Method for operating semiconductor fabrication apparatus and semiconductor fabrication apparatus

Abstract

The present invention provides a technology for improving the throughput of cleaning the inner walls of a processing chamber of a semiconductor fabrication apparatus. Provided is a method for operating a semiconductor fabrication apparatus that processes a wafer placed in a processing chamber, the method including: a step for placing another wafer inside the processing chamber after one wafer is finished being processed; and a step for irradiating the interior of the processing chamber with electromagnetic waves comprising a reduced amount of wavelengths that are smaller than a prescribed value while in the state in which the other wafer has been placed inside the processing chamber. Also provided is a semiconductor fabrication apparatus comprises: a processing chamber; a sample stage on which is laid a semiconductor wafer placed inside the processing chamber; a lamp that radiates electromagnetic waves with which to irradiate the interior of the processing chamber; and a shield which is disposed between the lamp and the processing chamber and which reduces the amount of wavelengths smaller than a prescribed value. The semiconductor fabrication apparatus comprises a control device that drives the lamp while in a state in which another wafer has been placed inside the processing chamber after one wafer is finished being processed, causing the interior of the processing chamber to be irradiated with electromagnetic waves through the shield.

Description

Method of operating semiconductor manufacturing equipment and semiconductor manufacturing equipment

[0001] The present disclosure relates to a method for operating a semiconductor manufacturing apparatus and the semiconductor manufacturing apparatus, and in particular to a method for operating a semiconductor manufacturing apparatus used for isotropic processing of semiconductors, which is a technology that is effective when applied to a method for cleaning the inner walls of a processing chamber inside a vacuum vessel of the semiconductor manufacturing apparatus.

[0002] Isotropic dry etching technology using activated species such as gases or radicals is essential in the manufacturing process of three-dimensional semiconductor devices. This method does not use chemicals, so it can prevent patterns from collapsing due to the surface tension of the chemicals. Advances in this technology are expected to accelerate high integration in the stacking direction.

[0003] In isotropic dry etching technology, an adsorption-desorption etching method has been devised as a method for precisely controlling the etching amount. This method involves adsorbing an etchant such as a gas or radical onto the surface of the film to be processed, causing a reaction, and then heating the wafer to desorb and remove the reaction products of the film and the etchant.

[0004] In this method, the amount of etching in one cycle of adsorption and desorption is constant and small, and it is possible to control the amount of etching with high precision by repeating the cycle.

[0005] A common method of heating wafers to remove reaction products is to heat the stage on which the wafer is placed. However, this method has the problem of reducing processing throughput because the stage has a large heat capacity and it takes time to heat the wafer.

[0006] As a technique for solving this problem, a high-speed wafer heating technique using electromagnetic waves such as infrared light irradiation is known (see, for example, Patent Document 1).

[0007] Japanese Patent Application Laid-Open No. 2016-178257

[0008] Isotropic dry etching equipment used in semiconductor manufacturing is roughly divided into radical etching equipment equipped with a plasma generating unit and dedicated gas etching equipment that does not have a plasma generating unit.

[0009] In these isotropic dry etching apparatuses, in order to stabilize the etching rate, aging and in-situ cleaning of the processing chamber inside the vacuum vessel are performed to remove foreign matter and excess etchant that have adhered to the inner walls of the processing chamber during the etching process.

[0010] Different methods are used for aging and cleaning of the processing chamber in a radical etching system and in a dedicated gas etching system.

[0011] In radical etching equipment equipped with a plasma generation unit, gases such as sulfur hexafluoride (SF6), nitrogen trifluoride (NF3), and oxygen (O2) are often converted into plasma, and the generated F radicals and F ions are used to perform in-situ cleaning of the inner walls of the processing chamber.

[0012] On the other hand, in the case of dedicated gas etching equipment that does not have a plasma generation unit, cleaning methods are used in which the inner walls of the processing chamber are heated to vaporize any foreign matter that has adhered thereto, or highly reactive fluoride gas is introduced to react with the foreign matter and vaporize it.

[0013] In these cleaning methods, cleaning methods using plasma or gas may generate secondary contaminants or particles in some cases, and there is also the problem of corrosion resistance of the equipment materials to reactive gases.

[0014] In the cleaning method of heating the inner wall of the processing chamber, it is structurally difficult to heat the entire inner wall of the processing chamber. In particular, it is not easy to change the temperature of the stage on which the wafer is placed, so there is a problem that foreign particles vaporized by heating are re-adsorbed to cold spots generated inside the processing chamber.

[0015] The present disclosure has been made primarily to solve the above-mentioned problems, and aims to provide a technique for improving the throughput of cleaning the inner walls of a processing chamber of a semiconductor manufacturing apparatus, and more specifically, to provide a technique for improving the throughput of cleaning the inner walls of an isotropic dry etching apparatus.

[0016] A method for operating a semiconductor manufacturing apparatus according to one embodiment of the present disclosure is a method for operating a semiconductor manufacturing apparatus that processes wafers placed inside a processing chamber inside a vacuum vessel, and includes the steps of: placing one wafer inside the processing chamber after processing of another wafer is completed; and irradiating the inside of the processing chamber with electromagnetic waves in which the amount of wavelengths smaller than a predetermined value is reduced while the other wafer is placed inside the processing chamber.

[0017] Furthermore, a semiconductor manufacturing apparatus according to an embodiment of the present disclosure is a semiconductor manufacturing apparatus comprising: a processing chamber disposed within a vacuum vessel; a sample stage disposed within the processing chamber and having a semiconductor wafer placed above its upper surface; a lamp disposed above the processing chamber and emitting electromagnetic waves to be irradiated into the interior of the processing chamber; and a shield disposed between the lamp and the processing chamber and reducing the amount of wavelengths smaller than a predetermined value, the semiconductor manufacturing apparatus processing the wafers within the processing chamber; and a control device that, after processing of one of the wafers is completed, drives the lamp with another wafer disposed within the processing chamber to irradiate the electromagnetic waves through the shield into the interior of the processing chamber.

[0018] Furthermore, a method for operating a semiconductor manufacturing apparatus according to an embodiment of the present disclosure includes a chamber cleaning method including the steps of placing a wafer on a stage disposed inside a processing chamber, cooling the wafer by the stage, heating an inner wall of the processing chamber by an electromagnetic wave heater or a wall heater, and vaporizing foreign matter adhering to the inner wall of the processing chamber by the step of heating the inner wall of the processing chamber and adsorbing the foreign matter onto the cooled wafer.

[0019] A semiconductor manufacturing apparatus according to one embodiment of the present disclosure includes a processing chamber, a heater disposed outside the processing chamber and configured to heat a wafer or an inner wall inside the processing chamber with electromagnetic waves, a removable filter disposed between the heater and the processing chamber and configured to select wavelength components of the electromagnetic waves reaching the processing chamber from the heater, a stage disposed inside the processing chamber and positioned below the wafer, and a gas introduction system and a gas exhaust system required for etching.

[0020] According to one embodiment of the present disclosure, it is possible to provide a technology for improving the throughput of cleaning the inner walls of a processing chamber of a semiconductor manufacturing apparatus. It is also possible to provide a technology for efficiently cleaning the inner walls of a processing chamber in a semiconductor manufacturing apparatus equipped with a heater that heats a wafer or the inner walls of the processing chamber (processing chamber) using electromagnetic waves. Note that problems, configurations, and effects other than those described above will become clear from the description of the following embodiment.

[0021] 1 is a cross-sectional view showing a schematic configuration of a semiconductor manufacturing apparatus according to a first embodiment; FIG. 2 is a flowchart showing an example of a process flow in the semiconductor manufacturing apparatus according to the first embodiment; FIG. 3 is a cross-sectional view showing a schematic configuration of a semiconductor manufacturing apparatus according to a second embodiment; FIG. 4 is a graph showing a schematic relationship between the spectrum of electromagnetic waves radiated from a halogen lamp and the spectral emissivity of silicon and alumina in the semiconductor manufacturing apparatus according to the second embodiment; FIG. 5 is a graph showing a schematic relationship between the spectrum of electromagnetic waves radiated from a halogen lamp after passing through a silicon filter and the spectral emissivity of silicon and alumina in the semiconductor manufacturing apparatus according to the second embodiment; FIG. 6 is a flowchart showing an example of a process flow in the semiconductor manufacturing apparatus according to the second embodiment; FIG. 7 is a cross-sectional view showing a schematic configuration of a semiconductor manufacturing apparatus according to a third embodiment; FIG. 8 is a flowchart showing an example of a process flow in the semiconductor manufacturing apparatus according to the third embodiment;

[0022] First, the background of the investigation by the present inventors will be described.

[0023] <Background of Study by the Disclosers> The semiconductor manufacturing process includes processes such as pattern transfer, etching, cleaning, and planarization for wafers made of, for example, silicon, gallium arsenide, etc. Here, attention is focused on the devices and techniques used in the etching process.

[0024] As described above, when cleaning foreign particles adhering to the inner wall of a processing chamber, the inner wall is heated by a wall heater. However, it is difficult to heat the entire inner wall, and there is a problem that the desorbed foreign particles and excess etchant may re-adhere to cold spots generated in the processing chamber.

[0025] To heat the entire inner wall of the processing chamber, one possible approach is to use a heater that utilizes electromagnetic waves to assist the wall heater in heating the inner wall of the processing chamber. However, it takes time to completely evacuate the foreign particles vaporized by the heating. If the heater is turned off before the particles are completely evacuated, the foreign particles that could not be evacuated will re-adhere to low-temperature areas such as around the stage, resulting in incomplete cleaning.

[0026] In view of these circumstances, the present inventors conducted extensive research and discovered a technology for efficiently cleaning the inner walls of a processing chamber in a semiconductor manufacturing apparatus equipped with a heater that heats the wafer or the inner walls of the processing chamber using electromagnetic waves and a stage for cooling the wafer, by making part or the entire surface of the wafer a cold spot.

[0027] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, elements, members, or parts having the same configuration are designated by the same reference numerals, and repeated description will be omitted unless necessary. Furthermore, the following embodiments are merely examples, and do not limit the technical scope of the present invention in any way.

[0028] Example 1 (first embodiment) of the present disclosure will be described.

[0029] <Configuration Example of Semiconductor Manufacturing Apparatus According to First Embodiment> FIG. 1 is a side view that schematically shows the configuration of a semiconductor manufacturing apparatus 1 according to a first embodiment.

[0030] As shown in FIG. 1 , semiconductor manufacturing equipment 1 includes a processing chamber 2, which is made of, for example, aluminum or the like and has a generally cylindrical shape with an opening at the top. The processing chamber 2 includes a plate-shaped stage 4 for placing a wafer 3 therein. The stage 4 serves as a sample holder for the wafer 3. The stage 4 may or may not include an electrostatic chuck mechanism. The processing chamber 2 is located inside a vacuum vessel of the semiconductor manufacturing equipment 1. As shown enlarged in FIG. 1 , the wafer 3 is held with a gap between it and the upper surface of the stage 4, which serves as a sample holder. The stage 4 includes, for example, multiple pins 41, each of which has a tip that can protrude from the upper surface of the stage 4, allowing the tip of the pin 41 to lift up the lower surface of the wafer 3 from the upper surface of the stage 4.

[0031] A flow path 5 is provided inside the stage 4, through which a fluid such as water flows as a medium for cooling the stage 4. The temperature of the upper surface of the stage 4 can be adjusted by adjusting the temperature of the fluid flowing through the flow path 5. The upper surface of the stage 4 and the wafer 3 are in thermal contact. The flow path 5 and the processing chamber 2 are sealed.

[0032] A top plate 6 is installed on the upper side, i.e., the ceiling side, of the processing chamber 2. The top plate 6 is made of, for example, quartz and has the property of transmitting electromagnetic waves. A heater 8 is installed above the top plate 6, and irradiates electromagnetic waves 7, such as infrared rays, toward the wafer 3 and the inner wall of the processing chamber 2.

[0033] A wall heater 9, such as an electric heating wire, is attached to the outside of the side wall of the processing chamber 2, and can heat the inner wall of the processing chamber 2 as required.

[0034] An opening 10 is formed in the sidewall of the processing chamber 2 for supplying gas into the interior of the processing chamber 2. A gas supply source 11, such as a gas cylinder, is installed outside the processing chamber 2. The opening 10 and the gas supply source 11 are connected via a mass flow controller 12. The operation of the mass flow controller 12 controls the flow rate of the gas so that the gas can be introduced into the processing chamber 2.

[0035] An opening 13 is formed in the bottom of the processing chamber 2 for discharging gases and particles inside the processing chamber 2. A dry pump 14 for sucking gases and particles is installed outside the processing chamber 2. The opening 13 and the dry pump 14 are connected via a variable valve 15. When the dry pump 14 is operating, the gases and particles inside the processing chamber 2 are discharged by the operation of the variable valve 15, making it possible to control the gas pressure inside the processing chamber 2.

[0036] <Example of Cleaning in Semiconductor Manufacturing Apparatus According to First Embodiment> Next, a flow of processing (method of operating the semiconductor manufacturing apparatus) in the semiconductor manufacturing apparatus 1 having the above-described configuration will be described.

[0037] FIG. 2 is a flowchart showing an example of a process flow in the semiconductor manufacturing apparatus 1 according to the first embodiment.

[0038] Assume that after a silicon (Si) wafer is loaded, etched, and unloaded, foreign matter such as excess etchant adheres to the inner wall of the processing chamber 2. In other words, in the semiconductor manufacturing apparatus 1, after processing of one wafer is completed, a step is performed in which another wafer (3) is placed on the stage 4 inside the processing chamber 2 as a processing chamber. In other words, the stage 4, which serves as a sample holder for the wafer 3, will carry the one wafer or another wafer (3).

[0039] 2 , first, in step S101, another wafer 3 is placed on the mounting surface on the stage 4. Specifically, a robot or the like transports the wafer 3 from the load lock chamber to the processing chamber 2 and places the wafer 3 on the mounting surface on the stage 4.

[0040] Next, in step S102, the temperature of the fluid flowing inside the flow channel 5 is adjusted to control the temperature of the upper surface of the stage 4 to a low temperature of, for example, −20° C. to −40° C., thereby cooling the wafer 3.

[0041] Next, in step S103, the inner wall of the processing chamber 2 is heated to, for example, 100° C. or higher using the heater 8 and the wall heater 9. At this time, since the wafer 3 is cooled by the stage 4, the wafer 3 is kept at a lower temperature than the temperature of the inner wall of the processing chamber 2, even though it is heated by the heater 8.

[0042] After the heating is completed, in step S104, the wafer 3 is cooled and then unloaded from the processing chamber 2, which is the processing chamber.

[0043] According to the first embodiment, the inner wall of the processing chamber 2 is heated to a high temperature in step S102, vaporizing foreign matter adhering to the inner wall of the processing chamber 2. Some of the vaporized foreign matter is exhausted by the dry pump 14, but the remaining foreign matter is adsorbed to the wafer 3 during or after heating. By unloading the wafer 3 with the adsorbed foreign matter in step S104, cleaning of the inner wall of the processing chamber 2 is completed. By adsorbing the vaporized foreign matter to a wafer that can be unloaded, it is possible to prevent the foreign matter from re-adhering to the inner wall of the processing chamber 2.

[0044] Example 2 (second embodiment) of the present disclosure will be described.

[0045] <Configuration Example of Semiconductor Manufacturing Apparatus According to Second Embodiment> FIG. 3 is a side view schematically showing the configuration of a semiconductor manufacturing apparatus 16 according to a second embodiment.

[0046] In FIG. 3, the device configurations 2 to 15 are similar to those of the semiconductor manufacturing device 1 according to the first embodiment, and therefore, redundant explanations will be omitted.

[0047] In the semiconductor manufacturing equipment 16 , a filter 17 made of, for example, silicon material or the like is provided between the top plate 6 and the heater 8 for selecting wavelength components of the electromagnetic wave 7 .

[0048] A filter 17 removes certain wavelength components from the electromagnetic wave 7, and the electromagnetic wave 7 reaches the inner wall of the processing chamber 2 or another wafer 3 as an electromagnetic wave 19. A driving mechanism 18 is connected to the filter 17, and the filter 17 can also be removed from between the top plate 6 and the heater 8.

[0049] The filter 17 is provided with a cooling mechanism 20 that uses, for example, air cooling, so that the temperature of the filter 17 can be adjusted.

[0050] The influence of the presence or absence of the filter 17 on the heating of the wafer 3 and the inner wall of the processing chamber 2 in the semiconductor manufacturing equipment 16 will be described below with reference to the drawings.

[0051] 4 and 5 are graphs showing the relationship between the spectrum of electromagnetic waves 7 radiated from a halogen lamp, which is an example of the heater 8, and the spectral emissivity of silicon, which is a possible material for the wafer 3, and alumina, which is a possible material for the inner wall of the processing chamber 2.

[0052] 4 is a graph showing the results when filter 17 is not placed between top plate 6 and heater 8. Electromagnetic waves 7 have an intensity peak at a wavelength of approximately 1 μm, and the spectrum of electromagnetic waves 7 contains wavelength components absorbed by silicon and alumina, so that heater 8 can be used to heat wafer 3 and the inner wall of processing chamber 2. Conversely, if the output of heater 8 is increased to heat the inner wall of processing chamber 2 to a high temperature, wafer 3 will also become hot at the same time as the inner wall of processing chamber 2, and therefore, even if wafer 3 is cooled by stage 4, it will not be possible to keep it at a low temperature, and there is a risk that the temperature of wafer 3 will become too high to create a cold spot for adsorbing vaporized foreign matter.

[0053] 5 is a graph showing the results when a silicon filter 17 is placed between the top plate 6 and the heater 8. The filter 17 absorbs the electromagnetic waves 7 with wavelengths of approximately 1.3 μm or less, thereby removing the wavelength components of the electromagnetic waves 7 that heat the wafer 3. This makes it possible to heat the inner wall of the processing chamber 2 to a high temperature while maintaining the wafer 3 at a low temperature.

[0054] When the filter 17 is placed between the top plate 6 and the heater 8, the filter 17 is heated to a high temperature by the electromagnetic waves 7. When the temperature of the filter 17 rises, the absorption wavelength of the filter 17 also changes, so when the filter 17 is used, it is necessary to use the cooling mechanism 20 to control the temperature of the filter 17 to a certain temperature or below.

[0055] <Example of Cleaning in Semiconductor Manufacturing Apparatus According to Second Embodiment> Next, a flow of processing (method of operating the semiconductor manufacturing apparatus) in the semiconductor manufacturing apparatus 16 having the above-described configuration will be described.

[0056] FIG. 6 is a flowchart showing an example of a process flow in the semiconductor manufacturing apparatus 16 according to the second embodiment.

[0057] It is assumed that after the Si wafer is loaded, etched, and unloaded, foreign matter such as excess etchant adheres to the wall surface of the processing chamber. That is, similar to the first embodiment, in the semiconductor manufacturing apparatus 16, after the processing of one wafer is completed, a step is performed in which another wafer (3) is placed on the stage 4 inside the processing chamber 2 serving as the processing chamber.

[0058] Steps S201, S202, S204, and S205 in the flowchart according to the second embodiment shown in Fig. 6 are similar to steps S101, S102, S103, and S104 in the flowchart according to the first embodiment shown in Fig. 2. The semiconductor manufacturing apparatus 16 according to the second embodiment is characterized by the processing in steps S203 and S206.

[0059] In step S203, the filter 17 is placed between the top plate 6 and the heater 8 using the driving mechanism 18.

[0060] Next, in step S204, the inner wall of the processing chamber 2 is heated using the heater 8 and the wall heater 9. At this time, the wavelength component of the electromagnetic waves 7 radiated from the heater 8 that heats the wafer 3 is removed by the filter 17, and the electromagnetic waves 7 reach the wafer 3 and the inner wall of the processing chamber 2 as electromagnetic waves 19. Therefore, the inner wall of the processing chamber 2 can be heated while the wafer 3 is not heated and is kept at a low temperature. At this time, the filter 17 is cooled by the cooling mechanism 20.

[0061] In other words, in the semiconductor manufacturing equipment 16, a process is carried out in which, with another wafer 3 placed inside the processing chamber 2, which is a processing chamber, electromagnetic waves with the amount of wavelengths smaller than a predetermined value reduced are irradiated into the inside of the processing chamber 2 via the filter 17.

[0062] Here, the electromagnetic waves irradiated into the interior of the processing chamber 2 are filtered by the filter 17 to reduce the amount of wavelengths of, for example, 1 μm or less as a predetermined value. Alternatively, the electromagnetic waves are filtered by the filter 17 to reduce the amount of wavelengths of, for example, 1.3 μm or less as a predetermined value. Furthermore, in the step of irradiating the interior of the processing chamber 2 with the electromagnetic waves, particles inside the processing chamber 2 are caused to adhere to another wafer 3. Furthermore, the electromagnetic waves are irradiated into the interior of the processing chamber 2 while another wafer 3 is held on a stage 4 serving as a sample stage disposed inside the processing chamber 2. Furthermore, the stage 4 serving as the sample stage is maintained at a temperature that cools the other wafer.

[0063] After the heating is completed, in step S205, the wafer 3 is unloaded from the processing chamber 2. As a result, foreign matter is removed from the inside of the processing chamber 2, and cleaning is completed.

[0064] Next, in step S206, the filter 17 is removed from between the top plate 6 and the heater 8 using the driving mechanism 18.

[0065] According to the second embodiment, it is possible to heat the inner wall of the processing chamber 2 to a high temperature while keeping the wafer 3 at a low temperature, which is expected to improve the efficiency of adsorption of foreign matter onto the wafer 3 compared to the first embodiment and to reduce cleaning time.

[0066] Example 3 (third embodiment) of the present disclosure will be described.

[0067] <Configuration Example of Semiconductor Manufacturing Apparatus According to Third Embodiment> FIG. 7 is a side view schematically showing the configuration of a semiconductor manufacturing apparatus 21 according to a third embodiment.

[0068] 7 are similar to the semiconductor manufacturing apparatus 16 according to the second embodiment shown in FIG. 3, and therefore redundant explanations will be omitted.

[0069] The semiconductor manufacturing apparatus 21 is a radical etching apparatus having a plasma generating unit 22 at the center of the apparatus. Although any plasma generation method may be used for the plasma generating unit 22, we will assume here that it is an inductive coupling method. High-frequency power is supplied from a high-frequency power source 24 to a coil antenna 23 wound around the outer periphery of the sidewall of the plasma generating unit 22, and plasma 25 is generated.

[0070] A heater 26 such as a halogen lamp unit is arranged to surround the outer periphery of a plasma generating unit 22 at the center of the device. A flow path 27 through which a fluid such as water flows as a cooling medium is provided within the housing of the heater 26, thereby cooling the housing of the heater 26. The heater 26 is arranged above the processing chamber 2, which is a processing chamber, and can be rephrased as a lamp that emits electromagnetic waves that are irradiated into the interior of the processing chamber 2.

[0071] A filter 28, made of, for example, silicon, is disposed on the inner periphery of the heater 26. Here, the filter 28 is assumed to be a cylindrical solid; however, the shape and material are not critical as long as it can appropriately filter or shield the electromagnetic waves radiated from the heater 26. The filter 28 is disposed between the lamp (26) and the processing chamber 2, which is the processing chamber. It can also be described as a shield that reduces the amount of wavelengths smaller than a predetermined value. The filter 28 is connected to a drive mechanism 29, which can move the filter 28 up and down. The filter 28 may be placed in thermal contact with the housing of the heater 26, allowing the filter 28 to be cooled by the fluid flowing through the flow path 27. The filter 28 has the function of reducing the amount of electromagnetic waves with wavelengths of, for example, 1 μm or less.

[0072] The heater 26 is separated from the processing chamber 2 by a top plate 30. The top plate 30 is made of, for example, quartz, and transmits electromagnetic waves radiated from the heater 26. A groove 31 is carved in the top plate 30, and the filter 28 is inserted into the groove 31 when it is lowered by a drive mechanism (also called a drive device) 29.

[0073] The drive mechanism 29 is electrically connected to the control device 210 of the semiconductor manufacturing equipment 21, and the control device controls the drive mechanism 29 to drive the filter 28 up and down. The control device 210 is also electrically connected to the heater 26 and is configured to drive the heater 26. The control device 210 is also electrically connected to the wall heater 9 and is configured to drive the wall heater 9. The control device 210 is also electrically connected to the gas supply source 11, the mass flow controller 12, the dry pump 14, and the variable valve 15 and is configured to control the gas supply source 11, the mass flow controller 12, the dry pump 14, and the variable valve 15. The configuration of the control device 210 is similarly applied to the semiconductor manufacturing equipments 1 and 16 to the extent that it is not inconsistent. In the semiconductor manufacturing equipment 16, the control device 210 is also electrically connected to the drive mechanism 18 and the cooling mechanism 20 and is configured to control the drive mechanism 18 and the cooling mechanism 20.

[0074] In addition, the control device 210 drives the drive mechanism 29 of the filter 28 acting as a shield while one wafer is being processed, moving the filter 28 to a position different from the position when another wafer 3 is placed in the processing chamber 2 acting as a processing chamber, thereby irradiating the one wafer with electromagnetic waves radiated from the heater 26 without passing through the filter 28.

[0075] <Example of Cleaning in Semiconductor Manufacturing Apparatus According to Third Embodiment> Next, a flow of processing (method of operating the semiconductor manufacturing apparatus) in the semiconductor manufacturing apparatus 21 having the above-described configuration will be described.

[0076] 8 is a flowchart showing an example of a process flow in the semiconductor manufacturing apparatus 21 according to the third embodiment. Here, as in the first and second embodiments, in the semiconductor manufacturing apparatus 21, after the processing of one wafer is completed, a step of placing another wafer (3) on the stage 4 inside the processing chamber 2 serving as a processing chamber is executed.

[0077] Steps S301 and S302 in the flowchart according to the third embodiment shown in FIG. 8 are the same processes as steps S201 and S202 in the flowchart according to the second embodiment shown in FIG.

[0078] In step S303, the filter 28 is lowered using the driving mechanism 29 and inserted into the groove 31 formed in the top plate 30.

[0079] Next, in step S304, the inner wall of the processing chamber 2 is heated using the heater 26 and the wall heater 9.

[0080] Next, in step S305, plasma is generated using an appropriate gas as needed. Since the inner wall of the processing chamber 2 is heated by the heater 26 and the wall heater 9, the reaction between the activated species generated by the plasma and the foreign matter is promoted, and it is expected that the efficiency of desorption of the foreign matter from the inner wall of the processing chamber 2 is improved.

[0081] Next, in step S306, the supply of high frequency power from the high frequency power supply 24 to the coil antenna 23 is stopped, and the plasma is extinguished.

[0082] Next, in step S307, the heater 26 and the wall heater 9 are stopped, and the wafer 3 is unloaded from the processing chamber 2, thereby completing the cleaning.

[0083] Finally, in step S308, the filter 28 is raised, completing the series of processes.

[0084] Steps S303 and S304 will be described in detail below.

[0085] In steps S303 and S304, the control device (not shown) of the semiconductor manufacturing equipment 21 drives the lamp (26) to irradiate the electromagnetic waves passing through the filter 28 as a shield into the interior of the processing chamber 2 as a processing chamber, with another wafer 3 placed inside the processing chamber 2 as a processing chamber.

[0086] 9 is a side view showing a schematic configuration of the semiconductor manufacturing apparatus 21 when steps S303 and S304 are performed. The electromagnetic waves radiated from the heater 26 toward the center of the wafer 3 are wavelength-discriminated or blocked by a filter 28 inserted into a groove 31 formed on the top plate 30. As a result, the electromagnetic waves radiated from the heater 26 and having wavelength components that heat the wafer 3 only reach the outer periphery of the wafer 3 beyond the arrow indicated by the dotted line 32. Therefore, the portion of the wafer 3 inside the dotted line 32 is maintained at a low temperature. The center of the wafer 3, maintained at a low temperature, functions as a cold trap, allowing cleaning by adsorption of vaporized foreign matter.

[0087] Example 4 (fourth embodiment) of the present disclosure will be described.

[0088] <Configuration Example of Semiconductor Manufacturing Apparatus According to Fourth Embodiment> Fig. 10 is a diagram schematically illustrating the configuration and function of the heaters 8 and 26 in the semiconductor manufacturing apparatus according to the first, second, and third embodiments, with the heater 33 being used instead. Note that Fig. 10 shows an example in which the substrate resistance of the filter 36 is 10 to 100 Ω and the thickness is 775 μm.

[0089] It is assumed that the heater 33 is a halogen lamp. The heater 33 has a halogen lamp 34 and a reflector 35 located nearby. The number of halogen lamps and reflectors is not important. In other words, the semiconductor manufacturing equipment 21 is equipped with a reflector 35 that reflects electromagnetic waves from the lamp (26) and directs the electromagnetic waves toward the inside of the processing chamber 2 serving as a processing chamber.

[0090] A filter 36 is disposed below the heater 33 to remove certain wavelength components of the electromagnetic waves radiated from the halogen lamp 34. Here, it is assumed that the filter 36 is made of silicon. The filter 36 can be rephrased as a shield that reduces the amount of wavelengths smaller than a predetermined value.

[0091] Of the components of the electromagnetic waves radiated from the halogen lamp 34 that have wavelengths of 1 μm or more, approximately 50% are transmitted through the filter 36, approximately 40% are reflected, and the remainder is absorbed by the filter 36. At this time, the electromagnetic waves reflected by the filter 36 are further reflected by the reflector 35 located above the filter 36 and reach the filter 36, resulting in transmission, reflection, and absorption. By repeating this process, it is possible to transmit up to approximately 83% of the components of the electromagnetic waves radiated from the halogen lamp 34 that have wavelengths of 1 μm or more through the filter 36.

[0092] Conversely, about 40% of the components of the electromagnetic waves radiated from the halogen lamp 34 with wavelengths of 1 μm or less are reflected by the filter 36 , and the remainder is absorbed by the filter 36 and does not pass through the filter 36 .

[0093] By utilizing the above phenomenon, it is possible to remove the components (wavelengths of 1 μm or less) of the electromagnetic waves radiated from the halogen lamp 34 that heat the wafer, while increasing the illuminance of the electromagnetic wave components with wavelengths of 1 μm or more that are necessary for heating the inner walls of the processing chamber 2.

[0094] The configuration of the present disclosure is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present disclosure.

[0095] 1: semiconductor manufacturing equipment, 2: processing chamber, 3: wafer (another wafer), 4: stage, 5: flow path, 6: top plate, 7: electromagnetic wave, 8: heater, 9: wall heater, 10: opening, 11: gas supply source, 12: mass flow controller, 13: opening, 14: dry pump, 15: variable valve, 16: semiconductor manufacturing equipment, 17: filter, 18: drive mechanism, 19: electromagnetic wave, 20: cooling mechanism, 21: semiconductor manufacturing equipment, 22: plasma generation unit, 23: coil antenna, 24: high frequency power supply, 25: plasma, 26: heater, 27: flow path, 28: filter, 29: drive mechanism (drive device), 30: top plate, 31: groove, 33: heater, 34: halogen lamp, 35: reflector, 36: filter

Claims

1. A method for operating semiconductor manufacturing equipment that processes wafers placed inside a processing chamber inside a vacuum vessel, comprising the steps of: placing a new wafer inside the processing chamber after processing of one wafer is completed; and irradiating the inside of the processing chamber with electromagnetic waves in which the amount of wavelengths smaller than a predetermined value has been reduced while the new wafer is placed inside the processing chamber.

2. A method for operating a semiconductor manufacturing apparatus according to claim 1, wherein the amount of electromagnetic waves with wavelengths of 1 μm or less is reduced.

3. A method for operating a semiconductor manufacturing apparatus according to claim 1 or 2, wherein particles inside the processing chamber are caused to adhere to the other wafer during the step of irradiating the electromagnetic waves into the processing chamber.

4. A method for operating a semiconductor manufacturing apparatus according to claim 1 or 2, wherein the electromagnetic waves are irradiated into the interior of the processing chamber while the other wafer is held on a sample stage disposed inside the processing chamber.

5. A method for operating a semiconductor manufacturing apparatus according to claim 4, wherein the sample stage is maintained at a temperature that cools the other wafer, and the other wafer is held with a gap between it and the upper surface of the sample stage.

6. A semiconductor manufacturing apparatus comprising: a processing chamber arranged inside a vacuum vessel; a sample stage arranged inside the processing chamber and having a wafer placed above its upper surface; a lamp arranged above the processing chamber and emitting electromagnetic waves to be irradiated into the interior of the processing chamber; and a shield arranged between the lamp and the processing chamber and reducing the amount of wavelengths smaller than a predetermined value, the semiconductor manufacturing apparatus processing the wafers inside the processing chamber, and further comprising a control device that, after processing of one of the wafers is completed, drives the lamp with another wafer placed inside the processing chamber to irradiate the electromagnetic waves through the shield into the interior of the processing chamber.

7. A semiconductor manufacturing apparatus according to claim 6, wherein the shield has a function of reducing the amount of the electromagnetic waves having a wavelength of 1 μm or less.

8. A semiconductor manufacturing apparatus according to claim 6 or 7, comprising a sample stage disposed inside the processing chamber and having one of the wafers and another of the wafers placed on its upper surface, the sample stage having a flow path therein through which a medium for cooling the sample stage is supplied.

9. A semiconductor manufacturing apparatus according to claim 6 or 7, wherein the control device drives the shield drive device during processing of one of the wafers, moving the shield to a position different from the position when another of the wafers is placed in the processing chamber, and irradiating the electromagnetic waves onto one of the wafers without passing through the shield.

10. A semiconductor manufacturing apparatus according to claim 6 or 7, further comprising a reflector that reflects electromagnetic waves from said lamps and directs said electromagnetic waves toward the inside of said processing chamber.

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