pair of light-transmitting windows respectively. The plurality of LED elements and the flash lamp are configured to emit light from the outside of the chamber through the light-transmitting window toward each main surface of the substrate supported by the support member.

5. The photoheating device according to claim 1, characterized in that, It is equipped with a radiation thermometer for measuring the temperature of the main surface of the substrate. The first lighting control unit controls the flash lamp to light up after a predetermined time has elapsed since the LED element was lit up, during which the temperature of the main surface of the substrate measured by the radiation thermometer has reached a predetermined temperature.

6. The photoheating device according to claim 5, characterized in that, The second lighting control unit controls the current supplied to the LED element based on the temperature measured by the radiation thermometer, and performs the following control: supplies the same current to each LED element to start lighting the LED element; after the LED element is lit, based on the temperature distribution of the main surface of the substrate measured by the radiation thermometer, it reduces the current supplied to the LED element that irradiates light to the area representing the highest temperature, or increases the current supplied to the LED element that irradiates light to the area representing the lowest temperature.

7. The photoheating device according to claim 1, characterized in that, The substrate is a semiconductor substrate or a glass substrate.

8. The photoheating device according to any one of claims 1 to 7, characterized in that, The main emission wavelengths of the light emitted by the multiple LED elements are within the range of 300nm to 1050nm.

9. A heat treatment method, specifically a heat treatment method for a substrate, characterized in that, The process includes the following steps: The process (A) of housing the substrate in the cavity; The process (B) of illuminating a plurality of LED elements that emit light into the substrate housed within the cavity; and After step (B), after a predetermined time, step (C) is performed to light up a flash lamp that emits light to the substrate housed in the cavity, either simultaneously with or after the current supplied to the LED element decreases.

10. The heat treatment method according to claim 9, characterized in that, In step (C), after a predetermined time has elapsed since the start of step (B) when the temperature of the main surface of the substrate, as detected by a radiation thermometer, reaches a predetermined temperature, the flash lamp is turned on simultaneously with or after the current supplied to the LED element is reduced.

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