JP2008153519A - Vapor deposition apparatus, and vapor deposition method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vapor deposition apparatus and vapor deposition method that allow formation of a film having an excellent film quality. <P>SOLUTION: A processing apparatus 1 as the vapor deposition apparatus comprises a susceptor 5, a reaction tube 3, a cooling member (a gap between an outer periphery member 6 and an inner periphery member 8 of an upper wall 4 of the reaction tube, and a cooling material 10), and a heater 9. The susceptor 5 holds a substrate 7 on the surface of which a film is formed by the vapor deposition method. The reaction tube 3 has therein the substrate 7 held by the susceptor, and the upper wall 4 of the reaction tube as a transparent window for observing the substrate 7. The cooling member cools the upper wall 4 of the reaction tube. The heater 9 heats the substrate 7. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vapor phase growth apparatus and a vapor phase growth method, and more particularly to a vapor phase growth apparatus and a vapor phase growth method for forming a film on a surface of a substrate using a vapor phase reactive growth method.

Conventionally, a vapor phase growth apparatus (hereinafter also referred to as a film formation apparatus) and a vapor phase growth method (hereinafter also referred to as a film formation method) that form a film on the surface of a substrate using a vapor phase reactive growth method are known. (For example, refer nonpatent literature 1). Non-Patent Document 1 discloses growing a gallium nitride based semiconductor on a sapphire substrate using an MOCVD apparatus. In addition, a heating method using a lamp or an excimer laser is also conventionally used as a heating method in a film forming apparatus or a film forming method as described above, or a processing step for a film formed by such a film forming method. Known (for example, refer to Patent Document 1 and Patent Document 2). In Patent Document 1, in an apparatus for crystallizing an amorphous semiconductor film, a plurality of chambers are connected, a film forming process is performed in one chamber, an infrared lamp is heated in the next chamber, and the next chamber is used. It is disclosed that a polycrystalline semiconductor film is obtained by heating using an excimer laser or the like. Further, in Patent Document 2, the film forming apparatus includes two connected chambers, and the first chamber is heated while the substrate is heated by a heater built in a substrate holder on which the substrate is mounted. A dichlorosilane gas is supplied into the chamber to form a dichlorosilane monomolecular layer on the surface of the substrate. Thereafter, the substrate is moved to the second chamber, and the substrate is heated using a heater and an excimer lamp built in the substrate holder while supplying ammonia gas in the second chamber. As a result, dichlorosilane molecules and ammonia molecules react on the surface of the substrate to form a monolayer of silicon nitride.
JP-A-6-342757 JP-A-2005-19499 Takashi Egawa, “Research Activities of Nagoya Institute of Technology, Metalorganic Chemical Vapor Deposition Technology (Taiyo Nippon Sanso)”, Taiyo Nippon Sanso Technical Report No. 23 (2004), p2-7

As shown in Non-Patent Document 1, when forming a gallium nitride-based semiconductor, for example, trimethylgallium (TMG) gas, trimethylaluminum (TMA) gas, and ammonia (NH ₃ ) gas are used as source gases for the AlGaN film. When the substrate is heated to form a gallium nitride based semiconductor, the ambient temperature around the substrate also rises. In this case, TMA is known to cause a gas phase reaction with ammonia. In this gas phase reaction, TMA and ammonia are combined to form an additive compound of TMA-NH ₃ , and the reaction occurs one after another in the gas phase to form particulate matter. When such a gas phase reaction occurs, organic metals other than TMA in the source gas are also deposited on the particles, so that the source gas is consumed due to the gas phase reaction and film formation on the substrate surface can be sufficiently performed. There was no problem.

  In order to suppress the occurrence of such a gas phase reaction, it is effective to increase the flow rate of the raw material gas by increasing the flow rate of the raw material gas or reducing the pressure of the reaction vessel (reaction tube) of the processing apparatus. . On the other hand, in order to improve the quality of the formed film, it is necessary to increase the film formation temperature. For this reason, the substrate surface is directly heated using an excimer laser as described above to increase the film forming temperature on the substrate surface, while suppressing the amount of heat input to the entire substrate to minimize the temperature rise in the atmosphere around the substrate. The inventor also examined the suppression. However, in a film forming apparatus for forming a gallium nitride based semiconductor, the temperature of the inner peripheral wall surface of the chamber facing the substrate holding member (susceptor) on which the substrate is mounted is likely to rise due to radiant heat from the susceptor. In some cases, a film grows. When the film grows in this way, even if the portion of the chamber facing the substrate holding member is made of a transparent member such as quartz, the portion of the chamber is blocked by the film, and as a result, excimer laser or the like is applied to the substrate. Irradiation is not possible, and it becomes difficult to measure the temperature of the substrate surface using a radiation thermometer or the like. Further, when a film grows on the inner peripheral wall surface of the chamber as described above, the temperature condition inside the chamber may be affected and change depending on the growth state of the film. In this case, since the film forming conditions of the film formed on the substrate are changed, the film quality of the film grown on the substrate may be deteriorated. In particular, when forming a nitride film, the film forming temperature is 1000 ° C. or more, and there is a difference in the film forming temperature depending on the type of film to be grown (for example, a film is formed for a GaN film or an AlGaN film). The temperature is 1000 ° C. or higher. In the case of an InGaN film, the film forming temperature is about 800 ° C.). Therefore, the control of the film formation temperature is extremely important for the management of the film quality of the formed film.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a vapor phase growth apparatus and a vapor phase growth method capable of forming a film having excellent film quality. It is to be.

  A vapor phase growth apparatus according to the present invention includes a substrate holding member, a reaction vessel, a cooling member, and a heating member. The substrate holding member holds a substrate on which a film is formed by a vapor deposition method. In the reaction container, a substrate held by a substrate holding member is disposed inside, and has a transparent window for observing the substrate. The cooling member cools the transparent window. The heating member heats the substrate.

  In this case, since the transparent window portion is cooled by the cooling member, even if the ambient temperature in the vicinity of the substrate rises by radiant heat from the substrate by heating the substrate by the heating member, the inner peripheral surface of the transparent window portion This temperature can be kept lower than the lower limit of the film forming temperature (the film forming lower limit temperature). For this reason, formation of the film | membrane on the inner peripheral surface of a transparent window part can be suppressed.

  In addition, since the formation of a film on the inner peripheral surface of the transparent window portion can be suppressed in this way, the film formation conditions (for example, temperature conditions) inside the reaction vessel may become unstable due to the formation of the film. Can be reduced. That is, since the film formation conditions inside the reaction vessel can be stabilized with good reproducibility, the film quality of the film formed as a result can be improved.

  In addition, since no film is formed on the inner peripheral surface of the transparent window portion, the surface temperature of the substrate can be measured by a temperature measuring device such as a pyrometer through the transparent window portion. Therefore, the controllability of the film forming conditions can be improved. As a result, the quality of the formed film can be kept high.

  In addition, it is possible to locally heat the surface of the substrate by irradiating the substrate surface with energy rays through the transparent window portion.

  Here, the vapor phase growth apparatus supplies a film forming material (raw material) for growing a film in a gas (raw material gas) state and grows a predetermined film from the raw material in a gaseous state by an arbitrary method. An apparatus means, for example, a film forming apparatus such as a CVD apparatus.

  The vapor phase growth method according to the present invention includes a step of preparing a substrate on which a film is formed by a vapor phase growth method inside a reaction vessel having a transparent window, and a film formation step. In the film forming step, the temperature of the transparent window is lower than the film forming lower limit temperature of the film formed on the surface of the substrate and the substrate surface temperature is equal to or higher than the film forming lower limit temperature. Is supplied to a region facing the surface of the substrate.

  In this case, since the temperature of the transparent window portion is set to the film formation lower limit temperature or less, even if the ambient temperature in the vicinity of the substrate rises due to radiant heat from the substrate by heating the substrate with the heating member, Formation of a film on the peripheral surface can be suppressed.

  In addition, since the formation of a film on the inner peripheral surface of the transparent window portion can be suppressed in this way, the film formation conditions (for example, temperature conditions) inside the reaction vessel may become unstable due to the formation of the film. Can be reduced. That is, since the film formation conditions inside the reaction vessel can be stabilized with good reproducibility, the film quality of the film formed as a result can be improved.

  In addition, since no film is formed on the inner peripheral surface of the transparent window, the surface temperature of the substrate can be measured by a temperature measuring device such as a pyrometer through the transparent window. Therefore, the controllability of the film forming conditions can be improved. As a result, the quality of the formed film can be kept high. Further, since no film is formed on the inner peripheral surface of the transparent window portion, it is possible to irradiate the substrate surface with energy rays through the transparent window portion by the heating member.

  Here, the film formation lower limit temperature means the lower limit of the temperature at which the film to be formed on the substrate surface can be formed. For example, when the film to be formed is an AlGaN film, the film forming lower limit temperature is 400 ° C.

  According to the present invention, since the film formation on the inner peripheral surface of the transparent window can be suppressed, the film formation conditions inside the reaction vessel can be stabilized, so that the film quality of the formed film can be improved. it can.

  Next, embodiments and examples of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

(Embodiment 1)
FIG. 1 is a schematic cross-sectional view showing a first embodiment of a processing apparatus which is an example of a vapor phase growth apparatus according to the present invention. 2 is a schematic cross-sectional view taken along line II-II in FIG. 3 is a schematic cross-sectional view taken along line III-III in FIG. A first embodiment of a processing apparatus according to the present invention will be described with reference to FIGS.

  1 to 3, a processing apparatus 1 is an OMVPE (Organo Metallic Vapor Phase Epitaxy) apparatus for forming, for example, a GaN-based semiconductor film, and includes a reaction tube 3 made of a transparent member such as quartz, A susceptor 5 that is disposed on the reaction tube bottom wall 11 of the reaction tube 3 and holds the substrate 7 that is a processing target, and a heater 9 that is disposed on the back side of the susceptor 5 are provided. In the reaction tube 3, the reaction tube upper wall 4, which is an upper wall facing the susceptor 5, includes an outer peripheral member 6 positioned on the outer peripheral side and an inner peripheral member 8 positioned on the inner peripheral side. The inner peripheral member 8 is formed so as to extend substantially in parallel with the outer peripheral member 6 at a distance. In the gap between the outer peripheral member 6 and the inner peripheral member 8, the coolant 10 can flow.

  In the gap between the outer peripheral member 6 and the inner peripheral member 8, an inlet 16 located on the upstream side in the flow direction of the raw material gas indicated by an arrow 20 in FIG. 1 and an outlet 17 located on the downstream side are formed. ing. Further, the gap is arranged so as to cover the susceptor 5 so as to overlap the susceptor 5 in a plan view and to extend in a region larger than the planar shape of the susceptor 5. Here, the outer peripheral member 6 and the inner peripheral member 8 are made of, for example, quartz, the outer peripheral member 6 has a thickness of 1 mm, the inner peripheral member 8 has a thickness of 1 mm, and the gap between the outer peripheral member 6 and the inner peripheral member 8 has a thickness of 10 mm. It can be.

  The coolant 10 is introduced from the inlet 16 into the gap between the outer peripheral member 6 and the inner peripheral member 8, and the coolant 10 is discharged from the outlet 17. After being discharged from the outlet 17, the coolant 10 is introduced into a heat exchanger (not shown) disposed outside the reaction tube 3 through a pipe connected from the outlet 17. In the heat exchanger, in the gap between the outer peripheral member 6 and the inner peripheral member 8, the coolant 10 whose temperature has been increased by absorbing heat from the outer peripheral member 6 and the inner peripheral member 8 is exchanged with external air or the like. It is cooled by exchanging heat. Then, the cooled coolant 10 is returned to the gap through the inlet 16 again. As the coolant 10, any conventionally known liquid or gas can be used. Also, any conventionally known configuration can be used as the configuration of the heat exchanger.

  A temperature measuring member 13 is disposed outside the upper tube 4 of the reaction tube 3 and at a position facing the susceptor 5. The temperature measuring member 13 measures the surface temperature of the substrate 7. As the temperature measuring member 13, for example, a non-contact type thermometer such as a pyrometer can be used. The temperature measuring member 13 is connected to the control member 15.

  Further, in order to measure the temperature of the inner peripheral surface of the inner peripheral member 8 of the reaction tube upper wall 4, the temperature measuring member 14 is arranged so as to contact the inner peripheral surface. As the temperature measuring member 14, a thermocouple etc. can be used, for example. The temperature measuring member 14 is also connected to the control member 15.

  The control member 15 is connected to the heater 9. The control member controls the power supplied to the heater 9 based on the temperature data from the temperature measuring member 13. As a result, the substrate surface temperature can be controlled to fall within a predetermined temperature range. For example, a target value (or target numerical value range) of temperature data measured by the temperature measuring member 13 is set in advance, and if the actually measured temperature data is higher than the target value, the amount of electric power supplied to the heater 9 is set. On the other hand, if the actually measured temperature data is lower than the target value, the control member 15 can perform control such that the amount of power supplied to the heater 9 is increased.

  Further, the supply of the source gas indicated by the arrow 20 is performed by a gas supply member (not shown). As the gas supply member, a conventionally known apparatus having an arbitrary configuration can be used. For example, a tank in which source gas is accumulated, a pipe for transferring the source gas from the tank to the reaction tube 3, a flow rate control member such as a mass flow controller arranged in the path of the pipe, and the start of supply of the source gas / The gas supply member may be composed of a valve for controlling the stop.

  Next, referring to FIG. 4, a film forming method for forming a film on the surface of the substrate 7 using the processing apparatus 1 shown in FIGS. 1 to 3 as an example of the vapor phase growth method according to the present invention. Will be explained. FIG. 4 is a flowchart for explaining a film forming method using the processing apparatus shown in FIGS.

  As shown in FIG. 4, in the film forming method according to the present invention, first, a substrate preparation step (S10) is performed. In the substrate preparation step (S 10), the substrate 7 is disposed on the susceptor 5 inside the reaction tube 3. Thereafter, the pressure of the atmosphere inside the reaction tube 3 is controlled to a predetermined value. Such pressure control can be performed by a pressure adjusting member (not shown) connected to the reaction tube 3. A conventionally well-known arbitrary structure can be employ | adopted for such a pressure adjustment member. For example, a device comprising a pipe connected to the reaction tube 3, an exhaust pump connected to the pipe, an on-off valve arranged on the pipe path, or the like can be used as the pressure adjusting member.

  Next, a cooling process is started (S20). Specifically, the coolant 10 is circulated in the gap between the outer peripheral member 6 and the inner peripheral member 8 of the reaction tube upper wall 4, and cooling of the reaction tube upper wall 4 is started. As a result, the reaction tube upper wall 4 can be set to a predetermined temperature (for example, a predetermined temperature of 200 ° C. or lower, which is a temperature at which the organic metal decomposes).

  Further, the susceptor heating step is started (S30) simultaneously with the start of the cooling step (S20) or after the start of the step (S20). Specifically, by starting to apply power from the control member 15 to the heater 9, heat generation from the heater 9 is started, and the substrate 7 is heated via the susceptor 5 and the susceptor 5. Further, simultaneously with the start of the susceptor heating step (S30), the measurement of the surface temperature of the substrate 7 by the temperature measuring member 13 is also started. The surface temperature data of the substrate 7 measured by the temperature measuring member 13 is input to the control member 15. Further, the measurement of the temperature of the inner peripheral member 8 of the reaction tube upper wall 4 by the temperature measuring member 14 is also started. The inner peripheral surface temperature of the inner peripheral member 8 measured by the temperature measuring member 14 is also input to the control member 15.

  Next, a confirmation step (S40) for confirming whether or not the temperature condition satisfies a predetermined condition is performed. Specifically, the surface temperature of the inner peripheral member 8 measured by the temperature measuring member 14 is lower than the film formation lower limit temperature of the film formed on the surface of the substrate 7 and the substrate measured by the temperature measuring member 13. It is confirmed whether or not the condition that the surface temperature of No. 7 is higher than the film forming lower limit temperature is satisfied. In this confirmation step (S40), when it is determined that the above-described conditions are not satisfied (when NO is determined), the confirmation step (S40) is performed again.

  On the other hand, when it is determined in the confirmation step (S40) that the above-described conditions are satisfied (when YES is determined), a film formation step (S50) is performed. Specifically, a raw material gas serving as a raw material for a film to be formed is caused to flow inside the reaction tube 3 by a gas supply member (not shown). This source gas reacts on the surface of the substrate 7, whereby a predetermined film can be formed on the surface of the substrate 7. At this time, since the reaction tube upper wall 4 is cooled by the coolant 10, no film is formed on the inner peripheral surface of the inner peripheral member 8 of the reaction tube upper wall 4. For this reason, the surface temperature of the substrate 7 can be accurately measured by the temperature measuring member 13 through the reaction tube upper wall 4. And by controlling the heater 9 based on the measurement result of the temperature measuring member 13, the control accuracy of the surface temperature of the board | substrate 7 can be raised as a result. As a result, the reproducibility of the film forming conditions is improved, and the yield of devices (such as light emitting elements) using the formed film is improved.

  Further, when the film forming step (S50) is being performed, the confirmation step (S40) may be periodically performed. In this case, if it is determined in the confirmation step (S40) that the temperature condition described above is not satisfied, the film formation step is stopped and / or the amount of power input to the heater 9 is adjusted, or the coolant 10 By changing the flow rate or temperature setting, control is performed so that the temperature condition satisfies a predetermined condition. If it is determined in the confirmation step (S40) that the temperature condition described above is satisfied, the film forming step is continued.

  Next, a modification of the processing apparatus shown in FIGS. 1 to 3 will be described with reference to FIGS. 5 to 9 are schematic cross-sectional views illustrating first to fifth modifications of the first embodiment of the processing apparatus according to the present invention shown in FIGS. 5 to 8 correspond to FIG. 3, and FIG. 9 corresponds to FIG.

  With reference to FIG. 5, a first modification of the first embodiment of the processing apparatus according to the present invention shown in FIGS. 1 to 3 will be described. The processing apparatus shown in FIG. 5 basically has the same configuration as the processing apparatus shown in FIGS. 1 to 3, but is formed between the outer peripheral member 6 and the inner peripheral member 8 of the reaction tube upper wall 4. The arrangement of the inlet 16 and the outlet 17 in the gap is different from that of the processing apparatus 1 shown in FIGS. That is, in the processing apparatus shown in FIG. 5, the inlet 16 and the outlet 17 each intersect the direction (specifically orthogonal) of the flow direction of the source gas in the reaction tube 3 (the direction indicated by the arrow 20 in FIG. 1). In the direction to face). Even if it does in this way, the effect similar to the processing apparatus shown in FIGS. 1-3 can be acquired. In the processing apparatus shown in FIG. 5, the inlet 16 and the outlet 17 are arranged in a straight line, but the inlet 16 and the outlet 17 may be arranged in other ways. For example, the inlet 16 and the outlet 17 may be arranged so as not to overlap (shifted) in a direction intersecting with the flow direction of the source gas.

  With reference to FIG. 6, the 2nd modification of Embodiment 1 of the processing apparatus by this invention shown in FIGS. 1-3 is demonstrated. The processing apparatus shown in FIG. 6 basically has the same configuration as the processing apparatus shown in FIGS. 1 to 3, but is formed between the outer peripheral member 6 and the inner peripheral member 8 of the reaction tube upper wall 4. The difference is that a plurality of wall portions 19 are formed inside the gap. The wall portion 19 is formed so that the coolant 10 flows through the inside of the gap by bending the flow path of the coolant 10. Specifically, the plurality of wall portions 19 are formed so as to extend in a direction intersecting (orthogonal direction) with respect to the direction from the inlet 16 toward the outlet 17. The plurality of wall portions 19 are arranged so as to be spaced apart from each other in the direction from the inlet 16 to the outlet 17. Further, the plurality of wall portions 19 are disposed so as to extend from two side walls of the reaction tube upper wall 4 disposed so as to face each other in a direction intersecting with the direction from the inlet 16 toward the outlet 17. Further, the wall portions 19 are alternately arranged with the wall portions 19 extending from the two side walls in the direction from the inlet 16 to the outlet 17. As a result, the flow path of the coolant 10 has a shape having a plurality of bent portions (zigzag shape). Even if it does in this way, the effect similar to the processing apparatus shown in FIGS. 1-3 can be acquired. Furthermore, since the coolant 10 flows through the gaps in the reaction tube upper wall 4 evenly, the reaction tube upper wall 4 can be cooled more uniformly.

  Next, with reference to FIG. 7, the 3rd modification of Embodiment 1 of the processing apparatus by this invention shown in FIGS. 1-3 is demonstrated. The processing apparatus shown in FIG. 7 basically has the same configuration as the processing apparatus shown in FIG. 5, but, like the processing apparatus shown in FIG. 6, the outer peripheral member 6 and the inner periphery of the reaction tube upper wall 4. The difference is that a plurality of wall portions 19 are formed inside a gap formed between the members 8. In the processing apparatus shown in FIG. 7, the wall portion 19 is formed so as to extend substantially in parallel with the direction in which the source gas flows (the direction indicated by the arrow 20 in FIG. 1). In the processing apparatus shown in FIG. 7, the wall portion 19 that does not contact (independently) the side wall of the reaction tube upper wall 4 and the wall portion 19 formed so as to extend from the side wall are provided from the inlet 16 to the outlet 17. It arrange | positions so that it may rank with a space | interval in the direction which goes to. Even with such a configuration, the same effect as that of the processing apparatus shown in FIG. 6 can be obtained.

  Next, with reference to FIG. 8, the 4th modification of Embodiment 1 of the processing apparatus by this invention shown in FIGS. 1-3 is demonstrated. The processing apparatus shown in FIG. 8 basically has the same configuration as the processing apparatus shown in FIG. 6, except that the arrangement of the inlet 16 and the outlet 17 is opposite to that of the processing apparatus shown in FIG. Is different. In this case, in the processing apparatus shown in FIG. 6, the coolant 10 flowing in the gap between the reaction tube upper walls 4 flows from the upstream side to the downstream side in the reaction gas flow direction in the reaction tube 3. On the other hand, in the processing apparatus shown in FIG. 8, the direction in which the coolant 10 flows is the direction from the downstream side to the upstream side in the flow direction of the reaction gas. Even with such a configuration, the same effect as that of the processing apparatus shown in FIG. 6 can be obtained, and a film formed by making the temperature condition inside the reaction tube 3 more uniform in the flow direction of the source gas. The film quality and film thickness can be made more uniform.

  Next, with reference to FIG. 9, the 5th modification of Embodiment 1 of the processing apparatus by this invention shown in FIGS. 1-3 is demonstrated. The processing apparatus shown in FIG. 9 basically has the same configuration as the processing apparatus shown in FIGS. 1 to 3, but the method for cooling the reaction tube upper wall 4 is different. That is, in the processing apparatus 1 shown in FIG. 9, the contact member 23 made of a transparent member is disposed so as to contact the outer peripheral surface of the reaction tube upper wall 4. A cooling unit 24 is disposed at the end of the contact member 23. As the cooling unit 24, any configuration can be used as long as the heat of the contact member 23 can be removed. For example, a Peltier element or a cooling body in which a coolant flow path is formed can be used as the cooling unit 24. The contact member 23 and the cooling unit 24 constitute a solid cooling member 22. Also with the processing apparatus 1 having such a configuration, the same effects as those of the processing apparatus shown in FIGS. 1 to 3 can be obtained. Moreover, in the processing apparatus 1 shown in FIG. 9, the structure of the reaction tube upper wall 4 can be simplified compared with the processing apparatus shown in FIGS.

(Embodiment 2)
FIG. 10 is a schematic cross-sectional view showing a second embodiment of a processing apparatus which is an example of a vapor phase growth apparatus according to the present invention. A second embodiment of the processing apparatus according to the present invention will be described with reference to FIG.

  Referring to FIG. 10, processing apparatus 1 basically has the same configuration as the processing apparatus shown in FIGS. 1 to 3, but is on the outer peripheral side of reaction tube upper wall 4 and faces susceptor 5. The point which the lamp | ramp 25 for a heating is arrange | positioned in the area | region differs from the processing apparatus 1 shown in FIGS. The lamp 25 is connected to the control member 15. The input power of the lamp 25 is controlled by the control member 15. Therefore, the control member 15 can control the amount of light emitted from the lamp 25 and ON / OFF of light emission. An arbitrary light source can be used as the lamp 25. For example, a halogen lamp can be used as the lamp 25. Such a lamp 25 can be used to heat the surface of the substrate 7. For this reason, in the processing apparatus 1 shown in FIG. 10, while being able to acquire the effect similar to the processing apparatus shown in FIGS. 1-3, the emitted-heat amount in the heater 9 can be reduced. That is, the amount of heat generated by the heater 9 can be made smaller than when only the heater 9 is used to raise the surface temperature of the substrate 7 to a predetermined film forming temperature. As a result, the life of the heater 9 can be extended. Further, when the surface temperature of the substrate 7 is set to a high temperature close to the melting point of the material constituting the substrate 7, the entire substrate 7 may be melted only by the heater 9. However, by using the lamp 25, only the surface of the substrate 7 can be preferentially heated to a high temperature by the lamp 25, while it is possible to prevent the temperature at the central portion of the substrate 7 in the thickness direction or the back side from becoming excessively high.

  FIG. 11 is a schematic cross-sectional view showing a modification of the second embodiment of the processing apparatus according to the present invention shown in FIG. A modification of the second embodiment of the processing apparatus according to the present invention will be described with reference to FIG.

  Referring to FIG. 11, processing device 1 basically has the same configuration as processing device 1 shown in FIG. 10, but the configuration of the lamp is different from the processing device shown in FIG. 10. That is, in the processing apparatus 1 shown in FIG. 11, three lamps 25a to 25c are arranged as lamps. The plurality of lamps 25 a to 25 c are arranged so as to be aligned in a direction along the flow direction of the source gas indicated by the arrow 20. Each of the lamps 25 a to 25 c is connected to the control member 15. In FIG. 11, three lamps 25a to 25c are arranged, but the number of lamps is not limited to three, and may be two or four or more. A plurality of lamps may be arranged outside the reaction tube 3 in a matrix.

  Here, as shown in FIG. 11, when three lamps 25 a to 25 c are arranged, the control member 15 can change the outputs (the amount of emitted light) of these lamps 25 a to 25 c. For example, considering the temperature rise and diffusion of the raw material gas flowing inside the reaction tube 3, the output of the lamp is gradually lowered from the lamp 25a located on the upstream side to the lamp 25c located on the downstream side (power to be input) As a result, the substrate temperature (susceptor temperature) and the uniformity of the reaction can be improved as compared with the case where the substrate 7 is heated using only the heater 9. This effect will be described in more detail with reference to FIG.

  FIG. 12 is a graph schematically showing changes in the susceptor temperature in the flow direction of the source gas when only the heater is used for heating the substrate and when a plurality of lamps are used. Referring to FIG. 12, the horizontal axis indicates the position of the susceptor 5 in the flow direction of the source gas, that is, the distance from the upstream side of the susceptor 5 in the flow direction of the source gas. The origin is the position of the upstream end of the susceptor 5 in the flow direction of the source gas. The vertical axis represents the temperature (° C.) of the susceptor 5. As for the temperature of the susceptor 5, temperature data may be measured by arranging a plurality of temperature measuring members (for example, thermocouples) not shown in FIG. 11 and the like in the raw material gas flow direction on the surface of the susceptor 5. Further, the temperature data of the susceptor 5 may be measured by measuring the temperature distribution of the surface temperature of the susceptor 5 with the temperature measuring member 13 shown in FIG.

  As shown in FIG. 12, when the susceptor 5 and the substrate 7 are heated using only the heater 9, it is difficult to locally change the heating state in the flow direction of the source gas. The temperature of the susceptor 5 tends to rise as it goes downstream. On the other hand, as shown in FIG. 11, three lamps 25a to 25c are used, and as described above, the output of the lamp is gradually lowered from the lamp 25a located on the upstream side to the lamp 25c located on the downstream side. As a result, the temperature of the susceptor in the flow direction of the source gas can be kept uniform. For this reason, the uniformity of the film thickness and film quality of the film | membrane formed can be improved.

  10 and 11, when the heater 9 and the lamp 25 (or lamps 25a to 25c) are used in combination, as shown in FIG. The flow direction can be adjusted so as to change linearly (specifically, monotonously decrease). This effect will be described in more detail with reference to FIG. FIG. 13 is a graph schematically showing changes in the GaN growth rate (film formation rate) in the flow direction of the source gas when only the heater is used for heating the substrate and when a plurality of lamps are used in combination. Referring to FIG. 13, the horizontal axis indicates the position of the substrate 7 fixed to the susceptor 5 in the flow direction of the source gas, that is, the distance from the upstream side of the flow direction of the source gas most in the substrate 7. The origin is the position of the upstream end of the substrate 7 in the flow direction of the source gas. The vertical axis indicates the GaN growth rate (deposition rate) (unit: μm / hour). At this time, the susceptor 5 is fixed without rotating. FIG. 13 shows growth rate data when a GaN film is formed on the GaN substrate surface.

  As shown in FIG. 13, when only the heater 9 is used to heat the substrate 7, the growth rate of the GaN film in the flow direction of the source gas shows a distribution that changes in a curved line. On the other hand, when the heater 9 and the three lamps 25a to 25c are used in combination, the growth rate of the GaN film in the flow direction of the source gas is indicated as lamp 3 zone in FIG. Shows a linear distribution, which is a so-called monotonic decrease. Thus, if the growth rate of the GaN film can be made a linear distribution, the film formation rate distribution on the surface of the substrate 7 disposed on the susceptor 5 is made uniform by rotating (revolving) the susceptor 5. it can. For this reason, the film thickness distribution of the film formed on the surface of the substrate 7 can be made uniform only by rotating the susceptor 5 (that is, without using a self-revolving mechanism that rotates (spins) the substrate 7 in addition to the susceptor 5). Can be For this reason, according to this invention, the structure of the processing apparatus 1 can be simplified rather than the case where a self-revolving mechanism is employ | adopted as a structure of the processing apparatus 1. FIG. Further, since the auto-revolution mechanism is not employed, it is not necessary to arrange a gear for rotating the substrate 7 on the susceptor 5. For this reason, it is possible to increase the number of substrates 7 arranged on the susceptor 5 as compared with the case where the self-revolving mechanism is employed. That is, when the area of the susceptor 5 is the same, more substrates 7 can be processed at a time.

  FIG. 14 is a schematic sectional view showing another modification of the second embodiment of the processing apparatus according to the present invention shown in FIG. Referring to FIG. 14, another modification of the second embodiment of the processing apparatus according to the present invention will be described.

  Referring to FIG. 14, the processing apparatus 1 basically has the same configuration as the processing apparatus 1 shown in FIG. 11, except that the coolant supply member 35 and the gas supply member 32 are clearly shown. 11 is different from the processing apparatus shown in FIG. That is, in the processing apparatus 1 shown in FIG. 14, the coolant supply member 35 for supplying the coolant 10 between the outer peripheral member 6 and the inner peripheral member 8 of the reaction tube upper wall 4 is connected to the control member 15. It is arranged in the state. Further, in the processing apparatus 1 shown in FIG. 14, a gas supply member 32 for supplying a source gas for film formation into the reaction tube 3 is arranged in a state of being connected to the control member 15. Here, the coolant supply member 35 is a member for supplying the coolant 10 between the outer peripheral member 6 and the inner peripheral member 8. Specifically, the coolant 10 is connected to the outer peripheral member 6 and the inner peripheral member 8. And a heat exchanger for removing heat from the coolant 10 discharged from the gap (temperature rise). The gas supply member 32 can employ any conventionally known configuration. For example, the gas supply member 32 may include a tank for accumulating the source gas, a controller for supplying a predetermined amount of the source gas from the tank at a predetermined pressure, and the like.

  In the processing apparatus 1 having such a configuration, the same effect as that of the processing apparatus 1 shown in FIG. 11 can be obtained, and the coolant supply member 35 is controlled by the control member 15, whereby the reaction tube upper wall 4. The cooling state can be controlled. Specifically, the surface temperature of the inner peripheral member 8 of the reaction tube upper wall 4 can be controlled by controlling the supply amount and temperature of the coolant 10 via the coolant supply member 35. Then, by controlling the surface temperature of the inner peripheral member 8, the temperature of the source gas contacting the surface of the inner peripheral member 8 (the surface on the side facing the susceptor 5) can also be indirectly controlled.

  Further, the flow rate of the source gas supplied into the reaction tube 3 can be adjusted by the gas supply member 32. For this reason, by combining the control of the surface temperature of the inner peripheral member 8 by the coolant supply member 35 and the control of the supply amount of the raw material gas by the gas supply member 32, the temperature of the raw material gas at the portion facing the susceptor 5 is combined. Can be controlled (the temperature distribution of the source gas in the portion facing the susceptor 5 is made uniform in the flow direction of the source gas and / or in the direction perpendicular to the flow direction). As a result, the surface temperature distribution of the substrate 7 mounted on the susceptor 5 and the reaction on the surface can be made more uniform.

  Moreover, about the three lamps 25a-25c, as demonstrated in the processing apparatus 1 shown in FIG. 11, the inside of the reaction tube 3 is changed by changing the output of these lamps 25a-25c individually by the control member 15. In consideration of the temperature rise and diffusion of the flowing source gas, by controlling the lamp output gradually from the upstream lamp 25a to the downstream lamp 25c, the substrate temperature (susceptor temperature) and reaction Uniformity can be further improved.

  In the processing apparatus 1 shown in FIG. 10, FIG. 11 and FIG. 14 described above, the wavelength of the light emitted from the lamps 25, 25a to 25c includes a wavelength in the ultraviolet region (the emitted light includes ultraviolet rays, more preferably It is preferable to emit ultraviolet rays as a component. In this case, since the light emitted from the lamps 25 and 25a to 25c is absorbed only near the surface of the substrate 7, only the surface of the substrate 7 can be effectively heated. For this reason, without increasing the temperature of the whole substrate 7 (for example, the temperature in the center in the thickness direction or the back side), only the surface of the substrate 7 is set to a high temperature that is close to the melting point of the material of the substrate 7, for example. it can. Therefore, the above-described processing apparatus 1 is particularly effective when forming an AlGaN-based film from which a high-quality film can be obtained under a high film formation temperature.

  When a GaN substrate is used as the substrate 7, it is preferable to use Hg lamps (wavelength 253 nm) as the lamps 25 and 25a to 25c. Further, when a wider band gap material is used as the substrate 7, for example, a dielectric barrier lamp can be used. For example, when an AlN substrate or a sapphire substrate is used as the substrate 7, a dielectric barrier lamp having a wavelength of 172 nm can be used.

(Embodiment 3)
FIG. 15 is a schematic cross-sectional view showing a third embodiment of the processing apparatus which is an example of the vapor phase growth apparatus according to the present invention. A third embodiment of the processing apparatus according to the present invention will be described with reference to FIG.

  Referring to FIG. 15, the processing apparatus 1 basically has the same configuration as the processing apparatus shown in FIGS. 1 to 3, but heating for heating the substrate 7 on the outer peripheral side of the reaction tube upper wall 4. The laser light source 27 and the optical system 29 as members are different from the processing apparatus 1 shown in FIGS. Specifically, in the processing apparatus 1 shown in FIG. 15, the optical system 29 is disposed at a position on the outer peripheral side of the reaction tube upper wall 4 and facing the susceptor 5. Laser light emitted from the laser light source 27 is incident on the optical system 29. The optical system 29 and the laser light source 27 are connected to the control member 15. In the optical system 29, the laser light is incident on the surface of the substrate 7 on the susceptor 5 by changing the traveling direction of the laser light incident from the laser light source 27. The optical system 29 can arbitrarily change the traveling direction of the emitted laser light. Therefore, the laser light emitted from the optical system 29 is irradiated so as to scan the surface of the substrate 7 as indicated by an arrow 30 in FIG. Even with such a configuration, the same effect as that of the processing apparatus shown in FIG. 10 can be obtained. As the optical system 29, any conventionally known mechanism can be adopted. Even with such an apparatus, the same effect as the processing apparatus shown in FIG. 11 can be obtained.

  As the laser light source 27, any laser light source can be used. For example, a laser light source that emits an excimer laser may be used as the laser light source 27. In this case, the excimer laser can irradiate the substrate 7 as a pulse laser having a pulse width in units of ns (nanoseconds). For this reason, the temperature of the substrate 7 can be controlled with high accuracy. Further, since the excimer laser can have a relatively high energy density, the surface temperature of the substrate 7 can be locally increased to nearly 2000 ° C. by irradiating the substrate 7. For this reason, the control range of the surface temperature of the substrate 7 can be controlled within a practically sufficient range, and the control range can be extended to a relatively high temperature region.

  Regarding the laser light irradiated to the substrate 7, for example, by adjusting the laser output from the laser light source 27, the frequency of the pulsed laser, or the focus of the laser light on the surface of the substrate 7 in the optical system 29, The temperature can be locally changed on the surface of the substrate 7. For this reason, it is possible to make the temperature distribution on the surface of the substrate 7 uniform without employing a self-revolving mechanism or the like in the susceptor 5. In this case, the optical system 29 and the like are increased as equipment instead of the self-revolving mechanism. However, since the optical system 29 only needs to operate at room temperature, the self-revolving mechanism of the susceptor 5 made of a heat-resistant material. The manufacturing cost of the processing apparatus 1 can be reduced compared with the case where the apparatus is installed.

  For example, when a KrF (246 nm) excimer laser is used as the laser light source 27 and a GaN substrate is used as the substrate 7, the laser light is almost absorbed by the surface of the substrate 7, and only the surface of the substrate 7 is effectively heated. it can.

  Next, a modification of the third embodiment of the processing apparatus shown in FIG. 15 will be described with reference to FIG. FIG. 16 is a schematic sectional view showing a modification of the third embodiment of the processing apparatus according to the present invention shown in FIG. A modification of the third embodiment of the processing apparatus according to the present invention will be described with reference to FIG.

  Referring to FIG. 16, processing apparatus 1 basically has the same configuration as the processing apparatus shown in FIG. 15, but a gas for supplying a raw material gas for film formation into reaction tube 3. It differs from the processing apparatus shown in FIG. 15 in that the supply member 32 is clearly shown and the gas supply member 32 is controlled by the control member 15 so that the laser light source 27 and the optical system 29 are synchronized. Specifically, in the processing apparatus 1 shown in FIG. 16, the gas supply member 32 is connected to the control member 15, and the operation of the gas supply member 32 is controlled by the control member 15. As the configuration of the gas supply member 32, any conventionally known configuration can be adopted. In the processing apparatus 1 shown in FIG. 16, the control member 15 controls the laser irradiation timing and source gas supply timing to be synchronized as shown in FIG. Hereinafter, it will be described in more detail with reference to FIG.

  FIG. 17 is a timing chart showing changes in the supply timing of the source gas (TMA), the irradiation timing of the laser beam to the substrate, and the substrate surface temperature when the film forming process is performed in the processing apparatus shown in FIG. As shown in FIG. 17, in a state where the temperature of the substrate surface is adjusted to a predetermined base temperature, supply of the source gas (TMA) is first started at time T1. Thereafter, at the time T2, the laser light source 27 and the optical system 29 are controlled from the control member 15 to start irradiation of the laser beam onto the surface of the substrate 7. As a result, the surface temperature of the substrate 7 rises and is set to a predetermined film formation temperature higher than the base temperature. As described above, since the source gas is supplied in a state where the surface temperature of the substrate 7 is raised to the film forming temperature, a predetermined film (for example, a GaN film, an AlGaN film, or an InGaN film) is formed on the surface of the substrate 7. The Thereafter, the supply of the raw material gas is stopped at time T3. Thereafter, the laser beam irradiation is stopped at time T4. As a result, the surface temperature of the substrate 7 is also lowered to the base temperature.

  Such a cycle is repeated a plurality of times. That is, the supply of the raw material gas (TMA) is started again at time T5 (or time T9). Thereafter, at time T6 (or time T10), irradiation of the laser beam onto the surface of the substrate 7 is started. As a result, the surface temperature of the substrate 7 rises and is set to a predetermined film formation temperature higher than the base temperature. Thus, since the source gas is supplied in a state where the surface temperature of the substrate 7 is raised to the film forming temperature, a predetermined film is formed on the surface of the substrate 7. Thereafter, the supply of the raw material gas is stopped at time T7 (or time T11). Thereafter, the laser beam irradiation is stopped at time T8 (or time T12).

  In this way, by repeating the cycle in which the laser beam irradiation and the supply of the source gas are synchronized, a sharp change in the surface temperature of the substrate 7 is difficult, which is difficult to heat the substrate 7 using only the normal heater 9. Can be realized. In addition, since the surface temperature of the substrate 7 can be arbitrarily controlled by controlling the energy of the laser light and the number of irradiation cycles (irradiation frequency), it is possible to stack layers of different compositions having steep interfaces. it can.

  For example, it is possible to manufacture a superlattice composed of layers having a composition of InGaN and GaN or AlGaN. In this case, the film formation temperature when forming the InGaN-based layer can be set to 800 ° C., for example, and the film formation temperature when forming the GaN or AlGaN-based layer can be set to 1050 ° C., for example. In the processing apparatus shown in FIGS. 15 and 16, such different film forming temperatures can be realized in a short time. Further, in the processing apparatus 1 shown in FIG. 15 and FIG. 16, the laser beam can be irradiated so as to scan the surface of the substrate 7, so that by changing the irradiation frequency for each region on the surface of the substrate 7, Similar to the processing apparatus 1 shown in FIG. 1, the surface temperature of the substrate 7 can be controlled so as to compensate for the temperature gradient of the substrate surface due to the flow of the source gas.

  Moreover, the utilization efficiency of source gas can be improved by implementing the film-forming method as demonstrated in FIG. 17 with the processing apparatus 1 shown in FIG. In addition, since the type of the source gas and the film formation temperature can be individually controlled, when the films having different film qualities are stacked, the change in the film quality between the films can be made steep.

  In Embodiments 1 to 3 described above, any liquid and gas can be used as the coolant 10. Moreover, in Embodiment 2 and 3 mentioned above, you may employ | adopt the cooling structure of the reaction tube upper wall 4 shown in FIGS. Moreover, in Embodiment 1-3 mentioned above, when using a liquid as the coolant 10, you may use water. Further, when a gas is used as the coolant 10, hydrogen, helium, or nitrogen (for example, nitrogen vaporized from liquid nitrogen) may be used. Further, the contact member 23 of the solid cooling member 22 shown in FIG. 9 may be plate-shaped so as to cover the entire reaction tube upper wall 4, but the upper surface of the reaction tube upper wall 4 is partially covered. Such a structure (for example, the planar shape is a mesh shape) may be used. In this case, as the material constituting the contact member 23, a material having high thermal conductivity, particularly relatively inexpensive copper or aluminum may be used.

  Although there is a part which overlaps with embodiment mentioned above, embodiment of this invention is enumerated and demonstrated. A processing apparatus 1 as a vapor phase growth apparatus according to the present invention includes a susceptor 5 as a substrate holding member, a reaction tube 3 as a reaction vessel, a cooling member (an outer peripheral member 6 and an inner peripheral member 8 of the reaction tube upper wall 4). , The coolant 10, the coolant supply member 35, or the solid cooling member 22 in FIG. 9) and a heating member (heater 9, lamps 25, 25a to 25c, laser light source 27, and optical system 29). The susceptor 5 holds a substrate 7 on which a film is formed by a vapor deposition method. The reaction tube 3 includes a substrate 7 held by a susceptor and has a transparent window portion (reaction tube upper wall 4) for observing the substrate 7. The cooling member (the gap between the outer peripheral member 6 and the inner peripheral member 8 of the reaction tube upper wall 4, the coolant 10, or the solid cooling member 22 in FIG. 9) cools the transparent window (the reaction tube upper wall 4). To do. Heating members (heater 9, lamps 25, 25a to 25c, laser light source 27, and optical system 29) heat the substrate.

  In this case, since the reaction tube upper wall 4 is cooled by the coolant 10 or the like, even if the ambient temperature in the vicinity of the substrate 7 is increased by radiant heat from the substrate 7 by heating the substrate 7 with the heater 9 or the like, The temperature of the inner peripheral surface of the reaction tube upper wall 4 can be kept lower than the lower limit of the film forming temperature (deposition lower limit temperature). For this reason, the formation of a film on the inner peripheral surface of the reaction tube upper wall 4 can be suppressed.

  Further, since the formation of a film on the inner peripheral surface of the reaction tube upper wall 4 can be suppressed in this way, the film formation conditions (for example, temperature conditions) inside the reaction tube 3 are unstable due to the formation of the film. The possibility of becoming can be reduced. That is, since the film formation conditions inside the reaction tube 3 can be stabilized with good reproducibility, the film quality of the film formed as a result can be improved.

  Further, since no film is formed on the inner peripheral surface of the reaction tube upper wall 4, the surface temperature of the substrate 7 can be measured by the temperature measuring member 13 such as a pyrometer through the reaction tube upper wall 4 made of a transparent member. . Therefore, the controllability of the film forming conditions can be improved. As a result, the quality of the formed film can be kept high.

  Further, as shown in FIGS. 10, 11, 14, 15 and the like, energy is supplied by a part of the heating member (lamps 25, 25a to 25c, laser light source 27, and optical system 29) via the reaction tube upper wall 4. By irradiating the surface of the substrate 7 with lines, the surface of the substrate 7 can be locally heated.

  In the processing apparatus 1, the heating member is an irradiation heating member (lamps 25, 25 a to 25 c) that heats the substrate 7 by irradiating the substrate 7 with energy rays (such as visible light or ultraviolet rays) via the reaction tube upper wall 4. A laser light source 27 and an optical system 29) may be included. In this case, the surface of the substrate 7 can be locally heated by irradiation with energy rays. For this reason, compared with the case where the whole board | substrate 7 is heated only using the heater 9 which consists of an electric heater etc., the calorie | heat amount of the radiant heat from the board | substrate 7 can be reduced. As a result, it is possible to suppress the occurrence of an unnecessary reaction of the source gas due to the radiant heat (for example, a gas phase reaction when TMA or ammonia is used as the source gas). Therefore, the utilization efficiency of the source gas can be improved and the film quality of the formed film can be prevented from being deteriorated.

  In the processing apparatus 1, the irradiation heating member (lamps 25, 25a to 25c, laser light source 27, and optical system 29) may irradiate the substrate with pulsed energy rays (laser light). In this case, since the substrate 7 is irradiated with pulsed laser light, the amount of heat given to the substrate 7 by irradiation with the laser light can be controlled with high accuracy. For this reason, the temperature control of the surface of the substrate 7 can be performed with higher accuracy. As a result, the film quality of the formed film can be improved.

  In the processing apparatus 1, the irradiation heating members (lamps 25, 25 a to 25 c, the laser light source 27, and the optical system 29) use energy rays including a component having a wavelength shorter than the transmission wavelength of the material constituting the substrate 7 as energy rays. The substrate may be irradiated. In this case, most of the energy rays irradiated on the substrate 7 can be absorbed by the surface layer of the substrate 7. For this reason, the surface layer of the board | substrate 7 can be heated locally by irradiation of an energy ray. Therefore, since the amount of radiant heat transmitted from the substrate 7 to the surroundings can be reduced as compared with the case where the entire substrate 7 is heated using the heater 9 or the like, the occurrence of a parasitic reaction of the source gas can be more effectively suppressed.

  Further, since only the surface layer of the substrate 7 is heated in this way, the entire surface of the substrate 7 is not melted, and only the surface layer of the substrate 7 is heated to a high temperature close to the melting point of the material constituting the substrate 7. Will also be possible. For this reason, a high temperature close to the melting point of the material constituting the substrate 7 can be adopted as the film formation temperature.

Here, when only the surface of the substrate 7 is heated, the absorption length of the light irradiated on the substrate 7 (from the surface irradiated with the light on the substrate 7 from the surface irradiated with the light is determined by the absorption coefficient of the material constituting the substrate 7. Of these, the depth to the position where 90% is absorbed is determined. For example, if the absorption coefficient is 1 × 10 ⁴ cm ⁻¹ , the absorption length is 1 μm. Further, considering the case where the substrate 7 is a GaN substrate, the absorption edge is 365 nm in the case of ideal GaN, but the GaN substrate absorbs even in the wavelength range above the above wavelength. For this reason, an optimum wavelength can be selected according to the absorption coefficient of the substrate 7. For example, when an excimer laser with a wavelength of 248 nm is used, the absorption coefficient of the GaN substrate exceeds 1 × 10 ⁴ cm ⁻¹ , so only the surface of the GaN substrate (only the region having a depth of 1 μm or less from the surface) is heated. be able to.

  In the processing apparatus 1, the irradiation heating members (lamps 25, 25 a to 25 c, the laser light source 27 and the optical system 29) may include the laser light source 27 and a scanning member (optical system 29). The laser light source 27 may emit an excimer laser as an energy beam. The optical system 29 may irradiate the excimer laser emitted from the laser light source 27 while scanning the surface of the substrate 7, and thus the traveling direction of the excimer laser may be changed.

  In this case, since the irradiation position of the excimer laser on the substrate 7 can be controlled by the optical system 29, the scanning state of the excimer laser can be adjusted so as to make the temperature distribution on the surface of the substrate 7 uniform. For this reason, the temperature distribution on the surface of the substrate 7 can be made more uniform.

  Further, since the excimer laser can be irradiated while scanning the surface of the substrate 7, it is not necessary to employ an apparatus configuration that rotates the substrate 7 itself (for example, a mechanism that rotates the susceptor 5 on which the substrate 7 is mounted). The temperature distribution of the substrate 7 can be made uniform. For this reason, the apparatus configuration of the processing apparatus 1 can be simplified.

  In the processing apparatus 1, the irradiation heating members (lamps 25, 25a to 25c, the laser light source 27, and the optical system 29) include a laser light source 27 that emits an excimer laser as an energy beam as shown in FIGS. You may go out. The wavelength of the excimer laser emitted from the laser light source 27 may be set to be a value within a wavelength range that does not transmit through the substrate 7. In this case, the surface layer of the substrate 7 can be efficiently heated by the excimer laser.

  The processing apparatus 1 may include a raw material supply member (gas supply member 32) and a control member 15. The gas supply member 32 is for supplying a raw material gas, which is a raw material of the gas formed on the surface of the substrate 7, into the reaction vessel (reaction tube 3). The control member 15 may be for controlling the gas supply member 32 and the heating member (heater 9, lamps 25, 25a to 25c, laser light source 27, and optical system 29).

  In this case, the timing at which the source gas is supplied into the reaction tube 3 by the gas supply member 32 can be controlled by the control member 15. The control member 15 can also control the irradiation timing of the energy rays that are irradiated onto the surface of the substrate 7 from the irradiation heating member such as the lamp 25. As a result, as shown in FIG. 17, the surface of the substrate 7 can be heated to a predetermined temperature only when the source gas is flowing by synchronizing the supply timing of the source gas and the irradiation timing of the energy beam. Therefore, the film can be formed more efficiently.

  The processing apparatus 1 may include a raw material supply member (gas supply member 32) and a control member 15. The gas supply member 32 is for supplying a raw material gas, which is a raw material of the gas formed on the surface of the substrate 7, into the reaction vessel (reaction tube 3). The control member 15 may control the gas supply member 32 and the cooling member (the coolant supply member 35 in FIG. 14 or the solid cooling member 22 in FIG. 9). In this case, the transparent window portion cooled by the flow conditions (flow rate and the like) of the source gas supplied into the reaction tube 3 and the cooling member (the cooling material supply member 35 in FIG. 14 or the solid cooling member 22 in FIG. 9). By controlling the temperature of the (reaction tube upper wall 4) by the control member 15, the temperature condition of the source gas in the region facing the susceptor 5 can be made uniform, for example, in the flow direction of the source gas. As a result, it becomes possible to further improve the uniformity of the surface temperature of the substrate 7 in contact with the raw material gas.In addition to the gas supply member 32 and the cooling member, the control member 15 described above is a heating member (heater 9). The lamps 25, 25a to 25c, the laser light source 27, and the optical system 29) may be controlled, in which case the surface temperature uniformity of the substrate 7 is also controlled by controlling the heating conditions by the heating member. Ri can be improved.

  In the processing apparatus 1, the substrate 7 contains GaN, and the raw material supply member (gas supply member 32) is used as a raw material gas to grow an AlGaN film (for example, trimethylgallium (TMG) gas, TMA gas, Ammonia gas or the like) may be supplied to a region facing the surface of the substrate.

  In this case, since the formation temperature of the AlGaN film is relatively high, parasitic reactions of the source gas and film growth on the inner peripheral surface of the reaction tube 3 become problems, and the present invention is particularly effective.

  In the film forming method as the vapor phase growth method according to the present invention, a film is formed on the surface by the vapor phase growth method inside the reaction vessel (reaction tube 3) having the transparent window (reaction tube upper wall 4). A step of preparing the substrate 7 to be prepared (substrate preparation step (S10) in FIG. 4) and a film forming step (S50). In the film formation step (S50), the temperature of the reaction tube upper wall 4 is lower than the film formation lower limit temperature of the film formed on the surface of the substrate 7 and the surface temperature of the substrate 7 is equal to or higher than the film formation lower limit temperature. The source gas for the film is supplied to a region facing the surface of the substrate 7.

  In this case, since the temperature of the reaction tube upper wall 4 is set to be equal to or lower than the film formation lower limit temperature, the substrate 7 is heated by a heating member (heater 9, lamps 25, 25a to 25c, laser light source 27, and optical system 29). Even if the ambient temperature in the vicinity of the substrate 7 rises due to radiant heat from the substrate 7, film formation on the inner peripheral surface of the reaction tube upper wall 4 can be suppressed.

  Further, since the formation of a film on the inner peripheral surface of the reaction tube upper wall 4 can be suppressed in this way, the film formation conditions (for example, temperature conditions) inside the reaction tube 3 are unstable due to the formation of the film. The possibility of becoming can be reduced. That is, since the film formation conditions inside the reaction tube 3 can be stabilized with good reproducibility, the film quality of the film formed as a result can be improved.

  Further, since no film is formed on the inner peripheral surface of the reaction tube upper wall 4, the surface temperature of the substrate 7 can be measured by the temperature measuring member 13 such as a pyrometer through the reaction tube upper wall 4. Therefore, the controllability of the film forming conditions can be improved. As a result, the quality of the formed film can be kept high.

  In addition, since no film is formed on the inner peripheral surface of the reaction tube upper wall 4, it becomes possible to irradiate the surface of the substrate 7 with energy rays by the lamp 25 or the like through the reaction tube upper wall 4.

  In the film forming method, in the film forming step (S50), the substrate 7 is irradiated with energy rays through the reaction tube upper wall 4 as shown in FIG. 10, FIG. 11, FIG. May be heated. In this case, since the surface of the substrate 7 where the film-forming reaction occurs can be directly heated by energy rays, only the surface of the substrate 7 can be heated by appropriately selecting the wavelength of the energy rays. It becomes possible. As a result, the amount of radiant heat from the substrate 7 to the surroundings can be reduced as compared with the case where only the heater 9 is used to heat the entire substrate 7. Therefore, it is possible to reliably suppress the occurrence of unnecessary reaction (for example, parasitic reaction) of the source gas around the substrate 7.

  In the film forming method, in the film forming step (S50), the substrate 7 may be irradiated with pulsed energy rays (laser light) as shown in FIGS. In this case, it is possible to accurately control the amount of heat given to the substrate 7 by irradiation with energy rays.

  In the film forming method, in the film forming step (S50), the substrate 7 may be irradiated with energy rays including a component having a wavelength shorter than the transmission wavelength of the material constituting the substrate 7 as energy rays. In this case, most of the energy rays applied to the substrate 7 can be absorbed by the surface layer of the substrate 7. For this reason, the surface layer of the substrate 7 can be locally heated by irradiation with energy rays.

  Further, since only the surface layer of the substrate 7 is heated in this way, the entire surface of the substrate 7 is not melted, and only the surface layer of the substrate 7 is heated to a high temperature close to the melting point of the material constituting the substrate 7. Will also be possible. Therefore, the film forming method is particularly effective for forming a film that can realize excellent film quality under such high temperature conditions.

  In the film forming method, in the film forming step (S50), as shown in FIGS. 15 and 16, an excimer laser may be irradiated as energy rays while scanning the surface of the substrate 7. In this case, by adjusting the scanning state of the excimer laser using the optical system 29 so as to make the temperature distribution on the surface of the substrate 7 uniform, the temperature distribution on the surface of the substrate can be adjusted even when the substrate 7 remains fixed. It can be made more uniform.

  In the film forming method, in the film forming step (S50), the surface of the substrate 7 may be irradiated with an excimer laser whose wavelength is set to a value within a wavelength range that does not transmit the substrate 7. . In this case, since the excimer laser is almost absorbed by the surface layer of the substrate 7, the surface layer of the substrate 7 can be efficiently heated.

  In the film forming method, in the film forming step (S50), as shown in FIG. 17, the irradiation timing of the energy beam (laser light) and the supply timing of the source gas may be synchronized. In this case, the surface of the substrate 7 can be heated to a predetermined temperature by irradiating the substrate 7 with energy rays only when the source gas (TMA gas) is flowing. Therefore, the film can be formed more efficiently.

  In the film forming method, in the film forming step (S50), the flow conditions (flow rate and the like) of the source gas and the cooling conditions of the transparent window may be adjusted based on the surface temperature conditions of the substrate 7. In this case, the surface temperature of the substrate 7 in contact with the source gas is adjusted by adjusting the flow condition of the source gas and the cooling condition of the transparent window so that the temperature distribution of the source gas in the region facing the substrate 7 is made uniform. Can improve the uniformity.

  In the film forming method, the substrate 7 may contain GaN, and the source gas may be a gas used for growing an AlGaN film. In this case, since the formation temperature of the AlGaN film becomes relatively high, the parasitic reaction of the source gas, the growth of the film on the inner peripheral surface of the reaction vessel, and the like become problems, and the present invention is particularly effective.

  A substrate according to the present invention includes a base substrate (substrate 7) and a film formed on the base substrate by using the vapor phase growth method. In this way, a substrate having an excellent film quality film can be obtained.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above-described embodiment but by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

  The present invention is particularly advantageously applied to a vapor phase growth apparatus and a vapor phase growth method for forming a film of, for example, GaN, AlGaN, or InGaN.

It is a cross-sectional schematic diagram which shows Embodiment 1 of the processing apparatus which is an example of the vapor phase growth apparatus according to this invention. It is a cross-sectional schematic diagram in line segment II-II of FIG. It is a cross-sectional schematic diagram in line segment III-III of FIG. It is a flowchart for demonstrating the film-forming method using the processing apparatus shown in FIGS. It is a cross-sectional schematic diagram explaining the 1st modification of Embodiment 1 of the processing apparatus by this invention shown in FIGS. 1-3. It is a cross-sectional schematic diagram explaining the 2nd modification of Embodiment 1 of the processing apparatus by this invention shown in FIGS. 1-3. It is a cross-sectional schematic diagram explaining the 3rd modification of Embodiment 1 of the processing apparatus by this invention shown in FIGS. 1-3. It is a cross-sectional schematic diagram explaining the 4th modification of Embodiment 1 of the processing apparatus by this invention shown in FIGS. 1-3. It is a cross-sectional schematic diagram explaining the 5th modification of Embodiment 1 of the processing apparatus by this invention shown in FIGS. 1-3. It is a cross-sectional schematic diagram which shows Embodiment 2 of the processing apparatus which is an example of the vapor phase growth apparatus according to this invention. It is a cross-sectional schematic diagram which shows the modification of Embodiment 2 of the processing apparatus by this invention shown in FIG. It is a graph which shows typically the change of the susceptor temperature in the flow direction of source gas in the case where only a heater is used for heating a substrate, and the case where a plurality of lamps are used. It is a graph which shows typically the change of the GaN growth rate (film-forming speed | rate) in the flow direction of source gas with the case where only a heater is used for the heating of a board | substrate, and the case where several lamps are used together. It is a cross-sectional schematic diagram which shows the other modification of Embodiment 2 of the processing apparatus by this invention shown in FIG. It is a cross-sectional schematic diagram which shows Embodiment 3 of the processing apparatus which is an example of the vapor phase growth apparatus according to this invention. It is a cross-sectional schematic diagram which shows the modification of Embodiment 3 of the processing apparatus by this invention shown in FIG. FIG. 17 is a timing chart showing changes in source gas (TMA) supply timing, laser beam irradiation timing to the substrate, and substrate surface temperature when performing the film forming process in the processing apparatus shown in FIG. 16.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Processing apparatus, 3 reaction tube, 4 reaction tube upper wall, 5 susceptor, 6 outer peripheral member, 7 board | substrate, 8 inner peripheral member, 9 heater, 10 coolant, 11 reaction tube bottom wall, 13, 14 temperature measuring member, 15 Control member, 16 inlet, 17 outlet, 19 wall, 20, 30 arrow, 22 solid cooling member, 23 contact member, 24 cooling unit, 25, 25a to 25c lamp, 27 laser light source, 29 optical system, 32 gas supply member 35 Coolant supply member.

Claims (10)

A substrate holding member for holding a substrate on which a film is formed by vapor deposition;
A reaction vessel having a transparent window for observing the substrate, wherein the substrate held by the substrate holding member is disposed inside;
A cooling member for cooling the transparent window,
A vapor phase growth apparatus comprising: a heating member that heats the substrate.   The vapor deposition apparatus according to claim 1, wherein the heating member includes an irradiation heating member that heats the substrate by irradiating the substrate with an energy ray through the transparent window portion.   The vapor deposition apparatus according to claim 2, wherein the irradiation heating member irradiates the substrate with the pulsed energy beam.   The vapor deposition apparatus according to claim 2 or 3, wherein the irradiation heating member irradiates the substrate with energy rays including a component having a wavelength shorter than a transmission wavelength of a material constituting the substrate as the energy rays. The irradiation heating member is
A laser light source that emits an excimer laser as the energy beam;
The scanning member which changes the advancing direction of the excimer laser in order to irradiate the excimer laser emitted from the laser light source while scanning the surface of the substrate. The vapor phase growth apparatus described in 1. The irradiation heating member includes a laser light source that emits an excimer laser as the energy beam,
5. The vapor phase growth apparatus according to claim 2, wherein the wavelength of the excimer laser emitted from the laser light source is set to have a value within a wavelength range that does not transmit through the substrate. A raw material supply member for supplying a raw material gas, which is a raw material of a gas formed on the surface of the substrate, into the reaction vessel;
The vapor phase growth apparatus according to claim 1, further comprising a control member for controlling the raw material supply member and the heating member. A raw material supply member for supplying a raw material gas, which is a raw material of a gas formed on the surface of the substrate, into the reaction vessel;
The vapor phase growth apparatus according to any one of claims 1 to 6, further comprising a control member for controlling the raw material supply member and the cooling member. The substrate comprises GaN;
The vapor deposition apparatus according to claim 7 or 8, wherein the raw material supply member supplies, as the raw material gas, a gas used for growing an AlGaN film to a region facing the surface of the substrate. Preparing a substrate on the surface of which a film is formed by vapor deposition, inside a reaction vessel having a transparent window;
In the state where the temperature of the transparent window is lower than the film formation lower limit temperature of the film formed on the surface of the substrate and the surface temperature of the substrate is equal to or higher than the film formation lower limit temperature, the source gas of the film is changed. A vapor deposition method comprising: a film forming step of supplying a region facing the surface of the substrate.

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